Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA; Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
Chemosphere. 2020 May;247:125954. doi: 10.1016/j.chemosphere.2020.125954. Epub 2020 Jan 18.
Landfill leachate is challenging to treat due to its complex composition. Advanced oxidation processes such as Fenton process can be effective to treat leachate. Herein, a previously developed membrane electrochemical reactor (MER) was coupled with Fenton oxidation through providing synergistic benefits with the low solution pH, reduced organics, and ammonia removal/recovery. This two-stage coupled system reduced the leachate COD by 88%, much higher than that from the standalone Fenton process treating raw leachate. In addition, the usage of chemical reagents has been greatly reduced. At a dimensionless oxidant dose of 1.0, the coupled MER-Fenton system reduced the consumption of both FeSO⋅7HO and HO by 39%, HSO by 100%, and NaOH by 55%. Consequently, the sludge production was reduced by 51% in weight and 12% in volume. Despite electricity consumption by the MER, the coupled system cost $4.76 per m leachate less than the standalone Fenton treatment. More notably, direct Fenton oxidation removed only 21% of ammonia; in comparison the MER-Fenton system removed ammonia by 98% with the possibility for recovery at a rate of 30.6-55.2 kg N m reactor d. Those results demonstrate that coupling MER with Fenton process could mitigate some inherent drawbacks of Fenton oxidation such as ineffective ammonia removal, high acid and chemical reagents dose requirements, and a large amount of sludge generation. This system may be moved towards practical applications by addressing a few challenges such as using renewable energy to power MER.
垃圾渗滤液由于其复杂的组成而难以处理。高级氧化工艺如芬顿工艺可以有效地处理渗滤液。在此，通过提供低溶液 pH 值、减少有机物和氨的去除/回收等协同效益，将先前开发的膜电化学反应器（MER）与芬顿氧化相结合。该两段耦合系统将渗滤液 COD 降低了 88%，明显高于单独的芬顿工艺处理原渗滤液的效果。此外，化学试剂的用量大大减少。在无量纲氧化剂剂量为 1.0 时，耦合 MER-Fenton 系统减少了 39%的 FeSO⋅7HO 和 HO、100%的 HSO 和 55%的 NaOH 的消耗。因此，污泥产量在重量上减少了 51%，在体积上减少了 12%。尽管 MER 需要用电，但耦合系统每处理 1 立方米渗滤液的成本比单独的芬顿处理低 4.76 美元。更值得注意的是，直接芬顿氧化仅去除了 21%的氨；相比之下，MER-Fenton 系统以 30.6-55.2kgN/m反应器 d 的速率去除氨，去除率达到 98%，同时具有回收氨的可能性。这些结果表明，将 MER 与芬顿工艺相结合可以减轻芬顿氧化的一些固有缺点，如氨去除效果不佳、需要高酸和化学试剂剂量以及产生大量污泥。通过解决使用可再生能源为 MER 供电等一些挑战，该系统可能会朝着实际应用推进。
