Abstract

In this study, electrochemical treatment and application of O₃/UV/H₂O₂ in various combinations were evaluated in respect to their efficiency to depurate mature landfill leachate. Based on preliminary experiments, electrochemical treatment using stainless-steel electrodes at 2 cm gap was performed optimally at 50 mA/cm² and pH 6, while application of O₃ at 120 L/h, UV at 991 J/cm² and H₂O₂ concentration of 1 g/L was carried out. Electrochemical treatment and O₃/UV/H₂O₂ under optimal conditions were applied as follows: I) electrochemical treatment, followed by O₃/UV/H₂O₂ and solids precipitation, II) electrochemical treatment, followed by precipitation and then by O₃/UV/H₂O₂ treatment, and III) O₃/UV/H₂O₂, followed by electrochemical treatment. A low performance was observed when O₃/UV/H₂O₂ preceding electrochemical treatment. Solids, TKN and total COD (tCON) removal was primarily achieved through electrocoagulation, whereas color and soluble COD (sCOD) reduction was mainly attributed to electrochemical oxidation. Experimental setup I was the most efficient treatment scheme, resulting in tCOD, sCOD, TKN, TSS, SAC_UV254nm and color number reduction of 73%, 80%, 76%, 79%, 94% and 98%, respectively. Indeed, O₃/UV/H₂O₂ step could be omitted since its effectiveness was restricted during landfill leachate treatment. In conclusion, electrochemical treatment followed by precipitation could result in effective reduction of nutrients and color.

摘要

在这项研究中，电化学处理和应用 O ₃ /UV/H ₂ O ₂的各种组合对其净化成熟垃圾填埋场渗滤液的效率进行了评估。根据初步实验，在 2 cm 间隙处使用不锈钢电极进行电化学处理的最佳条件为 50 mA/cm ²和 pH 6，而 O ₃的应用速度为 120 L/h，UV 的应用速度为 991 J/cm ²和 H ₂进行1g/L的O _2浓度。电化学处理和O ₃ /UV/H ₂ O ₂在最佳条件下应用如下：I）电化学处理，然后是O ₃ /UV/H ₂ O ₂和固体沉淀，II）电化学处理，然后是沉淀，然后是O ₃ /UV/H ₂ O ₂处理， III)O ₃ /UV/H ₂ O ₂，​​然后进行电化学处理。当 O ₃ /UV/H ₂ O _{2观察到低性能}前电化学处理。固体、TKN 和总 COD (tCON) 的去除主要通过电凝实现，而颜色和可溶性 COD (sCOD) 的减少主要归因于电化学氧化。实验装置 I 是最有效的处理方案，导致 tCOD、sCOD、TKN、TSS、SAC _UV254nm和色数分别减少 73%、80%、76%、79%、94% 和 98%。事实上，O ₃ /UV/H ₂ O ₂步骤可以省略，因为它的有效性在垃圾渗滤液处理过程中受到限制。总之，电化学处理后进行沉淀可以有效减少营养物质和颜色。