Hydrolytic Enzyme Effects on Total Coliforms in Surfactant-Rich Industrial Wastewater and Soil Extracts: A Control-Adjusted Assessment

Detergent manufacturing wastewater contains surfactants, organic contaminants, and microbial populations that may challenge conventional treatment processes. This study evaluated the response of total coliforms to hydrolytic enzyme treatments in detergent-impacted industrial wastewater and aqueous soil extracts under controlled laboratory conditions. Cellulase, amylase, protease, an enzyme-supplemented detergent formulation, an enzyme-free detergent formulation, and untreated controls were assessed during a ۷-day incubation period. Total coliform abundance was determined using the five-tube Most Probable Number (MPN) method, and treatment performance was evaluated using endpoint abundance and residual coliform counts. A substantial decline occurred in the untreated wastewater control, which exhibited an ۸۸.۵% reduction in coliform abundance, indicating that natural attenuation represented a major component of the overall response. Among wastewater treatments, cellulase (WW-CEL) and the enzyme-supplemented detergent formulation (WW-D+E) exhibited the lowest endpoint coliform abundances, with endpoint values at or near the analytical detection limit. Relative to the untreated control, WW-CEL was associated with an additional reduction of approximately ۱۱.۴% beyond the baseline decline observed under the experimental conditions. In contrast, the enzyme-free detergent treatment produced an endpoint response comparable to the untreated control. Most soil extract treatments exhibited baseline coliform abundances at or below the analytical detection limit, limiting interpretation of treatment-specific responses. These findings suggest that hydrolytic enzymes may contribute to incremental reductions in coliform abundance in surfactant-rich industrial wastewater. However, the overall response was strongly dominated by natural attenuation, and observed treatment effects were highly dependent on matrix characteristics and baseline microbial load.

کلیدواژه ها:

Enzymatic bioaugmentation ، Industrial wastewater treatment ، Coliform suppression ، Cell envelope disruption ، Surfactant synergism ، Matrix-dependent attenuation