This study compares the effectiveness of various biopolymers and alum in recovering pulp fibers from paper mill wastewater through flocculation. Guar gum was found to be the most effective biopolymer, recovering 3.86 mg/L of fibers. Alum displayed the highest particle removal rate. Guar gum, alum, xanthan gum, and locust bean gum removed 94.68%, 97.46%, 92.39%, and 92.46% of turbidity, respectively, at a settling velocity of 0.5 cm/min. Response surface methodology was used to optimize conditions like pH, dose, and mixing speed to obtain the lowest sludge volume index for guar gum. The results indicate similar performance
Mass Transfer, Kinetic, Equilibrium, and Thermodynamic Study on Removal of Di...Ratnakaram Venkata Nadh
Three distinct agricultural waste materials, viz., casuarina fruit powder (CFP), sorghum stem powder
(SSP), and banana stem powder (BSP) were used as low-cost adsorbents for the removal of toxic lead(II)
from aqueous solutions. Acid treated adsorbents were characterized by scanning electron microscopy (SEM),
energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The
effects of parameters like adsorbent dose, pH, temperature, initial metal ion concentration, and time of
adsorption on the removal of Pb(II) were analyzed for each adsorbent individually and the efficiency order
was BSP > SSP > CFP. Based on the extent of compatibility to Freundlich/Langmuir/Dubinin–Radushkevich/
Temkin adsorption isotherms and different models (pseudo-first and second order, Boyd, Weber’s, and
Elovich), chemisorption primarily involved in the case of BSP and SSP, whereas simultaneous occurrence of
chemisorption and physisorption was proposed in the case of CFP correlating with the thermodynamic study
results conducted at different temperatures. Based on the observations, it was proposed that three kinetic
stages involve in the adsorption process, viz., diffusion of sorbate to sorbent, intra particle diffusion, and then
establishment of equilibrium. These adsorbents have a promising role towards the removal of Pb(II) from
industrial wastewater to contribute environmental protection
Mass Transfer, Kinetic, Equilibrium, and Thermodynamic Study on Removal of Di...Ratnakaram Venkata Nadh
Three distinct agricultural waste materials, viz., casuarina fruit powder (CFP), sorghum stem powder
(SSP), and banana stem powder (BSP) were used as low-cost adsorbents for the removal of toxic lead(II)
from aqueous solutions. Acid treated adsorbents were characterized by scanning electron microscopy (SEM),
energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The
effects of parameters like adsorbent dose, pH, temperature, initial metal ion concentration, and time of
adsorption on the removal of Pb(II) were analyzed for each adsorbent individually and the efficiency order
was BSP > SSP > CFP. Based on the extent of compatibility to Freundlich/Langmuir/Dubinin–Radushkevich/
Temkin adsorption isotherms and different models (pseudo-first and second order, Boyd, Weber’s, and
Elovich), chemisorption primarily involved in the case of BSP and SSP, whereas simultaneous occurrence of
chemisorption and physisorption was proposed in the case of CFP correlating with the thermodynamic study
results conducted at different temperatures. Based on the observations, it was proposed that three kinetic
stages involve in the adsorption process, viz., diffusion of sorbate to sorbent, intra particle diffusion, and then
establishment of equilibrium. These adsorbents have a promising role towards the removal of Pb(II) from
industrial wastewater to contribute environmental protection
Phycoremediation of malachite green and reduction of physico chemical paramet...eSAT Journals
Abstract
Water is the elixir of life, a precious gift of nature to all the living species on earth. It is rapidly becoming a scare commodity in most parts of the world. Only 0.35% of the total availability of water found in lakes and wetlands and 0.01% in rivers and streams which are likely getting depleted due to the discharge of the effluents such as dyes simultaneously increases the water quality parameters. Malachite green is a common textile dye being discharged in lake water situated near textile industries. The phycoremediation method employs the use of algae, say, Chlorella pyrenoidosa which helps in decolorizing the water and due to its growth in the lake water, the physico-chemical parameters higher in the polluted water found to be reduced and water can be used for various purposes. The trails were made using Chlorella pyrenoidosa and Malachite green at different concentrations. The optimum concentration for the degradation of dye was completely done at the concentration 15 mg confirming the decolorization capacity by Chlorella pyrenoidosa. The same experiment was performed with adjusting the pH at 6, 7 and 8. Optimum pH for the dye degradation was found as pH 7 at which all the concentrations Chlorella pyrenoidosa was able to degrade the dye with the decolourization capacity of above 95%. The phyico-chemical parameters checked after the decolorization by Chlorella were found to be within the limits and thus Chlorella which is available in nature can be used in the decolorization of effluent water by eco-friendly method.
Keywords: Chlorella pyrenoidosa, Malachite Green, Phycoremediation, Physico-chemical parameters
Deep eutectic solvents (DESs) are a relatively new topic in science. Their usage is not yet clearly defined, and the areas in which DESs may be applied are constantly growing. A simple and clean fractionation of the main components of biomass represents a very important step in creating a clean, renewable carbon economy. A major challenge is the use of DESs for fractionation of biomass components at lower temperatures, without the use of expensive raw materials. In this work, wheat straw was pretreated with six different DES systems composed of choline chloride with urea (1:2), malonic acid (1:1), lactic (1:9; 1:10), malic (1:1), and oxalic acid (1:1). The pretreated biomass was characterized in terms of lignin content, ash, and holocellulose. A deep eutectic solvent, composed of choline chloride and oxalic acid, was found to produce the best delignification results. The solvents are not selective in the process of delignification.
Structural Characterization and Antimicrobial Activity of Cocculus hirsutus L...BRNSS Publication Hub
Many number of the plant species including Cocculus hirsutus L. is being used as the sources of herbal
medicine. Present work was mainly focused with the identification of the therapeutic properties of
C. hirsutus L. leaf extracts. The leaf extracts of methanol, aqueous, chloroform, and benzene showed
solvent dependent qualitative and quantitative phytochemical presence as well as antimicrobial activity.
Whereas the leaf extracts of methanol and chloroform showed significantly high antimicrobial activity
than water and benzene extracts. Further methanol leaf extract of C. hirsutus performed to liquid
chromato y-mass spectroscopy (LC-MS) for identification of active antimicrobial compound structure.
LC-MS studies give 26 structural compounds. Docking (annotating) studies revealed that among 26
compounds the Compound-5 (Hexadecanoic acid - (1R, 2R, 3S, 4R, 6S)-4, 6-diamino-2, 3-dihydroxy
cyclohexyl 2,6-diamino-2,6-dideoxy-α-D-glucopyranoside) showed highest docking fitness score with
the bacterial membrane protein sortase-A. Our data suggest that methanol extract of C. hirsutus leaf
possess medicinally significant antimicrobial compounds and thus justify the use of this leaf as folklore
medicine for preventing human microbial related diseases.
