Treatment of synthetic textile wastewater containing dye mixtures with microcosms

The aim was to assess the ability of microcosms (laboratory-scale shallow ponds) as a post polishing stage for the remediation of artificial textile wastewater comprising two commercial dyes (basic red 46 (BR46) and reactive blue 198 (RB198)) as a mixture. The objectives were to evaluate the impact of Lemna minor L. (common duckweed) on the water quality outflows; the elimination of dye mixtures, organic matter, and nutrients; and the impact of synthetic textile wastewater comprising dye mixtures on the L. minor plant growth. Three mixtures were prepared providing a total dye concentration of 10 mg/l. Findings showed that the planted simulated ponds possess a significant (p < 0.05) potential for improving the outflow characteristics and eliminate dyes, ammonium-nitrogen (NH4-N), and nitrate-nitrogen (NO3-N) in all mixtures compared with the corresponding unplanted ponds. The removal of mixed dyes in planted ponds was mainly due to phyto-transformation and adsorption of BR46 with complete aromatic amine mineralisation. For ponds containing 2 mg/l of RB198 and 8 mg/l of BR46, removals were around 53%, which was significantly higher than those for other mixtures: 5 mg/l of RB198 and 5 mg/l of BR46 and 8 mg/l of RB198 and 2 mg/l of BR46 achieved only 41 and 26% removals, respectively. Dye mixtures stopped the growth of L. minor, and the presence of artificial wastewater reduced their development

Evaluation of bioremediation competence of indigenous bacterial strains isolated from fabric dyeing effluent

© 2020 Elsevier Ltd In this present assessment, fabric dyeing wastewater was subjected to the characterization of physical-chemical parameters in terms of colour, TDS, COD and chloride. The indigenous bacterial strains were isolated from the effluent and identified as Bacillus velezensis, Chryseomicrobium imtechense, Planococcus maritimus and Sphingobacterium daejeonense by 16S rRNA gene sequencing method. The bioremediation competency of the strains was evaluated by conducting treatment process with monoculture and bacterial consortium. The consortia removed about 98%, 71.5%, 79%, 69.65% of colour, TDS, COD and chloride, respectively. Among the four isolates, monoculture of B. velezensis showed effective diminution of pollutants from the effluent than other strains. The bacterial degradation of pollutants was determined by GC–MS based on the disappearance of certain peaks after bioremediation. The results suggested that the bioremediation efficiency of bacterial strains can be utilized as an eco-friendly and inexpensive method for dyeing effluent treatment

Evaluation of efficacy of indigenous acidophile- bacterial consortia for removal of pollutants from coffee cherry pulping wastewater

© 2020 Elsevier Ltd The efficiency of indigenous bacteria to remove colour, TDS and COD pollutants from coffee cherry pulping wastewater (CCPWW) in an acidic pH without any manipulation of the effluent was studied. For the removal of such pollutants, the CCPWW was subjected to treatment with four indigenous microbial test strains isolated from CCPWW and characterised using 16S rRNA molecular technique, namely Enterobacter ludwigii, Bacilllus cereus, Enterobacter aerogenes and Enterobacter cloacae. Among the individual microbial treatments, the Enterobacter cloacae bacterial strain removed higher amount of TDS (37.6%) and COD (40.1%). Treatment with the bacterial consortia removed about 40.9% TDS, 48.7% COD from CCPWW after 48 h. The correlation coefficient ‘r’ between TDS and COD removal for each individual treatment was 1, showed the positive linear relationship. The microbes had endured in the harsh–low pH environment of the effluent and effectively removed the pollutants without any addition of other nutrient support