Effectiveness, stabilization, and potential feasible analysis of a biochar material on simultaneous remediation and quality improvement of vanadium contaminated soil

Abstract

Biochar additions to soil have been proposed as an environment-friendly way to enhance the soil nutrients or to amend the contaminated soils; however, few studies have evaluated the effectiveness of biochars from an integrated perspective of soil remediation and quality improvement, especially for the soil contaminated by vanadium with increasing prevalence, complex species and chemistry, widespread toxicity to organisms. Herein, this gap is addressed by using a biochar to evaluate the effectiveness of both remediation and quality improvement of a vanadium contaminated soil. Based on the physicochemical and morphology properties, the optimal biochar with a good porous structure and abundant surface functional groups prepared by pyrolyzing rice straw at 650 °C and sieving through a 200 mesh (RS-T650-P0.075) was selected from 18 candidates. The increase of pH (1.72), organic matter content (3.80%), and available P content (9.17 mg kg−1) of soil and the decrease of bioavailable vanadium (225.59 ± 16.25 mg vanadium kg−1 soil) in soil during a 10-week experiment indicated an effective and stable improvement of soil quality and treatment for soil vanadium pollution, by high RS-T650-P0.075 application (3%) to soil contaminated at high exogenous vanadium level (1000 mg vanadium kg−1 soil). Analysis of the cost-benefit and environmental influence confirmed the potential feasibility for practical applicating the RS-T650-P0.075 to treat the vanadium contaminated soils. Overall, the RS-T650-P0.075 can be served as a cost-effective and ecofriendly amendment for both soil quality improvement and the vanadium contaminated soil remediation.