School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang, 330013, China.
Jiangxi JDL Environmental Protection Co., Ltd, Nanchang, 330199, China.
Environ Sci Pollut Res Int. 2023 Oct;30(48):106421-106430. doi: 10.1007/s11356-023-29841-7. Epub 2023 Sep 20.
As a sustainable management of fossil fuel resources and ecological environment protection, recycling used lubricating oil has received widespread attention. However, large amounts of waste lubricating-oil regeneration wastewater (WLORW) are inevitably produced in the recycling process, and challenges are faced by traditional biological treatment of WLORW. Thus, this study investigated the effectiveness of electrocoagulation (EC) as pretreatment and its removal mechanism. The electrolysis parameters (current density, initial pH, and inter-electrode distance) were considered, and maximal 60.06% of oil removal was achieved at a current density of 15 mA/cm, initial pH of 7, and an inter-electrode distance of 2 cm. The dispersed oil of WLORW was relatively easily removed, and most of the oil removal was contributed by emulsified oil within 5-10 μm. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that effective removal of the biorefractory organic compounds could contribute to the improvement of biodegradability of WLORW. Thus, the 5-day biochemical oxygen demand/chemical oxygen demand ratio (BOD/COD) was significantly enhanced by 4.31 times, which highly benefits future biological treatment. The routes of WLORW removal could be concluded as charge neutralization, adsorption bridging, sweep flocculation, and air flotation. The results demonstrate that EC has potential as an effective pretreatment technology for WLORW biological treatment.
作为化石燃料资源的可持续管理和生态环境保护的手段，回收利用废润滑油受到了广泛关注。然而，在回收过程中不可避免地会产生大量的废润滑油再生废水（WLORW），这给传统的 WLORW 生物处理带来了挑战。因此，本研究探讨了电凝聚（EC）作为预处理的有效性及其去除机制。考虑了电解参数（电流密度、初始 pH 值和电极间距离），在电流密度为 15 mA/cm、初始 pH 值为 7 和电极间距离为 2 cm 的条件下，油去除率最大可达 60.06%。WLORW 中的分散油相对容易去除，大部分油去除是由 5-10 μm 内的乳化油贡献的。气相色谱-质谱联用（GC-MS）分析表明，有效去除生物难降解有机化合物有助于提高 WLORW 的可生物降解性。因此，废水的五日生化需氧量/化学需氧量（BOD/COD）比值显著提高了 4.31 倍，这非常有利于未来的生物处理。WLORW 的去除途径可以归结为电荷中和、吸附桥接、扫集絮凝和气浮。结果表明，EC 作为 WLORW 生物处理的有效预处理技术具有潜力。
