Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China.
School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, People's Republic of China.
Environ Technol. 2024 Jan;45(4):667-680. doi: 10.1080/09593330.2022.2119608. Epub 2022 Sep 8.
Refractory substances (humus) and salts (chloride (Cl) and sulphate (SO) ions) remain in the biotreated landfill leachate treatment, and it is necessary to carry out further treatments by a suitable method before discharge. In this study, the effect and operational mechanism of a combination of the coagulation Fe/HO and ultra-high lime aluminium (UHLA) processes for the treatment of refractory organic substances and salts in the leachate effluent of a semi-aerobic aged refuse biofilter (SAARB) were investigated. The results showed that polyferric sulphate is a relatively efficient coagulant comparing to FeCl, Al(SO), and polyaluminium chloride. The Fe/HO process further removed refractory organics from wastewater, achieving 49.8% of total organic carbon removed. Further treatment by the UHLA process was carried. The results demonstrated that the amount of precipitant, reaction duration, and temperature had a significant impact on the Cl and SO removals. After three treatments, the cumulative SO and Cl removal efficiencies were 98% and 80%, respectively. The SO and Cl were removed in the form of precipitates such as UHLA, specific components of which included calcium alumina, Fremy's salt of calcium, aluminium chloride, and calcium hydroxide. Overall, the UV, CN, Cl, and SO removal efficiencies from the SAARB effluent were 94.08%, 98.73%, 79.96%, and 98.44%, respectively, for the combined coagulation Fe/HO and UHLA processes. Therefore, the combined processes could effectively remove residual pollutants in the biologically-treated landfill leachate, and the study provides a useful reference for the removal of refractory organic matter and salts in landfill leachate.Coagulation-Fe/HO-UHLA process is effective to SAARB effluent treatment.Refractory organics are substantially degraded by the coagulation-Fenton-like stage.Both Cl and SO in SAARB effluent are greatly removed by UHLA process.
难处理物质（腐殖质）和盐分（氯离子（Cl）和硫酸盐（SO）离子）仍然存在于生物处理垃圾渗滤液处理中，在排放之前需要通过合适的方法进行进一步处理。在这项研究中，研究了混凝-Fe/HO 和超高石灰铝（UHLA）工艺相结合对半好氧老化垃圾生物滤池（SAARB）渗滤液中难处理有机物质和盐分的处理效果和作用机制。结果表明，相对于 FeCl、Al(SO) 和聚合氯化铝，聚合硫酸铁是一种相对高效的混凝剂。Fe/HO 工艺进一步去除废水中的难处理有机物，总有机碳去除率达到 49.8%。然后进行 UHLA 工艺的进一步处理。结果表明，沉淀剂用量、反应时间和温度对 Cl 和 SO 的去除有显著影响。经过三次处理，SO 和 Cl 的累积去除效率分别为 98%和 80%。SO 和 Cl 以 UHLA 等沉淀物的形式被去除，其特定成分包括钙铝氧化物、钙、铝氯化物和氢氧化钙的 Fremy 盐。总的来说，SAARB 渗滤液经混凝-Fe/HO-UHLA 联合工艺处理后，UV、CN、Cl 和 SO 的去除率分别为 94.08%、98.73%、79.96%和 98.44%。因此，该联合工艺可以有效地去除生物处理垃圾渗滤液中的残留污染物，为去除垃圾渗滤液中的难处理有机物和盐分提供了有益的参考。混凝-Fe/HO-UHLA 工艺对 SAARB 渗滤液处理有效。混凝-Fenton 阶段可有效降解难处理有机物。SAARB 渗滤液中的 Cl 和 SO 均可通过 UHLA 工艺有效去除。
