Effects and mechanisms of Humin on the migration and transformation of arsenic and cadmium in the soil-rice system
The accumulation of arsenic(As)and cadmium(Cd)in rice leading to human health risks has attracted much attention worldwide.Different water management and organic matter addition during rice growth have important effects on arsenic and cadmium uptake by rice,but the mecha-nisms involved have not been systematically elucidated.Therefore,this paper mainly investigated the effects of Humin addition under different water management conditions on arsenic and cadmium con-tent and morphological changes at the water-soil-iron membrane interface,and found that the addi-tion of Humin under submerged water reduction conditions could further promote arsenic reduction and increase the trivalent arsenic content in pore water,thus increase the accumulation of arsenic in various parts of rice.However,the addition of Humin can promote the fixation of cadmium and fur-ther reduce the accumulation of cadmium in all parts of rice.