Journal: Journal of Hazardous Materials 

Author: Ergang Wen, Xing Yang, Hanbo Chen, Sabry M. Shaheen, Binoy Sarkar, Song Xu, Hocheol Song, Yong Liang, Jörg Rinklebe, Deyi Hou, Yong Li, Fengchang Wu, Michael Pohořelý, Jonathan W.C. Wong, Hailong Wang 

Abstract: 

The aim of this study was to evaluate the effect of raw (RawBC) and iron (Fe)-modified biochar (FeBC) derived from Platanus orientalis Linn branches on the plant growth, enzyme activity, and bioavailability and uptake of As, Cd, and Pb by rice in a paddy soilwith continuously flooded (CF) or alternately wet and dry (AWD) irrigation in a pot experiment. Application of RawBC (3%, w/w) significantly increased soil pH, while FeBC decreased it. The FeBC was more effective in reducing As and Pb bioavailability, particularly under the AWD water regime, while RawBC was more conducive in reducing Cd bioavailability under the CF water regime. The FeBC decreased As concentration, but increased concentrations of Cd and Pb in the straw and brown rice, as compared to the untreated soil. Soil catalase and urease activities were enhanced by RawBC, but decreased by FeBC treatment. The FeBC increased the grain yield by 60% and 32% in CF and AWD treatments, respectively. The FeBC can be recommended for immobilization of As in paddy soils, but a potential human health risk from Cd and Pb in FeBC-treated soils should be considered due to increased uptake and translocation of the metals to brown rice. 

Keywords: Heavy metal, Bioavailability, Soil enzyme, Engineered Biochar, Irrigation

DOI: https://doi.org/10.1016/j.jhazmat.2020.124344