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Philippe Moulin - One of the best experts on this subject based on the ideXlab platform.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:International audienceThe key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate
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effect of Antiscalant degradation on salt precipitation and solid liquid separation of ro concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.
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Effect of Antiscalants on precipitation of an RO concentrate: metals precipitated and particle characteristics for several water compositions
Water Research, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:Inland brackish water reverse osmosis (RO) is economically and technically limited by the large volume of salty waste (concentrate) produced. The use of a controlled precipitation step, followed by solid/liquid separation (filtration), has emerged as a promising side-stream treatment process to treat reverse osmosis concentrate and increase overall system recovery. The addition of Antiscalants to the RO feed prevents precipitation within the membrane system but might have a deleterious effect on a concentrate treatment process that uses precipitation to remove problematic precipitates. The effects of Antiscalant type and concentration on salt precipitation and precipitate particle morphology were evaluated for several water compositions. The primary precipitate for the synthetic brackish waters tested was calcium carbonate; the presence of magnesium, sulfate, minor ions, and Antiscalant compounds affected the amount of calcium precipitated, as well as the phases of calcium carbonate formed during precipitation. Addition of Antiscalant decreased calcium precipitation but increased incorporation of magnesium and sulfate into precipitating calcium carbonate. Antiscalants prevented the growth of nucleated precipitates, resulting in the formation of small (100-200 nm diameter) particles, as well as larger (6-10 μm) particles. Elemental analysis revealed changes in composition and calcium carbonate polymorph with Antiscalant addition and Antiscalant type. Results indicate that the presence of Antiscalants does reduce the extent of calcium precipitation and can worsen subsequent filtration performance.
Lauren F. Greenlee - One of the best experts on this subject based on the ideXlab platform.
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Ozonation of phosphonate Antiscalants used for reverse osmosis desalination: Parameter effects on the extent of oxidation
Chemical Engineering Journal, 2014Co-Authors: Lauren F. Greenlee, Benny D. Freeman, Desmond F LawlerAbstract:Abstract The recovery of usable product water in brackish water reverse osmosis (RO) desalination is limited by the potential for membrane scaling. This limited recovery results in high costs of disposal of the concentrate (waste) stream. Concentrate treatment to improve recovery is vital, and treatment that includes Antiscalant oxidation prior to precipitation and solid/liquid separation might allow increased precipitation through Antiscalant deactivation. Ozone and hydrogen peroxide were used to oxidize phosphonate-type Antiscalants under varying conditions of water composition, pH, ozone dose, and Antiscalant type; orthophosphate (P) is an oxidation product and was used to measure the extent of oxidation. Antiscalant oxidation increases with ozone dose (1–10 mg/L O 3 ) and in the presence of calcium, from 1 mg/L P to 7 mg/L P for an Antiscalant concentration of 27 mg/L as P. The addition of hydrogen peroxide causes only minor increases in Antiscalant oxidation. The extent of oxidation varies with pH as a function of metal–ligand speciation, with the doubly-protonated metal–ligand species dominating the reactivity of the Antiscalant. In the presence of calcium, the primary oxidation pathway for phosphonate Antiscalants is through direct reaction with ozone (70–80% of measured P). In the absence of calcium, ozone and hydroxyl radicals appear to contribute relatively equally to oxidation. These results suggest phosphonate Antiscalants can be oxidized with relatively low ozone doses, thereby deactivating the chelating behavior of the Antiscalant and allowing increased precipitation of scaling salts such as calcium and magnesium.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:International audienceThe key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate
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effect of Antiscalant degradation on salt precipitation and solid liquid separation of ro concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.
F. Pujadas - One of the best experts on this subject based on the ideXlab platform.
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Performance test of a new Antiscalant “AQUAKREEN KC-550” under high temperature conditions at the MSF desalination plant in Dubai
Desalination, 1991Co-Authors: Y. Fukumoto, K. Isobe, N. Moriyama, F. PujadasAbstract:Abstract Polycarboxyl type Antiscalants in general have a tendency to become less effective in the presence of multi-valent metal ions such as Ca++ and Mg++ in sea water. However, Kao's new Antiscalant “AQUAKREEN KC-550” improved by the copolymerization technology, has much higher stability against such multi-valance ions. AQUAKREEN KC-550 was tested by Dubai Electricity Company of the unit No.3 desalination plant at Jebel Ali “D” station under the dosing rate of 2 ppm at the brine top temperature of 105°C for a period of 5 months, with caution steps taken to set the optimum dosing rate beforehand. Through this performance test, it was proved that “AQUAKREEN KC-550” could successfully keep very stable all operation parameters such as the Heat Transfer Coefficients of both the brine heater and the heat recovery section and the Gained Output Ratio.
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performance test of a new Antiscalant aquakreen kc 550 under high temperature conditions at the msf desalination plant in dubai
Desalination, 1991Co-Authors: Y. Fukumoto, K. Isobe, N. Moriyama, F. PujadasAbstract:Abstract Polycarboxyl type Antiscalants in general have a tendency to become less effective in the presence of multi-valent metal ions such as Ca++ and Mg++ in sea water. However, Kao's new Antiscalant “AQUAKREEN KC-550” improved by the copolymerization technology, has much higher stability against such multi-valance ions. AQUAKREEN KC-550 was tested by Dubai Electricity Company of the unit No.3 desalination plant at Jebel Ali “D” station under the dosing rate of 2 ppm at the brine top temperature of 105°C for a period of 5 months, with caution steps taken to set the optimum dosing rate beforehand. Through this performance test, it was proved that “AQUAKREEN KC-550” could successfully keep very stable all operation parameters such as the Heat Transfer Coefficients of both the brine heater and the heat recovery section and the Gained Output Ratio.
