Abstract：
Heavy-metal contamination in soil has long been a persistent challenge and the utilization of agricultural waste for in-situ stabilization remediation presents a promising approach to tackle this problem. Agricultural wastes exhibit promising potential in the remediation of contaminated land and modification could improve the adsorption performance markedly. Citric acid and Fe3O4 treated sugarcane bagasse adsorbed more heavy metals than raw materials in the aqueous system, employing these materials for heavy metal remediation in soil holds significant implications for broadening the raw material source of passivators and enhancing waste utilization efficiency. In this paper, a 120-day soil incubation study was conducted to compare the effects of pristine sugarcane bagasse (SB), citric-acid modified (SSB1, SSB2 and SSB3 with increasing proportion of citric acid) and citric-acid/Fe3O4 modified (MSB1, MSB4 and MSB7 with increasing proportion of Fe3O4) sugarcane bagasse at 1 % addition rate on cadmium (Cd) and copper (Cu) passivation. The SB, SSB1 and MSB1 did not always decrease the content of CaCl2-extractable Cd while all the seven amendments decreased the CaCl2-extractable Cu during the experiment period. Among all materials, SSB3 and MSB7 exhibited the highest efficiency in reducing the concentrations of CaCl2-extractable Cd and Cu. At Day 120, SB, SSB3 and MSB7 reduced the content of CaCl2-extractable Cd by 8 %, 18 % and 24 %, and of CaCl2-extractable Cu by 25 %, 50 % and 61 %, respectively. The efficiency of Cd and Cu immobilization was associated positively with the pH, functional groups and H-bonds of the amendments. The results suggest that the efficiency of sugarcane bagasse in heavy-metal passivation can be largely enhanced through chemical modifications using high proportions of citric acid and Fe3O4.
摘要：
土壤中的重金属污染长期以来一直是一个持续的挑战，利用农业废物进行原位稳定修复是解决这一问题的有希望的方法。农业废物在修复受污染的土地方面具有广阔的潜力，而改性可以显着提高吸附性能。柠檬酸和Fe3O4处理的甘蔗渣在水体系中比原料吸附更多的重金属，将这些材料用于土壤中的重金属修复对于扩大钝化剂的原料来源和提高废物利用效率具有重要意义。在本文中,进行了120天的土壤孵化研究，以比较原始甘蔗渣（SB）的影响，柠檬酸改性（SSB1，SSB2和SSB3随柠檬酸比例增加）和柠檬酸/Fe3O4改性（MSB1，MSB4和MSB7随Fe3O4比例增加）甘蔗渣在1％的添加率下对镉（Cd）和铜（Cu）钝化。SB,SSB1和MSB1并不总是降低CaCl2可萃取Cd的含量，而在实验期间，所有七个修正案均降低了CaCl2可萃取Cu的含量。在所有材料中,SSB3和MSB7在降低CaCl2可萃取的Cd和Cu的浓度方面表现出最高的效率。在第120天，SB，SSB3和MSB7将CaCl2可萃取Cd的含量降低了8％，18%和24%，和25%的CaCl2可萃取Cu，50%和61%，分别。Cd和Cu的固定化效率与pH呈正相关,修订的官能团和H-键。结果表明，通过使用高比例的柠檬酸和Fe3O4进行化学修饰，可以大大提高甘蔗渣在重金属钝化中的效率。
