Phosphate fertilizers facilitated the Cd contaminated soil remediation by sepiolite: Cd mobilization, plant toxicity, and soil microbial community

Ecotoxicology and Environmental Safety

Zhimin Wu¹  Yanqiong Li²  Feng Li³  Rong Huang⁴  Xuefeng Liang⁵  Zhian Li⁵  Xiuling Yin⁶  Ran Li⁶ 

[1] Department of Chemistry and Life Science, Xiangnan University, Chenzhou, Hunan Province 423000, PR China;Key Laboratory of Original Environmental Pollution Control, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, PR China;Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China;Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410221, PR China;Key Laboratory of Original Environmental Pollution Control, Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, PR China;Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China;

关键词: Phosphate fertilizers;    Sepiolite;    Cadmium;    Rice;    Bacterial community structure;   

DOI  :  

来源: DOAJ

【 摘 要 】

In-situ immobilization does not remove Cd from the contaminated soil. It is vital to investigate the effects of fertilizers on soil Cd mobility during remediation with amendments. In the current study, a pot experiment was conducted to investigate the effects of calcium magnesium phosphate (CMP) and calcium superphosphate (SSP) on the remediation of Cd-contaminated soil by sepiolite. We mainly focused on changes in soil Cd immobilization, plant toxicity, and soil microbial communities after applying two phosphates during Cd-contaminated soil remediation by sepiolite. The results demonstrated that sepiolite decreased Cd concentration in brown rice, straw, and roots by 32.66%, 38.89%, and 30.94%, respectively. During soil remediation by sepiolite, the Cd concentrations of brown rice and straw were not affected by CMP or SSP, except for the treatment with sepiolite plus high-dose CMP. Sepiolite significantly decreased HCl-extractable Cd and DTPA-extractable Cd by 32.21% and 10.50%, respectively. During soil remediation by sepiolite, the HCl-extractable and DTPA-extractable Cd further decreased with CMP or SSP. The decreasing amplitude with CMP was 40.57–72.60% and 7.05–14.53%, and that of SSP was 37.68–59.66% and 20.71–25.07%, respectively. The superoxide dismutase, peroxidase, catalase activities, and malondialdehyde concentration in rice roots decreased inordinately with the addition of sepiolite, CMP, and SSP, indicating that the application of sepiolite, CMP, or SSP alleviated Cd-induced rice root stress and protected rice roots from Cd toxicity. Alpha diversity estimators (including the Chao, ACE, and Shannon indices) indicated that sepiolite, CMP, or SSP applications had no adverse effects on soil bacterial richness and diversity. Hierarchical clustering analysis revealed that the two phosphate fertilizers and sepiolite were the main factors affecting changes in the bacterial communities structure. Redundancy analysis revealed that soil pH, Eh, and soil-extractable Cd were critical factors affecting the structure of the bacterial communities.

【 授权许可】

Unknown