Abstract
With the growing number of industries there are large volumes of wastewater generated every day. Pulp and paper mills are highly polluting as they release effluents containing organic pollutants, and high levels of Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Even though well-established processes exist to treat these effluents, there are only a few processes which are energy efficient. Conventional treatment methods are not effective for the degradation of toxic organic pollutants, hence other treatment techniques are necessary. One of the recent developments in this field is the Advanced Oxidation Process (AOP). Solar photocatalysis is a type of AOP which utilises UV light to activate semiconductor photocatalyst in order to produce highly reactive radical species. TiO2 is a widely used catalyst for this purpose, to oxidise or reduce the organic pollutants in industrial wastewater. However, photocatalysis using visible light has been receiving increased attention hence, modification of TiO2 is necessary for its enhanced response to visible light. There are many methods for modifying TiO2, such as doping and photo-sensitisation. This study focusses on the modification of TiO2 using the method of dye-sensitisation (photo-sensitisation) with the dyes rhodamine B and methylene blue. Solar photocatalytic experiments were carried out for the degradation of pulp and paper wastewater, at different conditions like varying catalyst loading (500mg, 600mg, 750mg and 1000mg of catalyst for 300ml of aqueous wastewater) and effluent concentration (20ml, 25ml, 30ml and 35ml of wastewater). Preliminary tests were done to determine the best conditions for photocatalytic degradation, and these were applied for final tests. Keywords - Solar Photocatalysis, Visible Light, Dye Sensitisation, Pulp and paper, Methylene blue, Rhodamine B, TiO2 catalyst.
degradation of pollution and photocatalysisPraveen Vaidya
The presentation deals with the use of conduction of photocatalytic reaction using the transition metal doped transparent semiconducting thinfilms. The precursor to film is prepared by the SILAR method, which is a chemical method.
PHOTOCATALYTIC DEGRADATION OF RB21 DYE BY TIO2 AND ZNO UNDER NATURAL SUNLIGHT...IAEME Publication
The present work aims to degrade the RB21 dye from synthetic wastewater using
semiconductors TiO2 and ZnO. The activity of photocatalytic degradation process of dye was
carried out using different light sources of 900 W/m
2
intensity in natural sunlight from 02:00 to
04:00 pm with 48°C temperature in Ahmedabad city in the month of May, 600 Watt microwave
oven and high pressure UV-light photocatalytic reactor of wavelength 200-450 nm. All the
experiments were performed with dye concentration 50 mg/L, catalyst dosage 0.8 g, pH 7, room
temperature, irradiation time 240 min followed by 30 min in dark. All the samples were collected at
different time intervals of 30, 60, 90, 120, 150, 180, 210, 240 min for the analysis of COD
degradation and color removal. The best performances was achieved using high pressure UVphotocatalytic
reactor using TiO2. The successful result obtained using TiO2is 80% COD
degradation and 99% color removal followed by 75% COD and 99% color removal with ZnO.
Chemical kinetics was found to follow first order mechanism. The formation of intermediate
compounds and identification of the final products were carried out using LCMS/MS analysis and
FT-IR techniques.
Photocatalytic application of TiO2/SiO2-based magnetic nanocomposite (Fe3O4@S...Iranian Chemical Society
In this research we have developed a treatment method for textile wastewater by TiO2/SiO2-based magnetic nanocomposite. Textile wastewater includes a large variety of dyes and chemicals and needs treatments. This manuscript presents a facile method for removing dyes from the textile wastewater by using TiO2/SiO2-based nanocomposite (Fe3O4@SiO2/TiO2) under UV irradiation. This magnetic nanocomposite, as photocatalytically active composite, is synthesized via solution method in mild conditions. A large range of cationic, anionic and neutral dyes including: methyl orange, methylene blue, neutral red, bromocresol green and methyl red are used for treatment investigations. Neutral red and bromocresol green have good results in reusing treatment. The high surface area of nanocomposites improve the kinetic of wastewater treatment. In this method, by using the magnetic properties of Fe3O4 nanoparticles, TiO2-based photocatalyst could be separated and reused for 3 times. The efficiency of this method is respectively 100% and 65% for low concentration (10 ppm) and high concentration (50 ppm) of neutral red and bromocrosol green after 3 h treatment. The efficiency of treatment using the second used nanocomposite was 90% for 10 ppm of the same dyes.
PHOTOCATALYTIC DEGRADATION AND REMOVAL OF HEAVY METALS IN PHARMACEUTICAL WAST...Journal For Research
In recent years pharmaceutical wastes (PW) deposal of has become a major difficulty for the environment. Therefore, pharmaceutical waste removal is very necessary before its discharge from the pharma industry. The separation of drugs containing organic compounds in wastewater streams is failed by convectional and biological treatments. Thus, the reduction of harmful effects of pharmaceutical compounds is possible by heterogeneous photocatalysis process. Herein we reported the degradation of pharmaceutical concentration in pharmaceutical waste by heterogeneous photocatalyst ZnO doped with Selenium prepared by cost effective hydrothermal method. In addition the heavy metals in pharmaceutical waste were also removed by ZnO/Se nanocomposite. The average band gap of nanocomposite (~2.5 eV) increase the photocatalytic activity and degrade the organic compounds in pharmaceutical waste. The heavy metals get adsorbed on the high surface area of nanocomposite and removed completely by filtration method. The Selenium doped ZnO photocatalyst semiconductor was characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDAX) and also the characteristic crystalline forms of ZnO/Se nanocomposite was confirmed by XRD. The functional groups and particle size distribution of ZnO/Se nanocomposite was characterized by FTIR and DLS respectively. The reduction of organic compounds in the pharmaceutical waste was confirmed by COD analysis and removal of heavy metals was performed by AAS analysis.
degradation of pollution and photocatalysisPraveen Vaidya
The presentation deals with the use of conduction of photocatalytic reaction using the transition metal doped transparent semiconducting thinfilms. The precursor to film is prepared by the SILAR method, which is a chemical method.
PHOTOCATALYTIC DEGRADATION OF RB21 DYE BY TIO2 AND ZNO UNDER NATURAL SUNLIGHT...IAEME Publication
The present work aims to degrade the RB21 dye from synthetic wastewater using
semiconductors TiO2 and ZnO. The activity of photocatalytic degradation process of dye was
carried out using different light sources of 900 W/m
2
intensity in natural sunlight from 02:00 to
04:00 pm with 48°C temperature in Ahmedabad city in the month of May, 600 Watt microwave
oven and high pressure UV-light photocatalytic reactor of wavelength 200-450 nm. All the
experiments were performed with dye concentration 50 mg/L, catalyst dosage 0.8 g, pH 7, room
temperature, irradiation time 240 min followed by 30 min in dark. All the samples were collected at
different time intervals of 30, 60, 90, 120, 150, 180, 210, 240 min for the analysis of COD
degradation and color removal. The best performances was achieved using high pressure UVphotocatalytic
reactor using TiO2. The successful result obtained using TiO2is 80% COD
degradation and 99% color removal followed by 75% COD and 99% color removal with ZnO.
Chemical kinetics was found to follow first order mechanism. The formation of intermediate
compounds and identification of the final products were carried out using LCMS/MS analysis and
FT-IR techniques.
Photocatalytic application of TiO2/SiO2-based magnetic nanocomposite (Fe3O4@S...Iranian Chemical Society
In this research we have developed a treatment method for textile wastewater by TiO2/SiO2-based magnetic nanocomposite. Textile wastewater includes a large variety of dyes and chemicals and needs treatments. This manuscript presents a facile method for removing dyes from the textile wastewater by using TiO2/SiO2-based nanocomposite (Fe3O4@SiO2/TiO2) under UV irradiation. This magnetic nanocomposite, as photocatalytically active composite, is synthesized via solution method in mild conditions. A large range of cationic, anionic and neutral dyes including: methyl orange, methylene blue, neutral red, bromocresol green and methyl red are used for treatment investigations. Neutral red and bromocresol green have good results in reusing treatment. The high surface area of nanocomposites improve the kinetic of wastewater treatment. In this method, by using the magnetic properties of Fe3O4 nanoparticles, TiO2-based photocatalyst could be separated and reused for 3 times. The efficiency of this method is respectively 100% and 65% for low concentration (10 ppm) and high concentration (50 ppm) of neutral red and bromocrosol green after 3 h treatment. The efficiency of treatment using the second used nanocomposite was 90% for 10 ppm of the same dyes.
