This document presents the results of experiments on a new method for removing nitrates from drinking water. The method involves incorporating nitrate ions into calcium aluminium storage crystals. A series of batch experiments were conducted with drinking water from wells in Spain and Germany containing 164-230 mg/L of nitrates. The best results achieved a 41% nitrate reduction from 164 mg/L in a single step, and a 67% reduction from 230 mg/L using multiple treatment steps. Varying experimental conditions like magnesium chloride concentration, pH, and removing carbonate ions affected the nitrate removal efficiency. The results demonstrate the potential of this storage crystal method for reducing high nitrate levels in groundwater.
This presentation explores a new method of measuring total nitrogen (TN) using a TOC analyzer. Techniques, benefits and results are discussed. For more information, visit ssi.shimadzu.com. Thanks for viewing.
This presentation discusses continuous monitoring and why a new method is needed that measures total nitrogen (TN) as a single result. High temperature catalytic oxidation (HTCO) is also presented as an method for monitoring TN. For more information, go to ssi.shimadzu.com or follow Shiamdzu on Twitter @shimadzussi. Thanks for viewing.
SYNTHESIS AND CHARACTERIZATION OF KAOLINITE COATED WITH CU-OXIDE AND ITS EFFE...Premier Publishers
In this paper, the effect of copper oxide coated kaolinite on mercury (II) removal based on initial metal concentration, particle concentration, and prolonged residence time have been investigated. Experimental methods involved batch mode techniques at ambient temperature. The content was analysed for Hg(II) adsorbed, using standard laboratory procedures. Here, using empirical models derived from Freundlich isotherm, adsorption capacity increased from 300 to 400 mg/kg over the range of initial metal concentration investigated. The complex behavior of existing reactive sites and the generation of new active sites accounted for these changes in adsorption capacity. Increase in particle concentration led to decrease in adsorption. This was over the range of 2, 4, 6, 8 and 10 gL-1 solid concentration. Higher Cp reduced the specific surface area for adsorption. Hg(II) ions removal increased with increase in residence time. The most efficient ratio of Cu-Oxide coated kaolinite was at 0.002kgL-1 at 40mgL-1 mercury concentration. Values of between 600 to 900 mg/kg for Cu-Oxide coated kaolinite was higher when compared with the uncoated kaolinite. As ageing was increased, hydroxylation probably increased thus leading to the formation of new reactive sites.
Equilibrium and Kinetics Adsorption of Cadmium and Lead Ions from Aqueous Sol...theijes
Sourcing cheap adsorbents for the treatment of waste water is imperative for local environments. The adsorption of cadmium (Cd) and lead (Pb) from aqueous solution onto bamboo activated carbon prepared by chemical activation with ZnCl2 was investigated. The unwashed chemical activated bamboo carbon (UCABC) achieved up to 87.81% and 96.45% removal of Cd and Pb at pH-5 and 11, respectively. Removal equilibrium was attained within 1hr and 2.5hrs for Cd and Pb, respectively. The Cd and Pb adsorption increased with adsorbent dosage decrease while removal rate (%) increased with Cd and Pb concentration. Adsorption isotherm of Cd and Pb onto UCABC was determined and correlated with four isotherm models (Langmuir, Freundlich, Temkin and Hills). The equilibrium data fitted into Freundlich Cd (R2 = 0.9873, SSE = 0.045), Pb (R2 =0.9903, SSE = 0.051); Temkin Cd (R2 =0.9730, SSE = 0.052), Pb (R2 = 0.9079, SSE = 0.056); Hills Cd (R2 = 0.9961, SSE = 0.048), Pb (R2.= 0.9183, SSE = 0.053) and Langmuir Cd (R2 = 0.9653, SSE = 0.302), Pb (R2 = 0.9899, SSE = 0.136) isotherms. The Freundlich fitting showed isotherm adsorption capacity constants Kf = 7.843 and 5.098 (mg/g) for Cd and Pb, respectively. Furthermore, their adsorption kinetics correlated with the Pseudo-first order, Pseudo-second order and Intra-particle diffusion models and could be best described by the Pseudo-second order equation, suggesting chemisorptions as the limiting process. This study demonstrated that the UCABC can remove Cd2+ and Pb+ ions from aqueous solution to avert expensive commercial adsorbents
This presentation explores a new method of measuring total nitrogen (TN) using a TOC analyzer. Techniques, benefits and results are discussed. For more information, visit ssi.shimadzu.com. Thanks for viewing.
