The Effects of Organic, Inorganic, and Microbiological Stabilizers on the Transfer of Arsenic and Heavy Metals to Rice Plant

To assess the effectiveness of stabilization techniques on the transfer of As and heavy metals in soil to rice plant, pot experiments were conducted using organic (biochar), inorganic (limestone-steel slag mixture), and microbiological (sulfate-reducing bacteria, SRB) stabilizers. The results showed that microbiological treatments, particularly when SRB and SO42- were co-injected, achieved higher stabilization efficiencies for Pb, Cu, and Cd in soil solution by the end of the experiments (153 days). The transfer of Pb, Zn, Cu, and Cd to the rice stems, leaves, and husks was reduced across all stabilization treatments. Notably, in husks, the stabilization efficiencies of Pb, Zn, Cu, and Cd ranged from 30% to 65% for organic stabilizers and 23% to 69% for inorganic stabilizers, surpassing those achieved with microbiological stabilizers. This study highlighted the potential of SRB as an effective alternative or supplementary stabilizer to conventional options such as limestone, steel slag, and biochar in reducing the transfer of heavy metals to crops in paddy soils.