PHOTOCATALYTIC DEGRADATION AND REMOVAL OF HEAVY METALS IN PHARMACEUTICAL WAST...Journal For Research
In recent years pharmaceutical wastes (PW) deposal of has become a major difficulty for the environment. Therefore, pharmaceutical waste removal is very necessary before its discharge from the pharma industry. The separation of drugs containing organic compounds in wastewater streams is failed by convectional and biological treatments. Thus, the reduction of harmful effects of pharmaceutical compounds is possible by heterogeneous photocatalysis process. Herein we reported the degradation of pharmaceutical concentration in pharmaceutical waste by heterogeneous photocatalyst ZnO doped with Selenium prepared by cost effective hydrothermal method. In addition the heavy metals in pharmaceutical waste were also removed by ZnO/Se nanocomposite. The average band gap of nanocomposite (~2.5 eV) increase the photocatalytic activity and degrade the organic compounds in pharmaceutical waste. The heavy metals get adsorbed on the high surface area of nanocomposite and removed completely by filtration method. The Selenium doped ZnO photocatalyst semiconductor was characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDAX) and also the characteristic crystalline forms of ZnO/Se nanocomposite was confirmed by XRD. The functional groups and particle size distribution of ZnO/Se nanocomposite was characterized by FTIR and DLS respectively. The reduction of organic compounds in the pharmaceutical waste was confirmed by COD analysis and removal of heavy metals was performed by AAS analysis.
Photocatalytic degradation of some organic dyes under solar light irradiation...Iranian Chemical Society
Nanoparticles of the ZnO and TiO2 were synthesized and the physicochemical properties of the compounds were characterized by IR, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD patterns of the ZnO and TiO2 nanoparticles could be indexed to hexagonal and rutile phase, respectively. Aggregated nanoparticles of ZnO and TiO2 with spherical-like shapes were observed with particle diameter in the range of 80-100 nm. These nanoparticles were used for photocatalytic degradation of various dyes, Rhodamine B (RhB), Methylene blue (MB) and Acridine orange (AO) under solar light irradiation at room temperature. Effect of the amount of catalyst on the rate of photodegradation was investigated. In general, because ZnO is unstable, due to incongruous dissolution to yield Zn(OH)2 on the ZnO particle surfaces and thus leading to catalyst inactivation,the catalytic activity of the system for photodegradation of dyes decreased dramatically when TiO2 was replaced by ZnO.
Sunlight induced removal of Rhodamine B from water through Semiconductor Pho...Hariprasad Narayanan
Application of Advanced Oxidation Processes (AOP) for the removal of toxic pollutants from water has been receiving increasing
attention in recent times. Photocatalysis using semiconductor oxides is one such AOP which is being investigated extensively for
the degradation of dyes in effluent water. This paper reports our findings on the sunlight induced photocatalytic removal of the
hazardous xanthene dye Rhodamine B from water, mediated by TiO2 and ‘platinum deposited TiO2’ (Pt/TiO2).Unlike in the case of
photocatalytic degradation of many organic pollutants which are driven by UV light, Rhodamine B can be removed in presence of
TiO2 even by visible light. Pt/TiO2 is ~5 times more active than TiO2 alone for the solar photocatalytic degradation of the dye,
which is attributed to extension of the absorption of light to the visible range and retardation of the recombination of
photogenerated electrons and holes. The dye itself can absorb visible light and act as a photo sensitizer to activate TiO2. The
effects of various parameters such as catalyst loading, concentration of the dye, pH, Pt concentration in Pt/TiO2, externallyadded
H2O2 etc on the adsorption and /or degradation of the dye are evaluated. The degradation of the dye proceeds through
intermediates and complete removal of Total Organic Carbon (TOC) is achieved many hours after the decolorisation of the dye.
The rate of degradation decreases beyond a critical concentration of the dye, possibly due to reduction in the path length of
photons in deeply colored solution. The higher degradation in alkaline pH is explained in terms of the ionization state of the
catalyst surface and the enhanced adsorption facilitated by the electrostatic attraction between the negatively charged catalyst
surface and the zwitter ionic form of the dye. H2O2, upto a critical concentration, accelerates the degradation. The observations are
critically analysed and suitable mechanism for the photocatalytic mineralisation of RhB is proposed.
Solar Photocatalysis a green and novel technology for wastewater treatment. It is a sustainable way to harvest solar energy for treatment of wastewater at a lower cost thus helping in achieving some of the Sustainable Development Goals(i.e. Good Health and Wellbeing).
This is based on the advanced oxidation process i.e. generation of reactive oxygen species which can help in the degradation of pollutants
Preparation and photocatalytic activity of alkali titanateSoumya Ranjan Sahoo
Photocatalysts nano A2TinO2n+1 (A = Li, Na, K) were prepared successfully by novel hydrothermal synthesis process. The nano crystals of Li2TiO3 were self-assembled as snowflakes while that of Na2Ti3O7 and K2Ti8O17 were nanorods. The results indicated that alkali titanates as prepared have higher photocatalytic activities compared with P25TiO2 in the degradation of chloroform under UV light irradiation. A combination of K2Ti8O17 and NiO produces a photo catalyst effective for the degradation of chloroform in aqueous solution.
The investigation of photo-oxidation of gas phase cyclohexane was an experimental study used to determine how the concentration of cyclohexane in a bulk flow influent to a photcatalytic reactor affects the rate of degradation. In addition, a secondary set of tests will be conducted to aide in obtaining data for determining the effect of particle size on degradation
Preparation, characterization and application of sonochemically doped fe3+ in...eSAT Journals
Abstract In this present study, mechanistic investigation of ultrasound–assisted dye decolorization/degradation was investigated using sonochemically prepared Fe3+ doped ZnO. Fe3+ doped ZnO nanoparticle was prepared under ultrasound (20 kHz) irradiation using a doping concentration of 2 wt% of Fe(III). To investigate the catalytic activity of Fe3+ doped ZnO, Acid Red 14 (azo dye) was chosen for decolorization/degradation using sonolysis, photocatalysis and sono–photocatalysis processes. To study the influence of dopant onto structure, crystallinity, and optical properties, different analytical analyses were performed such as X–ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Zeta potential, Delsa Nano Particle Size Analyzer (PSA), Vibrating Sample Magnetometer analysis (VSM) and Field Emission Scanning Electron Microscopy (FE–SEM) etc. For photocatalytic experiments, a blended high pressure mercury UV lamp with maximum peak emission at 365 nm was used. The decolorization/degradation of dye with modified photocatalyst showed faster reaction kinetics under sono–photocatalytic process. Ultrasound showed an additive effect for degradation/decolorization process. The maximum decolorization of AR14 was achieved (~ 82%) under sono–photocatlytic process with an initial dye concentration of 20 ppm. The sono–photocatalysis process showed 1.4 – 1.6 higher reaction rates with Fe–doped ZnO than pure ZnO. Index Terms: ZnO, Fe–ZnO, Fe-doped ZnO, Sonocatalytic, Photocatalytic, Advanced Oxidation Process, AOP
Photocatalytic degradation of some organic dyes under solar light irradiation...Iranian Chemical Society
Nanoparticles of the ZnO and TiO2 were synthesized and the physicochemical properties of the compounds were characterized by IR, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD patterns of the ZnO and TiO2 nanoparticles could be indexed to hexagonal and rutile phase, respectively. Aggregated nanoparticles of ZnO and TiO2 with spherical-like shapes were observed with particle diameter in the range of 80-100 nm. These nanoparticles were used for photocatalytic degradation of various dyes, Rhodamine B (RhB), Methylene blue (MB) and Acridine orange (AO) under solar light irradiation at room temperature. Effect of the amount of catalyst on the rate of photodegradation was investigated. In general, because ZnO is unstable, due to incongruous dissolution to yield Zn(OH)2 on the ZnO particle surfaces and thus leading to catalyst inactivation,the catalytic activity of the system for photodegradation of dyes decreased dramatically when TiO2 was replaced by ZnO.