This presentation discusses continuous monitoring and why a new method is needed that measures total nitrogen (TN) as a single result. High temperature catalytic oxidation (HTCO) is also presented as an method for monitoring TN. For more information, go to ssi.shimadzu.com or follow Shiamdzu on Twitter @shimadzussi. Thanks for viewing.
SYNTHESIS AND CHARACTERIZATION OF KAOLINITE COATED WITH CU-OXIDE AND ITS EFFE...Premier Publishers
In this paper, the effect of copper oxide coated kaolinite on mercury (II) removal based on initial metal concentration, particle concentration, and prolonged residence time have been investigated. Experimental methods involved batch mode techniques at ambient temperature. The content was analysed for Hg(II) adsorbed, using standard laboratory procedures. Here, using empirical models derived from Freundlich isotherm, adsorption capacity increased from 300 to 400 mg/kg over the range of initial metal concentration investigated. The complex behavior of existing reactive sites and the generation of new active sites accounted for these changes in adsorption capacity. Increase in particle concentration led to decrease in adsorption. This was over the range of 2, 4, 6, 8 and 10 gL-1 solid concentration. Higher Cp reduced the specific surface area for adsorption. Hg(II) ions removal increased with increase in residence time. The most efficient ratio of Cu-Oxide coated kaolinite was at 0.002kgL-1 at 40mgL-1 mercury concentration. Values of between 600 to 900 mg/kg for Cu-Oxide coated kaolinite was higher when compared with the uncoated kaolinite. As ageing was increased, hydroxylation probably increased thus leading to the formation of new reactive sites.
Equilibrium and Kinetics Adsorption of Cadmium and Lead Ions from Aqueous Sol...theijes
Sourcing cheap adsorbents for the treatment of waste water is imperative for local environments. The adsorption of cadmium (Cd) and lead (Pb) from aqueous solution onto bamboo activated carbon prepared by chemical activation with ZnCl2 was investigated. The unwashed chemical activated bamboo carbon (UCABC) achieved up to 87.81% and 96.45% removal of Cd and Pb at pH-5 and 11, respectively. Removal equilibrium was attained within 1hr and 2.5hrs for Cd and Pb, respectively. The Cd and Pb adsorption increased with adsorbent dosage decrease while removal rate (%) increased with Cd and Pb concentration. Adsorption isotherm of Cd and Pb onto UCABC was determined and correlated with four isotherm models (Langmuir, Freundlich, Temkin and Hills). The equilibrium data fitted into Freundlich Cd (R2 = 0.9873, SSE = 0.045), Pb (R2 =0.9903, SSE = 0.051); Temkin Cd (R2 =0.9730, SSE = 0.052), Pb (R2 = 0.9079, SSE = 0.056); Hills Cd (R2 = 0.9961, SSE = 0.048), Pb (R2.= 0.9183, SSE = 0.053) and Langmuir Cd (R2 = 0.9653, SSE = 0.302), Pb (R2 = 0.9899, SSE = 0.136) isotherms. The Freundlich fitting showed isotherm adsorption capacity constants Kf = 7.843 and 5.098 (mg/g) for Cd and Pb, respectively. Furthermore, their adsorption kinetics correlated with the Pseudo-first order, Pseudo-second order and Intra-particle diffusion models and could be best described by the Pseudo-second order equation, suggesting chemisorptions as the limiting process. This study demonstrated that the UCABC can remove Cd2+ and Pb+ ions from aqueous solution to avert expensive commercial adsorbents
This Presentation Clarifying about potable Water analysis and their methods which i gave training on operation and maintenance team for Oman Al Ghubrah Independence Water Project (SWRO Desalination 42 MIGD)
Engineering Research Publication
Best International Journals, High Impact Journals,
International Journal of Engineering & Technical Research
ISSN : 2321-0869 (O) 2454-4698 (P)
www.erpublication.org
Deals with the measurement of organic matter concentration in water and wastewater. BOD, BOD kinetics and COD tests are discussed at length. Further, as part of the ultimate BOD measurement, other associated tests like Dissolved Oxygen and Ammonical, Nitrate and Nitrite forms of nitrogen are also discussed.