Natural Deep Eutectic Solvents as Agents for Improving Solubility, Stability ...Maciej Przybyłek
Purpose
Study on curcumin dissolved in natural deep eutectic solvents (NADES) was aimed at exploiting their beneficial properties as drug carriers.
Methods
The concentration of dissolved curcumin in NADES was measured. Simulated gastrointestinal fluids were used to determine the concentration of curcumin and quantum chemistry computations were performed for clarifying the origin of curcumin solubility enhancement in NADES.
Results
NADES comprising choline chloride and glycerol had the highest potential for curcumin dissolution. This system was also successfully applied as an extraction medium for obtaining curcuminoids from natural sources, as well as an effective stabilizer preventing curcumin degradation from sunlight. The solubility of curcumin in simulated gastrointestinal fluids revealed that the significant increase of bioavailability takes place in the small intestinal fluid.
Conclusions
Suspension of curcumin in NADES offers beneficial properties of this new liquid drug formulation starting from excreting from natural sources, through safe storage and ending on the final administration route. Therefore, there is a possibility of using a one-step process with this medium. The performed quantum chemistry computations clearly indicated the origin of the enhanced solubility of curcumin in NADES in the presence of intestinal fluids. Direct intermolecular contacts leading to hetero-molecular pairs with choline chloride and glycerol are responsible for elevating the bulk concentration of curcumin. Choline chloride plays a dominant role in the system and the complexes formed with curcumin are the most stable among all possible homo- and hetero-molecular pairs that can be found in NADES-curcumin systems.
Application of response surface methodology for biosorption of reactive dyes ...IJLT EMAS
Response Surface Methodology was employed for
studying the biosorption of reactive dyes from textile effluent by
utilization of dead biomass of Rhizopus arrhizus in a batch
system. Central Composite Design at the specified combinations
of four variables (pH, biosorbent dosage, speed of agitation,
contact time) was adopted to achieve maximum biosorption. The
fitted quadratic model (P<0.0001) was used to arrive at the best
operating conditions. Under the following optimum conditions
i.e., pH 2.0; biosorbent dosage 3 g /L; speed of agitation 80 rpm
and contact time 60 min, 99.60% of the dyes were removed from
the wastewater. The mechanism of biosorption was elucidated by
FTIR, XRD and BET analysis. This work demonstrated the
feasibility of employing Rhizopus arrhizus as an effective and
economical fungal biosorbent for the removal of dyes from the
textile effluent.
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
Adsorption of Methylene blue and Malachite Green in Aqueous Solution using Ja...IJEAB
The adsorption of mixture of two basic dyes methylene blue and malachite green in aqueous solution onto jack fruit leaf ash in a batch system with respect to initial dye concentrations, pH, contact time, shaker speed and adsorbent doses was investigated.. The pseudo-first-order and pseudo-second- order kinetics model were used to describe the kinetic data. The rate constants at different pH values (3-9.1) were evaluated. The experimental data fitted well with the pseudo-second-order kinetic model. Equilibrium isotherms were analyzed by Langmuir, Freundlich and Temkin isotherm models. Maximum adsorption capacity was 20.41mg/g was achieved by Langmuir isotherm model. Error analysis was done to find the best model that described the experimental data well and it was the Langmuir model. The result indicated that jack fruit leaf ash could be fruitfully employed as low cost adsorbent for the removal of mixture of two basic dyes MB and MG from the wastewater.
Seaweed (Hypnea musciformis) Versus Freshwater Weed (Ipomoea aquatica): A Com...SaadAldin2
An undergraduate Thesis work accomplished in the dept. of Food Engineering and Tea Technology. This is the Defense power-point slide of the main Paper.
Phycoremediation of malachite green and reduction of physico chemical paramet...eSAT Journals
Abstract
Water is the elixir of life, a precious gift of nature to all the living species on earth. It is rapidly becoming a scare commodity in most parts of the world. Only 0.35% of the total availability of water found in lakes and wetlands and 0.01% in rivers and streams which are likely getting depleted due to the discharge of the effluents such as dyes simultaneously increases the water quality parameters. Malachite green is a common textile dye being discharged in lake water situated near textile industries. The phycoremediation method employs the use of algae, say, Chlorella pyrenoidosa which helps in decolorizing the water and due to its growth in the lake water, the physico-chemical parameters higher in the polluted water found to be reduced and water can be used for various purposes. The trails were made using Chlorella pyrenoidosa and Malachite green at different concentrations. The optimum concentration for the degradation of dye was completely done at the concentration 15 mg confirming the decolorization capacity by Chlorella pyrenoidosa. The same experiment was performed with adjusting the pH at 6, 7 and 8. Optimum pH for the dye degradation was found as pH 7 at which all the concentrations Chlorella pyrenoidosa was able to degrade the dye with the decolourization capacity of above 95%. The phyico-chemical parameters checked after the decolorization by Chlorella were found to be within the limits and thus Chlorella which is available in nature can be used in the decolorization of effluent water by eco-friendly method.
Keywords: Chlorella pyrenoidosa, Malachite Green, Phycoremediation, Physico-chemical parameters
Deep eutectic solvents (DESs) are a relatively new topic in science. Their usage is not yet clearly defined, and the areas in which DESs may be applied are constantly growing. A simple and clean fractionation of the main components of biomass represents a very important step in creating a clean, renewable carbon economy. A major challenge is the use of DESs for fractionation of biomass components at lower temperatures, without the use of expensive raw materials. In this work, wheat straw was pretreated with six different DES systems composed of choline chloride with urea (1:2), malonic acid (1:1), lactic (1:9; 1:10), malic (1:1), and oxalic acid (1:1). The pretreated biomass was characterized in terms of lignin content, ash, and holocellulose. A deep eutectic solvent, composed of choline chloride and oxalic acid, was found to produce the best delignification results. The solvents are not selective in the process of delignification.
Structural Characterization and Antimicrobial Activity of Cocculus hirsutus L...BRNSS Publication Hub
Many number of the plant species including Cocculus hirsutus L. is being used as the sources of herbal
medicine. Present work was mainly focused with the identification of the therapeutic properties of
C. hirsutus L. leaf extracts. The leaf extracts of methanol, aqueous, chloroform, and benzene showed
solvent dependent qualitative and quantitative phytochemical presence as well as antimicrobial activity.
Whereas the leaf extracts of methanol and chloroform showed significantly high antimicrobial activity
than water and benzene extracts. Further methanol leaf extract of C. hirsutus performed to liquid
chromato y-mass spectroscopy (LC-MS) for identification of active antimicrobial compound structure.
