Regulation of rhizosphere microenvironment by rice husk ash for reducing the accumulation of cadmium and arsenic in rice  

作　　者：Yi Jiang Ya Liu Xuantao Yi Peng Zeng Bohan Liao Hang Zhou Jiaofeng Gu 

机构地区：[1]College of Environmental Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China [2]Hunan Engineering Laboratory for Control of Rice Quality and Safety,Changsha 410004,China

出　　处：《Journal of Environmental Sciences》2024年第2期1-10,共10页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.41907126);the Key Research and Development Program of Hunan Province (No.2021NK2027);the Science and Technology Talent Lifting Project of Hunan Province (No.2019TJ-N05)。

摘　　要：It is important to reduce Cd and As content in brown rice in contaminated paddy soils.We conducted research on the effects of rice husk ash (RHA) on the Cd and As in the rhizosphere microenvironment (soil,porewater,and iron plaque) and measured the Cd,As,and Si content in rice plants.The main elements in RHA were Si (29.64%) and O (69.17%),which had the maximum adsorption capacity for Cd was 42.49 mg/kg and for As was 18.62 mg/kg.Soil pH and available Si content increased,while soil available Cd and As decreased following application of 0.5%–2%RHA.RHA promote the transformation of Cd to insoluble fraction,while As was transformed from a poorly soluble form to a more active one.RHA reduced Cd content and increased Si content in porewater,and reduced As only at the later rice growth stages.RHA increased the amount of iron plaque,thereby decreasing the Cd content in iron plaque,while increased the As content in it.Cd and inorganic As content in brown rice were decreased,to 0.31 mg/kg and 0.18 mg/kg,respectively.The decrease of Cd in brown rice was due to the decrease of Cd mobility in soil,thereby reducing root accumulation,while the decrease of As in brown rice was affected by the transport from roots to stems.Therefore,RHA can be considered as a safe and efficient in-situ remediation amendment for Cd and As co-contaminated paddy soil.

关 键 词：Rice husk ash(rha) CADMIUM ARSENIC Silicon RICE Soil 

分 类 号：X53[环境科学与工程—环境工程] X503.231