Acta Petrologica et Mineralogica

Metal nano ferrous sulfide (FeS) has broad application prospects in heavy/metalloid remediation. Using Acidiphilum cryptum iron-reducing bacteria (JF-5) and sulfate-reducing bacteria (SRB) to synthesize biological nano-FeS, to explore its natural sedimentation law, and to use sodium carboxymethyl cellulose (CMC) as a stabilizer to explore CMC-FeS mobility characteristics in quartz sand columns. The results showed that the nano-FeS could be formed by mixing SRB and JF-5 bacterial solution with certain proportions, and when the n(Fe):n(S)=0.2 in the mixed bacterial solution, the amount of FeS was the largest with 2 400 mg/L of the particle concentration; the natural sedimentation rate of FeS could be effectively slowed down in 0.1% CMC solution. The convection diffusion model can well describe the migration behavior of CMC-FeS suspended particles in quartz sand columns. Compared with the purewater-FeS system (R²=0.20), the model correlation was as high as 0.85. Under three imput flow rates (90, 180 and 360 mL/h), the medium flow rate could obtain the best permeability, and the average permeability coefficient was 243.97 cm/h. Therefore, the stability and migration of CMC-FeS have been enhanced compared with the purewater-FeS, which may provide a theoretical reference for soil pollution remediation.

biological FeS; settlement; column migration