水科学与水工程2008，Vol.1Issue(2)：102-111,10.DOI:10.3882/j.issn.1674-2370.2008.02.010
Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment
Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment
摘要
Abstract
The quantitative change and size distribution of particles in the effluents from a sand filter and a granular activated carbon (GAC) filter in a drinking water treatment plant were investigated. The average total concentration of particles in the sand filter effluent during a filter cycle was 148 particles/mL, 27 of which were larger than 2 μm in size. The concentration in the GAC effluent (561 particles/mL) was significantly greater than that in the sand filter effluent. The concentration of particles larger than 2 μm in the GAC filter effluent reached 201 particles/mL, with the amount of particles with sizes between 2 μm and 15 μm increasing. The most probable number (MPN) of carbon fines reached 43 unit/L after six hours and fines between 0.45 μm and 8.0 μm accounted for more than 50%. The total concentration of outflowing bacteria in the GAC filter effluent, 350 CFU (colony-forming units) /mL, was greater than that in the sand filter effluent, 210 CFU/mL. The desorbed bacteria concentration reached an average of 310 CFU/mg fines. The disinfection efficiency of desorbed bacteria was lower than 40% with 1.5 mg/L of chlorine. The disinfection effect showed that the inactivation rate with 2.0 mg/L of chloramine (90%) was higher than that with chlorine (70%). Experimental results indicated that the high particle concentration in raw water and sedimentation effluent led to high levels of outflowing particles in the sand filter effluent. The activated carbon fines in the effluent accounted for a small proportion of the total particle amount, but the existing bacteria attached to carbon fines may influence the drinking water safety. The disinfection efficiency of desorbed bacteria was lower than that of free bacteria with chlorine, and the disinfection effect on bacteria attached to carbon fines with chloramine was better than that with only chlorine.关键词
drinking water treatment/particles/size distribution/bacteria attached to carbon fines/inactivationKey words
drinking water treatment/particles/size distribution/bacteria attached to carbon fines/inactivation引用本文复制引用
Wang Leilei,Chen Wei,Lin Tao..Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment[J].水科学与水工程,2008,1(2):102-111,10.基金项目
This work was supported by the National Natural Science Foundation of China (Grant No. 50638020), the National Key High-Tech Program (863) of China (Grant No. 2006AA06Z311) and the Natural Science Foundation of Jiangsu Province (Grant No.BK2006170). （Grant No. 50638020）
