摘要
本研究通过一锅法制备了坡缕石负载聚磷酸盐钝化材料,并探究了材料对圆叶红苋镉毒害效应的缓解效果。钝化剂表征结果表明,磷以无定形聚磷酸盐的形式均匀负载于坡缕石上。盆栽实验表明,施加该钝化材料几乎不影响圆叶红苋的生长,并可有效降低圆叶红苋对镉的吸收。当钝化材料中聚磷酸盐负载量为600mg/kg(以P_(2)O_(5)质量浓度计算)时,圆叶红苋叶子镉含量相比于空白处理下降了49.56%,且该钝化材料中的坡缕石和聚磷酸盐在抑制植物镉吸收方面存在协同作用。钝化剂的施加提高了土壤中有效磷含量和土壤pH值,促使土壤中的镉以低溶态的磷酸镉、氢氧化镉等形式存在,进而降低了土壤有效镉含量,抑制了圆叶红苋可食部分(叶子)对镉的吸收;同时,施加该钝化剂提高了土壤中有效态Zn/Cd和Mn/Cd的值,增强了土壤中锌、锰和镉在植物吸收通道的竞争,这也是圆叶红苋叶子镉累积受到抑制的可能原因。综上,本研究合成了一种坡缕石负载聚磷酸盐钝化材料,并对钝化机理进行了简要分析,合成的材料有望在实际镉污染农田土壤治理中提供实际效用。
In this study, polyphosphate-loaded palygorskite stabilizer was synthesized via one-pot treatment method and the novel stabilizer was examined for its performance in relieving cadmium toxicity of Amaranthus tricolor L. Characterization results of the stabilizer showed that phosphate existed as amorphous polyphosphate evenly loaded on palygorskite. The results of the pot experiment showed that the stabilizer had negligible effects on plant growth, resulting in a remarkable decrease in cadmium concentration in the edible part(leaf) of Amaranthus tricolor L. When 600 mg/kg of polyphosphate was loaded on the stabilizer, a 49.56% decrease in leaf cadmium concentration was observed compared with the blank treatment. Palygorskite and polyphosphate in the novel stabilizer showed synergistic effects in reducing cadmium uptake by plant. Application of the stabilizer also elevated soil available phosphate concentration and soil pH, which could favor transformation of cadmium towards insoluble cadmium hydroxide and cadmium phosphate precipitate, thus decreasing soil available cadmium concentration and inhibiting leaf uptake of cadmium. Meanwhile, the application of the stabilizer increased the ratio of soil available Zn/Cd and Mn/Cd, intensifying competition for absorption channels between cadmium and coexistent zinc and manganese, which could also account for reducing cadmium leaf uptake. In summary, polyphosphate loaded palygorskite was synthesized as a novel stabilizer in this study and is expected to be used in soil remediation in the future.
作者
何宏飞
傅浩洋
朱润良
毛鹏
陈情泽
HE Hongfei;FU Haoyang;ZHU Runliang;MAO Peng;CHEN Qingze(CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials,Guangzhou Institute of Geochemistry,Chinese Academy of Science,Guangzhou 510640,Guangdong,China;CAS Center for Excellence in Deep Earth Science,Guangzhou 510640,Guangdong,China;University of Chinese Academy of Sciences,Beijing 100049,China;South China Botanical Garden,Chinese Academy of Science,Guangzhou 510650,Guangdong,China)
出处
《地球化学》
CAS
CSCD
北大核心
2022年第3期294-304,共11页
Geochimica
基金
中国科学院创新交叉团队项目(JCTD-2019-15)
广东省科技计划项目(2020B1212060055)
中国科学院青年创新促进会专项项目(2020347)联合资助。
关键词
坡缕石
聚磷酸盐
钝化
苋菜
镉
palygorskite
polyphosphate
stabilization
Amaranthus tricolor L.
cadmium