[关键词]
[摘要]
工业废弃物引发的重金属污染问题日益严峻,对人类健康和生态环境造成了深远影响。生物炭在重金属污染修复中展现出较大潜力,但原状生物炭在低pH和高浓度重金属条件下的修复效果有限。为有效应对这一难题,本研究以火龙果皮为前驱体,在500℃条件下热解2小时制备生物炭,并研发了一种名为GBMSs(绿色生物炭-偏高岭土-硅酸钠)的高效绿色吸附剂。响应面法试验结果表明,在pH=2条件下,GBMSs对锌的吸附量高达67.37mg/L,表现出卓越的吸附性能。动力学和等温吸附研究显示,GBMSs对铜和锌的吸附过程与Langmuir模型和伪二阶动力学方程高度吻合,属于均质单分子层表面吸附,吸附速度较快,且吸附量随着pH值增加而增加。通过XRD和SEM-EDS技术深入分析,发现GBMSs的主要吸附机制为化学吸附,离子交换、表面络合、共沉淀等作用起重要作用。综合以上结果,研究证实GBMSs作为一种环保高效的吸附剂,在重金属污染治理方面具有广阔的应用前景。
[Key word]
[Abstract]
Heavy metal contamination stemming from industrial waste is an increasingly grave issue with extensive repercussions for human health and the ecological environment. Biochar demonstrates significant potential in remedying heavy metal pollution; however, the effectiveness of raw biochar is constrained under low pH and high heavy metal concentrations. To address this challenge effectively, this study utilized dragon fruit peels as precursors to produce biochar through pyrolysis at 500 °C for 2 hours. An efficient green adsorbent, termed GBMSs (green biochar-metakaolin-sodium silicate), was developed. Response surface methodology (RSM) tests revealed that GBMSs exhibited exceptional adsorption performance for zinc, achieving up to 67.37 mg/L at pH=2. Kinetic and isothermal adsorption studies indicated that the adsorption process of GBMSs on Cu and Zn closely followed the Langmuir model and the pseudo-second-order kinetic equation, suggesting surface adsorption of a homogeneous monomolecular layer with a rapid adsorption rate that increased with rising pH. In-depth analysis using XRD and SEM-EDS techniques identified chemisorption as the primary adsorption mechanism, with ion exchange, surface complexation, and co-precipitation playing significant roles. These findings confirm that GBMSs, as an environmentally friendly and efficient adsorbent, holds considerable promise for the treatment of heavy metal pollution.
[中图分类号]
[基金项目]
沿海滩涂复合污染底泥CSGP固化/稳定作用机制及长期效应