Sunlight induced removal of Rhodamine B from water through Semiconductor Pho...Hariprasad Narayanan
Application of Advanced Oxidation Processes (AOP) for the removal of toxic pollutants from water has been receiving increasing
attention in recent times. Photocatalysis using semiconductor oxides is one such AOP which is being investigated extensively for
the degradation of dyes in effluent water. This paper reports our findings on the sunlight induced photocatalytic removal of the
hazardous xanthene dye Rhodamine B from water, mediated by TiO2 and ‘platinum deposited TiO2’ (Pt/TiO2).Unlike in the case of
photocatalytic degradation of many organic pollutants which are driven by UV light, Rhodamine B can be removed in presence of
TiO2 even by visible light. Pt/TiO2 is ~5 times more active than TiO2 alone for the solar photocatalytic degradation of the dye,
which is attributed to extension of the absorption of light to the visible range and retardation of the recombination of
photogenerated electrons and holes. The dye itself can absorb visible light and act as a photo sensitizer to activate TiO2. The
effects of various parameters such as catalyst loading, concentration of the dye, pH, Pt concentration in Pt/TiO2, externallyadded
H2O2 etc on the adsorption and /or degradation of the dye are evaluated. The degradation of the dye proceeds through
intermediates and complete removal of Total Organic Carbon (TOC) is achieved many hours after the decolorisation of the dye.
The rate of degradation decreases beyond a critical concentration of the dye, possibly due to reduction in the path length of
photons in deeply colored solution. The higher degradation in alkaline pH is explained in terms of the ionization state of the
catalyst surface and the enhanced adsorption facilitated by the electrostatic attraction between the negatively charged catalyst
surface and the zwitter ionic form of the dye. H2O2, upto a critical concentration, accelerates the degradation. The observations are
critically analysed and suitable mechanism for the photocatalytic mineralisation of RhB is proposed.
Solar Photocatalysis a green and novel technology for wastewater treatment. It is a sustainable way to harvest solar energy for treatment of wastewater at a lower cost thus helping in achieving some of the Sustainable Development Goals(i.e. Good Health and Wellbeing).
This is based on the advanced oxidation process i.e. generation of reactive oxygen species which can help in the degradation of pollutants
Preparation and photocatalytic activity of alkali titanateSoumya Ranjan Sahoo
Photocatalysts nano A2TinO2n+1 (A = Li, Na, K) were prepared successfully by novel hydrothermal synthesis process. The nano crystals of Li2TiO3 were self-assembled as snowflakes while that of Na2Ti3O7 and K2Ti8O17 were nanorods. The results indicated that alkali titanates as prepared have higher photocatalytic activities compared with P25TiO2 in the degradation of chloroform under UV light irradiation. A combination of K2Ti8O17 and NiO produces a photo catalyst effective for the degradation of chloroform in aqueous solution.
The investigation of photo-oxidation of gas phase cyclohexane was an experimental study used to determine how the concentration of cyclohexane in a bulk flow influent to a photcatalytic reactor affects the rate of degradation. In addition, a secondary set of tests will be conducted to aide in obtaining data for determining the effect of particle size on degradation
Preparation, characterization and application of sonochemically doped fe3+ in...eSAT Journals
Abstract In this present study, mechanistic investigation of ultrasound–assisted dye decolorization/degradation was investigated using sonochemically prepared Fe3+ doped ZnO. Fe3+ doped ZnO nanoparticle was prepared under ultrasound (20 kHz) irradiation using a doping concentration of 2 wt% of Fe(III). To investigate the catalytic activity of Fe3+ doped ZnO, Acid Red 14 (azo dye) was chosen for decolorization/degradation using sonolysis, photocatalysis and sono–photocatalysis processes. To study the influence of dopant onto structure, crystallinity, and optical properties, different analytical analyses were performed such as X–ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Zeta potential, Delsa Nano Particle Size Analyzer (PSA), Vibrating Sample Magnetometer analysis (VSM) and Field Emission Scanning Electron Microscopy (FE–SEM) etc. For photocatalytic experiments, a blended high pressure mercury UV lamp with maximum peak emission at 365 nm was used. The decolorization/degradation of dye with modified photocatalyst showed faster reaction kinetics under sono–photocatalytic process. Ultrasound showed an additive effect for degradation/decolorization process. The maximum decolorization of AR14 was achieved (~ 82%) under sono–photocatlytic process with an initial dye concentration of 20 ppm. The sono–photocatalysis process showed 1.4 – 1.6 higher reaction rates with Fe–doped ZnO than pure ZnO. Index Terms: ZnO, Fe–ZnO, Fe-doped ZnO, Sonocatalytic, Photocatalytic, Advanced Oxidation Process, AOP
The US government expects a million drones to be sold this Christmas and has even recently mandated registration of certain types of drones. Because many boys and girls will find these devices underneath the tree this year, Future Point of View presents: A Very Drone Christmas
II ENCUENTRO DE REFLEXIÓN CRITICA SOBRE SOSTENIBILIDAD, DESARROLLO Y EDUCACIÓN EN EL MARCO DEL PROYECTO SIMÓN BOLIVAR. TEMATICA CENTRAL: GERENCIA EMERGENTE
HYDROGEN GENERATION FROM WASTE WATER BY USING SOLAR ENERGY | J4RV3I11004Journal For Research
Objective of this paper is to produce hydrogen which is an ideal fuel for the next generation because it is abundantly available in nature, energy efficient and clean. Wide varieties of technologies are available to produce hydrogen but only few of them are considered environmental friendly. Solar water splitting via photo catalytic reaction is one of them which have attracted tremendous attention. In this paper we are working on hydrogen production via solar splitting. Photo catalytic water splitting is one of the promising technologies to produce pure and clean hydrogen. Since it is reasonable having low process cost and has a small reactor, it can be made for house hold application and hence has a huge market potential. Generation of hydrogen under visible irradiation is the main area of work. Based on the literature reported here, visible irradiation can be achieved by doping of TiO2 with metal or non-metal. We have used Fe doping to increase the efficiency. The result indicates that Fe doped sieves produce more hydrogen than the normal TiO2 coated sieve and the efficiency can be increased if we increase the number of doped sieves and surface area.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The effect of band engineering of semiconductors on photocatalyic water split...eSAT Journals
Abstract
The direct conversion of solar energy using a photocatalyst in a water splitting reaction is a source of a sustainable and clean hydrogen supply. In general, photocatalysts are semiconductors that possess valence and conduction bands. These energy bands permit the absorption of photon energy to excite electrons in the outer orbitals of the photocatalysts. Photoexcited electron and hole pairs can subsequently induce a watersplitting reaction to produce hydrogen and oxygen. Photocatalytic water splitting is affected by the band level and crystallinity of the photocatalyst. Therefore, band engineering using chemical modifications such as cationic and anionic modification could createa photocatalyst suitable for the large-scale production of hydrogen. In this paper, cationic and anionic modifications of photocatalysts and the effects of these modifications onphotocatalytic water splitting are reviewed. Keywords: Water splitting; Photocatalysis; Hydrogen
Uv radiation assisted photocatalytic transformation of azo dye direct yellow 9eSAT Journals
Abstract
Advanced oxidation process (AOP) is best for treatment of textile industries effluents (waste water). Methylene blue immobilized resin dowex-11; a photocatalyst is used for transformation of azo dyes. The mechanism of the photo transformation depends on the radiation used. Activity of catalyst remains unaffected on continuous use. The process follows pseudo first order kinetics according to Langmuir Hinshelwood model, the value of rate constant k is 1.43*10-2 min-1 and approximately 94.60% of the dye was transforms within 160 min of irradiation.
Keywords: Transformation, Direct Yellow-9, Methylene blue immobilized resin, Textile effluents; Dowex-11, Photocatalyst.
