Zhao He, Hu Chengzhi, Zhang Di, Liu Huijuan, Qu Jiuhui
State key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Beijing Engineering Research Center of Process Pollution Control, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
PLoS One. 2016 Jan 29;11(1):e0148020. doi: 10.1371/journal.pone.0148020. eCollection 2016.
Coagulation behavior of aluminum chloride and polyaluminum chloride (PACl) for removing corresponding disinfection byproduct (DBP) precursors was discussed in this paper. CHCl3, bromine trihalomethanes (THM-Br), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) formation potential yields were correlated with specific ultraviolet absorbance (SUVA) values in different molecular weight (MW) fractions of humic substances (HS), respectively. Correlation analyses and principal component analysis were performed to examine the relationships between SUVA and different DBP precursors. To acquire more structural characters of DBP precursors and aluminum speciation, freeze-dried precipitates were analyzed by fourier transform infrared (FTIR) and C 1s, Al 2p X-ray photoelectron spectroscopy (XPS). The results indicated that TCAA precursors (no MW limits), DCAA and CHCl3 precursors in low MW fractions (MW<30 kDa) had a relatively good relations with SUVA values. These DBP precursors were coagulated more easily by in situ Al13 of AlCl3 at pH 5.0. Due to relatively low aromatic content and more aliphatic structures, THM-Br precursors (no MW limits) and CHCl3 precursors in high MW fractions (MW>30 kDa) were preferentially removed by PACl coagulation with preformed Al13 species at pH 5.0. Additionally, for DCAA precursors in high MW fractions (MW>30 kDa) with relatively low aromatic content and more carboxylic structures, the greatest removal occurred at pH 6.0 through PACl coagulation with aggregated Al13 species.
本文探讨了氯化铝和聚合氯化铝（PACl）去除相应消毒副产物（DBP）前体的混凝行为。分别将三氯甲烷（CHCl3）、溴代三卤甲烷（THM-Br）、二氯乙酸（DCAA）和三氯乙酸（TCAA）的生成势产率与腐殖质（HS）不同分子量（MW）组分中的特定紫外吸光度（SUVA）值相关联。进行了相关性分析和主成分分析，以研究SUVA与不同DBP前体之间的关系。为了获得DBP前体和铝形态的更多结构特征，通过傅里叶变换红外光谱（FTIR）以及C 1s、Al 2p X射线光电子能谱（XPS）对冻干沉淀物进行了分析。结果表明，TCAA前体（无分子量限制）、低分子量组分（MW<30 kDa）中的DCAA和CHCl3前体与SUVA值具有相对较好的相关性。在pH 5.0时，这些DBP前体更容易被AlCl3原位生成的Al13混凝。由于芳香族含量相对较低且脂肪族结构较多，在pH 5.0时，高分子量组分（MW>30 kDa）中的THM-Br前体（无分子量限制）和CHCl3前体优先被含有预制Al13物种的PACl混凝去除。此外，对于芳香族含量相对较低且羧酸结构较多的高分子量组分（MW>30 kDa）中的DCAA前体，在pH 6.0时通过含有聚集Al13物种的PACl混凝去除效果最佳。
