Physicochemical quality and mycodegradation of commercial paint effluents from factories in Ado-Ekiti, southwestern region, Nigeria

Abstract

Bioremediation is a useful method for restoring contaminated soils because of its cost effectiveness and environmental friendliness. However, the process is slow in soils with low pH. This study sought to explore the isolation and bioremediation of oil-based paint in aqueous medium using indigenous fungal isolates from paint contaminated soil from Ado Ekiti. The fungal isolates were initially screened for bioremediation potential in mineral salts medium containing oil-based paint (conc. 300 ppm, w/v) under shake flask conditions. Results of the physicochemical analysis of the soil showed: pH, 5.60-6.25; organic carbon, 2.28-4.70%; temperature, 27 -35 ^oC; BOD, 182-219 mg/L; COD, 292-719 mg/L; sulphate, 30-42 mg/L; nitrate, 2.25-8.0 mg/L. The load of heterotrophic fungi ranged from 1.21 × 10⁴ to 17.0 ×10⁴ cfu/g while paint-utilizing fungal counts in the samples ranged from 0.27 × 10³ to 3.5 ×10³cfu/g. The isolated fungi mainly belonged to six (6) fungal genera, namely; Penicillium spp (43.75%), Fusarium spp (18.75%), Rhizopus oryzae (12.5%), Aspergillus niger (12.5%). Among them, Penicillium notatum showed the greatest paint degradation ability from day 7 to day 21 while Penicillium citrium showed the least among the fungal isolates on day 7. The results suggest that Penicllium isolates in this study could be exploited in bioremediation of paint effluents and contaminated soil.

Keywords: Biodegradation, Fungi, Contamination, Isolate, Paint effluent