Removal of Pb II from Aqueous Solutions using Activated Carbon Prepared from ...ijtsrd
The recent study explains about the removal of Pb II ions from aqueous solution using activated carbon prepared from Garlic waste. Garlic peels have been used for the production of Carbon by treating with conc.H2SO4 for metal ions removal. Fourier Transform Infrared Spectroscopy and Boehm titration have been used for various physicochemical characterization of the outcome of activated carbon which proclaimed the presence of oxygen containing surface functional groups like phenolic, lactonic and carboxylic in the carbons. In a batch adsorption process the effect of pH and initial metal ion concentration was calculated. The optimum pH for lead adsorption is found to be equal to 6.The resultant activated carbon showed maximum adsorption capacity of Pb II was 210 mg g 1. The waste material which is used in this work is cost effective and easily available for the production of activated carbon. Hence the removal of Pb II from water using the carbons prepared from Garlic peels can act as possible low cost adsorbents for the removal of Pb II from water. R. Mary Nancy Flora | Ashok | Ramanathan ""Removal of Pb (II) from Aqueous Solutions using Activated Carbon Prepared from Garlic Waste"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23365.pdf
Paper URL: https://www.ijtsrd.com/engineering/chemical-engineering/23365/removal-of-pb-ii-from-aqueous-solutions-using-activated-carbon-prepared-from-garlic-waste/r-mary-nancy-flora
The microprocessor based automatic, advance, electronic and latest designed COD Analyzers are used for detection of Chemical Oxygen Demand. The Laboratory COD analyzer acts as water analyzer for detection of Chemical Oxygen Demand in both polluted and normal water. Weiber water analyzer works as high quality analysis tool for determination of inorganic pollution, waste water, sewage and Plant Effluent Treatment. For More Information Please Logon http://goo.gl/gaktwZ
More Affordable, Reliable and Recoverable Nutrient RemovalBlack & Veatch
Recurring harmful algal blooms in Lake Erie and other water bodies keep nutrients at the forefront of water quality priorities in the Great Lakes, Upper Mississippi River and elsewhere in the Midwest. Recent regulatory strategies have focused on nonpoint source controls and more stringent point source limits. In response, more treatment utilities will likely consider biological nutrient removal (BNR) technologies along with other alternatives. Since the invention of the Phoredox and Bardenpho processes in South Africa in the early 1970s, understanding of underlying BNR mechanisms has grown significantly, especially for enhanced biological phosphorus removal (EBPR).
This webinar will look at recent developments that have further improved the reliability and cost-effectiveness of EBPR for cold and wet conditions encountered in the Midwest and Great Lakes. Case studies will be discussed demonstrating innovative design features that can turn unintended BNR consequences into positive results, including:
Side-stream EBPR (S2EBPR) – moves anaerobic zones out of the main liquid stream. This configuration is much more reliable and efficient than conventional mainstream anaerobic zones, making EBPR viable in more cases than previously thought possible.
Struvite recovery processes – minimizes nuisance scaling in digestion and dewatering, reduces nutrient return loads to the main liquid stream, improves biosolids dewaterability, and produces a high-quality, eco-friendly fertilizer product.
Step-feed anoxic zones – are a lower-energy denitrification alternative to the traditional Modified Ludzack-Ettinger (MLE) approach to offset nitrification oxygen and alkalinity demands and avoid clarifier sludge blanket flotation.
Wet-weather step-feed and biomass transfer – manage peak flows and protect biomass from washout. Auxiliary enhanced high-rate treatment (EHRT) facilities offer even greater resiliency and excellent phosphorus removal.
Deals with the biological removal of nitrogen and phosphorus, Nitrification-denitrification removal of nitrogen, and Phosphate accumulating organisms and poly-hydroxibutirate in the phosphorus removal.
This Presentation Clarifying about potable Water analysis and their methods which i gave training on operation and maintenance team for Oman Al Ghubrah Independence Water Project (SWRO Desalination 42 MIGD)
Engineering Research Publication
Best International Journals, High Impact Journals,
International Journal of Engineering & Technical Research
ISSN : 2321-0869 (O) 2454-4698 (P)
www.erpublication.org
Deals with the measurement of organic matter concentration in water and wastewater. BOD, BOD kinetics and COD tests are discussed at length. Further, as part of the ultimate BOD measurement, other associated tests like Dissolved Oxygen and Ammonical, Nitrate and Nitrite forms of nitrogen are also discussed.
