Ying Jidong, Fan Kaiqing, Niazi Nabeel Khan, Gustave Williamson, Li Huashou, Wang Hailong, Bolan Nanthi S, Qin Junhao, Qiu Rongliang
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Faisalabad 38040, Pakistan.
Sci Total Environ. 2024 Jan 15;908:168300. doi: 10.1016/j.scitotenv.2023.168300. Epub 2023 Nov 6.
Arsenic (As) contamination is a global concern, especially in paddy fields, as it represents a significant pathway for As reaching in the food chain. This is primarily due to the high accumulation of As in rice grains, which is a staple food for billions of people globally. Here we investigated the effect of synthetic rainwater-borne hydrogen peroxide (HO)-induced Fenton oxidation process in paddy soil on As uptake and speciation in rice plants at different growth stages. Results showed that adding Fenton reagents significantly accelerated root iron (Fe) plaque formation, thereby enhancing As retention in soil. Arsenic accumulation in different rice plant parts followed the order: Fe plaque > root > stem > leaf. In rice grains, inorganic As and dimethylarsinic acid (DMA) were the major As species for the first and second-season crops. Notably, that the addition of Fenton reagents to paddy soil led to a significant reduction in As accumulation in rice grains. The synthetic rainwater-borne HO-induced Fenton reaction significantly promoted As(V) precipitation and decreased concentration of the dissolved As in soil porewater. The current study highlights that the HO-induced Fenton process is an important pathway decreasing As bioavailability in paddy soil and its accumulation in rice grain. The findings have implications for understanding As behavior in paddy fields receiving rainwater-borne HO and for developing cost-effective remediation programs to reduce As accumulation in rice grains.
砷（As）污染是一个全球关注的问题，尤其是在稻田中，因为它是砷进入食物链的一条重要途径。这主要是由于全球数十亿人主食的稻米中砷的高积累。在此，我们研究了合成雨水中的过氧化氢（HO）诱导的芬顿氧化过程对不同生长阶段水稻植株吸收砷及砷形态的影响。结果表明，添加芬顿试剂显著加速了根表铁（Fe）膜的形成，从而增强了土壤对砷的固定。砷在水稻植株不同部位的积累顺序为：铁膜＞根＞茎＞叶。在稻米中，无机砷和二甲基砷酸（DMA）是第一季和第二季作物中主要的砷形态。值得注意的是，向稻田土壤中添加芬顿试剂导致稻米中砷的积累显著减少。合成雨水中的HO诱导的芬顿反应显著促进了As（V）的沉淀，并降低了土壤孔隙水中溶解态砷的浓度。当前研究强调，HO诱导的芬顿过程是降低稻田土壤中砷的生物有效性及其在稻米中积累的重要途径。这些发现对于理解受雨水中HO影响的稻田中砷的行为以及制定经济有效的修复方案以减少稻米中砷的积累具有重要意义。
