Investigation into arsenic retention in arid contaminated soils with biochar application

The contamination of arsenic (As) in soil and groundwater has posed serious hazards to food chain and ecosystem. The aim of the present study was to assess the impacts of different biochar (rice husk biochar and plant biowaste biochar at 10 and 20 t ha(-1)) on the retention and immobilization of As in wheat. For this purpose, soil and herbage samples were collected in the vicinity of Gujranwala, Pakistan, and characterized for different physicochemical parameters. Pot experiment was carried out on wheat plant to check the effect and uptake of As (at two concentrations, i.e., 10 and 15 mg L-1) from irrigation water as affected by biochar. The results of the collected samples showed a minimum concentration of As and maximum concentration of lead (Pb) in Gujranwala City. Moreover, iron (Fe), chromium (Cr), and manganese (Mn) were the dominant elements in the sampling area. The application of biochar increased the plant biomass of wheat as compared to control. Among the studied biochars, the application of plant biowaste biochar significant increased the retention and immobilization of As at a higher level (15 mg L-1). However, the rich husk performs better at lower As level (10 mg L-1). Both the studied amendments increased the immobilization of As but plant biowaste biochar was more effective. The plant waste biochar could be used to improve agricultural production in polluted soil by minimizing the risk of food chain contamination.