Mechanistic understanding of biochar-bacteria system for enhanced chlorpyrifos bioremediation in water and soil medium

Abstract

Chlorpyrifos (CP) is a commonly used chlorinated organophosphorus insecticide in agriculture, but its improper handling and long-term application have led to the contamination of groundwater, soil, and sediments. The use of functional microorganisms immobilized on biochar is an innovative and sustainable solution to this issue. In this study, CP-degrading Aeromonas veronii (A.veronii) was immobilized on rice husk biochar (ARHB) to investigate its efficacy in remediating CP-contaminated water and soil. Box-Behnken designs were employed to optimize the parameters, resulting in 96.25 % removal within 24 h in water medium. Adding 2 g kg−1 ARHB in soil achieved a maximum removal rate of 92.4 % within 42 days. Moreover, ARHB enhanced soil properties and plant growth through bio-augmentation and bio-stimulation. LC-MS analyses identified the degradation products, signifying a synergistic effect of bacterial metabolism and adsorption in the CP removal mechanism. These findings highlight the potential of immobilized A.veronii and biochar for efficient remediation of pesticide-contaminated environments. © 2024 Elsevier B.V.