Özet:

Phenolic compounds that are mixed with soil through various waste are considered as an important pollutant group that is threatening soils because of their toxicity and carcinogenicity, their biological accumulation capacity and stability. Among the phenolic compounds, phenol is one of the most frequent environmental pollutants in soils and groundwater. Phenol-rich wastewater discharges from industries such as the petrochemical industry, explosive production, resin and coke production, the iron and steel industry, and the pharmaceutical industry pose a risk both to soils and to other environments. The aim of this study was to determine the effect of different concentrations of phenol on some soil enzyme activities and to show the remedial effect of stabilized domestic sludge on phenol contaminated soils. In this context, soils were contaminated with low and high doses of phenol (15 mg/kg and 150 mg/kg) and urease, dehydrogenase and alkaline phosphatase activities were determined after contamination. 100 t/ha of domestic sludge was applied to soils contaminated with phenol at different doses and the effects of sludge were evaluated by a 30-day incubation study. According to the results of the study, the effect of phenol application at 15 mg/kg concentration on soil enzyme activities was not significant. Phenol contamination at a concentration of 150 mg/kg inhibited determined enzyme activities by 25 to 52%. Wastewater sludges applied to phenol containing soils and control soil significantly increased enzyme activity values in soils. The negative effect of high-dose phenol application on enzyme activities was observed to be largely eliminated by wastewater sludge application.