title: [Characteristics of dissolved organic matter in A/DAT-IAT system for municipal wastewater treatment based on ecological safety].
abstract: To ensure the water-quality safety and harmlessness of effluent from municipal wastewater, based on the lab-scale improved SBR-A/DAT-IAT process, dissolved organic matter (DOM) in municipal wastewater, demand aeration tank (DAT) supernatant and final effluent were classified and separated by applying the ultrafiltration membranes, and indexes such as TOC, UV254, 3D-EEM and toxicity were measured, to find out the sources of the toxic substances. The results showed that the lab-scale A/DAT-IAT process performed well on each molecular-weight fraction of DOM. The main composition in the effluent was humic-like substance. Along the process, The DOM distribution presented a trend of shifting to high molecular weight. Meanwhile, the aromaticity of DOM in the fraction with relative molecular weight below 1 x 10(3) increased significantly, leading to the increase in the reactivity of effluent with chlorine, which then increased the risk of disinfection by-products. In the raw wastewater, the toxic effects were originated from the fraction with relative molecular weight below 1 x 10(3), although the toxic effects were still originated from the same fraction in the effluent, they came from the biological treatment itself instead of the raw wastewater. Based on the analysis of TOC, UV254, 3D-EEM and toxicity, the removal of low molecular-weight humic-like substance should be emphasized to achieve the effluent organic emissions standards and to control the risk of chlorination by-products and toxicity. Therefore, future studies should focus on the removal of this fraction of DOM by adjusting technological parameters or adding a targeted processing unit.
authors.forename: Sai
authors.initials: S
authors.lastname: Yang
authors.forename: Qi-Xing
authors.initials: QX
authors.lastname: Zhou
authors.forename: Tao
authors.initials: T
authors.lastname: Hua
mesh_terms: D002713:Chlorine / Q000737:chemistry; D004203:Disinfection; D004784:Environmental Monitoring; D054879:Halogenation; D008970:Molecular Weight; D009930:Organic Chemicals / Q000737:chemistry*; D014462:Ultrafiltration / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D060753:Water Quality
chemical_list: D002713:Chlorine; D009930:Organic Chemicals; D062065:Wastewater