Efficient removal of atrazine by iron-modified biochar loaded Acinetobacter lwoffii DNS32

In order to efficiently remove commonly used herbicide atrazine in farmland, an iron-modified biochar (FeMBC) was fabricated via chemical co-precipitation of Fe³⁺ onto corn stalks biochar. The composites of FeMBC and Acinetobacter lwoffii DNS32 (bFeMBC) effectively accelerated the degradation rate of atrazine (100 mg L^-1) in inorganic salt culture solution. TEM，XRD，XPS and FTIR were used to study the basic properties of the Materials. FeMBC promoted the formation of bacterial biofilm, -NH functional group on the surface of bacterial extracellular polymers (EPS) and FeMBC could interact with the aromatic ring of atrazine through Hbonding, which were conducive for microbial capture of atrazine. Meanwhile, the pores (2-10 μm) of FeMBC facilitated the passage of the DNS32 strain and the atrazine molecule, which contributed to the efficient capture and degradation of atrazine by DNS32 strain. BFeMBC amendment helped to maintain the bacterial diversity in the atrazine contaminated soil. The increase of rare bacteria (relative abundance of 0.01%-0.05%) richness plays a certain role in stabilizing nutrient cycling, thereby promoting microbial nutrient utilization activities and has the function of pollutant degradation. This may contribute to the digestion of atrazine and its intermediate metabolites，reducing the stress of microbial in atrazine contaminated soil. bFeMBC amendment may be a promising in situ remediation technique for soil atrazine contamination.