Removal of Pb II from Aqueous Solutions using Activated Carbon Prepared from ...ijtsrd
The recent study explains about the removal of Pb II ions from aqueous solution using activated carbon prepared from Garlic waste. Garlic peels have been used for the production of Carbon by treating with conc.H2SO4 for metal ions removal. Fourier Transform Infrared Spectroscopy and Boehm titration have been used for various physicochemical characterization of the outcome of activated carbon which proclaimed the presence of oxygen containing surface functional groups like phenolic, lactonic and carboxylic in the carbons. In a batch adsorption process the effect of pH and initial metal ion concentration was calculated. The optimum pH for lead adsorption is found to be equal to 6.The resultant activated carbon showed maximum adsorption capacity of Pb II was 210 mg g 1. The waste material which is used in this work is cost effective and easily available for the production of activated carbon. Hence the removal of Pb II from water using the carbons prepared from Garlic peels can act as possible low cost adsorbents for the removal of Pb II from water. R. Mary Nancy Flora | Ashok | Ramanathan ""Removal of Pb (II) from Aqueous Solutions using Activated Carbon Prepared from Garlic Waste"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23365.pdf
Paper URL: https://www.ijtsrd.com/engineering/chemical-engineering/23365/removal-of-pb-ii-from-aqueous-solutions-using-activated-carbon-prepared-from-garlic-waste/r-mary-nancy-flora
The microprocessor based automatic, advance, electronic and latest designed COD Analyzers are used for detection of Chemical Oxygen Demand. The Laboratory COD analyzer acts as water analyzer for detection of Chemical Oxygen Demand in both polluted and normal water. Weiber water analyzer works as high quality analysis tool for determination of inorganic pollution, waste water, sewage and Plant Effluent Treatment. For More Information Please Logon http://goo.gl/gaktwZ
More Affordable, Reliable and Recoverable Nutrient RemovalBlack & Veatch
Recurring harmful algal blooms in Lake Erie and other water bodies keep nutrients at the forefront of water quality priorities in the Great Lakes, Upper Mississippi River and elsewhere in the Midwest. Recent regulatory strategies have focused on nonpoint source controls and more stringent point source limits. In response, more treatment utilities will likely consider biological nutrient removal (BNR) technologies along with other alternatives. Since the invention of the Phoredox and Bardenpho processes in South Africa in the early 1970s, understanding of underlying BNR mechanisms has grown significantly, especially for enhanced biological phosphorus removal (EBPR).
This webinar will look at recent developments that have further improved the reliability and cost-effectiveness of EBPR for cold and wet conditions encountered in the Midwest and Great Lakes. Case studies will be discussed demonstrating innovative design features that can turn unintended BNR consequences into positive results, including:
Side-stream EBPR (S2EBPR) – moves anaerobic zones out of the main liquid stream. This configuration is much more reliable and efficient than conventional mainstream anaerobic zones, making EBPR viable in more cases than previously thought possible.
Struvite recovery processes – minimizes nuisance scaling in digestion and dewatering, reduces nutrient return loads to the main liquid stream, improves biosolids dewaterability, and produces a high-quality, eco-friendly fertilizer product.
Step-feed anoxic zones – are a lower-energy denitrification alternative to the traditional Modified Ludzack-Ettinger (MLE) approach to offset nitrification oxygen and alkalinity demands and avoid clarifier sludge blanket flotation.
Wet-weather step-feed and biomass transfer – manage peak flows and protect biomass from washout. Auxiliary enhanced high-rate treatment (EHRT) facilities offer even greater resiliency and excellent phosphorus removal.
Deals with the biological removal of nitrogen and phosphorus, Nitrification-denitrification removal of nitrogen, and Phosphate accumulating organisms and poly-hydroxibutirate in the phosphorus removal.
Presentation contain Waste-water treatment technologies for the removal of nitrogen and phosphorus. It includes Eutrophication, Nitrogen Removal by Nitrification and denitrification, Phosphorus Removal by Enhanced Biological Phosphorus Removal and by Chemical Treatment.
