School of Municipal & Environmental Engineering, Shandong Jianzhu University, No. 1000 Fengming Road, Licheng District, Jinan, 250101, People's Republic of China.
Shandong (Jinan) Water & Waste Water Monitoring Center, Jinan, 250101, People's Republic of China.
Environ Sci Pollut Res Int. 2020 Jul;27(21):26079-26090. doi: 10.1007/s11356-020-08894-y. Epub 2020 May 1.
Humic acid (HA) in water is the main precursor of disinfection by-products in the chlorination process of drinking water. In this study, an ultraviolet/persulfate (UV/PS) process, in a laboratory-scale system, is successful in the degradation of HA. The results showed that HA was significantly degraded (UV removal rate of ~ 89%) and partially mineralized (~ 62.5%) by UV/PS treatment at a PS dose of 0.4 mM, pH of 7.12, and UV irradiation time of 160 min. The trihalomethane formation potential (THMFP) was also significantly reduced (THMFP reduction of ~ 85.4%). A strong linear relationship was observed between UV and dissolved organic carbon. The removal rate of HA at low pH was better than that at high pH conditions, and the inhibition by Cl slowed down after an initial increase, and the inhibition was weaker than HCO. By analyzing the fluorescence spectrum of two humic-like substances, the fluorescent compounds C1 and C2 in HA were significantly degraded, and the change in C1 and C2 concentration was correlated with the decrease of THMFP. The degradation of different fractions of natural organic matter in real-world water samples indicated that UV/PS has significant potential to decrease HA in water.
水中的腐殖酸（HA）是饮用水氯化消毒过程中消毒副产物的主要前体。在这项研究中，紫外/过硫酸盐（UV/PS）工艺在实验室规模的系统中成功地降解了 HA。结果表明，在 PS 剂量为 0.4 mM、pH 值为 7.12 和紫外辐照时间为 160 min 的条件下，UV/PS 处理可显著降解（UV 去除率约为 89%）和部分矿化（~62.5%）HA。三卤甲烷生成潜能（THMFP）也显著降低（THMFP 降低约 85.4%）。UV 与溶解有机碳之间存在很强的线性关系。低 pH 值条件下 HA 的去除率优于高 pH 值条件，Cl 的抑制作用在初始增加后减缓，抑制作用弱于 HCO。通过分析两种腐殖质类物质的荧光光谱，发现 HA 中的荧光化合物 C1 和 C2 明显降解，C1 和 C2 浓度的变化与 THMFP 的降低相关。对实际水样中天然有机物不同组分的降解表明，UV/PS 具有显著降低水中 HA 的潜力。