Recent progress in Tungsten disulphide based Photocatalyst for Hydrogen Produ...MaiyalaganT
Semiconductor-based photocatalysis has dramatically increased interest in the field of photocatalysis, because of
its ability to directly utilize solar energy into fuels and for the degradation of various pollutants. However, the
photocatalytic performance of semiconductor-based photocatalys still lower due to the quick recombination
photogenerated electron–hole pairs and low visible light utilization. Therefore, numerous efforts have been made
to solve these complications. Particularly, cocatalysts supported semiconductor have been extensively applied in
designing and developing highly effective composite photocatalysts for hydrogen photocatalytic application.WS2
has attracted enormous attention in photocatalysis due to its unusual properties like enhancing visible lightharvesting,
charge transfer dynamics and surface reactions of a photocatalytic system. In this review, we
begin by describing synthesis route, different morphologies and brief sketch properties of WS2. A brief discussion
of the WS2 supported metal oxide, metal sulphide, carbon based materials, silver based materials and bismuth
based materials photocatalysts is then provided. While various plausible photocatalytic mechanisms of
photogenerated-electrons and holes in WS2 composite should be proposed. The applications of WS2 as cocatalyst
in the Photocatalytic hydrogen production, organic contaminant degradation and Cr(VI) removal. This review
may offer motivation for designing and fabricating novel and efficient WS2 based composite photocatalysts for
highly efficient photocatalytic applications.
A Review on Applicability of Photocatalyst Titanium dioxide for Treatment of ...IJERA Editor
Greywater reuse has attracted great attention for sustainable management of water especially under water
scarcity conditions. However, the effort has been limited by the presence of toxic organics in the effluent which
in turn inhibits the public acceptance of recycling water. The existence of those organic pollutants, which cannot
be eliminated by conventional primary and secondary treatment processes, can be problematic. Hence it is
necessary to explore a sustainable, robust and affordable method for treatment of greywater. Photocatalytic
oxidation is an emerging technology that could be suitable to remove refractory organic compounds found in
greywater. Recently titanium dioxide (TiO2) gained wide attention for photocatalytic oxidation of organic matter
of wastewater. Because it is biologically and chemical inert, resistant to chemical corrosion and can work at
ambient temperature and pressure, without addition of chemical species. The irradiation of titanium dioxide
dispersions by ultraviolet (UV) (300-400 nm) light can lead to the formulation of highly reactive hydroxyl
radicals which attack the pollutant molecule to degrade it into carbon dioxide, water and mineral acids.This
technology has advantages, such as, the integration into small places, low maintenance and easy operation.
Mechanical properties of hybrid fiber reinforced concrete for pavementseSAT Journals
Abstract
The effect of addition of mono fibers and hybrid fibers on the mechanical properties of concrete mixture is studied in the present
investigation. Steel fibers of 1% and polypropylene fibers 0.036% were added individually to the concrete mixture as mono fibers and
then they were added together to form a hybrid fiber reinforced concrete. Mechanical properties such as compressive, split tensile and
flexural strength were determined. The results show that hybrid fibers improve the compressive strength marginally as compared to
mono fibers. Whereas, hybridization improves split tensile strength and flexural strength noticeably.
Keywords:-Hybridization, mono fibers, steel fiber, polypropylene fiber, Improvement in mechanical properties.
Material management in construction – a case studyeSAT Journals
Abstract
The objective of the present study is to understand about all the problems occurring in the company because of improper application
of material management. In construction project operation, often there is a project cost variance in terms of the material, equipments,
manpower, subcontractor, overhead cost, and general condition. Material is the main component in construction projects. Therefore,
if the material management is not properly managed it will create a project cost variance. Project cost can be controlled by taking
corrective actions towards the cost variance. Therefore a methodology is used to diagnose and evaluate the procurement process
involved in material management and launch a continuous improvement was developed and applied. A thorough study was carried
out along with study of cases, surveys and interviews to professionals involved in this area. As a result, a methodology for diagnosis
and improvement was proposed and tested in selected projects. The results obtained show that the main problem of procurement is
related to schedule delays and lack of specified quality for the project. To prevent this situation it is often necessary to dedicate
important resources like money, personnel, time, etc. To monitor and control the process. A great potential for improvement was
detected if state of the art technologies such as, electronic mail, electronic data interchange (EDI), and analysis were applied to the
procurement process. These helped to eliminate the root causes for many types of problems that were detected.
Managing drought short term strategies in semi arid regions a case studyeSAT Journals
Abstract
Drought management needs multidisciplinary action. Interdisciplinary efforts among the experts in various fields of the droughts
prone areas are helpful to achieve tangible and permanent solution for this recurring problem. The Gulbarga district having the total
area around 16, 240 sq.km, and accounts 8.45 per cent of the Karnataka state area. The district has been situated with latitude 17º 19'
60" North and longitude of 76 º 49' 60" east. The district is situated entirely on the Deccan plateau positioned at a height of 300 to
750 m above MSL. Sub-tropical, semi-arid type is one among the drought prone districts of Karnataka State. The drought
management is very important for a district like Gulbarga. In this paper various short term strategies are discussed to mitigate the
drought condition in the district.
Keywords: Drought, South-West monsoon, Semi-Arid, Rainfall, Strategies etc.
Life cycle cost analysis of overlay for an urban road in bangaloreeSAT Journals
Abstract
Pavements are subjected to severe condition of stresses and weathering effects from the day they are constructed and opened to traffic
mainly due to its fatigue behavior and environmental effects. Therefore, pavement rehabilitation is one of the most important
components of entire road systems. This paper highlights the design of concrete pavement with added mono fibers like polypropylene,
steel and hybrid fibres for a widened portion of existing concrete pavement and various overlay alternatives for an existing
bituminous pavement in an urban road in Bangalore. Along with this, Life cycle cost analyses at these sections are done by Net
Present Value (NPV) method to identify the most feasible option. The results show that though the initial cost of construction of
concrete overlay is high, over a period of time it prove to be better than the bituminous overlay considering the whole life cycle cost.
The economic analysis also indicates that, out of the three fibre options, hybrid reinforced concrete would be economical without
compromising the performance of the pavement.
Keywords: - Fatigue, Life cycle cost analysis, Net Present Value method, Overlay, Rehabilitation
Laboratory studies of dense bituminous mixes ii with reclaimed asphalt materialseSAT Journals
Abstract
The issue of growing demand on our nation’s roadways over that past couple of decades, decreasing budgetary funds, and the need to
provide a safe, efficient, and cost effective roadway system has led to a dramatic increase in the need to rehabilitate our existing
pavements and the issue of building sustainable road infrastructure in India. With these emergency of the mentioned needs and this
are today’s burning issue and has become the purpose of the study.
In the present study, the samples of existing bituminous layer materials were collected from NH-48(Devahalli to Hassan) site.The
mixtures were designed by Marshall Method as per Asphalt institute (MS-II) at 20% and 30% Reclaimed Asphalt Pavement (RAP).
RAP material was blended with virgin aggregate such that all specimens tested for the, Dense Bituminous Macadam-II (DBM-II)
gradation as per Ministry of Roads, Transport, and Highways (MoRT&H) and cost analysis were carried out to know the economics.
Laboratory results and analysis showed the use of recycled materials showed significant variability in Marshall Stability, and the
variability increased with the increase in RAP content. The saving can be realized from utilization of recycled materials as per the
methodology, the reduction in the total cost is 19%, 30%, comparing with the virgin mixes.
Keywords: Reclaimed Asphalt Pavement, Marshall Stability, MS-II, Dense Bituminous Macadam-II
Laboratory investigation of expansive soil stabilized with natural inorganic ...eSAT Journals
Abstract
Soil stabilization has proven to be one of the oldest techniques to improve the soil properties. Literature review conducted revealed
that uses of natural inorganic stabilizers are found to be one of the best options for soil stabilization. In this regard an attempt has
been made to evaluate the influence of RBI-81 stabilizer on properties of black cotton soil through laboratory investigations. Black
cotton soil with varying percentages of RBI-81 viz., 0, 0.5, 1, 1.5, 2, and 2.5 percent were studied for moisture density relationships
and strength behaviour of soils. Also the effect of curing period was evaluated as literature review clearly emphasized the strength
gain of soils stabilized with RBI-81 over a period of time. The results obtained shows that the unconfined compressive strength of
specimens treated with RBI-81 increased approximately by 250% for a curing period of 28 days as compared to virgin soil. Further
the CBR value improved approximately by 400%. The studies indicated an increasing trend for soil strength behaviour with
increasing percentage of RBI-81 suggesting its potential applications in soil stabilization.
