Abstract：
Arsenic (As) and cadmium (Cd) accumulation in rice grains is a global food safety issue, and various methods and materials have been used to remove or reduce As and Cd in agricultural soils and rice grains. Despite the availability of synthesized materials capable of simultaneous As and Cd reduction from soil and rice grains, the contributions, efficiency, and main ingredients of the materials for As and Cd immobilization remain unclear. The present study first summarized the biogeochemistry of As and Cd in paddy soils and their transfer in the soil-food-human continuum. We also reviewed a series of reported inorganic and organic materials for simultaneous immobilization of As and Cd in paddy soils, and their reduction efficiency of As and Cd bioavailability were listed and compared. Based on the abovementioned materials, the study conducted a meta-analysis of 38 articles with 2565 observations to quantify the impacts of materials on simultaneous As and Cd reduction from soil and rice grains. Meta-analysis results showed that combining organic and inorganic amendments corresponded to effect sizes of -62.3% and -67.8% on As and Cd accumulation in rice grains, while the effect sizes on As and Cd reduction in paddy soils were -44.2% and -46.2%, respectively. Application of Fe based materials significantly (P < 0.05) reduced As (-54.2%) and Cd (-74.9%), accounting for the highest immobilization efficiency of As and Cd in rice grain among all the reviewed materials, outweighing S, Mn, P, Si, and Ca based materials. Moreover, precipitation, surface complexation, ion exchange, and electrostatic attraction mechanisms were involved in the co-immobilization tactics. The present study underlines the application of combined organic and inorganic amendments in simultaneous As and Cd immobilization. It also highlighted that employing Fe-incorporated biochar material may be a potential strategy for co-mitigating As and Cd pollution in paddy soils and accumulation in rice grains.
摘要：
水稻籽粒中砷(As)和镉(Cd)的积累是一个全球性的食品安全问题,以及各种方法和材料已被用于去除或减少农业土壤和稻粒中的As和Cd。尽管有能够同时从土壤和稻粒中减少As和Cd的合成材料，的贡献,效率,As和Cd固定化材料的主要成分尚不清楚。本研究首先总结了稻田土壤中As和Cd的生物地球化学及其在土壤-食物-人类连续体中的转移。我们还回顾了一系列报道的无机和有机材料，用于同时固定稻田土壤中的As和Cd，列出并比较了它们对As和Cd生物利用度的降低效率。根据上述材料，该研究对38篇文章进行了荟萃分析，其中有2565个观察值，以量化材料对土壤和稻粒中同时减少As和Cd的影响。荟萃分析结果表明，有机和无机改良剂组合对水稻籽粒中As和Cd积累的影响大小分别为-62.3％和-67.8％，而水稻土对As和Cd还原的影响大小分别为-44.2%和-46.2%，分别。铁基材料的应用显著(P<0.05)降低了As(-54.2%)和Cd(-74.9%),在所有审查的材料中，水稻籽粒中砷和镉的固定化效率最高，超过S，Mn,P,Si,和Ca基材料。此外，降水,表面络合,离子交换,静电吸引机制参与了共同固定策略。本研究强调了有机和无机联合改良剂在同时固定As和Cd中的应用。它还强调，采用掺入Fe的生物炭材料可能是共同减轻稻田土壤中As和Cd污染以及稻谷积累的潜在策略。
