Gyawali Deepak, Poudel Samjhana, Poudel Madan, Ghimire Kedar Nath, Pokhrel Megh Raj, Basnet Prabin, Bahadur Bk Krishna, Paudyal Hari
Central Department of Chemistry, Tribhuvan University, Kirtipur, Nepal.
Ministry of Forest and Environment, Department of Environment, Government of Nepal, Nepal.
Heliyon. 2024 Aug 16;10(16):e36496. doi: 10.1016/j.heliyon.2024.e36496. eCollection 2024 Aug 30.
Raw mango peel (RMP) was first saponified to yield saponified mango peel (SMP), which was then loaded with Zr(IV) ions to form a biosorbent for As(III) scavenging.The biosorption behaviors and mechanisms of As(III) scavenging using RMP and Zr(IV)-loaded saponified mango peel (Zr(IV)-SMP) were investigated batchwise. The As(III) scavenging efficiency of RMP increased from 20.13 % to 87.32 % after Zr(IV) loading. Optimum contact time of 6 h has been investigated for As(III) scavenging by Zr(IV)-SMP, and the data on kinetics is well fitted to the pseudo-second-order (PSO) model. Similarly, isotherm data of Zr(IV)-SMP fitted well to the Langmuir isotherm model with the maximum As(III) scavenging potential of 45.52 mg/g. Chloride (Cl) and nitrate (NO ) have negligible influence on As(III) scavenging, but sulphate (SO ) interferes significantly. The exhausted Zr(IV)-SMP could be easily regenerated by treating with 2MNaOH. A mechanistic study indicates that As(III) scavenging is primarily contributed to electrostatic interaction and ligand exchange, which is confirmed from both instrumental and chemical characterizations techniques. Tubewell underground water polluted with a trace amount of arsenic (98.63 μg/L) could be successfully lowered down to the WHO standard (10 μg/L) by applying a small amount of Zr(IV)-SMP. Therefore, the Zr(IV)-SMP investigated in this work can be a low-cost, environmentally benign, and promising alternative for scavenging trace levels of arsenic from contaminated water.
生芒果皮（RMP）首先进行皂化反应生成皂化芒果皮（SMP），然后负载Zr(IV)离子形成用于清除As(III)的生物吸附剂。采用分批实验法研究了RMP和负载Zr(IV)的皂化芒果皮（Zr(IV)-SMP）对As(III)的生物吸附行为及机制。负载Zr(IV)后，RMP对As(III)的清除效率从20.13%提高到了87.32%。研究得出Zr(IV)-SMP清除As(III)的最佳接触时间为6小时，动力学数据与伪二级（PSO）模型拟合良好。同样，Zr(IV)-SMP的等温线数据与Langmuir等温线模型拟合良好，最大As(III)清除潜力为45.52 mg/g。氯离子（Cl）和硝酸根（NO）对As(III)的清除影响可忽略不计，但硫酸根（SO）有显著干扰。耗尽的Zr(IV)-SMP用2M NaOH处理后可轻松再生。机理研究表明，As(III)的清除主要归因于静电相互作用和配体交换，这从仪器和化学表征技术中得到了证实。通过应用少量Zr(IV)-SMP，受微量砷（98.63 μg/L）污染的管井地下水可成功降低至世界卫生组织标准（10 μg/L）。因此，本研究中所研究的Zr(IV)-SMP可成为一种低成本、环境友好且有前景的从污染水中清除痕量砷的替代方法。
