氯化对二级处理出水中溶解性有机物结构的影响

以哈尔滨市W污水处理厂污水为研究对象,利用XAD树脂对二级处理出水中的溶解性有机物(DOM)进行分级分离.按照DOM在不同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).考察了二级处理出水中有机组分的组成分布、三卤甲烷生成势、紫外光谱和红外光谱.结果表明,二级处理出水中的主要成分是HPO-A和HPI,两者含量之和达70.8%.HPO-A是加氯消毒时产生三卤甲烷的主要有机组分,其三卤甲烷生成活性(STHMFP)为232.9μg/mg.而HPO-N、TPI-A、TPI-N和HPI的STHMFP介于100～125μg/mg之间.氯化反应后,HPO-A、HPO-N、TPI-A和HPI的紫外-可见吸光度均降低,而TPI-N则相反.并且HPO-A、HPO-N、TPI-A和TPI-N中的O-H、C=C和苯环的含量降低,而C-O的含量升高,还生成了C=O和C-Cl.

Effect of Chlorination on the Structure of Dissolved Organic Matters in Secondary Effluent

Dissolved organic matter in the secondary effluent from the W wastewater treatment plant (Harbin) 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 distribution, trihalomethane formation potential (THMFP), UV-Vis and FTIR spectra of organic fractions in the secondary effluent were examined. XAD fractionation results showed that HPO-A and HPI dominated in the secondary effluent, collectively accounting for about 70.8%. HPO-A was the main precursors for THMFP following chlorination. HPO-A had the highest specific THMFP (STHMFP) and averaged 232.9 microg/mg. The STHMFP of HPO-N, TPI-A, TPI-N and HPI ranged from 100 microg/mg to 125 microg/mg. Chlorination resulted in increased UV-Vis absorbance for TPI-N and decreased UV-Vis absorbance for HPO-A, HPO-N, TPI-A and HPI. After chlorination, O--H, C=C and aromatic ring were found to decrease while C--O was observed to increase for HPO-A, HPO-N, TPI-A and TPI-N. In addition,C=O and C--Cl were found to occur as by-products from the chlorination reaction.