A presentation about nitrogen removal from municipal wastewater in Falmouth, Massachusetts. Presented by Amy Lowell, Assistant Wastewater Manager for the town of Falmouth, during the Buzzards Bay Coalition's 2013 Decision Makers Workshop series. Learn more at www.savebuzzardsbay.org/DecisionMakers
The Phosphorus Problem: Treatment Options and Process Monitoring Solutions | YSIXylem Inc.
Recent events have demonstrated that excess phosphorus in receiving waters can create many serious problems including impairment of drinking water supplies. For this reason and others, incorporation of phosphorus limits into NPDES discharge permits is occurring in many states.
Many water resource recovery facilities (WRRFs) are being required to remove phosphorus for the first time and will need to add a process to the flow sheet. A discharge limit of 1.0 mg/L may be achieved most cost-effectively with chemical addition. Enhanced biological treatment may be needed to meet lower limits down to 0.5 mg/L and below. Additionally, biological treatment has other potential benefits.
Regardless of the treatment method, continuous monitoring is essential. Critical parameters include orthophosphate, dissolved oxygen, oxidation-reduction potential (ORP), total suspended solids, and nitrate.
Advanced oxidation processes to recover reverse osmosis cleaning watersacciona
Marina Arnaldos, responsable de desalación de desalación y nuevas tecnologías de ACCIONA Agua, presentó la ponencia “Advanced oxidation processes to recover reverse osmosis cleaning waters for irrigation purposes” en la conferencia anual que la asociación europea de desalación ha celebrado en Roma entre los días 22-26 de mayo de 2016.
Because of strong Vander Waal force, carbon nanotubes tend to aggregate into bundle that
limits its applications in various fields. Homogenous dispersion of carbon nanotubes is an important issue. This
paper reports the effect of chemical functionalization of multiwalled carbon nanotubes (MWCNTs) by
introducing polar groups such as carboxyl groups in order to get better dispersibility in aqueous medium.
Functionalization of MWCNTs was done by acid (HCl, HNO3, Aquaregia)and non-acid (NH4OH/H2O2)
treatment.All treatments followed with variation of ultra-sonication time.The dispersion of MWCNTs was
monitored by UV-VIS absorption spectroscopy. Functionalization removes the impurities present in pristine
MWCNTs and adds different functional group on the surface of MWCNTs which helps further dispersion. The
chemical change after functionalization of MWCNTwas investigated by FT-IR and Raman spectroscopy. Among
four chemical reagents, HNO3acid treated MWCNTs show higher dispersion than other three. The dispersion
increases with increasing the sonication time.
presentation at DSMZ Braunschweig 19 nov 2015 highlighting "impossible" microbes like anammox, methylomirabilis oxyfera and nitrate AOM archaea, anaerobic microbiology
A short description of thermal technologies for the recovery of ammonia from N-rich wastewaters and expirementing with membrane distillation for getting better results.
Environmental Catalysis Module: Students examines different types of catalytic systems, including heterogeneous and homogeneous catalysis. Depending on the knowledge they gained during activities, the students are then asked to design their projects.
Our Project: Methanol Synthesizer Catalyst : A catalyst composed of copper alloys with ceria (cerium-oxide) nanoparticles, sometimes also mixed with titania. The catalyst were exposed to pressure of 0.5 atom of CO2 and 4.5 atom of H2 at a range of reaction temperatures 500-600 Kalvin.
By: ABJ_ Cobalt8, Ali Bin Jassim Secondary Independent School for Boys.
Karl fischer titration is an analytic system to determine the trace amount of water in solid, gases and liquids. It is a very efficient and accurate technique. In this presentation we go deeper about this titration system.