LC-MS studies give 26 structural compounds. Docking (annotating) studies revealed that among 26
compounds the Compound-5 (Hexadecanoic acid - (1R, 2R, 3S, 4R, 6S)-4, 6-diamino-2, 3-dihydroxy
cyclohexyl 2,6-diamino-2,6-dideoxy-α-D-glucopyranoside) showed highest docking fitness score with
the bacterial membrane protein sortase-A. Our data suggest that methanol extract of C. hirsutus leaf
possess medicinally significant antimicrobial compounds and thus justify the use of this leaf as folklore
medicine for preventing human microbial related diseases.
Natural Deep Eutectic Solvents as Agents for Improving Solubility, Stability ...Maciej Przybyłek
Purpose
Study on curcumin dissolved in natural deep eutectic solvents (NADES) was aimed at exploiting their beneficial properties as drug carriers.
Methods
The concentration of dissolved curcumin in NADES was measured. Simulated gastrointestinal fluids were used to determine the concentration of curcumin and quantum chemistry computations were performed for clarifying the origin of curcumin solubility enhancement in NADES.
Results
NADES comprising choline chloride and glycerol had the highest potential for curcumin dissolution. This system was also successfully applied as an extraction medium for obtaining curcuminoids from natural sources, as well as an effective stabilizer preventing curcumin degradation from sunlight. The solubility of curcumin in simulated gastrointestinal fluids revealed that the significant increase of bioavailability takes place in the small intestinal fluid.
Conclusions
Suspension of curcumin in NADES offers beneficial properties of this new liquid drug formulation starting from excreting from natural sources, through safe storage and ending on the final administration route. Therefore, there is a possibility of using a one-step process with this medium. The performed quantum chemistry computations clearly indicated the origin of the enhanced solubility of curcumin in NADES in the presence of intestinal fluids. Direct intermolecular contacts leading to hetero-molecular pairs with choline chloride and glycerol are responsible for elevating the bulk concentration of curcumin. Choline chloride plays a dominant role in the system and the complexes formed with curcumin are the most stable among all possible homo- and hetero-molecular pairs that can be found in NADES-curcumin systems.
Application of response surface methodology for biosorption of reactive dyes ...IJLT EMAS
Response Surface Methodology was employed for
studying the biosorption of reactive dyes from textile effluent by
utilization of dead biomass of Rhizopus arrhizus in a batch
system. Central Composite Design at the specified combinations
of four variables (pH, biosorbent dosage, speed of agitation,
contact time) was adopted to achieve maximum biosorption. The
fitted quadratic model (P<0.0001) was used to arrive at the best
operating conditions. Under the following optimum conditions
i.e., pH 2.0; biosorbent dosage 3 g /L; speed of agitation 80 rpm
and contact time 60 min, 99.60% of the dyes were removed from
the wastewater. The mechanism of biosorption was elucidated by
FTIR, XRD and BET analysis. This work demonstrated the
feasibility of employing Rhizopus arrhizus as an effective and
economical fungal biosorbent for the removal of dyes from the
textile effluent.
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
Adsorption of Methylene blue and Malachite Green in Aqueous Solution using Ja...IJEAB
The adsorption of mixture of two basic dyes methylene blue and malachite green in aqueous solution onto jack fruit leaf ash in a batch system with respect to initial dye concentrations, pH, contact time, shaker speed and adsorbent doses was investigated.. The pseudo-first-order and pseudo-second- order kinetics model were used to describe the kinetic data. The rate constants at different pH values (3-9.1) were evaluated. The experimental data fitted well with the pseudo-second-order kinetic model. Equilibrium isotherms were analyzed by Langmuir, Freundlich and Temkin isotherm models. Maximum adsorption capacity was 20.41mg/g was achieved by Langmuir isotherm model. Error analysis was done to find the best model that described the experimental data well and it was the Langmuir model. The result indicated that jack fruit leaf ash could be fruitfully employed as low cost adsorbent for the removal of mixture of two basic dyes MB and MG from the wastewater.
Seaweed (Hypnea musciformis) Versus Freshwater Weed (Ipomoea aquatica): A Com...SaadAldin2
An undergraduate Thesis work accomplished in the dept. of Food Engineering and Tea Technology. This is the Defense power-point slide of the main Paper.
Phytoremediation of industrial effluent and Reduction of physicochemical para...iosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
International Journal of Pharmaceutical Science Invention (IJPSI) is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Adsorption of dye from aqueous solutions by orange peel with Chitosan nanocom...Open Access Research Paper
This research focused on the development of adsorbents based on cheap, abundant, and locally available agricultural wastes in Tamil Nadu to adsorb dye from an aqueous solution. The goal of this study was to explore if chitosan-modified orange peel could be utilized as an adsorbent to remove colours from wastewater and if it could be employed as a traditional wastewater treatment approach in the textile sector. Using agricultural peel in decolouration technology has a lot of potential in terms of efficiency, cost-effectiveness, and environmental friendliness. Super nanocomposite is made from orange peel waste combined with chitosan nanoparticles. The purpose of this batch adsorption experiment was to determine the effects of adsorbent dosages, pH, and temperature on dye adsorption from wastewater. The experiment showed that the maximum amount of dye adsorbed was 53.3mg/g at pH 6.9 with a Temperature (of 600 C) and the adsorbent dose amount of adsorbent was 1.0g/L. The Langmuir adsorption isotherm model was used to investigate the equilibrium adsorption behaviour. The usage of orange peel with Nanocomposite as an adsorbent for the adsorption of methylene blue dye from solutions was demonstrated in this work. The functional groups and chemical compounds found in orange peels, chitosan, chitosan orange peel, chitosan nanoparticle, and chitosan nanoparticle with orange peel waste were identified using FTIR, TGA, and SEM techniques. Different types of Langmuir I, Langmuir II, Langmuir III, Langmuir IV, and the Freundlich model as adsorption isotherm models were investigated.
Treatment of Effluent from Granite Cutting Plant by Using Natural Adsorbents ...IJERD Editor
Granite cutting plant is one such industry that releases polluting and turbid effluent. The residue from all these processes is discharged with water as an effluent. The effluent mainly contains many solids that harm the environment. Hence it requires treatment techniques before disposal. Several conventional methods are available for removal of contaminants like coagulation, adsorption, polyelectrolyte methods and biological methods. Most of them are cost prohibitive. The reduction of solids concentration in the effluent before disposal by using the techniques, coagulation followed by adsorption using natural adsorbents, like rice husk carbon and saw dust carbon, in contrast to the usage of activated carbon as it is costly. From a local Granite cutting plant near Anantapur, the effluent is collected and its physico-chemical characteristics are estimated and found to be pH(7.5), TS(4240mg/l), TSS(21560mg/l), TDS(12373mg/l).Effluent obtained is subjected to coagulation by potash alum followed by adsorption using saw dust carbon and rice husk carbon.