Influence of reinforcement on the behavior of hollow concrete block masonry p...eSAT Journals
Abstract
Reinforced masonry was developed to exploit the strength potential of masonry and to solve its lack of tensile strength. Experimental
and analytical studies have been carried out to investigate the effect of reinforcement on the behavior of hollow concrete block
masonry prisms under compression and to predict ultimate failure compressive strength. In the numerical program, three dimensional
non-linear finite elements (FE) model based on the micro-modeling approach is developed for both unreinforced and reinforced
masonry prisms using ANSYS (14.5). The proposed FE model uses multi-linear stress-strain relationships to model the non-linear
behavior of hollow concrete block, mortar, and grout. Willam-Warnke’s five parameter failure theory has been adopted to model the
failure of masonry materials. The comparison of the numerical and experimental results indicates that the FE models can successfully
capture the highly nonlinear behavior of the physical specimens and accurately predict their strength and failure mechanisms.
Keywords: Structural masonry, Hollow concrete block prism, grout, Compression failure, Finite element method,
Numerical modeling.
Influence of compaction energy on soil stabilized with chemical stabilizereSAT Journals
Abstract
Increase in traffic along with heavier magnitude of wheel loads cause rapid deterioration in pavements. There is a need to improve
density, strength of soil subgrade and other pavement layers. In this study an attempt is made to improve the properties of locally
available loamy soil using twin approaches viz., i) increasing the compaction of soil and ii) treating the soil with chemical stabilizer.
Laboratory studies are carried out on both untreated and treated soil samples compacted by different compaction efforts. Studies
show that increase in compaction effort results in increase in density of soil. However in soil treated with chemical stabilizer, rate of
increase in density is not significant. The soil treated with chemical stabilizer exhibits improvement in both strength and performance
properties.
Keywords: compaction, density, subgradestabilization, resilient modulus
Geographical information system (gis) for water resources managementeSAT Journals
Abstract
Water resources projects are inherited with overlapping and at times conflicting objectives. These projects are often of varied sizes
ranging from major projects with command areas of millions of hectares to very small projects implemented at the local level. Thus,
in all these projects there is seldom proper coordination which is essential for ensuring collective sustainability.
Integrated watershed development and management is the accepted answer but in turn requires a comprehensive framework that can
enable planning process involving all the stakeholders at different levels and scales is compulsory. Such a unified hydrological
framework is essential to evaluate the cause and effect of all the proposed actions within the drainage basins.
The present paper describes a hydrological framework developed in the form of a Hydrologic Information System (HIS) which is
intended to meet the specific information needs of the various line departments of a typical State connected with water related aspects.
The HIS consist of a hydrologic information database coupled with tools for collating primary and secondary data and tools for
analyzing and visualizing the data and information. The HIS also incorporates hydrological model base for indirect assessment of
various entities of water balance in space and time. The framework would be maintained and updated to reflect fully the most
accurate ground truth data and the infrastructure requirements for planning and management.
Keywords: Hydrological Information System (HIS); WebGIS; Data Model; Web Mapping Services
Forest type mapping of bidar forest division, karnataka using geoinformatics ...eSAT Journals
Abstract
The study demonstrate the potentiality of satellite remote sensing technique for the generation of baseline information on forest types
including tree plantation details in Bidar forest division, Karnataka covering an area of 5814.60Sq.Kms. The Total Area of Bidar
forest division is 5814Sq.Kms analysis of the satellite data in the study area reveals that about 84% of the total area is Covered by
crop land, 1.778% of the area is covered by dry deciduous forest, 1.38 % of mixed plantation, which is very threatening to the
environmental stability of the forest, future plantation site has been mapped. With the use of latest Geo-informatics technology proper
and exact condition of the trees can be observed and necessary precautions can be taken for future plantation works in an appropriate
manner
Keywords:-RS, GIS, GPS, Forest Type, Tree Plantation
Factors influencing compressive strength of geopolymer concreteeSAT Journals
Abstract
To study effects of several factors on the properties of fly ash based geopolymer concrete on the compressive strength and also the
cost comparison with the normal concrete. The test variables were molarities of sodium hydroxide(NaOH) 8M,14M and 16M, ratio of
NaOH to sodium silicate (Na2SiO3) 1, 1.5, 2 and 2.5, alkaline liquid to fly ash ratio 0.35 and 0.40 and replacement of water in
Na2SiO3 solution by 10%, 20% and 30% were used in the present study. The test results indicated that the highest compressive
strength 54 MPa was observed for 16M of NaOH, ratio of NaOH to Na2SiO3 2.5 and alkaline liquid to fly ash ratio of 0.35. Lowest
compressive strength of 27 MPa was observed for 8M of NaOH, ratio of NaOH to Na2SiO3 is 1 and alkaline liquid to fly ash ratio of
0.40. Alkaline liquid to fly ash ratio of 0.35, water replacement of 10% and 30% for 8 and 16 molarity of NaOH and has resulted in
compressive strength of 36 MPa and 20 MPa respectively. Superplasticiser dosage of 2 % by weight of fly ash has given higher
strength in all cases.
Keywords: compressive strength, alkaline liquid, fly ash
Experimental investigation on circular hollow steel columns in filled with li...eSAT Journals
Abstract
Composite Circular hollow Steel tubes with and without GFRP infill for three different grades of Light weight concrete are tested for
ultimate load capacity and axial shortening , under Cyclic loading. Steel tubes are compared for different lengths, cross sections and
thickness. Specimens were tested separately after adopting Taguchi’s L9 (Latin Squares) Orthogonal array in order to save the initial
experimental cost on number of specimens and experimental duration. Analysis was carried out using ANN (Artificial Neural
Network) technique with the assistance of Mini Tab- a statistical soft tool. Comparison for predicted, experimental & ANN output is
obtained from linear regression plots. From this research study, it can be concluded that *Cross sectional area of steel tube has most
significant effect on ultimate load carrying capacity, *as length of steel tube increased- load carrying capacity decreased & *ANN
modeling predicted acceptable results. Thus ANN tool can be utilized for predicting ultimate load carrying capacity for composite
columns.
Keywords: Light weight concrete, GFRP, Artificial Neural Network, Linear Regression, Back propagation, orthogonal
Array, Latin Squares
Experimental behavior of circular hsscfrc filled steel tubular columns under ...eSAT Journals
Abstract
This paper presents an outlook on experimental behavior and a comparison with predicted formula on the behaviour of circular
concentrically loaded self-consolidating fibre reinforced concrete filled steel tube columns (HSSCFRC). Forty-five specimens were
tested. The main parameters varied in the tests are: (1) percentage of fiber (2) tube diameter or width to wall thickness ratio (D/t
from 15 to 25) (3) L/d ratio from 2.97 to 7.04 the results from these predictions were compared with the experimental data. The
experimental results) were also validated in this study.
Keywords: Self-compacting concrete; Concrete-filled steel tube; axial load behavior; Ultimate capacity.
Evaluation of punching shear in flat slabseSAT Journals
Abstract
Flat-slab construction has been widely used in construction today because of many advantages that it offers. The basic philosophy in
the design of flat slab is to consider only gravity forces; this method ignores the effect of punching shear due to unbalanced moments
at the slab column junction which is critical. An attempt has been made to generate generalized design sheets which accounts both
punching shear due to gravity loads and unbalanced moments for cases (a) interior column; (b) edge column (bending perpendicular
to shorter edge); (c) edge column (bending parallel to shorter edge); (d) corner column. These design sheets are prepared as per
codal provisions of IS 456-2000. These design sheets will be helpful in calculating the shear reinforcement to be provided at the
critical section which is ignored in many design offices. Apart from its usefulness in evaluating punching shear and the necessary
shear reinforcement, the design sheets developed will enable the designer to fix the depth of flat slab during the initial phase of the
design.
Keywords: Flat slabs, punching shear, unbalanced moment.
