Polyvinylpyrrolidone 담체 고정화를 통한 생물학적 황화수소 처리 향상

A novel facultative chemolithoautotrophic bacterium, Thiobacillus sp. IW, isolated from coal mine water, demonstrates broad substrate specificity while maintaining mixotrophic growth and denitrification capability under anaerobic conditions. This study characterizes the physiological, biochemical, and kinetic properties of this strain to evaluate its potential for sulfur compound remediation. Growth kinetics indicated that sulfate accumulation-induced acidification was identified as a key growth-limiting factor. To mitigate this limitation, cell immobilization using polyvinylpyrrolidone (PVP) was applied, resulting in enhanced cell stability and improved hydrogen sulfide (H₂S) removal performance. Kinetic analysis showed a maximum H₂S removal rate (V_m) of 52.4 g S kg^-1 PVP d^-1 (dry basis) and a saturation constant (K₅) of 62.9 ppm. Under immobilized conditions, H2S removal experiments conducted over an inlet concentration range of 200-1,800 ppm demonstrated removal efficiencies exceeding 90% at 1,000 ppm and remaining above 85% under shock load conditions (≥1,500 ppm). These results indicate that Thiobacillus sp. IW is a robust biocatalyst for high-load H2S treatment and a useful model organism for investigating sulfur oxidation processes.