ABSTRACT- The present study deals with the physicochemical characteristics of river water Aami. A pulp and paper mill namely Rayana Paper Board Industries Ltd Khalilabad, Uttar Pradesh, were studied for sample collection and analysis of various pollution parameters. Three sampling sites have been selected for this study. Water of this river has toxic effects on fish Channa punctatus. The 96h LC50 values of these sites are 8.99 % dilution for site 1, 22.96 % dilution for site 2 and 41.15 % dilution for site 3. Fishes were treated with different sub- lethal doses of water samples, it shown significant alterations in different biochemical and haematological parameters of fish. Key-words- Biochemistry, Haematological, Pulp and paper mill effluents, Physicochemical characteristics, River Aami
Bijay Thapa, Nawa Raj Khatiwada, Anish Ghimire and Bikash Adhikari . “Study of Pollutant Removal in Activated Sludge Process Using Lab Scale Plant by Intermittent Aeration” United International Journal for Research & Technology (UIJRT) 1.2 (2019): 01-07.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes present in
textile mill effluents under different aeration conditions. One fungal strain with five rates of air was
used to absorb direct brown dye. Five liters bioreactors were applied to study the removal performance.
The experimental results are compared for various operating conditions. The effects of airflow rate
(1/8, ¼, ½, 1, 2 v/v min) inlet on the dye removing were assessed. It was found that the rate of aeration
of ½ v/v min induced increase in dye removal percentages (72%) and fungal biomass (9.2 g); at the rate
of aeration of 2 v/v min, high dye removal percentage (77%) was recorded with a decrease in biomass
dry weight at the end of the incubation time. The results also indicated that the biomass dry weight
obtained at three flow rates of aeration was more or less similar until the end of the growth stage (after
incubation for three days). The results obtained indicate that using low rate of aeration (1/8, ¼, ½ v/v
min) was better for dye biosorption than high rate (1, 2 v/v min), and therefore it is recommended for
dis-azo dye removing.
Fertilizer plant waste carbon slurry has been investigated after some processing as an adsorbent for the removal of dyes and phenols using columns. The results show that the carbonaceous adsorbent prepared from carbon slurry being porous and having appreciable surface area (380 m2/g) can remove dyes both cationic (meldola blue, methylene blue, chrysoidine G, crystal violet) as well as anionic (ethyl orange, metanil yellow, acid blue 113), and phenols (phenol, 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol) fruitfully from water. The column type continuous flow operations were used to obtain the breakthrough curves. The breakthrough capacity, exhaustion capacity and degree of column utilization were evaluated from the plots. The results shows that the degree of column utilization for dyes lies in the range 60 to 76% while for phenols was in the range 53-58%. The exhaustion capacities were quite high as compared to the breakthrough capacities and were found to be 217, 211, 104, 126, 233, 248, 267 mg/g for meldola blue, crystal violet, chrysoidine G, methylene blue, ethyl orange, metanil yellow, acid blue 113, respectively and 25.6, 72.2, 82.2 and 197.3 mg/g for phenol, 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol, respectively
Focused researcher and environmental consultant with a thorough approach to groundwater, wastewater and soil treatment processes. I am based in Dublin, but engaged in a number of water treatment projects in South Asia. I take pleasure in solving green technology challenges and brainstorming over new concepts. I enjoy drafting technical documents- proposals, reports, ppt and articles. I am proficient in various graphical and statistical software packages.
Currently I am doing a Masters in Natural Resource Economics and Policy from NUI Galway, Ireland. Econometric modelling, data analysis and cost-benefit evaluations are the topics that I am most curious about. I am always looking for new opportunities in the field of environmental management involving stakeholder engagement.
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
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Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
2. content of the sludge would significantly reduce the sludge
volume (Scott and Smith, 1995).
Conventional equipment like screens, cleaners or wet air
oxidation have been used to separate fibre from the sludge
(Wiegand, 1993). The most common technique for reclaiming
fibre from sludge is to recycle primary sludge back into the fibre
processing system of the mill which is commonly used by
recycled paper-board mills and manufactures of bleached and
unbleached pulp and paper (Ochoa de Alda, 2008). Some systems
utilize sludge from the primary clarification of the effluent that
contains higher amounts of fibre. However, recovered fibre
sometimes loses its characteristics and becomes shorter in
length and brittle; thus reducing the strength of the paper and
other commercial attributes (Ochoa de Alda, 2006). Therefore,
care must be taken so that recycled fibre does not affect
the overall quality of the finished paper and reduce its market
price.
Flocculation is a separation process which is widely used in paper
mills for both paper making and effluent treatment. Flocculation
can also be used for recovery of fibres from paper mill effluent.
Traditionally, chemical coagulants such as ferric chloride, alumini-
um chloride, potassium alum and other polyelectrolytes are used for
coagulation and flocculation process. However studies have shown
that alum and other chemical coagulants reduce the bonding
capability of the fibres when they are recycled (Guest and Voss,
1983). Wastewater treatment by natural polymers is being increas-
ingly advocated in recent years. The biopolymers which are being
currently studied for industrial wastewater treatment are chitosan
(Guibal and Roussy, 2007), vegetable tannin (Özacar and Şengil, 2003),
Cassia javahikai seed gum (Sanghi et al., 2006b), okra gum (Agarwal et
al., 2003) and Ipomea dasysperma seed gum (Sanghi et al., 2006a). Guar
gum is known to be used in potable water treatment and in food
processing industry (Sen Gupta and Ako, 2005). These biopolymers
are renewable resources, biodegradable and non-toxic for the aquatic
organisms. Also secondary pollution due to accidental excess of
biopolymer can be avoided.
In the present study, three polysaccharides (biopolymers) have
been used as flocculents for separation of pulp fibres. Their efficiency
has been compared to alum, which is a known chemical flocculent.
The selected biopolymers viz. Guar gum, Locust bean gum and
Xanthan gum are non-toxic, biodegradable and widely available (Levy
et al., 1995). Guar gum is also a sizing additive commonly used in
paper industry (Whistler Roy, 1954).
Sludge volume index (SVI) is a common parameter used for
studying the settling characteristics of flocs. SVI establishes a
functional relationship between settling velocity and suspended
solids concentration (Koopman and Cadee, 1983) which is an
important requirement for designing the capacity of a secondary
clarifier's capacity. Dose, pH and mixing speed are the design
parameters that were optimised to obtain the lowest SVI for the
most effective flocculent. The floc settling rate at different pH
values and for different flocculents was studied and the data
from experimental runs were used to generate the settling
velocity distribution curves (SDVC).
