Department of Environmental Health Engineering, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran E-mail:
Water Sci Technol. 2022 May;85(10):3036-3054. doi: 10.2166/wst.2022.092.
The adsorption of benzotriazole (BTA) by chemically modified magnetic biochar (MMBC) as a cheap and abundant biosorbent was investigated and optimized using response surface methodology (RSM). Initially, the MMBC composite was synthesized and characterized by scanning electron microscopy (SEM) energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and Brunauer-Emmett-Teller (BET) techniques. The characterization results confirmed the existence of FeO in the composite structure, which had uniformly dispersed over biochar (BC) with porous texture. Moreover, the presence of Zn and Cl elements in EDX analysis indicated that the magnetic biochar (MBC) had been modified successfully. The effects of chemical modification methods on the adsorption capacity of magnetic biochar were investigated. Maximum BTA removal efficiency was demonstrated by MMBC, modifying using ZnCl (>99%). Optimization was carried out based on reaction time, BTA concentration and the concentration of adsorbent. Optimum experimental conditions for the removal of BTA from aqueous solutions were found to be 35 min of reaction time, 0.55 g/L of adsorbent, and 50 mg/L of initial BTA concentration. At these optimal conditions, the predicted BTA adsorption efficiency was 92.6%. The adsorption process followed the Avrami fractional-order reaction kinetic and the Langmuir adsorption isotherm with the maximum adsorption capacity of 563.1 mg/g. The values of thermodynamic parameters demonstrated that the adsorption of BTA on ZnCl-MBC is endothermic and spontaneous. Under optimum usage of MMBC, the adsorptive removal efficiency of BTA non-significantly decreased from 99.2 to 93.9% after the 5th cycle. Thus, MMBC can be recommended as an environmentally friendly and cost-effective adsorbent to remove micropollutants from water.
采用响应面法（RSM）研究和优化了化学改性磁性生物炭（MMBC）作为廉价且丰富的生物吸附剂对苯并三唑（BTA）的吸附。首先，通过扫描电子显微镜（SEM）、能量色散 X 射线光谱（EDX）、傅里叶变换红外光谱（FTIR）、拉曼光谱和 Brunauer-Emmett-Teller（BET）技术合成和表征了 MMBC 复合材料。表征结果证实了复合材料结构中存在 FeO，其均匀分散在具有多孔结构的生物炭（BC）上。此外，EDX 分析中 Zn 和 Cl 元素的存在表明磁性生物炭（MBC）已成功改性。研究了化学改性方法对磁性生物炭吸附能力的影响。通过 MMBC 修饰，最大 BTA 去除效率达到 99%以上（用 ZnCl 修饰）。基于反应时间、BTA 浓度和吸附剂浓度对吸附进行了优化。从水溶液中去除 BTA 的最佳实验条件为反应时间 35 分钟、吸附剂用量 0.55g/L 和初始 BTA 浓度 50mg/L。在这些最佳条件下，预测的 BTA 吸附效率为 92.6%。吸附过程遵循 Avrami 分数阶反应动力学和 Langmuir 吸附等温线，最大吸附容量为 563.1mg/g。热力学参数值表明，BTA 在 ZnCl-MBC 上的吸附是吸热和自发的。在 MMBC 的最佳使用条件下，BTA 的吸附去除效率从第 5 次循环的 99.2%略微下降至 93.9%。因此，MMBC 可推荐为一种环保且经济高效的吸附剂，用于去除水中的微量污染物。
