Mkilima Timoth, Dakieva Kulzipa, Adilbektegi Gulmira, Tatina Yelena, Khussainov Mansur, Kassymkhanov Salauat, Tolubayeva Kanagat, Zhantasuly Bitmanov Yertas, Daukenova Bibigul
Department of Environmental Engineering and Management, The University of Dodoma, Dodoma, Tanzania.
Department of Ecology and Geography, Sarsen Amanzholov East Kazakhstan University, Ust-Kamenogorsk, Kazakhstan.
Water Environ Res. 2025 Jun;97(6):e70105. doi: 10.1002/wer.70105.
Heavy metal contamination in industrial wastewater poses a critical environmental challenge due to the toxicity and persistence of metals such as Pb(II) and Cd(II). This study evaluated the performance of MIL-101(Fe)/Graphene Oxide (GO) electrospun nanofibrous membranes as advanced adsorbents for the efficient removal of these metal ions. Structural characterization confirmed a high surface area and uniform integration of MIL-101(Fe) and GO within the fibrous matrix. Batch adsorption experiments revealed maximum removal efficiencies of 93% for Pb(II) and 95% for Cd(II), with optimum performance observed at pH 5.5 and 6.0, respectively. The adsorption process followed pseudo-second-order kinetics (R > 0.98), suggesting chemisorption, and was well described by both Langmuir (q: 126 mg/g for Pb(II), 100 mg/g for Cd(II); R ≥ 0.98) and Freundlich isotherms (1/n < 1), indicating favorable monolayer and multilayer adsorption on heterogeneous surfaces. The thermodynamic analysis confirmed that adsorption was spontaneous (ΔG° values as low as -8.6 kJ/mol for Pb(II)) and endothermic (ΔH° values of 21.5 kJ/mol for Pb(II) and 18.9 kJ/mol for Cd(II)). In continuous flow systems, the membranes maintained removal efficiencies above 85% for both metals across 10 cycles at a flow rate of 10 mL/min. The membranes also exhibited excellent fouling resistance, with flux decline remaining below 10% over 5 cycles, and demonstrated high cleaning efficiency, recovering up to 99.2% of flux through simple deionized water rinsing. Reusability studies showed that the membranes retained over 80% of their original adsorption capacity after eight regeneration cycles in batch mode, and over 70% removal efficiency and 83% water flux after 10 regeneration cycles in real industrial wastewater conditions. These findings demonstrated the robustness, reusability, and scalability of MIL-101(Fe)/GO membranes for the effective treatment of heavy metal-contaminated industrial effluents. Future studies should explore membrane performance under mixed contaminant conditions and assess techno-economic feasibility at the pilot scale. PRACTITIONER POINTS: Advanced nanofibrous membranes with MIL-101(Fe)/Graphene Oxide (GO) tested for heavy metal removal. Outstanding performance compared to conventional adsorbents. 93% Pb(II) and 95% Cd(II) removal at optimum pH conditions (Pb(II): pH 5.5, Cd(II): pH 6.0). Rapid equilibrium kinetics with 60 minutes compared to 120 minutes. High surface area and optimal pore size critical for superior performance.
由于铅（II）和镉（II）等金属的毒性和持久性，工业废水中的重金属污染构成了严峻的环境挑战。本研究评估了MIL-101（铁）/氧化石墨烯（GO）电纺纳米纤维膜作为高效去除这些金属离子的先进吸附剂的性能。结构表征证实了MIL-101（铁）和GO在纤维基质中的高表面积和均匀整合。批量吸附实验表明，铅（II）的最大去除效率为93%，镉（II）的最大去除效率为95%，分别在pH 5.5和6.0时观察到最佳性能。吸附过程遵循准二级动力学（R＞0.98），表明为化学吸附，Langmuir等温线（铅（II）的q：126mg/g，镉（II）的q：100mg/g；R≥0.98）和Freundlich等温线（1/n＜1）均能很好地描述该过程，表明在异质表面上有利于单层和多层吸附。热力学分析证实吸附是自发的（铅（II）的ΔG°值低至-8.6kJ/mol）且是吸热的（铅（II）的ΔH°值为21.5kJ/mol，镉（II）的ΔH°值为18.9kJ/mol）。在连续流动系统中，膜在流速为10mL/min的情况下，经过10个循环，对两种金属的去除效率均保持在85%以上。该膜还表现出优异的抗污染性能，在5个循环中通量下降保持在10%以下，并显示出高清洗效率，通过简单的去离子水冲洗可恢复高达99.2%的通量。可重复使用性研究表明，在批量模式下经过8次再生循环后，膜保留了其原始吸附容量的80%以上，在实际工业废水条件下经过10次再生循环后，去除效率超过70%，水通量达到83%。这些发现证明了MIL-101（铁）/GO膜在有效处理重金属污染工业废水方面的稳健性、可重复使用性和可扩展性。未来的研究应探索混合污染物条件下的膜性能，并在中试规模上评估技术经济可行性。从业者要点：测试了具有MIL-101（铁）/氧化石墨烯（GO）的先进纳米纤维膜用于去除重金属。与传统吸附剂相比性能卓越。在最佳pH条件下（铅（II）：pH 5.5，镉（II）：pH 6.0），铅（II）和镉（II）的去除率分别为93%和95%。与120分钟相比，60分钟达到快速平衡动力学。高表面积和最佳孔径对卓越性能至关重要。