1. Methodology
1.1. Coagulants
The effluent was treated with one chemical coagulant and
three biopolymers viz. plant origin Guar gum and Locust bean
gum, and bacterial origin Xanthan gum. Guar gum is produced
by grinding the endosperm of Guar beans and is a straight
chain galactomannan that has galactose on every other
mannose unit. Locust bean gum is the extract from seeds of
carob tree. Locust bean gum is also a galactomannan with
galactose and mannose units linked by glycosidic linkages.
Xanthan gum is polysaccharide secreted by bacterium
Xanthomonas campestris. The structure of all the three
biopolymers is shown in Fig. 1. The polymers used for the
experiments were of food grade. The inorganic chemical
coagulant used is analytical grade hydrated potassium alumin-
ium sulphate (alum) with chemical formula KAl(SO4)2·12H2O. A
stock solution of concentration 1 g/L was prepared for all the
biopolymers. In the case of the biopolymers, the powdered
polymer was slowly added to distilled water and the beaker
containing the water was slowly shaken. This ensured an
evenly wetted solution. For the biopolymers, fresh solutions
were prepared after every 12 hr to avoid growth of moulds.
1.2. Effluent and its characterisation
Synthetic paper mill effluent stock solution was prepared in
the laboratory by mixing 2 g of ordinary tissue paper in 1 L
distilled water following the method reported by Hashim and
Sen Gupta (1998). The stock solution was diluted 10 times to
perform further experiments. No chemicals were added to
the diluted slurry and it was prepared fresh for each set of
experiment to avoid bacterial degradation. The effluent was
analysed for various physico-chemical parameters, namely,
total dissolved solids (TDS), total alkalinity (TA), total organic
carbon (TOC), hardness, total nitrogen and phosphorus using
standard methods (APHA, 1998). The COD was analysed using
a standard dichromate closed reflux method. The concentra-
tion of heavy metals, such as sodium, potassium, iron and
calcium were measured using inductively coupled plasma
optical emission spectrometry (Optima 7000 with Autosampler
S10, PerkinElmer, USA). The experiments were carried out in
duplicate under identical conditions. Functional groups present
in Guar gum, effluent and flocs were characterised by Fourier
transform infra red (FT-IR) spectra (Bruker Vertex 70/70 V
spectrophotometer).
1.3. Comparison of different biopolymers
A jar test apparatus (Phipps and Bird PB-900 Programmable
Jar Tester) was used for the flocculation studies with Guar
gum, Xanthan gum and Locust bean gum and alum. These
were tested for the separation efficiency of fibres from the
effluent. The tests were conducted in 500 mL glass beakers;
the pH was adjusted using HCl or NaOH. The mixing was
carried out in jar test apparatus in three phases. In the first
phase the stirring paddles were operated at maximum speed
(flash mixing) for 5 min. Dosing of the flocculents was done
as close to the hub of the propeller as possible, 2 min after
beginning of flash mixing and the flash mixing was
continued for another 3 min. The speed of the propeller was
reduced in two phases of 10 min each. There were two set
mixing designs used in the study. In one set the flash mixing
speed was kept at 185 r/min and the speed was subsequently
reduced to 60 r/min followed by 40 r/min. In the second
mixing design the flash mixing speed was set at 200 r/min
and the speed being further reduced to 70 r/min followed by a
slow mixing speed of 40 r/min. The supernatant obtained
after 30 min of settling was subjected to turbidity analysis in
HACH 2100 N Turbidimeter.
1852 J O U R N A L O F E N V I R O N M E N T A L S C I E N C E S 2 6 ( 2 0 1 4 ) 1 8 5 1 – 1 8 6 0
3. 1.4. Settling velocity distribution curves
The settling characteristics of the suspension were examined by
the method reported by Hudson (1981). Four experimental runs
were conducted in duplicate. The samples were dosed with
1.6 mg/L of Guar gum, 1.5 mg/L of Xanthan gum and Locust bean
gum, and 1.75 mg/L of alum. The dosing of the coagulant is
decided based on preliminary studies done in laboratory. After
adjusting the pH to 8.5, the content of each jar was flash mixed
at a stirrer speed of 185 r/min for 5 min followed by stirring at
40 r/min for another 25 min in order to produce flocs. After the
mixing stopped, the turbidity of the suspension was measured
for samples drawn from a fixed depth of 2 cm below the liquid
surface at 1, 2, 4, 8, 16, 32 and 68 min. Necessary precautions were
taken to avoid any significant floc breakage during handling of
the suspension (Bratby, 1981).
1.5. Optimization of sludge volume index
The settling characteristic of a sludge is generally defined by the
sludge volume index (SVI) which is the volume occupied by 1 mg
of sludge in mL after 30 min of selling and is calculated by Eq. (1):
SVI ¼
1000 Â H30
H0X0
ð1Þ
where, H30 (mm) is the height of sludge after 30 min of settling,
H0 (mm) is the initial height of the slurry and X0 (mg/L) is the
initial solids concentration in the slurry.
SVI is measured by observing the volume of uniformly
mixed slurry after 30 min of settling in a glass cylinder (Dick
and Vesilind, 1969). The slurry from the flocculation test was
transferred to a 500 mL cylinder and was allowed to settle. The
volume of the sludge after 30 min of settling was recorded. The
lower the SVI the higher the fibre concentration in a unit
volume of recovered sludge. High fibre concentration in small
quantity sludge would ensure high fibre recovery and less
handling problems. The dose of flocculent, pH and mixing
speed of the flocculation experiment were optimised to achieve
the lowest volume of SVI.
The modelling and optimization studies were performed
using Design Expert 7 software. The experiments were
modelled using Box Behnken design and the design summary
is presented in Table 1. Analysis of variance was used to
graphically analyse the data and determine the interaction
between process variables and response. Dose, pH and mixing
speed were the independent variables used in the study. All
three are numeric factors and were coded as A, B and C,
respectively. Preliminary experiments were carried out to
determine the range of independent variables. The variables
were allotted with three specific values ranging from −1, 0 and
+1. The Design Expert 7 software determined the fit of the
polynomial model, expressed by coefficient of determination,
R2
. The statistical significance of the model was ensured by the
Fisher F-test (Fisher variation ratio). The selection or rejection
of model terms was done based on the P value (probability) with
a 95% confidence level. The interaction among the three factors
i.e., pH, flocculent dose and mixing speed with the response
ie., SVI are shown in three dimensional plots.
The first step of RSM requires the addition of appropriate
approximation, with the purpose of finding a true relation-
ship between the set of independent variables (factors)
and the dependent variable i.e., the response. According to
Bayraktar (2001), a model is upgraded by adding higher
order terms to the preliminary model when the linear model
is insufficient to explain the shape of the response surface.
