以沈阳市B污水处理厂二级处理出水为研究对象,采用FeCl3.6H2O作为混凝剂,研究了强化混凝对二级处理出水中溶解性有机物(DOM)的卤代活性和荧光特性的影响.按照DOM在XAD树脂上的吸附特性将其分为5个部分:疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).结果表明,强化混凝(混凝剂投加量为80mg.L-1,pH=5.00)对DOC的去除率为55.3%.强化混凝对HPO-A的去除率最高,而对HPI的去除率最低.强化混凝后,HPO-N的三卤甲烷生成活性(STHMFP)上升,而其他4种DOM组分的STHMFP下降.强化混凝能够有效去除类富里酸荧光物质和具有高环数和高聚合度的稠环类芳香性荧光物质.强化混凝对DOM组分的去除率和DOM组分的荧光强度下降率的相关性不显著.
The effect of enhanced coagulation on the chlorination activity and fluorescence characteristics of dissolved organic matter(DOM) in the secondary treated effluent from the B wastewater treatment plant(Shenyang) was investigated.FeCl3 · 6H2O was used as a coagulant in this study.DOM was fractionated using XAD resins into five fractions:hydrophobic acid(HPO-A),hydrophobic neutral(HPO-N),transphilic acid(TPI-A),transphilic neutral(TPI-N) and hydrophilic fraction(HPI).The results showed that a DOC removal of 55.3% was obtained under the enhanced coagulations(coagulant dosage 80 mg · L-1,pH=5.00).The removal of HPO-A by enhanced coagulation was the highest while that of HPI was the lowest.HPO-N increased in specific trihalomethane formation potential(STHMFP),where the other four DOM fractions decreased in STHMFP,as a result of enhanced coagulation.Enhanced coagulation could effectively remove fulvic acid-like fluorescent materials and the polycyclic aromatic fluorescent materials with more aromatic rings and a higher degree of conjugation.The correlation between DOC removal and fluorescence intensity reduction of DOM fractions resulted from enhanced coagulation was not significant.