Multistage utilization of soybean straw-derived P-doped biochar for aquatic pollutant removal and biofuel usage

Biochar is of great importance to realizing solid biowastes reduction and environmental remediation. Modifying biochar for better performance is also of great concern to achieve property improvement. P-doped biochar from soybean straw is prepared for multistage utilization to realize water pollutant removal and biofuel usage. The results suggest that the prepared biochar is adequate for sulfadiazine adsorption and has stable performance under coexisting ions and aquatic pH. Furthermore, the higher heating value of the biochar is close to coal and thus can be an alternative to fossil fuel. The maximum sulfadiazine adsorption amount of P-doped biochar is 252.24 mg·g-¹, and the P-doped biochar HHV is 24 MJ·kg^-1 which can be an alternative to coal. The greenhouse gas and pollutant emission potential are also considered to explore the environmental impact of P-doped biochar production and usage. Overall, the optimal ratio of soybean straw: K₃PO₄ is 3:1.