Thus, the linear model is then explained by a quadratic
Fig. 1 – Structure of biopolymers, Guar gum (a), Locust bean gum (b) and Xanthan gum (c).
1853J O U R N A L O F E N V I R O N M E N T A L S C I E N C E S 2 6 ( 2 0 1 4 ) 1 8 5 1 – 1 8 6 0
4. equation, as defined in Eq. (2) (Adinarayana and Ellaiah,
2002; Bayraktar, 2001; Can et al., 2006; Montgomery, 2001):
y ¼ β0 þ
Xk
i¼1
βiXi þ
Xk
i¼1
βiiX2
i þ
Xk
i≤ j
Xk
j
βijXiXj þ ε ð2Þ
where, y is the response or dependent variable, i and j are
linear and quadratic coefficients respectively, β is the regression
coefficient, k is the number of factors studied and optimised in
the experiment and ε is the random error.
2. Results and discussion
2.1. Characteristics of the effluent
The characteristics of the synthetic effluent prepared for this
work were determined. The pH was 6.5 and contained both
organic and inorganic pollutants. The turbidity of 80.6 NTU was
considered high and must be reduced if the effluent had to
comply with discharge standard set by the Department of
Environment, Malaysia. The COD of the effluent at 156 mg/L
was lower than the Malaysian discharge standard of 200 mg/L.
However, the BOD5 of 41 mg/L was higher than the Malaysian
standard of 20 mg/L. The other parameters are as follows:
nitrate-N 1.29 mg/L, total nitrogen 20.3 mg/L, total organic
carbon 0.03 mg/L, phosphate 1.42 mg/L, alkalinity 21.1 mg/L,
and hardness 88.2 mg/L. The effluent also contained 16 mg/L of
calcium, 18.8 mg/L sodium, and 7.2 mg/L potassium. In this
study, the removal of turbidity, which indicates the separation
of reusable fibres has been analysed.
2.2. Physicochemical characterisation of sludge
The FT-IR spectra in Fig. 2 reveal the presence of different
functional groups in the paper, effluent and flocs produced by
Guar gum and alum. It can be concluded that a physiochemical
interaction took place among the cationic and active groups of
the flocculents and the wastes present in the water resulting in
the removal of the suspended particulate matters. A broad peak
at 3246.14 cm−1
is visible in the spectra, which represents the
OH stretching in the water. There is also a C_N stretch at
1636.33 cm−1
which shows the presence of nitrogenous groups
in the effluent. The effluent characterisation also shows that
considerable amount of nitrogen i.e., 20.3 mg/L of total nitrogen,
is present in the effluent. FT-IR study of the paper used to make
the effluent also shows a peak at 1640.41 cm−1
which clearly
shows that nitrogenous groups are present in the paper and is
the main source of nitrogenous groups in the effluent. The flocs
of Guar gum and alum also show the presence of C _ N stretch,
indicating that nitrogenous groups were removed from the
effluent. Relatively smaller peaks at 771.13 and 673.14 cm−1
in
the effluent indicate the presence of aromatic rings; similar
peaks are also observed in the FT-IR spectra of the paper.
Average peak at 615.47 cm−1
shows the presence of CCl in the
paper. Similar peaks at 560–830 cm−1
are also observed in
the flocs of Guar gum and alum, indicating that halides were
also removed from the effluent by the flocculents. It may be
concluded that some complex physical–chemical interactions
were responsible for the different components of effluent
getting attached onto coagulants, resulting in the turbidity
removal. The SEM micrographs for Guar gum flocs in Fig. 3 show
a good distribution of fibres in the flocs, which could be reused
in the paper making process. The flocs produced by alum are
somewhat less compact and the fibre distribution is not even.
Also the mesh produced by the fibres in the alum flocs are not
as well structured as those produced by Guar gum, hence it can
be inferred that the flocs produced by Guar gum are much
denser compared to the flocs produced by alum. Hence, in
addition to excellent particle recovery, Guar gum flocs appear to
be more suitable for recycling. Fig. 4 shows the size distribution
of the flocs. It can be observed from the graph that Guar gum
produces marginally higher number of large flocs (500–
2000 μm), followed by alum. The volume of large flocs formed
by Locust bean gum and Xanthan gum is almost similar.
Therefore, Guar gum performs slightly better than alum, Locust
bean gum and Xanthan gum.
2.3. Separation of fibres by biopolymers and alum
All the flocculents have distinct behaviour with regard to fibre
removal from the effluent. The mechanism of separation of
fibres from the effluent by biopolymers is distinctly different
from that of chemical flocculents. The chemical flocculents act
by destabilization of the colloidal particle through charge
neutralization. On the other hand, the biopolymers have no
charge of their own and act on the principle of polymer bridging
(Mishra and Bajpai, 2005). The mechanism of flocculation by
biopolymers depends mainly on the affinity of the polymer for
the suspended particulate matter, and flocculation essentially
becomes an adsorption phenomenon. At higher than optimal
concentration of the flocculent, repulsive energy develops
between the flocculent and suspended particulate particles
resulting in redispersion of the aggregated particles and disturbs
particle settling (Chan and Chiang, 1995; Mishra and Bajpai, 2005,
2006). That is why finding out the optimal flocculent concentra-
tion is so important.
The box-plot shows that in the case of Guar gum, dose of the
biopolymer is the determining factor for separation of fibre
(Fig. 5). The highest turbidity removal is obtained at a dose
of 1.5 mg/L and the removal decreases at higher doses. The
highest removal obtained by Guar gum is 78 NTU. That accounts
for 0.193% fibre or 3.86 mg/L of wastewater. The raw effluent
contained 4 mg/L fibres so it can be said that 96.5% of fibres
were recovered using Guar gum. The process is minimally
affected by pH variation and hence Guar gum can be used over a
wide range of effluent pH without affecting its efficiency.
Fibre separation by Xanthan gum is high at pH 7 and 12 but
lower at pH 5 and 9. Therefore, the pH of effluent does not
have a clear pattern over turbidity removal by Xanthan gum
and only specific pH values are suitable for the process. In the
Table 1 – Control factors and levels for Box–Behnken
experiments.
Factor Name Low
actual
High
actual
Central
values
A Dose (mg/L) 1.5 5 3.25
B pH 6 9 7.5
C Mixing speed (r/min) 185 200
1854 J O U R N A L O F E N V I R O N M E N T A L S C I E N C E S 2 6 ( 2 0 1 4 ) 1 8 5 1 – 1 8 6 0
5. case of dose, no clear trend is observed for Xanthan gum.
However, a slightly higher removal is observed at 2 mg/L dose.
The turbidity removal at higher dose may be attributed to a
combined effect of all the design factors. Xanthan gum
recovered around 3.82 mg of fibres from a litre of effluent.