Evaluation of performance of intake tower dam for recent earthquake in indiaeSAT Journals
Abstract
Intake towers are typically tall, hollow, reinforced concrete structures and form entrance to reservoir outlet works. A parametric
study on dynamic behavior of circular cylindrical towers can be carried out to study the effect of depth of submergence, wall thickness
and slenderness ratio, and also effect on tower considering dynamic analysis for time history function of different soil condition and
by Goyal and Chopra accounting interaction effects of added hydrodynamic mass of surrounding and inside water in intake tower of
dam
Key words: Hydrodynamic mass, Depth of submergence, Reservoir, Time history analysis,
Evaluation of operational efficiency of urban road network using travel time ...eSAT Journals
Abstract
Efficiency of the road network system is analyzed by travel time reliability measures. The study overlooks on an important measure of
travel time reliability and prioritizing Tiruchirappalli road network. Traffic volume and travel time were collected using license plate
matching method. Travel time measures were estimated from average travel time and 95th travel time. Effect of non-motorized vehicle
on efficiency of road system was evaluated. Relation between buffer time index and traffic volume was created. Travel time model has
been developed and travel time measure was validated. Then service quality of road sections in network were graded based on
travel time reliability measures.
Keywords: Buffer Time Index (BTI); Average Travel Time (ATT); Travel Time Reliability (TTR); Buffer Time (BT).
Estimation of surface runoff in nallur amanikere watershed using scs cn methodeSAT Journals
Abstract
The development of watershed aims at productive utilization of all the available natural resources in the entire area extending from
ridge line to stream outlet. The per capita availability of land for cultivation has been decreasing over the years. Therefore, water and
the related land resources must be developed, utilized and managed in an integrated and comprehensive manner. Remote sensing and
GIS techniques are being increasingly used for planning, management and development of natural resources. The study area, Nallur
Amanikere watershed geographically lies between 110 38’ and 110 52’ N latitude and 760 30’ and 760 50’ E longitude with an area of
415.68 Sq. km. The thematic layers such as land use/land cover and soil maps were derived from remotely sensed data and overlayed
through ArcGIS software to assign the curve number on polygon wise. The daily rainfall data of six rain gauge stations in and around
the watershed (2001-2011) was used to estimate the daily runoff from the watershed using Soil Conservation Service - Curve Number
(SCS-CN) method. The runoff estimated from the SCS-CN model was then used to know the variation of runoff potential with different
land use/land cover and with different soil conditions.
Keywords: Watershed, Nallur watershed, Surface runoff, Rainfall-Runoff, SCS-CN, Remote Sensing, GIS.
Estimation of morphometric parameters and runoff using rs & gis techniqueseSAT Journals
Abstract
Land and water are the two vital natural resources, the optimal management of these resources with minimum adverse environmental
impact are essential not only for sustainable development but also for human survival. Satellite remote sensing with geographic
information system has a pragmatic approach to map and generate spatial input layers of predicting response behavior and yield of
watershed. Hence, in the present study an attempt has been made to understand the hydrological process of the catchment at the
watershed level by drawing the inferences from moprhometric analysis and runoff. The study area chosen for the present study is
Yagachi catchment situated in Chickamaglur and Hassan district lies geographically at a longitude 75⁰52’08.77”E and
13⁰10’50.77”N latitude. It covers an area of 559.493 Sq.km. Morphometric analysis is carried out to estimate morphometric
parameters at Micro-watershed to understand the hydrological response of the catchment at the Micro-watershed level. Daily runoff
is estimated using USDA SCS curve number model for a period of 10 years from 2001 to 2010. The rainfall runoff relationship of the
study shows there is a positive correlation.
Keywords: morphometric analysis, runoff, remote sensing and GIS, SCS - method
-
Effect of variation of plastic hinge length on the results of non linear anal...eSAT Journals
Abstract The nonlinear Static procedure also well known as pushover analysis is method where in monotonically increasing loads are applied to the structure till the structure is unable to resist any further load. It is a popular tool for seismic performance evaluation of existing and new structures. In literature lot of research has been carried out on conventional pushover analysis and after knowing deficiency efforts have been made to improve it. But actual test results to verify the analytically obtained pushover results are rarely available. It has been found that some amount of variation is always expected to exist in seismic demand prediction of pushover analysis. Initial study is carried out by considering user defined hinge properties and default hinge length. Attempt is being made to assess the variation of pushover analysis results by considering user defined hinge properties and various hinge length formulations available in literature and results compared with experimentally obtained results based on test carried out on a G+2 storied RCC framed structure. For the present study two geometric models viz bare frame and rigid frame model is considered and it is found that the results of pushover analysis are very sensitive to geometric model and hinge length adopted. Keywords: Pushover analysis, Base shear, Displacement, hinge length, moment curvature analysis
Effect of use of recycled materials on indirect tensile strength of asphalt c...eSAT Journals
Abstract
Depletion of natural resources and aggregate quarries for the road construction is a serious problem to procure materials. Hence
recycling or reuse of material is beneficial. On emphasizing development in sustainable construction in the present era, recycling of
asphalt pavements is one of the effective and proven rehabilitation processes. For the laboratory investigations reclaimed asphalt
pavement (RAP) from NH-4 and crumb rubber modified binder (CRMB-55) was used. Foundry waste was used as a replacement to
conventional filler. Laboratory tests were conducted on asphalt concrete mixes with 30, 40, 50, and 60 percent replacement with RAP.
These test results were compared with conventional mixes and asphalt concrete mixes with complete binder extracted RAP
aggregates. Mix design was carried out by Marshall Method. The Marshall Tests indicated highest stability values for asphalt
concrete (AC) mixes with 60% RAP. The optimum binder content (OBC) decreased with increased in RAP in AC mixes. The Indirect
Tensile Strength (ITS) for AC mixes with RAP also was found to be higher when compared to conventional AC mixes at 300C.
Keywords: Reclaimed asphalt pavement, Foundry waste, Recycling, Marshall Stability, Indirect tensile strength.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Final project report on grocery store management system..pdf
Visible light solar photocatalytic degradation of pulp and paper wastewater using dye sensitised tio2
1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 06 | June-2015, Available @ http://www.ijret.org 200
VISIBLE LIGHT SOLAR PHOTOCATALYTIC DEGRADATION OF
PULP AND PAPER WASTEWATER USING
DYE-SENSITISED TiO2
S.Shanmuga Priya1
, Aniruddha Deshpande2
, Ruthu Dwarakanath3
1
Associate Professor, Dept. of Chemical Engineering, MIT, Manipal University, Karnataka, India
2
Student, Dept. of Chemical Engineering, MIT, Manipal University, Karnataka, India
3
Student, Dept. of Chemical Engineering, MIT, Manipal University, Karnataka, India
Abstract
With the growing number of industries there are large volumes of wastewater generated every day. Pulp and paper mills are
highly polluting as they release effluents containing organic pollutants, and high levels of Biological Oxygen Demand (BOD) and
Chemical Oxygen Demand (COD). Even though well-established processes exist to treat these effluents, there are only a few
processes which are energy efficient. Conventional treatment methods are not effective for the degradation of toxic organic
pollutants, hence other treatment techniques are necessary. One of the recent developments in this field is the Advanced Oxidation
Process (AOP). Solar photocatalysis is a type of AOP which utilises UV light to activate semiconductor photocatalyst in order to
produce highly reactive radical species. TiO2 is a widely used catalyst for this purpose, to oxidise or reduce the organic pollutants
in industrial wastewater. However, photocatalysis using visible light has been receiving increased attention hence, modification of
TiO2 is necessary for its enhanced response to visible light. There are many methods for modifying TiO2, such as doping and
photo-sensitisation. This study focusses on the modification of TiO2 using the method of dye-sensitisation (photo-sensitisation)
with the dyes rhodamine B and methylene blue. Solar photocatalytic experiments were carried out for the degradation of pulp and
paper wastewater, at different conditions like varying catalyst loading (500mg, 600mg, 750mg and 1000mg of catalyst for 300ml
of aqueous wastewater) and effluent concentration (20ml, 25ml, 30ml and 35ml of wastewater). Preliminary tests were done to
determine the best conditions for photocatalytic degradation, and these were applied for final tests.
Keywords - Solar Photocatalysis, Visible Light, Dye Sensitisation, Pulp and paper, Methylene blue, Rhodamine B,
TiO2 catalyst.
