A submerged internal circulating membrane coagulation reactor （MCR） was used to treat surface water to produce drinking water. Polyaluminum chloride （PAC1） was used as coagulant, and a hydrophilic polyvinylidene f...A submerged internal circulating membrane coagulation reactor （MCR） was used to treat surface water to produce drinking water. Polyaluminum chloride （PAC1） was used as coagulant, and a hydrophilic polyvinylidene fluoride （PVDF） submerged hollow fiber microfiltration membrane was employed. The influences of trans-membrane pressure （TMP）, zeta potential （ZP） of the suspended particles in raw water, and KMnO4 dosing on water flux and the removal of turbidity and organic matter were systematically investigated. Continuous bench-scale experiments showed that the permeate quality of the MCR satisfied the requirement for a centralized water supply, according to the Standards for Drinking Water Quality of China （GB B749-2006）, as evaluated by turbidity （〈1 NTU） and total organic carbon （TOC） （〈5 mE/L） measurements. Besides water flux, the removal of turbidity, TOC and dissolved organic carbon （DOC） in the raw water also increased with increasing TMP in the range of 0.01-0.05 MPa. High ZP induced by PAC1, such as 5-9 mY, led to an increase in the number of fine and total particles in the MCR, and consequently caused serious membrane fouling and high permeate turbidity. However, the removal of TOC and DOC increased with increasing ZP. A slightly positive ZP, such as 1-2 mV, corresponding to charge neutralization coagulation, was favorable for membrane fouling control. Moreover, dosing with KMnO4 could further improve the removal of turbidity and DOC, thereby mitigating membrane fouling. The results are helpful for the application of the MCR in producing drinking water and also beneficial to the research and application of other coagulation and membrane separation hybrid processes.展开更多
Objective To investigate the reduction of chlorination by-products （CBPs） precursors using the fluidized-bed biofdm reactor （FBBR）. Methods Reduction of total organic carbon （TOC）, ultraviolet absorbance （UV254...Objective To investigate the reduction of chlorination by-products （CBPs） precursors using the fluidized-bed biofdm reactor （FBBR）. Methods Reduction of total organic carbon （TOC）, ultraviolet absorbance （UV254）, tfihalomethane （THM） formation potential （THMFP）, haloacetic acid （HAA） formation potential （HAAFP）, and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3℃, however, it could quickly rise to over 50% above 3℃. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.展开更多
The aims of this study were to evaluate two methods, qPCR and a chemiluminescent assay (ColiLight II), for rapid detection of E. coli in water, and to examine the survival and persistence of clinical E. coli in drinki...The aims of this study were to evaluate two methods, qPCR and a chemiluminescent assay (ColiLight II), for rapid detection of E. coli in water, and to examine the survival and persistence of clinical E. coli in drinking water and biofilm using qPCR and ColiLight II. qPCR and ColiLight II were compared with a cultivation-based method (MPN), and survival and persistence of four clinical E. coli strains in water and biofilms on stainless steel (SS) and polyethylene (PE) surfaces were studied in a flow-through reactor with non-disinfected drinking water using ColiLight II, qPCR, ATP bioluminescence, and MPN. ColiLight II and qPCR correlated well with MPN. In drinking water, some clinical E. coli strains showed prolonged survival in drinking water flow-through systems, and persisted 3 - 3.4 times longer than the theoretical washout due to incorporation into biofilms. Strain specific attributes can significantly affect detection and persistence of E. coli in drinking water matrices.展开更多
基金supported by the Special Funds for Technological Development of Research Institutes from the Ministry of Science and Technology of China(Nos.2012EG111122,2013EG111129,2014EG111126)the Program for Overseas Talents from Beijing Academy of Science and Technology(No.OTP-2013-015)the Six Talent Peaks Program from Jiangsu Province(No.JNHB-012)
文摘A submerged internal circulating membrane coagulation reactor （MCR） was used to treat surface water to produce drinking water. Polyaluminum chloride （PAC1） was used as coagulant, and a hydrophilic polyvinylidene fluoride （PVDF） submerged hollow fiber microfiltration membrane was employed. The influences of trans-membrane pressure （TMP）, zeta potential （ZP） of the suspended particles in raw water, and KMnO4 dosing on water flux and the removal of turbidity and organic matter were systematically investigated. Continuous bench-scale experiments showed that the permeate quality of the MCR satisfied the requirement for a centralized water supply, according to the Standards for Drinking Water Quality of China （GB B749-2006）, as evaluated by turbidity （〈1 NTU） and total organic carbon （TOC） （〈5 mE/L） measurements. Besides water flux, the removal of turbidity, TOC and dissolved organic carbon （DOC） in the raw water also increased with increasing TMP in the range of 0.01-0.05 MPa. High ZP induced by PAC1, such as 5-9 mY, led to an increase in the number of fine and total particles in the MCR, and consequently caused serious membrane fouling and high permeate turbidity. However, the removal of TOC and DOC increased with increasing ZP. A slightly positive ZP, such as 1-2 mV, corresponding to charge neutralization coagulation, was favorable for membrane fouling control. Moreover, dosing with KMnO4 could further improve the removal of turbidity and DOC, thereby mitigating membrane fouling. The results are helpful for the application of the MCR in producing drinking water and also beneficial to the research and application of other coagulation and membrane separation hybrid processes.
基金This work was supported by National Natural Science Foundation of China (No. 50408006).
文摘Objective To investigate the reduction of chlorination by-products （CBPs） precursors using the fluidized-bed biofdm reactor （FBBR）. Methods Reduction of total organic carbon （TOC）, ultraviolet absorbance （UV254）, tfihalomethane （THM） formation potential （THMFP）, haloacetic acid （HAA） formation potential （HAAFP）, and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3℃, however, it could quickly rise to over 50% above 3℃. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.
文摘The aims of this study were to evaluate two methods, qPCR and a chemiluminescent assay (ColiLight II), for rapid detection of E. coli in water, and to examine the survival and persistence of clinical E. coli in drinking water and biofilm using qPCR and ColiLight II. qPCR and ColiLight II were compared with a cultivation-based method (MPN), and survival and persistence of four clinical E. coli strains in water and biofilms on stainless steel (SS) and polyethylene (PE) surfaces were studied in a flow-through reactor with non-disinfected drinking water using ColiLight II, qPCR, ATP bioluminescence, and MPN. ColiLight II and qPCR correlated well with MPN. In drinking water, some clinical E. coli strains showed prolonged survival in drinking water flow-through systems, and persisted 3 - 3.4 times longer than the theoretical washout due to incorporation into biofilms. Strain specific attributes can significantly affect detection and persistence of E. coli in drinking water matrices.
