Environmental Science

CLC number: X835

Effect of Organic and Inorganic Soil Amendments on Cadmium Immobilization and Bioaccumulation in Chinese Cabbage

有机无机复合土壤调理剂对污染土壤中Cd的固定和小白菜中Cd的生物累积的影响

¹ College of Materials and Chemical Engineering, China Three Gorges University, Yichang 443002, Hubei, China
² Yangtze River Pharmaceutical (Group) Co., Ltd., Taizhou 225300, Jiangsu, China
³ Agro-Technology Extension Center of Lichuan, Enshi 445400, Hubei, China

^† Corresponding author. E-mail: ctguhb@ctgu.edu.cn

Received: 17 July 2023

Abstract

Chemical immobilization, as a cost-effective and environmentally friendly technique, has been widely researched in the remediation of cadmium (Cd)-contaminated soil. The key is to find appropriate amendments and optimize their use. In this study, the effects of the application of an inorganic material (phosphorus slag (PS)) and organic materials (biochar (BC) and beer lees (BL)), individually or combinedly on the immobilization of Cd in contaminated soil and subsequent bioaccumulation in Chinese cabbagewere investigated. The results showed that PS and PS+BL were more effective in decreasing exchangeable Cd (EX-Cd) than other treatments, decreased by 91.2% in the PS treatment and by 64.0% in the PS+BL treatment. However, the soil enzyme activity and soil microbial activity decreased in the treatment with PS alone. In contrast, the combination use of PS and BL could increase soil enzyme activity, soil microbial activity, and functional diversity, and decrease EX-Cd as well. Moreover, the PS+BL treatment reduced the accumulation of Cd in Chinese cabbage most effectively, 81.5% in roots and 72.5% in shoots. This treatment could also increase the aboveground height and chlorophyll content of Chinese cabbage while reducing the content of malondialdehyde (MDA). Thus, the PS + BL treatment is highly recommended for Cd immobilization, as it can improve soil quality and reduce Cd accumulation in Chinese cabbage at the same time and hence promote plant growth.

摘要

化学修复技术因为成本低效果好等优点，在修复镉(Cd)污染土壤中得到了广泛研究，其关键在于开发和应用优异的土壤改良剂。在本研究中，研究了无机材料(磷渣PS)和有机材料(生物炭BC和啤酒糟BL)单独或联合应用对受污染土壤中 Cd 的固定以及在小白菜中的生物积累的影响。结果表明，PS和PS+BL可显著降低土壤中的可交换镉(EX-Cd)，PS处理组降低了91.2%，PS+BL处理组降低了64.0%。然而，单独使用PS使土壤酶活性和土壤微生物活性明显降低。相比之下，PS+BL的联合使用不但增加了土壤的pH值也增加了其有机质含量，还增加了土壤酶活性、土壤微生物活性和功能多样性。同时，PS+BL处理组有效地减少了小白菜中镉的积累，其中根部减少81.5%，茎叶减少72.5%。PS+BL还可以增加小白菜的地上高度和叶绿素含量，同时减少丙二醛(MDA)的含量。因此，PS+BL的有机无机复合镉修复剂可有效固定污染土壤中的镉，从而减小镉在小白菜中的生物累积，同时改善土壤质量，促进植物生长。