Safety of treated water for re-use purposes--comparison of filtration and disinfection processes.
A study was conducted on the distribution of pollutants in treated wastewater and the its safety for re-use purposes. Based on the results of a series of tertiary treatment experiments, the effects of three filtration processes, i.e. coagulation-filtration, ozonation-biological activated carbon filtration (O3-BAC) and ultrafiltration (UF), and two chemical disinfection processes, i.e. chlorination and ozonation, on the safety of water re-use were evaluated. It was found that the concentrations of the main pollutants in the secondary effluent and further filtered water follow a log-normal distribution and, therefore, a log-normal probabilistic function can be used to evaluate the suitability of the treated water for re-use purposes. Among the three filtration processes evaluated, UF is the most effective in turbidity removal but less effective in colour and COD removal, while coagulation-filtration and O3-BAC can ensure a good removal of all these pollutants. Regarding chemical disinfection, although chlorine is very effective in inactivation of coliform bacteria, it can not achieve a substantial decrease in viruses. As ozone is applied, effective virus removal can be achieved.
Wang
X C
XC
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China. xcwang@xauat.edu.cn
Qiu
F G
FG
Jin
P K
PK
D002681:China; D003247:Conservation of Natural Resources; D004203:Disinfection / Q000592:standards; D005374:Filtration / Q000592:standards; D012449:Safety; D014867:Water / Q000592:standards*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000592:standards; D018508:Water Purification / Q000379:methods* / Q000592:standards
D014874:Water Pollutants, Chemical; D014867:Water