Department of Environmental Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq.
Department of Environmental Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq.
Chemosphere. 2023 Oct;338:139469. doi: 10.1016/j.chemosphere.2023.139469. Epub 2023 Jul 11.
The presence of toxic cadmium ions in the wastewater resulted from industrial sector forms the critical issue for public health and ecosystem. This study determines the ability of four vertical subsurface flow constructed wetlands units in the treatment of simulated wastewater laden with cadmium ions. This was achieved through using sewage sludge byproduct as alternative for the traditional sand to be substrate for aforementioned units in order to satisfy the sustainable concepts; however, Canna indica and Typha domingensis can apply to enhance the cadmium removal. The performance of constructed wetlands has been evaluated through monitoring of the pH, dissolved oxygen (DO), temperature, and concentrations of cadmium (Cd) in the effluents for retention time (0.5-120 h) and metal concentration (5-40 mg/L). The results demonstrated that the Cd removal percentage was exceeded 82% beyond 5 days and for concentration of 5 mg/L; however, this percentage was decreased with smaller retention time and higher metal concentration. The Grau second-order kinetic model accurately simulated the measurements of effluent Cd concentrations as a function of retention times. The FT-IR analysis indicated the existence of certain functional groups capable of enhancing the Cd removal. The treated wastewater's pH, DO, temperature, total dissolved solids (TDS), and electrical conductivity (EC) all meet the requirements for irrigation water.
工业废水所产生的有毒镉离子对公共健康和生态系统构成了重大问题。本研究旨在确定四种垂直潜流人工湿地单元对模拟含镉离子废水的处理能力。这是通过使用污水污泥副产品替代传统的沙子作为上述单元的基质来实现的，以满足可持续发展的理念；然而，美人蕉和香蒲可以应用于增强镉的去除。通过监测 pH 值、溶解氧（DO）、温度和废水中的镉（Cd）浓度（0.5-120 小时）和金属浓度（5-40mg/L）来评估人工湿地的性能。结果表明，在 5 天以上和 5mg/L 的浓度下，Cd 的去除率超过 82%；然而，随着保留时间的缩短和金属浓度的增加，该百分比会降低。Grau 二级动力学模型准确地模拟了流出物 Cd 浓度随保留时间的变化。FT-IR 分析表明存在某些功能基团能够增强 Cd 的去除。处理后的废水的 pH 值、DO 值、温度、总溶解固体（TDS）和电导率（EC）均符合灌溉用水的要求。
