Biomaterials Research Lab, Department of Chemistry, DKM College for Women (Autonomous), Vellore, India.
Biomaterials Research Lab, Department of Chemistry, DKM College for Women (Autonomous), Vellore, India.
Chemosphere. 2021 May;271:129415. doi: 10.1016/j.chemosphere.2020.129415. Epub 2021 Jan 2.
Elimination of heavy metals from wastewater has been a significant process to improve the aquatic source's quality. Various materials act as very effective adsorbents to remove heavy metals, which cause toxicity to plants and all other living organisms. Thus, the present work focuses on removing heavy metals chromium (Cr) and copper (Cu) ions containing wastewater using biodegradable and cost-effective chitosan-based hydrogel composite. The composite was prepared via chemical cross-linking of radical chitosan with polyacrylamide and N,N'-Methylene bisacrylamide and blended with orange peel. The synthesis of the adsorbent has been confirmed by using Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy - Energy dispersive X-ray analysis (SEM-EDAX) and X-ray diffraction (XRD) studies. The adsorption power of the composite of metal ions at different time, pH, adsorbent dosages, different metal ion concentrations were analyzed by using Atomic Absorption Spectroscopy (AAS). The results concluded that the optimum pH for Cr(VI) and Cu (II) were 4 and 5, contact time: 360 min, adsorbent dosage: 4 g, and initial metal ion concentration: 100 mg/L for each metal ions. The adsorption isotherm models follow the Freundlich model and pseudo-second-order kinetics. From the results, the adsorption capacity was observed to be 80.43% for Cr(VI) and 82.47% for Cu(II) ions, respectively.
从废水中去除重金属一直是提高水生资源质量的重要过程。各种材料都可以作为非常有效的吸附剂来去除重金属，重金属会对植物和所有其他生物产生毒性。因此，目前的工作重点是使用可生物降解且具有成本效益的壳聚糖基水凝胶复合材料去除含有重金属铬（Cr）和铜（Cu）离子的废水。该复合材料是通过自由基壳聚糖与聚丙烯酰胺和 N,N'-亚甲基双丙烯酰胺的化学交联以及与橙皮混合制备而成。通过傅里叶变换红外光谱（FT-IR）、扫描电子显微镜-能量色散 X 射线分析（SEM-EDAX）和 X 射线衍射（XRD）研究证实了吸附剂的合成。通过原子吸收光谱（AAS）分析了不同时间、pH 值、吸附剂用量、不同金属离子浓度下复合材料对金属离子的吸附能力。结果表明，Cr(VI)和 Cu(II)的最佳 pH 值分别为 4 和 5，接触时间为 360 min，吸附剂用量为 4 g，每种金属离子的初始金属离子浓度为 100 mg/L。吸附等温线模型符合 Freundlich 模型和拟二级动力学。从结果可以看出，Cr(VI)和 Cu(II)离子的吸附容量分别为 80.43%和 82.47%。
