| At present cationic polyacrylamide is the most widely used sludge condtioning agent.The emission of municipal and industrial wastewater and the wasterwater treatment depth are incrasing while the deteriorating water quality and the increasing volume of sewage,which increasedthe amount of sludge.So the CPAM is indispensable whether the demand or type.Butthe charge density of the conventionalcationic polyacrylamide mostly small because of itsrandomly distributedcationic units,which limits its application in sludge dewatering.To find out the CPAM with concentratecationic units and giving full use offlocculation dewatering sludgeis of great significance.At present cationic polyacrylamide is the most widely used sludge condtioning agent.The emission of municipal and industrial wastewater and the wasterwater treatment depth are incrasing while the deteriorating water quality and the increasing volume of sewage,which increasedthe amount of sludge.So the CPAM is indispensable whether the demand or type.Butthe charge density of the conventionalcationic polyacrylamide mostly small because of itsrandomly distributedcationic units,which limits its application in sludge dewatering.To find out the CPAM with concentratecationic units and giving full use offlocculation dewatering sludgeis of great significance.In this research,The cationic polyacrylamide called P(AM-DMDAAC) initiated by UV was synthesized with acrylamide (AM) and acryloyloxyethyl trimethyl ammonium chloride (DAC) as monomers and PAAS as template andEDTA as the complexing agent and V-044 as the initiator under certain pH condition, respectively.At present cationic polyacrylamide is the most widely used sludge condtioning agent.The emission of municipal and industrial wastewater and the wasterwater treatment depth are incrasing while the deteriorating water quality and the increasing volume of sewage,which increasedthe amount of sludge.So the CPAM is indispensable whether the demand or type.Butthe charge density of the conventionalcationic polyacrylamide mostly small because of itsrandomly distributedcationic units,which limits its application in sludge dewatering.To find out the CPAM with concentratecationic units and giving full use offlocculation dewatering sludgeis of great significance.In this research,The cationic polyacrylamide called P(AM-DMDAAC) initiated by UV was synthesized with acrylamide (AM) and acryloyloxyethyl trimethyl ammonium chloride (DAC) as monomers and PAAS as template andEDTA as the complexing agent and V-044 as the initiator under certain pH condition, respectively.The results of the two characterization methods called FT-IR and 1H NMR demonstrated that the P(AM-DMDAAC) prepared in this research was a copolymer of AM and DMDAAC with micro-block structure found at the molecular chain.The results of anothercharacterization method called DTA-TGA demonstrated that it wasnot easy to break as its good thermal stability,also the decomposition process could approve that micro-block structureexisted.At present cationic polyacrylamide is the most widely used sludge condtioning agent.The emission of municipal and industrial wastewater and the wasterwater treatment depth are incrasing while the deteriorating water quality and the increasing volume of sewage,which increasedthe amount of sludge.So the CPAM is indispensable whether the demand or type.Butthe charge density of the conventionalcationic polyacrylamide mostly small because of itsrandomly distributedcationic units,which limits its application in sludge dewatering.To find out the CPAM with concentratecationic units and giving full use offlocculation dewatering sludgeis of great significance.In this research,The cationic polyacrylamide called P(AM-DMDAAC) initiated by UV was synthesized with acrylamide (AM) and acryloyloxyethyl trimethyl ammonium chloride (DAC) as monomers and PAAS as template andEDTA as the complexing agent and V-044 as the initiator under certain pH condition, respectively.The results of the two characterization methods called FT-IR and 1H NMR demonstrated that the P(AM-DMDAAC) prepared in this research was a copolymer of AM and DMDAAC with micro-block structure found at the molecular chain.The results of anothercharacterization method called DTA-TGA demonstrated that it wasnot easy to break as its good thermal stability,also the decomposition process could approve that micro-block structureexisted.Through the determination of the monomer reactivity ratiowith the template or not in the system,the mechanism of template was studied by the reaction kinetics, the reaction kinetics was investigated in the polymerization reaction mechanism of template. Comparing the two situations was that the reactivity ratio of DMDAAC was obviously larger with the template,which illustrated that the template improved the reaction activity of DMDAAC,make it more likely self-polymerization,changed the polymer sequence at the same time and could also have produced the micro-block structure.At present cationic polyacrylamide is the most widely used sludge condtioning agent.The emission of municipal and industrial wastewater and the wasterwater treatment depth are incrasing while the deteriorating water quality and the increasing volume of sewage,which increasedthe amount of sludge.So the CPAM is indispensable whether the demand or type.Butthe charge density of the conventionalcationic polyacrylamide mostly small because of itsrandomly distributedcationic units,which limits its application in sludge dewatering.To find out the CPAM with concentratecationic units and giving full use offlocculation dewatering sludgeis of great significance.In this research,The cationic polyacrylamide called P(AM-DMDAAC) initiated by UV was synthesized with acrylamide (AM) and acryloyloxyethyl trimethyl ammonium chloride (DAC) as monomers and PAAS as template andEDTA as the complexing agent and V-044 as the initiator under certain pH condition, respectively.The results of the two characterization methods called FT-IR and 1H NMR demonstrated that the P(AM-DMDAAC) prepared in this research was a copolymer of AM and DMDAAC with micro-block structure found at the molecular chain.The results of anothercharacterization method called DTA-TGA demonstrated that it wasnot easy to break as its good thermal stability,also the decomposition process could approve that micro-block structureexisted.Through the determination of the monomer reactivity ratiowith the template or not in the system,the mechanism of template was studied by the reaction kinetics, the reaction kinetics was investigated in the polymerization reaction mechanism of template. Comparing the two situations was that the reactivity ratio of DMDAAC was obviously larger with the template,which illustrated that the template improved the reaction activity of DMDAAC,make it more likely self-polymerization,changed the polymer sequence at the same time and could also have produced the micro-block structure.Synthetic conditions were studied and optimized to improve the flocculant bridging effect by single-factor experiment with the intrinsic viscosity and the conversion rate as the target. Results werethe monomer mass ratio of AM and DMDAAC was 7:3, total monomer mass fraction of 20%,initiator V-044 of 0.04wt%,complexing agentEDTA of 0.3wt%,pH of 8and UV irradiation of 90 min.Under this synthetic condition, An intrinsic viscosity and the conversion rateof the P(AM-DAC) up to 11.3dL/g and 97.2% was attained.Through the single factor experiment of sludge dewatering, the optimal dosage of P (AM-DMDAAC) was 30-50mg/L withwater content of sludge,filtrate turbidity,specific resistance of sludge and Zeta potential as the target.The sludge dewateringperformed better under the pH of 6-8,the intrinsic viscosity of 11.3dL/g and the cationic degree of 30%,which could achieve the water content of 72.1～72.9%,the filtrate turbidity of 6.1～7.1NTU,the specific resistance of sludge of 2.1～2.5 (m/kg) (X 10.12).Comparing the effect of sludge dewatering between the P (AM-DMDAAC) s with the template or not,it illustrated that P (AM-DMDAAC) with template had more excellentsludge dewateringperformance. And through the Zeta potential curve,the electric neutralization capacity of P (AM-DMDAAC) by template polymerization had been significantly improved.Finally CPAM of Chongqing and Japan and self-made P (AM-DMDAAC) by template polymerization were compared through the sludge dewateringperformance,the self-made P (AM-DMDAAC)exhibited better,and had a wider flocculation dosage range,which could make an advantage of the application. |
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