School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan 430074, PR China.
School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan 430074, PR China.
Water Res. 2022 Aug 1;221:118769. doi: 10.1016/j.watres.2022.118769. Epub 2022 Jun 16.
Treatment of highly contaminated wastewaters containing refractory or toxic organic contaminants (e.g. industrial wastewaters) is becoming a global challenge. Most technologies focus on efficient degradation of organic contaminants. Here we improve the cathode/Fe/peroxydisulfate (PDS) technology by turning down the current density and develop an innovative mechanism for organic contaminants abatement, namely polymerization rather than degradation, which allows simultaneous contaminants removal and resource recovery from wastewater. This polymerization leads to organic-particles (suspended solid organic-polymers) formation in bulk solution, which is demonstrated by eight kinds of representative organic contaminants. Taking phenol as a representative, 83% of PDS is saved compared to degradation process, with 87.2% of DOC removal. The formed suspended solid organic-polymers occupy 59.2% of COD of the original organics in solution, and can be easily separated from aqueous solution by sedimentation or filtration. The separated organic-polymers are a series of polymers coupled by phenolic monomers, as confirmed by FTIR and ESI-MS analyzes. The energy contained in the recovered organic polymers (4.76 × 10 kWh for 100 mL of 1 mM phenol solution in this study) can fully compensate the consumed electrical energy (2.8 × 10 kWh) in the treatment process. A representative polymerization model for this process is established, in which the SO and HO generated from PDS activation initiate the polymerization and improve the polymerization degree by the production of oligomer intermediates. A practical coking wastewater treatment is carried out to verify the research results and get positive feedback, with 56.0% of DOC abatement and the suspended solid organic-polymers accounts for 42.5% of the total COD in the raw wastewater. The energy consumption (47 kWh/kg COD, including electricity and PDS cost) is lower than the values in previous reports. This study provides a novel method for industrial wastewater treatment based on polymerization mechanism, which is expected to recover resources while removing pollutants with low consumption.
处理含有难降解或有毒有机污染物的高度污染废水（例如工业废水）正成为全球性的挑战。大多数技术都侧重于高效降解有机污染物。在这里，我们通过降低电流密度来改进阴极/Fe/过一硫酸盐（PDS）技术，并开发了一种从废水中去除有机污染物的创新机制，即聚合而不是降解，这允许同时去除污染物并从废水中回收资源。这种聚合导致在 bulk solution 中形成有机颗粒（悬浮固体有机聚合物），这在八种代表性有机污染物中得到了证明。以苯酚为例，与降解过程相比，节省了 83%的 PDS，DOC 去除率为 87.2%。形成的悬浮固体有机聚合物占据了溶液中原有机污染物 COD 的 59.2%，可以通过沉淀或过滤很容易地从水溶液中分离出来。分离出的有机聚合物是一系列由酚单体偶联而成的聚合物，这一点通过 FTIR 和 ESI-MS 分析得到了证实。回收的有机聚合物中所含的能量（在本研究中，对于 100 毫升 1mM 苯酚溶液，为 4.76×10kWh）足以补偿处理过程中消耗的电能（2.8×10kWh）。建立了该过程的一个代表性聚合模型，其中 PDS 活化产生的 SO 和 HO 引发聚合，并通过产生低聚物中间体来提高聚合度。进行了实际的焦化废水处理以验证研究结果并获得了积极的反馈，DOC 去除率为 56.0%，悬浮固体有机聚合物占原废水总 COD 的 42.5%。能耗（包括电和 PDS 成本）为 47kWh/kgCOD，低于之前报道的值。本研究提供了一种基于聚合机制的工业废水处理新方法，有望在低消耗的情况下同时去除污染物并回收资源。