--------------------------------------------------------------------***-------------------------------------------------------------------
1. INTRODUCTION
Water is of great demand for household applications and
industrial purposes. In India the demand for water is ever
increasing in various sectors and it is projected that by 2020,
India will be a water-stressed nation. Industries are heavily
dependent on water as it has a vital role in numerous
processes, hence there is a need to undertake large scale,
well monitored treatment processes not only for the safe
disposal of wastewater, but also for reusing it. Indian paper
mills utilise a wide variety of cellulosic and non-cellulosic
raw materials, derived from forest wood, agro based and
recycled paper. For various operations, pulp and paper mills
require large volume of water and in turn release huge
amount of effluent in the form of black liquor loaded with
many pollutants. The black liquor effluent is dark brown in
colour and associated with high biochemical oxygen
demand (BOD), chemical oxygen demand (COD), total
solids and total organic carbon (TOC). Treatment methods
include chemical coagulation, flocculation, sedimentation,
flotation, filtration and other biological methods like
activated sludge process, trickling filters, stabilization pond,
anaerobic digestion, lagooning and the like [1]. Recently
solar treatment methods have also been incorporated for the
treatment of pulp and paper mill effluents.
Solar energy is the most abundant resource and has the
highest potential amongst all renewables. Hence, this
renewable energy can be harnessed to solve the energy and
water problems economically, efficiently and, in an eco-
friendly manner. Since India is situated in the tropical
region, most parts of the country experience clear, sunny
weather for about 250-300 days per annum which makes
India a suitable site for solar based treatment processes.
Advanced Oxidation Process (AOP) can effectively treat
organic pollutants found in industrial effluents having high
chemical stability and low biodegradability. AOPs are being
considered as alternatives to conventional technologies
because they degrade hazardous organic compounds rather
than transferring them from one to another phase [2].
Complete mineralisation of organic pollutants to CO2 and
halogenated compounds to halide ions maybe achieved by
AOPs [3]. Solar photocatalysis is a type of AOP which
mainly involves UV light, in the presence of a
semiconducting photocatalyst to convert contaminants to
simpler non-toxic compounds. This study focusses on the
visible light solar photocatalysis as it constitutes a larger
fraction of the solar spectrum, and due to this visible light
has greater quantum efficiency in comparison to UV light
[4].
2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 06 | June-2015, Available @ http://www.ijret.org 201
Photoreactions do not occur on illumination with light alone.
These reactions often require the use of a photocatalyst. In
the case of semiconductor material the role of photons is to
generate electron (e−) hole (h+) pairs that take part in
subsequent redox reactions with the surface adsorbed
molecules to yield the ultimate products. When light of a
certain wavelength falls on a semiconductor and its energy
is more than or equal to the band gap energy of the
semiconductor, electrons would be excited from the valence
band to the conduction band of the semiconductor and holes
would be left in the valence band. These electrons and holes
undergo subsequent oxidation and reduction reactions with
any species, which are adsorbed on the surface of the
semiconductor to give the necessary products [5].
TiO2 is the most widely used catalyst for photocatalytic
experiments as it is non-toxic, inexpensive, stable and
photoactive [6]. TiO2, as it is, can be excited only by UV
light due to its large band gap energy of 3.2ev. However
visible light does not possess enough energy to activate it as
a photocatalyst, hence the physicochemical properties of
TiO2 need to be modified suitably [5]. Dye sensitisation is a
technique used to reduce its band gap energy requirements.
Photosensitized degradation process, assisted by visible
light, involves the initial excitation of the surface adsorbed
dye followed by the charge injection to the conduction band
of the semiconductor which results in the photocatalytic
degradation reaction. Dye molecules adsorbed on the surface
extend the range of excitation energies of the semiconductor
into visible region. Fig 1 shows the chemical structure of the
dye used for study. In the recent studies, the prospect of
TiO2 surface adsorbed methylene blue and rhodamine B has
been examined for the decomposition of various water
bound organic pollutants in the presence of visible light and
air (Debabrata Chatterjee et.al. 2002). Photo-excited
methylene blue, accepts an electron to produce semi-
methylene blue dye species, whereas, surface adsorbed
rhodamine B upon excitation injects electrons to the
conduction band of the semiconductor [7].a
Fig 1: Chemical structure of the dyes used
Unlike solar thermal processes, which require large amounts
of photons at any wavelength to reach a specific temperature
range, solar photocatalytic processes require only the high-
energy short-wavelength photons to promote photochemical
reactions [8]. In photochemical processes
The fluid must be directly exposed to solar
radiation and therefore the absorber must be
transparent to the photons.
Temperature usually does not play a significant
role, so no insulation is required.
The different types of solar collectors are –
Concentrating type
Parabolic Trough concentrator
Compound parabolic concentrator
Non-Concentrating type – Flat plate collector
Parabolic Trough Collector (PTC) is a concentrating type of
collector and the design is based on the collector used for
solar thermal application. PTCs are unsuitable for
photocatalytic applications for several reasons: water is
heated, radiation flux is too high, and most of the photons
are not used efficiently and high cost.
Compound Parabolic Collector (CPC) is a type of low
concentration collector. They combine both the
characteristics and advantages of parabolic concentrators
and static flat systems. CPCs are considered the best option
for solar photocatalytic processes.
Flat Plate Collector is a type of non-concentrating collector
which consists of a static system with no solar tracking
mechanism. These devices are oriented towards the equator
at a specific inclination, depending on the latitude of the site.
Their main advantage is their simplicity and low
manufacturing cost. Their support structure is easier and
cheaper to install than the concentrating systems and the
area required for their installation is smaller. Also, these
collectors are more economical because there are no moving
parts or tracking mechanisms. However their beam-sunlight
collection maybe less energy efficient, given their fixed
orientation to the incoming radiation. They are much better
adapted to small scale operations and make use of diffused
radiation.[9-10]
In this study, the evaluation of the photocatalytic activity of
surface modified, dye-sensitised TiO2 is done to effectively
reduce the TOC and COD of pulp and paper mill effluent.
Experimental parameters taken into account are the catalyst
loading and the initial concentration of the effluent.
2. EXPERIMENTAL
2.1 Materials
Pulp and paper effluent samples were obtained from Bindal
Papers Limited. The samples were taken from taken after
primary treatment, hence being free of suspended solids.
Table 1 shows the characteristics of the obtained samples.
Table -1: Characteristics of the untreated wastewater
samples
pH 5.17
TOC 464.2 mg/lt
COD 1120 mg/lt
3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 06 | June-2015, Available @ http://www.ijret.org 202
Titanium dioxide nanopowder (TiO2, Degussa, Rutile-85%:
Anatase-15%, 99+% purity, 20nm) was purchased from
Nanoshel LLC. This TiO2 powder was dye-sensitised using
Methylene blue and Rhodamine B. Methylene blue was
purchased from Himedia, Mumbai (Ref RM116-100G,
minimum assay 99.0%). Rhodamine B AR (M.S) was
obtained from SD Fine Chemicals Ltd. (SDFCL), Mumbai.
2.2 Instrumentation
Total Organic Carbon (TOC) was determined using
Shimadzu TOC-L CPN. Calibration of the TOC analyser
was carried out using potassium hydrogen phthalate
standards.
UV-Vis spectrophotometer (Shimadzu UV-1800) was used
to determine the concentration of the adsorbed dye on the
TiO2. Spectrophotometry was carried out at 553.0 nm
wavelength.
Chemical Oxygen Demand (COD) was determined by
digesting the samples for two hours in the COD digester
(Spectralab COD digester 2015M).
2.3 Analytical Procedures
Stock solution of a mixture of the two dyes, rhodamine B
and methylene blue, was prepared by taking 60 mg and 40
mg respectively in 1 litre of distilled water. 40 ml of the
stock solution was taken and mixed with distilled water to
obtain 1 litre of this aqueous dye with a concentration of 10-
5
M and at pH ~ 5. Dye sensitisation of TiO2 was done by
taking 500 mg of TiO2 in 50 ml of aqueous solution of dye
and magnetically stirring (at 160 rpm) it in the dark for 4
hours [7] [9]. The resulting mixture was subjected to
vacuum filtration to obtain the dye adsorbed TiO2 and the
supernatant liquid. The concentration of the adsorbed dye
was determined spectrophotometrically by measuring the
difference in absorbance of free dye and that of the
supernatant liquid.
