Liu Bing, Yu Guo-Zhong, Gu Li, Zhao Cheng-Mei, Li Qing-Fei, Zhai Hui-Min
School of Urban and Environmental Science, Xinyang Normal University, Xinyang 464000, China.
Huan Jing Ke Xue. 2013 Apr;34(4):1392-401.
Dissolved organic nitrogen as a precursor of new type nitrogenous disinfection by-products in drinking water attracted gradually the attention of scholars all over the world. In order to explore the mechanism of DON removal in micro-polluted raw water by coagulation and adsorption, water quality parameters, such as DON, DOC, NH4(+) -N, UV254, pH and dissolved oxygen, were determined in raw water and the molecular weight distribution of the DON and DOC was investigated. The variations in DON, DOC and UV254 in the coagulation and adsorption tests were investigated, and the changes of DON in raw water were characterized using three-dimensional fluorescence spectroscopy. The results showed that DON, DOC and UV254 were 1.28 mg x L(-1), 8.56 mg x L(-1), 0.16 cm(-1), and DOC/DON and SUVA were 6.69 mg x mg(-1), 1.87 m(-1) x (mg x L(-1))(-1) in raw water, respectively. The molecular weight distribution of the DON in raw water showed a bimodal distribution. The small molecular weight (< 6 000) fractions accounted for a high proportion of 68% and the large (> 20 000) fractions accounted for about 22%. The removal of DON, DOC and UV254 was about 20%, 26% and 70%, respectively, in the coagulation test and the dosage of coagulant was 10 mg x L(-1). The removal of DON, DOC and UV254 was about 60%, 35% and 100%, respectively, in the adsorption test and the dosage of activated carbon was 1.0 g. In the combination of coagulation and adsorption, the removal of DON and DOC reached approximately 82% and 64%, respectively. 3DEEM revealed that the variation of DON in the coagulation and adsorption tests depended intimately on tryptophan protein-like substances, aromatic protein-like substances and fulvic acid-like substances.
溶解性有机氮作为饮用水中新型含氮消毒副产物的前体物，逐渐引起了全球学者的关注。为了探究微污染原水中溶解性有机氮通过混凝和吸附去除的机制，测定了原水中溶解性有机氮（DON）、溶解性有机碳（DOC）、铵态氮（NH4(+) -N）、紫外吸光度（UV254）、pH值和溶解氧等水质参数，并研究了DON和DOC的分子量分布。考察了混凝和吸附试验中DON、DOC和UV254的变化情况，并用三维荧光光谱对原水中DON的变化进行了表征。结果表明，原水中DON、DOC和UV254的含量分别为1.28 mg·L(-1)、8.56 mg·L(-1)、0.16 cm(-1)，DOC/DON和SUVA分别为6.69 mg·mg(-1)、1.87 m(-1)·(mg·L(-1))(-1)。原水中DON的分子量分布呈双峰分布。小分子质量（<6000）组分占比高达68%，大分子质量（>20000）组分占比约为22%。在混凝试验中，当混凝剂投加量为10 mg·L(-1)时，DON、DOC和UV254的去除率分别约为20%、26%和70%。在吸附试验中，当活性炭投加量为1.0 g时，DON、DOC和UV254的去除率分别约为60%、35%和100%。在混凝与吸附联合工艺中，DON和DOC的去除率分别达到了约82%和64%。三维荧光光谱分析表明，混凝和吸附试验中DON的变化与类色氨酸蛋白质物质、类芳香族蛋白质物质和类富里酸物质密切相关。