Statistical Optimization of Synthetic Soda Ash for Water Softeningijtsrd
Synthesized soda ash was prepared by Solvay process with different molar ratio for application of water softening process. In urban utilization, water supply is very important for safe condition. In this research, Box Behnken experimental design was employed for optimization of soda ash. The maximum yield percent of 19.882 of soda ash was obtained by the reaction salt to ammonium hydroxide to carbon dioxide 1 3 6.8 during the reaction time 90 min. The synthesized soda ash was analyzed by X ray diffraction XRD , Scanning Electron Microscope SEM , Energy Dispersive X ray Fluorescence EDXRF and Fourier Transform Infrared Spectroscopy FTIR . Soda ash obtained from optimum condition was applied in water softening of tap water. According to the experimental results of water softening process, the maximum removal of hardness of water was observed at 3 ml of 10 lime solution with 20 ml of 5 of soda ash solution for 1000 ml of water. After treated the lime soda process, the total hardness of water was reduced to initial condition of 255 ppm to 24 ppm. Su Mon Tun | May Myat Khine | Khin Thidar Cho "Statistical Optimization of Synthetic Soda Ash for Water Softening" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27841.pdf Paper URL: https://www.ijtsrd.com/engineering/chemical-engineering/27841/statistical-optimization-of-synthetic-soda-ash-for-water-softening/su-mon-tun
Statistical Optimization of Synthetic Soda Ash for Water Softening
Diplomarbeit imprimir_kurtz
1. U.P.V.
Esc. Univ. Ing. Téc. Industrial
Universität Essen
Nitrate removal for
drinking water conditioning
by fixing in storage crystals
Final work
Supervisors: Prof. J. García Garrido
Prof. Dr.-Ing. R. Widmann
Dr. M. Denecke
Dr. Alfons Grooterhorst
Author: cand.-Ing. Miguel García Hernández
Essen, Valencia, September 2002
2. i
Abstract
The increasing nitrate content in ground water of the Mediterranean Spanish coast is becom-
ing a serious problem. The reason for this nitrate increase is the excessive use of fertilisers
in intensive cultivation of orange trees.
In the last years, different physique-chemical, biological and catalytic methods for nitrate re-
moval had been developed. But there is still not a definitive method to treat the polluted wa-
ters containing nitrates. The proposal of the present work is due to the idea of CONZEPT
Gesellschaft für Unternehmerberatung mbH, Duisburg (Germany) to develop of a new
method which allows to reduce the nitrate concentration in water by the inclusion of these
anions in a crystal net. After the crystal formation process the crystals are removed from the
solution with the pollutant inside. The main reactants are sources of calcium and aluminium
ions required for the storage crystal formation process. The storage crystals are able to re-
place OH-
groups of the interlayer positions by mono, bi and trivalent ions in water. This fact
makes this technique very suitable to remove contaminants from water, obtaining a solid and
inert residue. Nevertheless, nitrates are not the first ions to get into the crystal-net. A hierar-
chy is established for the inclusion of anions in the crystals. First carbonates, sulphates, chlo-
rides, and then nitrates are included in the crystal net. So that better conditions must be
achieved to include in the crystal net as much nitrates as possible.
All experiments has been carried out with drinking water from a well placed in Alginet (Valèn-
cia - Spain) and with drinking water from the city of Essen. An important reduction of the ni-
trate concentration was observed. A 41% nitrate reduction was achieved in a single treat-
ment step experiment with a initial nitrate concentration of 164 mg/L. In multi-steps experi-
ments, the best result was a 67% nitrate reduction in a water with an initial concentration of
230 mg/L NO3
-
.
