Shuralla Ashrake Hussen, Hiruey Andualem Mekonnen, Gebreeyessus Getachew Dagnew
Africa Center of Excellence for Water Management, College of Natural and Computational Science, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
Center for Environmental Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
Heliyon. 2024 Jul 4;10(13):e34003. doi: 10.1016/j.heliyon.2024.e34003. eCollection 2024 Jul 15.
Heavy metals (HMs) in wastewater could pose a significant challenge to biological treatment systems such as in an Up-flow Anaerobic Sludge Blanket Reactor (UASBr) as well as Trickling Filter (TF) performances. These HMs are associated with retention and accumulation of solid precipitates, limitting solid-liquid separation, disrupting biochemical processes, which ultimately brings environmental risks, such as soil contamination and public health issues, dominantly due to the inhibited activities of degrading microorganisms. A cross-sectional study was applied to investigate the levels of HMs in sewage using composite and grab sampling taken from Kaliti Wastewater Treatment Plant and the samples were analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The HMs concentrations in mean±(SD) were, Ag ranges from below detection level (BDL) to 63.5 (13.5) mg/kg; Ba 60 (4.47) μg/l to 1291(58.5) mg/kg; Al, BDL to 2358.5(662.5) mg/kg; Cd 0 μg/l to 0.35(0.15) mg/kg; Cr 0 μg/l to 10.5(0.7) mg/kg; Cu 0 μg/l to 23.9(1.2) mg/kg; Zn 5.45 (12.3) to 165(5.4) mg/kg, and Mn 165 (49.5) μg/l to 92.5(3.8) mg/kg. Results indicated that Kaliti Wastewater Treatment Plant was effective in removing pollutants and thereby meeting local and international discharge limits. The plant was also found to be effective in removing Al, Cd, Cu, and Cr, but not in removing Ba and Zn. However, a real time data collection and monitoring of seasonal physicochemical parameters and HM levels in the wastewater treatment plant is suggested useful.
废水中的重金属（HMs）可能会对生物处理系统构成重大挑战，例如上流式厌氧污泥床反应器（UASBr）以及滴滤池（TF）的性能。这些重金属与固体沉淀物的滞留和积累有关，限制了固液分离，扰乱了生化过程，最终带来环境风险，如土壤污染和公共卫生问题，主要是由于降解微生物的活性受到抑制。采用横断面研究方法，通过从卡利蒂污水处理厂采集的混合样和瞬时样来调查污水中重金属的含量，并使用电感耦合等离子体发射光谱法（ICP-OES）对样品进行分析。重金属浓度的平均值±（标准差）为：银的含量范围从低于检测限（BDL）到63.5（13.5）mg/kg；钡为60（4.47）μg/l至1291（58.5）mg/kg；铝为BDL至2358.5（662.5）mg/kg；镉为0μg/l至0.35（0.15）mg/kg；铬为0μg/l至10.5（0.7）mg/kg；铜为0μg/l至23.9（1.2）mg/kg；锌为5.45（12.3）至165（5.4）mg/kg，锰为165（49.5）μg/l至92.5（3.8）mg/kg。结果表明，卡利蒂污水处理厂在去除污染物方面是有效的，从而达到了当地和国际排放标准。还发现该厂在去除铝、镉、铜和铬方面有效，但在去除钡和锌方面无效。然而，建议对污水处理厂的季节性理化参数和重金属含量进行实时数据收集和监测。