2.4 Photocatalytic Experiments
For this study a flat plate solar collector was fabricated using
a wooden table inclined at an angle in accordance to the
geographical location and borosilicate glass tubes were used
as reactors. A mirror was placed for effective utilization of
sunlight.
In a typical experiment 300 ml of aqueous pulp and paper
effluent was taken in the reactor, with a catalyst loading of
2000 mg/lt [7] [9]. 30 ml of the prepared dye solution was
also added to the reactor. The reactor was kept open to
provide adequate oxygen and its contents were stirred at
regular intervals. After chosen intervals samples of the
reaction mixture were collected and TOC analysis was done.
COD analysis was also done after the completion of the
reaction. The remainder of the reaction mixture was filtered
by vacuum filtration to recover the spent catalyst. The
recovered TiO2 was also dye-sensitised for further
experiments.
3. RESULTS AND DISCUSSION
The photocatalytic activity of the surface modified TiO2 was
evaluated in preliminary tests to determine the most
appropriate conditions to apply in the final tests and shown
in Table 2.
Table -2: Results of preliminary test
I II III IV
TOC-30min
(ppm)
260.7 234.5 215.6 379.8
TOC-3 hrs
(ppm)
218 193.8 212.5 332.2
COD-3 hrs
(ppm)
426.67 117.33 240 1066.67
Legend
I – Effluent without dye and dye adsorbed TiO2
II – Effluent with dye and dye adsorbed TiO2
III – Effluent with dye and dye adsorbed TiO2 (recycled)
IV – Effluent without dye or dye adsorbed TiO2
Inferring from the preliminary tests, the best suited
condition for photocatalytic degradation was found to be the
one which contained dye as well as dye adsorbed TiO2,
hence it was applied to the final tests. Evaluation of the
photocatalytic activity of the photocatalyst is highly
dependent on a number of parameters. The parameters that
were taken under consideration in this study were initial
effluent concentration and catalyst loading.
3.1 Catalyst Loading
Chart -1 illustrates the influence of catalyst concentration on
the degradation of the organic pollutants present in the
wastewater. Experiments were performed at 4 different
concentrations i.e. 500mg, 600mg, 750mg and 1000mg for
300 ml of aqueous wastewater. It can be seen that the
degradation rate is the highest in the first 20 minutes and it
follows a linear relationship. Chart -2 shows that the
maximum degradation is achieved at ~ 750mg (catalyst
loading - 2500mg/lt). In order to avoid excess catalyst usage
and to ensure total absorption of photons, optimum catalyst
loading must be determined. Table 3 gives us the COD
values after completion of the experiment.
4. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 06 | June-2015, Available @ http://www.ijret.org 203
Chart -1: Reduction in TOC for varying catalyst loading.
Table -3: COD results after completion of reaction for
varying catalyst loading.
Catalyst Loading (mg) COD after 1 hr (mg/lt)
500 426.66
600 639.99
750 373.33
1000 586.66
Chart -2: Graph showing the final TOC value as a function
of catalyst used.
3.2 Initial Effluent Concentration
Chart -3 shows the degradation profile of the organic
pollutants in the wastewater at different initial concentration
of the effluent. Experiments were done using 300 ml of
aqueous solution of the wastewater at different initial
concentrations i.e. 20ml, 25ml, 30ml and 35ml of effluent.
In the first 20 minutes, the degradation rate of the organic
pollutants is the same for all initial concentrations of the
effluent, hence it does not play a significant role in the rate
of degradation. COD was determined after completion of the
experiment, as shown in table 4.
Chart -3: Reduction in TOC for varying initial substrate
concentration.
Table -4: COD results after completion of reaction for
varying initial substrate concentration.
Initial Substrate
Concentration (ml)
COD after 1 hr (mg/lt)
20 660
25 576
30 640
35 514.28
4. CONCLUSION
From the studies conducted it can be inferred that in the
presence of visible light, the surface adsorbed methylene
blue and rhodamine B can sensitise TiO2 semiconductor for
the generation of oxidising and highly reactive radical
species which decompose organic pollutants. Amongst the
conditions considered for the experiments conducted, 750
mg of dye adsorbed TiO2 (catalyst loading – 2500mg/lt)
showed the maximum reduction in TOC and COD.
TiO2 based photocatalysis is an effective treatment technique
for wastewater although evaluation of photocatalytic
performance is a complicated process which is influenced by
many different parameters. These parameters include light
intensity, presence of oxygen, catalyst loading, initial
concentration of substrate, adsorption and pH. Reproducible
evaluation of results requires a careful selection of all
parameters.
ACKNOWLEDGEMENTS
We are grateful to the Department of Chemical Engineering,
MIT, Manipal, for providing us all the facilities to carry out
the work for this project.
REFERENCES
[1] Narsi R. Bishnoi, R.K. Khumukcham, Rajender
Kumar, “Biodegradation of pulp and paper mill
effluent using anaerobic followed by aerobic
digestion”, Journal of Environmental Biology, 27(2)
(2006) 405-408
5. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 06 | June-2015, Available @ http://www.ijret.org 204
[2] Julián Blanco-Galvez, Pilar Fernández-Ibáñez, Sixto
Malato-Rodríguez, “Solar Photocatalytic
Detoxification and Disinfection of Water: Recent
Overview”, Solar Energy Division of ASME for
publication in the Journal Of Solar Energy
Engineering (2007) 4-15.
[3] R. Bauer, G. Waldner, H. Fallmann, S. Hager, M.
Klare, T. Krutzler, S. Malato, P. Maletzky, “The
photo-fenton reaction and the TiO2/UV process for
waste water treatment − novel developments”,
Catalysis Today 53 (1999) 131–144.
[4] Yanlong Tian, Binbin Chang, Jie Fu, Fengna Xi,
Xiaoping Dong, “Yellow–colored mesoporous pure
titania and its high stability in visible light
photocatalysis”, Powder Technology 245 (2013)
227–232.
[5] Debabrata Chatterjee, Shimanti Dasgupta, “Visible
light induced photocatalytic degradation of organic
pollutants”, Journal of Photochemistry and
Photobiology C: Photochemistry Reviews 6 (2005)
186–205.
[6] Brijesh Pare, David Swami, Prakash More, Tehmina
Qureshi, T. R. Thapak, “Mineralization of Methylene
Violet Dye Using Titanium Dioxide in Presence of
Visible Light”, Int. J. Chem. Sci.: 9(4), 2011, 1685-
1697 ISSN 0972-768X
[7] Debabrata Chatterjee, Anima Mahata, “Visible light
induced photodegradation of organic pollutants on
dye adsorbed TiO2 surface”, Journal of
Photochemistry and Photobiology A: Chemistry 153
(2002) 199–204.
[8] Julian Blanco Galvez, Sixto Malato Rodriguez,
“Solar Detoxification”, United Nations Educational,
Scientific and Cultural Organization (2003).
[9] Debabrata Chatterjee, Anima Mahata,
“Demineralisation of organic pollutants on the dye
modified TiO2 semiconductor particulate system
using visible light”, Applied Catalysis B:
Environmental, 33 (2001) 119-125.
[10] T.Fotiou, T.M.Triantis, T.Kaloudis, A.Hiskia,
“Evaluation of the photocatalytic activity of TiO2
based catalyst for the degradation and mineralisation
of cyanobacterial toxins and water off-odour
compounds under UV-A, solar and visible light”,
Chemical Engineering Journal 261 (2015) 17-26.
BIOGRAPHIES
Dr.S.Shanmuga Priya is working as an
Associate Professor in the Department
of Chemical Engineering, Manipal
Institute of Technology, Manipal
University, Karnataka, India. She has 4
years of research experience and 6
years of teaching experience. She has
20 journals, 40 conferences, 1 book and 3 book chapters
to her credit in international and national publications.
Aniruddha Deshpande was born in 1993
in Saharanpur, India. He is currently
pursuing his Bachelor’s Degree in
Chemical Engineering from MIT,
Manipal. He is in the final year and
currently engaged in a project involving
photodegradation of organic pollutants in
industrial wastewater.
Ruthu Dwarakanath was born in 1993 in
Bangalore, India. She is currently
pursuing her Bachelor’s Degree in
Chemical Engineering from MIT,
Manipal. She is in the final year and
currently engaged in a project involving
photodegradation of organic pollutants in industrial
wastewater.