研究报告
刘彩风,胡海冬,廖可薇,王瑾丰,吴兵,任洪强.污水处理厂中溶解性有机硫的浓度分布和分子转化特征[J].环境科学学报,2022,42(6):12-23
污水处理厂中溶解性有机硫的浓度分布和分子转化特征
- Concentration and molecular transformation of dissolved organic sulfur in the wastewater treatment plant
- 基金项目:南京大学卓越研究计划(No.ZYJH005);中央高校科研业务费(No.021114380170)
- 刘彩风
- 南京大学环境学院,污染控制与资源化研究国家重点实验室,南京 210023
- 胡海冬
- 南京大学环境学院,污染控制与资源化研究国家重点实验室,南京 210023
- 廖可薇
- 南京大学环境学院,污染控制与资源化研究国家重点实验室,南京 210023
- 王瑾丰
- 南京大学环境学院,污染控制与资源化研究国家重点实验室,南京 210023
- 吴兵
- 南京大学环境学院,污染控制与资源化研究国家重点实验室,南京 210023
- 任洪强
- 南京大学环境学院,污染控制与资源化研究国家重点实验室,南京 210023
- 摘要:溶解性有机硫(DOS)是市政污水中溶解性有机物的重要组成成分,污水处理厂出水DOS对受纳水体中重金属的迁移转化与生物有效性以及污水回用与深度处理具有重要影响,然而目前缺乏对污水处理过程中DOS浓度和转化特征的认识.采用高分辨率等离子体质谱(HR-ICP-MS)和傅里叶变换离子回旋共振质谱(FT-ICR-MS)考察了DOS在某实际污水处理厂(厌氧/缺氧/好氧+混凝沉淀+反硝化滤池+次氯酸钠消毒)中的沿程浓度分布和分子转化特征.结果表明,污水处理过程中的DOS平均浓度为42.2~167.9 μg·L-1,是受纳水体中DOS的重要来源;混凝沉淀池对DOS的平均去除贡献率最高(101.4%),其次为厌氧池(65.0%),而好氧池和反硝化滤池对DOS的平均去除贡献率分别为-53.1%和-56.7%;厌氧池主要去除CHOS类物质,并将不饱和脂肪类CHOS类物质转化成高度不饱和CHOS类物质,同时产生高分子量的CHONS(P)类物质;多肽类CHONS(P)类物质在好氧池出水中的相对丰度最高;混凝沉淀池可去除生物处理段产生的多肽类CHONS(P)类物质,而反硝化滤池由于微生物的存在则会释放多肽类CHONS(P)类物质;生物处理段(厌氧/缺氧/好氧)将进水中具有O3S1结构的阴离子型表面活性剂转化为具有O5S1结构的降解产物;好氧池和反硝化滤池主要产生具有O6~12S2N4结构的多肽类物质.本研究可为了解实际污水处理过程中DOS的转化机制提供分子水平信息,并为污水处理厂出水DOS的控制提供理论指导.
- Abstract:Dissolved organic sulfur (DOS) is an important component of dissolved organic matter in municipal wastewater. DOS of effluent from wastewater treatment plant has an important impact on the migration and bioavailability of heavy metals in receiving water, as well as the reuse and advanced treatment of wastewater. However, little is known about the concentration and transformation characteristics of DOS in wastewater treatment processes. In this study, high-resolution plasma mass spectrometry (HR-ICP-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) were used to investigate the concentration and molecular transformation characteristics of DOS in a typical wastewater treatment plant (anaerobic/anoxic/aerobic + coagulation sedimentation + denitrification filter + sodium hypochlorite disinfection). The results showed that the average DOS concentration of wastewater treatment process was 42.2~167.9 μg·L-1, which was an important source of DOS in receiving water. The coagulation sedimentation tank had the highest average contribution rate to DOS removal (101.4%), followed by the anaerobic tank (65.0%). The average contribution rate of the aerobic tank and denitrification filter to DOS removal was -53.1% and -56.7%, respectively. The anaerobic tank mainly removed CHOS compound, converting unsaturated fatty CHOS molecules into highly unsaturated ones, and generating macromolecular CHONS(P) compounds at the same time. The peptide-like CHONS(P) compounds had the highest relative abundance in the effluent of aerobic tank. The coagulation sedimentation tank could reduce the peptide-like CHONS(P) compounds produced by the biological treatment unit, however, the denitrification filter would release the peptide-like CHONS(P) compounds due to the existence of microbes. The biological treatment section (anaerobic/anoxic/aerobic) converted the anionic surfactants with O3S1 structure into degradation products with O5S1 structure. The aerobic tank and denitrification filter mainly produced peptide-like compounds with O6-12S2N4 structure. This study can provide molecular-level information for understanding the transformation mechanism of DOS in actual wastewater treatment process, and provide theoretical guidance for the control of effluent DOS in wastewater treatment plants.