标题:Effect of pre-ozonation enhanced coagulation on dissolved organic nitrogen in municipal WWTP effluent.
作者:Bing Liu, Li Gu, Qingfei Li, Guozhong Yu, Chengmei Zhao & Huimin Zhai
来源出版物:Environmental Technology, 05卷;页: 1-28.
DOI: 10.1080/09593330.2018.1449897
出版年: 2018
文献类型:Article
语种:English
摘要:Municipal wastewater treatment plant (WWTP) effluent is increasingly used as reclaimed water and as water sources for downstream areas. Effluent dissolved organic nitrogen (DON) is considered to be the precursor to nitrogen disinfection by-products (N-DBPs), which have come into increasing focus due to environmental and public health risks associated with them. Here, we investigated DON removal by pre-ozonation enhanced coagulation and found that: (1) pre-ozonation significantly enhanced the removal of DON, DOC and UV254 by coagulation. (2) pH had an important impact on the pre-ozonation enhanced coagulation. At lower pH, the removal of DON, DOC and UV254 is higher. (3) Calcium plays a critical role in pre-ozonation enhanced coagulation. As ozone dosage increased, zeta potential gradually increased, while dissolved calcium concentrations declined and there was a strong correlation between zeta potential and dissolved calcium concentrations. (4) Small (20 kDa) and hydrophobic DON. Ozonation modified DON characteristics to become more hydrophilic and smaller in molecular weight. (5) Coagulation reduced overall DBP formation potentials to less than 20%. In contrast, overall DBP formation potentials increased after ozonation. Ozonation caused an approximately 10 fold increase in trichloronitro methane (TCNM) formation potential. However, pre-ozonation enhanced coagulation not only removed 71% DON, but also reduced overall DBP formation potentials by more than 40%. (6) 3-DEEM spectra indicated that DBP formation potentials and DON concentrations were related to three main 3 peaks, which corresponded to tryptophan-based proteins, aromatic proteins and fulvic acids.
关键词: municipal WWTPs effluent; dissolved organic nitrogen; ozonation; pre-ozonation enhanced coagulation; 3-DEEM
ISSN:0959-3330
影响因子:1.67(2018)