Textile effluents decolourization potential of metal tolerant Aspergillus species and optimization of biomass concentration and temperature

Abstract

This research was performed to assess the physicochemical properties of textile effluents collected from different sampling points (industrial park, Hosur, Tamil Nadu, India) and also evaluate the multiple metal tolerance efficiency of pre-isolated Aspergillus flavus. Moreover, their textile effluent decolourization potential was investigated and quantity and temperature required for effective bioremediation was optimized. About 5 textile effluent samples (S0, S1, S2, S3, and S4) were collected from various sampling points and noted that certain physicochemical properties (pH: 9.64 ± 0.38, Turbidity: 18.39 ± 1.4 NTU, Cl−: 3185.38 ± 15.8 mg L−1, BOD: 82.52 ± 6.9 mg L−1, COD: 342.28 ± 8.9 mg L−1, Ni: 74.21 ± 4.31 mg L−1, Cr: 48.52 ± 18.34 mg L−1, Cd: 34.85 ± 1.2 mg L−1, Zn: 25.52 ± 2.4 mg L−1, Pb: 11.25 ± 1.5 mg L−1, Hg: 1.8 ± 0.05 mg L−1, and As: 7.1 ± 0.41 mg L−1) were beyond the permissible limits. The A. flavus, showed remarkable metal tolerance to Pb, As, Cr, Ni, Cu, Cd, Hg, and Zn on PDA plates with elevated dosage up to 1000 μg mL−1. The optimal dosage required for effective decolourization was found as 3 g (48.2%) and compare to dead biomass (42.1%) of A. flavus, the viable biomass showed remarkable decolourization activity on textile effluents in a short duration of treatment process. The optimal temperature for effective decolourization by viable biomass was found at 32 ᵒC. The toxic effects of S4 samples treated at 32 ᵒC on O. sativa as well as brine shrimp larvae were significantly reduced. These findings show that pre-isolated A. flavus viable biomass can be used to decolorize metal-enriched textile effluent. Furthermore, the effectiveness of their metals remediation should be investigated using ex-situ and ex-vivo approaches.