Differential effects of sulfamethoxazole concentrations on the enzymatic dynamics of aerobic composting

Enzymatic activities play an important role in the biological composting processing of agricultural wastes. This paper explores the effect of sulfamethoxazole (SMX) (Control, 25 mg/kg, 50 mg/kg, and 100 mg/kg) on the enzymatic activities of cellulase, protease, urease, and arylsulfatase. Compost samples were taken at three different intervals for analysis (day 0, day 25, and day 45). The findings revealed that at the start of the composting process, a strongly negative effect on enzymatic behavior was observed, and this response was significantly dependent on SMX concentrations (p < 0.05). The inhibition was consistent across all treatments. According to the results, the negative impact of SMX on community structure can result in selection pressure. Furthermore, all of the treatments had drastically improved enzymatic activity by the end of the composting process (day 45). This effect was presumably caused by the deterioration of SMX and a substantial stress reduction.