Simultaneous removal of ammonia and N-nitrosamine precursors from high ammonia water by zeolite and powdered activated carbon  

作　　者：Runmiao Xue Ariel Donovan Haiting Zhang Yinfa Ma Craig Adams John Yang Bin Hua Enos Inniss Todd Eichholz Honglan Shi 

机构地区：[1]Department of Chemistry and Environmental Research Center, Missouri University of Science and Technology, RoIIa, MO 65409, USA [2]Center for Single Nanoparticle, Single Cell, and Single Molecule Monitoring (CS3M), Missouri University of Science and Technology, Rolla,MO 6S409, USA [3]Department of Civil Engineering, Saint Louis University, St. Louis, MO 63103, USA [4]Department of Agriculture and Environmental Sciences, Lincoln University of Missouri, Jefferson City, MO 65101, USA [5]Department of Civil & Environmental Engineering, University of Missouri-Columbia, Columbia, MO 65211, USA [6]Missouri Department of Natural Resources, Jefferson City, MO 65102, USA

出　　处：《Journal of Environmental Sciences》2018年第2期82-91,共10页环境科学学报（英文版）

基　　金：supported by US EPA STAR program(No.83517301);Missouri Department of Natural Resources;the support from Chemistry Department,Environmental Research Center,and Center for Single Nanoparticle,Single Cell,and Single Molecule Monitoring(CS3M)at Missouri University of Science and Technology

摘　　要：When adding sufficient chlorine to achieve breakpoint chlorination to source water containing high concentration of ammonia during drinking water treatment, high concentrations of disinfection by-products（DBPs） may form. If N-nitrosamine precursors are present, highly toxic N-nitrosamines, primarily N-nitrosodimethylamine（NDMA）, may also form. Removing their precursors before disinfection should be a more effective way to minimize these DBPs formation. In this study, zeolites and activated carbon were examined for ammonia and N-nitrosamine precursor removal when incorporated into drinking water treatment processes.The test results indicate that Mordenite zeolite can remove ammonia and five of seven N-nitrosamine precursors efficiently by single step adsorption test. The practical applicability was evaluated by simulation of typical drinking water treatment processes using six-gang stirring system. The Mordenite zeolite was applied at the steps of lime softening, alum coagulation, and alum coagulation with powdered activated carbon（PAC） sorption. While the lime softening process resulted in poor zeolite performance, alum coagulation did not impact ammonia and N-nitrosamine precursor removal. During alum coagulation, more than67% ammonia and 70%–100% N-nitrosamine precursors were removed by Mordenite zeolite（except 3-（dimethylaminomethyl）indole（DMAI） and 4-dimethylaminoantipyrine（DMAP））. PAC effectively removed DMAI and DMAP when added during alum coagulation. A combination of the zeolite and PAC selected efficiently removed ammonia and all tested seven N-nitrosamine precursors（dimethylamine（DMA）, ethylmethylamine（EMA）, diethylamine（DEA）, dipropylamine（DPA）, trimethylamine（TMA）, DMAP, and DMAI） during the alum coagulation process.When adding sufficient chlorine to achieve breakpoint chlorination to source water containing high concentration of ammonia during drinking water treatment, high concentrations of disinfection by-products（DBPs） may form. If N-nitrosamine precursors are present, highly toxic N-nitrosamines, primarily N-nitrosodimethylamine（NDMA）, may also form. Removing their precursors before disinfection should be a more effective way to minimize these DBPs formation. In this study, zeolites and activated carbon were examined for ammonia and N-nitrosamine precursor removal when incorporated into drinking water treatment processes.The test results indicate that Mordenite zeolite can remove ammonia and five of seven N-nitrosamine precursors efficiently by single step adsorption test. The practical applicability was evaluated by simulation of typical drinking water treatment processes using six-gang stirring system. The Mordenite zeolite was applied at the steps of lime softening, alum coagulation, and alum coagulation with powdered activated carbon（PAC） sorption. While the lime softening process resulted in poor zeolite performance, alum coagulation did not impact ammonia and N-nitrosamine precursor removal. During alum coagulation, more than67% ammonia and 70%–100% N-nitrosamine precursors were removed by Mordenite zeolite（except 3-（dimethylaminomethyl）indole（DMAI） and 4-dimethylaminoantipyrine（DMAP））. PAC effectively removed DMAI and DMAP when added during alum coagulation. A combination of the zeolite and PAC selected efficiently removed ammonia and all tested seven N-nitrosamine precursors（dimethylamine（DMA）, ethylmethylamine（EMA）, diethylamine（DEA）, dipropylamine（DPA）, trimethylamine（TMA）, DMAP, and DMAI） during the alum coagulation process.

关 键 词：Disinfection by-products Drinking water treatment Ammonia removal by zeolite N-nitrosodimethylamine（NDMA） N-NITROSAMINES N-nitrosamine precursor removal by zeolite and powdered activated carbon 

分 类 号：TU991.2[建筑科学—市政工程]