臭氧对二级出水中溶解性有机物的氧化特性

利用臭氧对二级出水进行深度处理对于缓解北方地区河流污染问题具有重要意义。为了探究臭氧对二级出水中溶解性有机物的氧化特性, 在取自北京市砂河污水处理厂二级出水的水样中分别持续通入不同浓度的臭氧, 检测 60 min 内各水样中溶解性有机碳( DOC) 、紫外吸收光谱、荧光光谱、分子量分布随时间变化情况。结果发现: 水样中 DOC 去除率与臭氧浓度和通入时间呈正相关, 在臭氧浓度为 1.31 mg / L、通入时间为 60 min 时, 可达到最大DOC 去除率( 70% ) ; 通入臭氧5 min 时, 水中溶解性有机物的荧光特性基本消失; 紫外吸光度值部分减少; 分子量为5~ 6 kDa、1~ 3 kDa 和 400 Da 的有机物显著减少, 部分转化为分子量为 60 Da 的有机物。经过臭氧氧化处理, 二级出水中有机物含量显著减少, 大分子有机物几乎被全部降解。 The use of ozone for advanced treatment of secondary effluent is of great significance for alleviating river pollution problems in the northern region.In order to investigate the oxidation characteristics of ozone to dissolved organic matter in the secondary effluent,different concentrations of ozone were continuously used in water samples taken from the secondary effluent of the Shahe Wastewater Treatment Plant in Beijing,and dissolved in each water sample within 60 minutes.The change of dissolved organic carbon (DOC),ultraviolet absorption spectrum,fluorescence spectrum and molecular weight distribution of water samples along with time were detected after ozone treatment.The experiment results showed that the removal efficiency of DOC increased with the increase of ozone dosage and ozone treatment time.The maximum removal efficiency was achieved up to 70% when the concentration of ozone was 1.31 mg / L and the reaction time was up to 60 minutes.After reaction of ozone for 5 minutes,the fluorescence of organic matter in the water was almost eliminated,while the UV absorbance value was partially reduced.The organic matter with the molecular weights of 5-6 kDa,1-3 kDa,and 400 Da was significantly reduced and partially converted into the organic matter with the molecular weight of 60 Da.The results indicated that after ozone oxidation treatment,the quantity of organic matter in the secondary effluent significantly reduced and the organic matter with large molecular weight in the secondary effluent almost completely degraded. 北京市科技计划课题( D161100000216001) ; 中国电力工程顾问集团有限公司科研项目( DG12G012 2016) ; 湖北省高等学校优秀中青年科技创新团队计划( T 201824)