In the case of Locust bean gum, the turbidity removal is
highest at lower pH levels and decreases as the effluent
becomes alkaline. Thus it is suitable only for the treatment of
acidic effluent. The dose of Locust bean gum has little effect
on the turbidity removal; however a small increase is observed
Transmittance(%)
4000 3500 3000 2500 2000 1500 1000 500
Wavenumber (cm-1
)
Paper mill effluent
Guar gum powder
Guar gum floc
Paper
Alum floc
Fig. 2 – FT-IR spectra of paper mill effluent, Guar gum powder, paper, Guar gum floc, and alum floc.
Fig. 3 – SEM images of flocs produced by (a) Guar gum (coagulant dose 1.5 mg/L, mixing speed 185 r/min, pH 7, pulp concentration
0.2%, temperature 25°C and zeta potential −0.0146 mV); (b) alum (coagulant dose 1.75 g/L, mixing speed 185 r/min, pH 7, pulp
concentration 0.2%, temperature 25°C and zeta potential −1.41 mV).
1855J O U R N A L O F E N V I R O N M E N T A L S C I E N C E S 2 6 ( 2 0 1 4 ) 1 8 5 1 – 1 8 6 0
6. as the dose increases. Locust bean gum recovers 0.193% of fibres
the same as that recovered by Guar gum, however the drawback
of using Locust bean gum is that it works best only under acidic
condition as seen from the box plot.
Removal of turbidity by alum is influenced by the pH. The
removal efficiency decreases as the effluent becomes alkaline.
Thus, alum works better under acidic condition and at higher
working pH, the solution becomes near neutral thus affecting
the flocculating capability of alum. This is also supported by the
fact that at higher working pH, the zeta potential of the alum
treated effluent is highly negative, −19.3 mV, which means
re-stabilization of colloids and consequently less floc formation.
However, at lower working pH i.e., at pH 5 and 7, the zeta
potential is found to be 0.557 and −0.627 mV, which indicates
destabilization and charge neutralization of colloidal particu-
late matters leading to better floc formation. The dose of alum
has considerable effect on turbidity removal. The removal is
highest at 1.5 mg/L and decreases after that. Therefore, a small
dose of alum is effective for turbidity removal.
Alum showed the highest turbidity removal among all the
flocculents studied. Among the biopolymers, Guar gum and
Locust bean gum showed the highest turbidity removal
followed by Xanthan gum. As mentioned earlier, the addition
of alum made the water acidic and traces of alum in the treated
water are not suitable for disposal. However, the biopolymers
did not affect the pH of the effluent. From the aspect of
recycling, any change in pH caused by alum has to be adjusted
whilst this does not apply to Guar gum. Guar gum would not
affect the pH and likely to save the additional cost of pH
adjustment in the process.
2.4. Effect of Guar gum dose on separation of fibres
Since Guar gum was the most effective flocculent, a set of
experiments were conducted to determine the optimum dosage
for turbidity removal, and the results are shown in Fig. 6. On
increasing the dose from 1.5 mg/L, the turbidity removal
increased and reached a maximum at a dose of 1.7 mg/L. Beyond
that, the turbidity removal decreased although a slight increase
was observed at 5 mg/L. This indicates the resuspension of solids
at higher concentration of biopolymer due to increase in
repulsion between the flocculent and the pulp fibres (Mishra
and Bajpai, 2005).
2.5. Flocculation studies
2.5.1. Optimization of SVI
The results of analysis of variance for response surface reduced
quadratic are presented in Table 2. The following second order
polynomial equation in terms of actual factors was obtained for
SVI for Guar gum:
SVI ¼ −36:62349 þ 7:60857dose þ 4:95500pH
þ 0:038833mixing speed−1:12  dose  pH: ð4Þ
Analysis of variance is an important tool for testing the
significance of a model. It is a statistical test for comparing the
means of several datasets (Sen and Swaminathan, 2004). In a
regression analysis, analysis of variance determines the impact
of independent variables on the dependent variables. As shown
in Table 2, the analysis of variance of the regression model
showed that a quadratic model was suitable for prediction of
SVI, as is evident from the Fisher's F-Test (Fmodel = 20.981), with
a very high low probability value (P model > F = 0.0001), as
suggested by Liu et al. (2004). There is only a 0.01% chance that a
model value of this magnitude can occur due to noise. The
accuracy of prediction of response value by a model can be
measured by the predicted R2
. For the model to be sufficient, a
difference of no more than 0.20 should be there between
predicted and adjusted R2
values. In the case of turbidity
removal, the predicted R2
value is 0.657, which is within
reasonable agreement with the adjusted R2
value of 0.833. A
signal to noise ratio of 4 or more is preferable and is indicative of
adequate precision, which is a measure of range of predicted
response relative to the associated error (Aghamohammadi et
al., 2007; Mason et al., 2003). The ratio of 20.94, in the case of SVI
indicates adequate signal. The error expressed as a percentage
of the mean gives the coefficient of variation for this model.
The response surface for SVI due to the addition of Guar
gum is shown in Fig. 7. The contour plot implies that SVI
increases with the increase in dose of the biopolymer. The
more compact the sludge is, the easier it is to handle and
dispose. Therefore the aim in this study is to reduce the SVI.
Here we can see that the sludge is more compact at lower
operating pH and at low coagulant dose.
2.5.2. Process optimization and model validation
Optimization of process parameters was performed for opti-
mum turbidity removal by a multiple response method called
desirability function in Design Expert 7. The goal is to minimise
SVI performance by Guar gum. To achieve maximum desirabil-
ity of SVI for Guar gum, mixing speed was set at 203 r/min, the
pH was set at neutral and the dose was maintained at the
lowest value of 1.5 mg/L, keeping in mind environmental
sustainability and economic constraints. At the optimum
conditions the predicted SVI value was 5.632 mL/g at a
desirability of 0.839. An SVI value of 5.428 mL/g was obtained
from confirmatory experiment. It can be concluded that the
generated model is an adequate prediction of SVI with relatively
minor error of 3.62%.
10 100 1000
0
1
2
3
4
5
Volume(%)
Size (μm)
Volume Alum
Volume Guar gum
Volume LBG
Volume XG
Fig. 4 – Particle size distribution of flocs after coagulation.