Desmond F Lawler - One of the best experts on this subject based on the ideXlab platform.
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Ozonation of phosphonate Antiscalants used for reverse osmosis desalination: Parameter effects on the extent of oxidation
Chemical Engineering Journal, 2014Co-Authors: Lauren F. Greenlee, Benny D. Freeman, Desmond F LawlerAbstract:Abstract The recovery of usable product water in brackish water reverse osmosis (RO) desalination is limited by the potential for membrane scaling. This limited recovery results in high costs of disposal of the concentrate (waste) stream. Concentrate treatment to improve recovery is vital, and treatment that includes Antiscalant oxidation prior to precipitation and solid/liquid separation might allow increased precipitation through Antiscalant deactivation. Ozone and hydrogen peroxide were used to oxidize phosphonate-type Antiscalants under varying conditions of water composition, pH, ozone dose, and Antiscalant type; orthophosphate (P) is an oxidation product and was used to measure the extent of oxidation. Antiscalant oxidation increases with ozone dose (1–10 mg/L O 3 ) and in the presence of calcium, from 1 mg/L P to 7 mg/L P for an Antiscalant concentration of 27 mg/L as P. The addition of hydrogen peroxide causes only minor increases in Antiscalant oxidation. The extent of oxidation varies with pH as a function of metal–ligand speciation, with the doubly-protonated metal–ligand species dominating the reactivity of the Antiscalant. In the presence of calcium, the primary oxidation pathway for phosphonate Antiscalants is through direct reaction with ozone (70–80% of measured P). In the absence of calcium, ozone and hydroxyl radicals appear to contribute relatively equally to oxidation. These results suggest phosphonate Antiscalants can be oxidized with relatively low ozone doses, thereby deactivating the chelating behavior of the Antiscalant and allowing increased precipitation of scaling salts such as calcium and magnesium.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:International audienceThe key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate
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effect of Antiscalant degradation on salt precipitation and solid liquid separation of ro concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.
Benny D. Freeman - One of the best experts on this subject based on the ideXlab platform.
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Ozonation of phosphonate Antiscalants used for reverse osmosis desalination: Parameter effects on the extent of oxidation
Chemical Engineering Journal, 2014Co-Authors: Lauren F. Greenlee, Benny D. Freeman, Desmond F LawlerAbstract:Abstract The recovery of usable product water in brackish water reverse osmosis (RO) desalination is limited by the potential for membrane scaling. This limited recovery results in high costs of disposal of the concentrate (waste) stream. Concentrate treatment to improve recovery is vital, and treatment that includes Antiscalant oxidation prior to precipitation and solid/liquid separation might allow increased precipitation through Antiscalant deactivation. Ozone and hydrogen peroxide were used to oxidize phosphonate-type Antiscalants under varying conditions of water composition, pH, ozone dose, and Antiscalant type; orthophosphate (P) is an oxidation product and was used to measure the extent of oxidation. Antiscalant oxidation increases with ozone dose (1–10 mg/L O 3 ) and in the presence of calcium, from 1 mg/L P to 7 mg/L P for an Antiscalant concentration of 27 mg/L as P. The addition of hydrogen peroxide causes only minor increases in Antiscalant oxidation. The extent of oxidation varies with pH as a function of metal–ligand speciation, with the doubly-protonated metal–ligand species dominating the reactivity of the Antiscalant. In the presence of calcium, the primary oxidation pathway for phosphonate Antiscalants is through direct reaction with ozone (70–80% of measured P). In the absence of calcium, ozone and hydroxyl radicals appear to contribute relatively equally to oxidation. These results suggest phosphonate Antiscalants can be oxidized with relatively low ozone doses, thereby deactivating the chelating behavior of the Antiscalant and allowing increased precipitation of scaling salts such as calcium and magnesium.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:International audienceThe key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate
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effect of Antiscalant degradation on salt precipitation and solid liquid separation of ro concentrate
Journal of Membrane Science, 2011Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A three-stage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate.
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Effect of Antiscalant degradation on salt precipitation and solid/liquid separation of RO concentrate
Journal of Membrane Science, 2010Co-Authors: Lauren F. Greenlee, Fabrice Testa, Desmond F Lawler, Benny D. Freeman, Philippe MoulinAbstract:The key limitation to the application of reverse osmosis (RO) desalination on inland brackish waters is concentrate disposal. Due to precipitation of sparingly soluble salts (CaCO3, CaSO4, BaSO4, SrSO4), RO membrane recovery cannot be increased further; therefore, other strategies must be investigated. Antiscalants are often added to RO feed water to help prevent precipitation and increase RO recovery, but in concentrate treatment, Antiscalants may prevent precipitation of problematic constituents. A threestage process to treat brackish water RO concentrate was investigated; the stages include oxidation of Antiscalants with ozone and hydrogen peroxide, precipitation at elevated pH, and solid/liquid separation. A model water concentrate was used to perform laboratory scale experiments for each treatment stage. Experimental results showed that the advanced oxidation process (AOP) of ozonation and hydrogen peroxide on phosphonate Antiscalants allowed increased calcium precipitation as well as loss of the solubilizing effects of Antiscalants as compared to precipitation without prior ozonation of the Antiscalants. The AOP also removed the effect of Antiscalant on precipitate particle size distribution and particle morphology. In some cases, the AOP also improved microfiltration performance for the solid/liquid separation stage. The concentrate treatment could increase overall recovery from 80% to 90% for non-ozonated, Antiscalant-dosed concentrate and from 80% to 94% for ozonated, Antiscalant-dosed concentrate. © 2010 Published by Elsevier B.V.