Department of Chemical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
Department of Chemistry, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
Environ Pollut. 2023 Jan 1;316(Pt 2):120612. doi: 10.1016/j.envpol.2022.120612. Epub 2022 Nov 8.
Alarming rates of water contamination by toxic herbicides have prompted the need and attention for easy, efficient, and affordable treatment options with a touch of circular economy aspects. This study valorized date palm leaf (DPL) wastes into a valuable adsorbent for remediating agricultural wastewater polluted with 2,4-Dichlorophenoxyacetic acid (2,4-DPA) herbicide. The DPL precursor was modified with HSO treatment and both biomass samples were characterized by various analytical techniques. Acid treatment modified the morphology, thermal, and textural properties of the final product (TDPL) while maintaining the structure and surface chemistry intact. Simulated wastewaters containing 2,4-DPA were subsequently treated using TDPL as an adsorbent. Optimum adsorption conditions of pH 2, dosage 0.95 g/L, shaking speed 200 rpm, time 120 min, and temperature 30 °C showed a good herbicide removal efficiency in the range of 55.1-72.6% for different initial feed concentrations (50-250 mg/L). Experimental kinetic data were better represented by the pseudo-second-order model, while the Freundlich isotherm was reliable in describing the equilibrium behavior of the adsorption system. Further, the thermodynamic analysis revealed that the adsorption occurred spontaneously, favorably, and exothermically. Plausible sorption mechanism involved electrostatic interactions, weak van der Waals forces, hydrogen bonds, and π-π interactions between the participating phases. Conspicuously, TDPL application to real-world situations of treating actual herbicide-polluted agricultural runoff resulted in a 69.4% remediation efficiency. Thus, the study demonstrated the valorization of date palm leaves into a valuable and industry-ready adsorbent that can sequester toxic 2,4-DPA herbicide contaminant from aqueous streams.
有毒除草剂对水的污染率令人震惊，这促使人们需要寻求简单、高效且经济实惠的处理方法，并带有一点循环经济的理念。本研究利用椰枣叶（DPL）废料制成一种有价值的吸附剂，用于修复受 2,4-二氯苯氧乙酸（2,4-DPA）除草剂污染的农业废水。DPL 前体经过 HSO 处理进行改性，并用各种分析技术对两种生物质样品进行了表征。酸处理改变了最终产物（TDPL）的形态、热和结构特性，同时保持了结构和表面化学性质的完整性。随后，用 TDPL 作为吸附剂处理含有 2,4-DPA 的模拟废水。在 pH 值为 2、用量为 0.95 g/L、搅拌速度为 200 rpm、时间为 120 min 和温度为 30°C 的最佳吸附条件下，不同初始进料浓度（50-250 mg/L）下，对不同初始进料浓度（50-250 mg/L）的除草剂去除效率均在 55.1-72.6%范围内。实验动力学数据更符合准二级模型，而 Freundlich 等温线可靠地描述了吸附体系的平衡行为。此外，热力学分析表明吸附是自发、有利和放热的。可能的吸附机制涉及静电相互作用、弱范德华力、氢键和参与相之间的π-π相互作用。值得注意的是，TDPL 在实际处理实际受除草剂污染的农业径流的情况下的应用，使得修复效率达到了 69.4%。因此，该研究表明，椰枣叶可以被转化为有价值的、适合工业应用的吸附剂，能够从水相中隔离出有毒的 2,4-DPA 除草剂污染物。