1856 J O U R N A L O F E N V I R O N M E N T A L S C I E N C E S 2 6 ( 2 0 1 4 ) 1 8 5 1 – 1 8 6 0
8. 2.6. Settling velocity distribution curves
The flocculating effect of Guar gum, Xanthan gum, Locust
bean gum and alum are illustrated by SVDCs which are
generated by plotting ‘percent turbidity remaining’ directly
against the corresponding settling velocities (Table 3 and
Fig. 8). Samples were drawn at the stated time intervals of 1, 2,
4, 8, 16, 32 and 64 min at the corresponding settling velocities
of 4, 2, 1, 0.5, 0.25, 0.125, and 0.0625 cm/min. The raw water
turbidity remaining at the depth of sampling can be expressed
as the ratio of the measured turbidity of the samples
withdrawn at the stated time intervals to the initial effluent
turbidity (80.6 NTU). The ratio or percent of raw water
turbidity remaining therefore describes the proportion of the
raw water turbidity that settles down at a rate equal to or less
than the corresponding settling velocity.
It is evident from Fig. 8 that at any of the settling velocities,
alum settles at the highest percentage of effluent turbidity
followed by Guar gum, Xanthan gum and Locust bean gum. At
0.5 cm/min settling velocity, 97.46% of effluent turbidity can
be removed by alum. However, the performances of Guar
gum, Xanthan gum and Locust bean gum are as good as alum,
which is a conventional chemical coagulant. Guar gum
Xanthan gum and Locust bean gum were able to achieve
94.68%, 92.39% and 92.46% turbidity removal respectively, at a
settling velocity of 0.5 cm/min. It thus proves their efficacy
for application as an alternative to chemical coagulants.
However, Guar gum performed the best among the three
biopolymers.
3. Conclusions
This work presents the performance of three biopolymers and
alum for the removal and recovery of pulp fibres from paper
mill effluent. Alum showed the highest turbidity removal of
97.46%, but in the process, turned the water acidic. This would
entail additional treatment cost to restore the pH of any
recycled pulp. Moreover, the use of alum for effluent
treatment is controversial due to the possible impact of
aluminium in the recycled water on Alzheimer disease (Pal
et al., 2011). Guar gum and Locust bean gum recovered
3.86 mg/L of fibre and Xanthan gum recovered 3.82 mg/L.
Guar gum was found be the most effective biopolymer for
removal and recovery of pulp fibre. Strong hydrophilic
character of Guar gum reduces the time required for hydra-
tion of fibres so that excellent paper sheet can be produced.
0 2 4 6 8 10 12 14 16
76.0
76.5
77.0
77.5
78.0
78.5
Turbidityremoval(NTU)
Dose (mg/L)
Fig. 6 – Turbidity removal with variation of dose.
Table 2 – Statistical models obtained from the analysis of variance for SVI.
Source Sum of squares df Mean square F value P-value
Model 83.761 4 20.940 20.981 <0.0001 Significant
A (dose) 15.346 1 15.346 15.375 0.002
B (pH) 31.126 1 31.126 31.186 0.0001
C (mixing speed) 2.714 1 2.714 2.720 0.125
AB 34.574 1 34.574 34.641 <0.0001
Residual 11.977 12 0.998
Lack of fit 9.903 8 1.238 2.388 0.2088 Not significant
Pure error 2.074 4 0.518
Cor total 95.738 16
Std. dev. 0.999 R-squared 0.875
Mean 5.734 Adj R-squared 0.833
C.V. % 17.424 Pred R-squared 0.657
Press 32.870 Adeq precision 18.134
1858 J O U R N A L O F E N V I R O N M E N T A L S C I E N C E S 2 6 ( 2 0 1 4 ) 1 8 5 1 – 1 8 6 0
9. Furthermore, by adhering to the fibres, Guar gum improves
the paper quality such as smoothness, fold resistance, and
increased wet strength (Whistler Roy, 1954). Statistical design
exhibited the influence of significant design parameters such
as effluent pH, mixing speed and coagulant dose on the SVI
through a quadratic model. SEM micrographs established that
Guar gum is more effective than alum in forming dense flocs
and has a superior floc structure. Thus using Guar gum to
treat paper mill effluent not only produces lower sludge
volume but also yields recyclable fibres. Treating the effluent
with alum may result in inferior paper formation and the
resultant water will have traces of alum which would be
harmful when discharged to natural water bodies. Since
Guar gum is biodegradable (Prasad et al., 1998), non-toxic
(Mukherjee et al., 2013; Sen Gupta and Ako, 2005) and a
common sizing chemical in a paper mill, it can replace alum
in recovery of reusable fibres from the effluent. From an
economic point of view, compared to alum, the amount of
biopolymers required for flocculation was only 1/100th of
alum and going by the current market prices, the studied
biopolymers such as Guar gum will cost only 1/80th of the
price of alum. For treating one million gallon of wastewater,
1.3 USD worth Guar gum (at 1.7 mg/L concentration) and
87 USD worth alum (at 1 g/L concentration) will be required.
Acknowledgments
The authors acknowledge the funding provided by University
of Malaya, Kuala Lumpur (nos. PV009-2012A and UMC/HIR/
MOHE/ENG/13) that helped carry out this research.
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Table 3 – Settling velocity vs. measured turbidity at different time intervals and percent turbidities remaining.
Time
(min)
Settling velocity
(cm/min)
Measured turbidity
(NTU)
Percent turbidity remaining
(NTU)
Guar
gum
Locust bean
gum
Xanthan
gum
Alum Guar
gum
Locust bean
gum
Xanthan
gum
Alum
1 4 13.3 39.5 23.4 13.3 16.50 49.01 29.03 16.50
2 2 6.55 14.4 10.8 5.85 8.13 17.87 13.39 7.25
4 1 6.25 7.04 6.39 5.12 7.75 8.73 7.92 6.35
8 0.5 4.29 6.08 6.14 2.05 5.32 7.54 7.61 2.54
16 0.25 3.93 4.55 3.9 1.94 4.88 5.64 4.83 2.41
32 0.125 2.61 3.99 3.34 1.15 3.24 4.95 4.14 1.43
64 0.0625 1.64 2.68 3.17 0.743 2.03 3.32 3.93 0.92
0.0 0.1 0.2 0.3 0.4 0.5 1 2 3 4
0
10
20
30
40
50
Percentturbidityremaining(%)
Settling velocity (cm/min)
Guar Gum
Locust Bean Gum
Xanthan Gum
Alum
Fig. 8 – Settling velocity distribution curves.
Design-Expert® Software
SVI
13.01
2.47
X1 = A: Dose
X2 = B: pH
Actual Factor
C: Mixing Speed = 200.00
1.50
2.38
3.25
4.13
5.00
6.00
6.75
7.50
8.25
9.00
2
5
8
11
14
SVI
A: DoseB: pH
Fig. 7 – Response surface plot of sludge volume index for
Guar gum. Mixing speed 200 r/min.
1859J O U R N A L O F E N V I R O N M E N T A L S C I E N C E S 2 6 ( 2 0 1 4 ) 1 8 5 1 – 1 8 6 0
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