Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, PR China.
Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China; Shanghai Engineering Research Center of Multi-source Solid Wastes Co-processing and Energy Utilization, Shanghai, 200092, PR China.
Water Res. 2023 Jan 1;228(Pt A):119348. doi: 10.1016/j.watres.2022.119348. Epub 2022 Nov 9.
The processes combining biological treatment with membrane separation technologies have been widely adopted for leachate treatment. However, dissolved organic matter (DOM) of leachate membrane concentrates generated from various membrane separation technologies has not been systematically investigated in field scale. Therefore, substance flow analysis based on DOM molecular information of leachate membrane concentrates from primary membrane systems (i.e. nanofiltration (NF) and reverse osmosis (RO)) and secondary membrane systems (i.e. disk-tube reverse osmosis (DTRO) and humic substance filtration system (HSF)) in five engineering-scale leachate treatment facilities, obtained via ultra-performance liquid chromatography coupled with hybrid quadrupole Orbitrap mass spectrometry, was given and simultaneously compared. In NF concentrates (NFC), 45.1-98.5% of DOM originated from raw leachate (L-DOM) was concentrated, showing poor biodegradability. The L-DOM interception characteristics of NFC-fed HSF were mainly based on volume reduction but concentration effect. L-DOM in RO concentrates (ROC) showed a higher proportion of peak intensity reduced components, accounting for 50.3-96.8%, and organic composition changes were more dependent on water quality characteristics than membrane types. ROC-fed DTRO intercepted 49.3-72.6% of L-DOM, but DTRO may be less effective at intercepting DOM molecules in landfill leachate with higher oxidation levels. Considering risks from feasible treatment technologies, the difficulty for the treatment of leachate membrane concentrates followed the order of DTRO concentrates > ROC > NFC. This study suggests that ROC-fed DTRO need to be controlled to avoid amplifying the treatment difficulty. Besides, treatment technologies for RO and DTRO concentrates with low-concentrated but refractory DOM and high salts should be explored.
生物处理与膜分离技术相结合的工艺已广泛应用于渗滤液处理。然而，各种膜分离技术产生的渗滤液膜浓缩液中的溶解有机物（DOM）尚未在现场规模上得到系统研究。因此，本研究采用基于 DOM 分子信息的物质流分析方法，对来自 5 个工程规模渗滤液处理设施中初级膜系统（纳滤（NF）和反渗透（RO））和二级膜系统（碟管式反渗透（DTRO）和腐殖质过滤系统（HSF））的渗滤液膜浓缩液中的 DOM 进行了分析。这些浓缩液是通过超高效液相色谱与混合四极杆轨道阱质谱联用技术获得的。结果表明，NF 浓缩液（NFC）中 45.1%-98.5%的 DOM 来源于原渗滤液（L-DOM），具有较差的生物降解性。NFC 进料 HSF 的 L-DOM 截留特性主要基于体积减少而不是浓度效应。RO 浓缩液（ROC）中 L-DOM 显示出更高比例的峰强度降低成分，占 50.3%-96.8%，有机组成变化更多地取决于水质特征而不是膜类型。ROC 进料 DTRO 截留了 49.3%-72.6%的 L-DOM，但 DTRO 对截留具有较高氧化水平的垃圾渗滤液中 DOM 分子的效果可能较差。考虑到可行处理技术的风险，渗滤液膜浓缩液处理难度的顺序为 DTRO 浓缩液>ROC>NFC。本研究表明，需要控制 ROC 进料 DTRO，以避免增加处理难度。此外，还需要探索针对 RO 和 DTRO 浓缩液中低浓度但难处理的 DOM 和高盐度的处理技术。