3. I
Contents
Page
Index I
Abbreviations III
List of figures V
List of tables VII
List of annexes VIII
1 Introduction 1
1.1 The nitrate problem 2
1.2 Objectives 3
2 Theoretical bases 4
3 Material and methods 7
3.1 Standard analytical methods 7
3.2 Chemicals 8
3.3 Laboratory equipment 9
3.4 Experimental procedure 11
3.4.1 Introduction 11
3.4.2 Preliminary tests 17
3.4.3 Experiments 19
3.4.3.1 Atmospheric batch experiments 19
3.4.3.1.1 Group 1: Nitrate group 20
3.4.3.1.2 Group 2: MgCl2 group 21
3.4.3.1.3 Group 3: pH group 22
3.4.3.1.4 Group 4: Multi-step-MgCl2-pH group 22
3.4.3.2 CO2-free batch experiments 23
3.4.3.2.1 Boiled water group 24
3.4.3.2.2 Mixture group 25
3.4.3.2.3 Standard procedure group 26
3.4.3.2.4 Calcium measurement group 26
3.4.3.3 Scaling-up. 28
3.4.3.4 Experimental tests 29
4 Results and Discussion 32
4.1 Preliminary test 32
4.2 Basic Experimental Data 35
4.3 Experiments 37
4. II
4.3.1 Batch 1: Atmospheric batch experiments 37
4.3.1.1 Nitrate group. 37
4.3.1.2 MgCl2 group 41
4.3.1.3 pH group 44
4.3.1.4 Multi-step, MgCl2, pH group 46
4.3.2 Batch 2: CO2-free atmospheric batch experiments 51
4.3.2.1 Carbonates polluted experiments 52
4.3.2.2 Carbonate-free experiments 54
4.3.2.2.1 Calcium measurement group 56
4.3.2.3 Scaling-up 59
5 Model explanation 63
5.1 Static model 64
5.2 Constant decreasing model 65
5.3 Dynamic decreasing model 66
5.4 Models comparison 67
5.5 Crystal formation model 70
5.5.1 Calcium solubility and nitrate reduction 72
6 Industrial scale 76
Summary and advises 80
7 References 82
8 Annexes 84
5. III
Abreviations
A Al2O3
Al3+
aluminium ion
Al2O3 aluminium oxide
C3 3 CaO
Ca2+
calcium ion
CaCO3 calcium carbonate
Ca(NO)3 calcium nitrate
CaO calcium oxide
Ca(OH)2 calcium hydroxide
CaSO4 calcium sulphate
CaCl2 calcium chloride
Cl-
chloride ion
CO2 carbon dioxide
CO3
2-
carbonate ion
°dH German hardness degrees
exp. experiment
FCO2 CO2 transfer rate across the solution interface
Fe2O3 iron oxide (III)
HCl hydrochloric acid
HCO3
-
bicarbonate ion
H2CO3 carbonic acid
K+
potassium ion
KH Henry’s law constant for CO2
Mg2+
magnesium ion
MgCl2 magnesium chloride
MgO magnesium oxide
min minute
M.M.A. Ministerio de Medio Ambiente
N2O nitrogen oxide (I)
Na+
sodium ion
NaNO3 sodium nitrate
Na2O sodium oxide
NaOH sodium hydroxide
NO2
-
nitrite
NO3
-
nitrate
NOx nitrogen oxides
OH-
hydroxide ion
pCO2 partial pressure of CO2
Pa Pascal
pp precipitate
rpm rounds per minute
SiO2 silicon oxide
SO3 sulphur oxide (VI)
7. V
List of figures
Page
Figure 1-1 Location of wells in Spain which nitrate concentration overcomes
50 mg/L (M.M.A., 1998)
1
Figure 2-1 Structure of a-monochloride (Auer, 1992) 5
Figure 2-2 Theoretical calcium solubility according to the pH (Schröter et al.
1986) 6
Figure 3.4.1-1. General experimental procedure 13
Figure 3.4.2-1 Equilibrium system carbonic acid-carbonate (Schröter et al. 1986) 18
Figure 3.4.3.1-1 Water pre-treatment in atmospheric batch of experiments 20
Figure 3.4.3.2.1-1 CO2-free atmosphere water pre-treatment 25
Figure 3.4.3.2.4-1 Procedure in calcium measurement group 27
Figure 3.4.3.4-1 Water pre-treatment in test 5 to 10 30
Figure 4.1-1 Air filter interference 32
Figure 4.1-2 A
A and B
pH decrease in time in two solutions: without/with aluminium
source 34
Figure 4.3.1.1-1 Reduction of the nitrate concentration at different initial concentra-
tions in group 1 37
Figure 4.3.1.1-2 Dependence of the initial nitrate concentration with the relative
nitrate reduction 38
Figure 4.3.1.1-3 Different tendencies of the relative nitrate reduction according to
the theoretical reactants ratios 39
Figure 4.3.1.2-1 Effect of the MgCl2 addition to A water on the nitrate reduction 41
Figure 4.3.1.2-2 Effect of the MgCl2 addition to A water in the relative nitrate reduc-
tion 42
Figure 4.3.1.3-1 Effect of pH in the nitrate reduction 44
Figure 4.3.1.3-2 Effect of pH in the relative nitrate reduction 44
Figure 4.3.1.4-1 Nitrate reduction in multi-step, MgCl2, pH group 46