Namaldi Onur, Azgin Sukru Taner
Department of Environment Engineering, Erciyes University, 38039, Kayseri, Turkey.
Department of Environment Engineering, Erciyes University, 38039, Kayseri, Turkey; Energy Conversions Research and Application Center, Erciyes University, 38039, Kayseri, Turkey.
J Environ Manage. 2023 Feb 1;327:116865. doi: 10.1016/j.jenvman.2022.116865. Epub 2022 Nov 28.
Vermifiltration (VF) is a natural and sustainable biofilter that has many advantages, including being energy-free, cost-effective, and allowing ease of application and maintenance. In this study, the effectiveness of a lab-scale VF system was assessed by the removal efficiency of total suspended solids, electrical conductivity, chemical oxygen demand, total nitrogen, total phosphorus, fecal coliform, and heavy metals in organized industrial zones (OIZ) and domestic wastewater (DW) for the first time. Additionally, the reuse suitability of the treated wastewater was determined by comparing different countries' and global irrigational criteria. The lab systems were built with four layers: one worm-bed and three varying filtering materials, and operated at an optimum hydraulic loading rate of 1.8-2 m/m/day for 45 days with Eisenia fetida as the earthworm species. The results demonstrated that removal efficiencies of total suspended solids and chemical oxygen demand were found to be 95% and 80% in OIZ wastewater and 90% and 88% in DW, respectively. Total nitrogen and total phosphorus were removed at rates of 69% and 67% in OIZ wastewater, respectively, and 84% and 74% in DW. Besides, the VF system has shown satisfactory removal performance for heavy metals ranging from 51% to 77% in OIZ wastewater that has met Turkish national wastewater discharge limits. Although the final characterization of treated wastewater was suitable, heavy metal and fecal coliform levels have not met many countries' irrigation water quality criteria. To meet global irrigation standards and to enhance the VF performance, further experimental studies should be carried out, including parameters such as bed material type in the reactor, worm type, and different operating conditions.
蚯蚓过滤（VF）是一种天然且可持续的生物滤池，具有诸多优点，包括无需能源、成本效益高、易于应用和维护。在本研究中，首次通过去除有组织工业区（OIZ）和生活污水（DW）中的总悬浮固体、电导率、化学需氧量、总氮、总磷、粪大肠菌群和重金属的效率，评估了实验室规模的VF系统的有效性。此外，通过比较不同国家和全球灌溉标准，确定了处理后废水的回用适宜性。实验室系统由四层构建而成：一层蚯蚓床和三种不同的过滤材料，并以1.8 - 2米/米/天的最佳水力负荷率运行45天，蚯蚓品种为赤子爱胜蚓。结果表明，OIZ废水中总悬浮固体和化学需氧量的去除效率分别为95%和80%，DW中分别为90%和88%。OIZ废水中总氮和总磷的去除率分别为69%和67%，DW中分别为84%和74%。此外，VF系统对重金属的去除性能令人满意，在符合土耳其国家废水排放限值的OIZ废水中，去除率为51%至77%。尽管处理后废水的最终特性适宜，但重金属和粪大肠菌群水平未达到许多国家的灌溉水质标准。为了符合全球灌溉标准并提高VF性能，应开展进一步的实验研究，包括反应器中床料类型、蚯蚓类型和不同运行条件等参数。
