Faculty of Environmental Sciences, University of Science, Viet Nam National University, Hanoi, Vietnam.
Laboratory for Process Engineering for Sustainable Systems, Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, 3001, Leuven, Belgium.
Environ Sci Pollut Res Int. 2022 Jun;29(28):42074-42089. doi: 10.1007/s11356-022-19013-4. Epub 2022 Feb 7.
Single-use plastic waste is gradually considered a potential material for circular economy. Ion exchange resin obtained from polystyrene waste by sulfonating with HSO was used for heavy metal removal from electroplating wastewater. Batch mode experiments of Cu, Zn, and Cd were carried out to determine effect of pH, initial concentration, equilibrium time, and the isotherm and kinetic parameters; the stability of the resin in continuous operation was then evaluated. Finally, the longevity of the resin after being exhausted was explored. The results indicated that at pH 6, a pseudo-second-order kinetic model was applicable to describe adsorption of studied heavy metals by sulfonated polystyrene with adsorption capacities of 7.48 mg Cu/g, 7.23 mg Zn/g, and 6.50 mg Cd/g, respectively. Moreover, the ion exchange process between sulfonated polystyrene resin and Cu, Zn, Cd ions followed the Langmuir isotherm adsorption model with R higher than 96%. The continuous fixed-bed column in conditions of a sulfonated polystyrene mass of 500 g, and a flow rate of 2.2 L/h was investigated for an influent solution with known initial concentration of 20 mg/L. Thomas and Yoon-Nelson models were tested with regression analysis. When being exhausted, the sulfonated polystyrene was regenerated by NaCl in 10 min with ratio 5 mL of NaCl 2 M per 1 g saturated resins. After 4 times regeneration, the heavy metal removal efficiency of sulfonated polystyrene was reduced to 50%. These aforementioned results can figure out that by sulfonating polystyrene waste to synthesize ion exchanging materials, this method is technically efficient and environmentally friendly to achieve sustainability.
一次性塑料废物逐渐被认为是循环经济的潜在材料。通过用 HSO3 磺化聚苯乙烯废物获得的离子交换树脂用于从电镀废水中去除重金属。进行了 Cu、Zn 和 Cd 的批量模式实验，以确定 pH 值、初始浓度、平衡时间以及等温线和动力学参数的影响；然后评估了树脂在连续操作中的稳定性。最后，探讨了耗尽后的树脂的寿命。结果表明，在 pH 6 时，拟二级动力学模型适用于描述磺化聚苯乙烯对研究重金属的吸附，Cu、Zn 和 Cd 的吸附容量分别为 7.48mg/g、7.23mg/g 和 6.50mg/g。此外，磺化聚苯乙烯树脂与 Cu、Zn 和 Cd 离子之间的离子交换过程遵循 Langmuir 等温吸附模型，R 高于 96%。在磺化聚苯乙烯质量为 500g 和流速为 2.2L/h 的条件下，对已知初始浓度为 20mg/L 的进水溶液进行了连续固定床柱实验。用回归分析测试了 Thomas 和 Yoon-Nelson 模型。当耗尽时，用 10min 的 2M NaCl 以 5mL NaCl/1g 饱和树脂的比例对磺化聚苯乙烯进行再生。经过 4 次再生后，磺化聚苯乙烯去除重金属的效率降低到 50%。上述结果表明，通过磺化聚苯乙烯废物合成离子交换材料，该方法在技术上是高效的，对环境友好的，可实现可持续性。
