Detection and identification of hazardous organic pollutants from distillery wastewater by GC-MS analysis and its phytotoxicity and genotoxicity evaluation by using Allium cepa and Cicer arietinum L

Distillery industry generates a huge amount of wastewater, which contains a high strength of organic and inorganic load. Accordingly, this study aims to analyze the physico-chemical pollution parameters and the occurrence of phytotoxic, cytotoxic and genotoxic pollutants in wastewater. The result revealed that values of wastewater parameters were recorded as 13268 mg l^-1 (BOD), 25144 mg l^-1 (COD), 25144 mg l^-1 (TS), and 6634 mg l^-1 (phosphate), while pH was alkaline. The organic compounds detected by GC-MS were quercetin 7,3',4'-trimethoxy, octadecadienoic acid, propanoic acid, glycocholic acid methyl ester, cantaxanthin, etc. The Allium cepa was used for the toxicity test with different concentrations of wastewater showed a significant level of reduction in root growth and length after exposure and the maximum reduction was at 25% and 20%. Phytotoxicity studies were performed using Cicer arietinum L. with different concentrations of wastewater, which showed adverse effects on seed germination, root length, and the effect was associated with the increasing concentration of wastewater. A. cepa root tips were used for the analysis of mitotic index (MI), nuclear abnormalities (NA), and chromosomal aberrations (CA). MI was decreasing significantly from 72% (control) to 33%, 22%, 23%, 21%, and 18% at 5%, 10%, 15%, 20%, and 25% wastewater concentration, respectively. The A. cepa root tip cells showed chromosomal aberrations and nuclear abnormalities like vagrant, stickiness, chromosomal loss, c-mitosis, binucleated, micronuclei, and aberrant cell. This study concluded that the wastewater treatment process is insufficient and the discharged waste needs a proper assessment to know the associated health risk.

Bacterial degradation of distillery wastewater pollutants and their metabolites characterization and its toxicity evaluation by using Caenorhabditis elegans as terrestrial test models

Distillery wastewater has significant amount of coloring compounds and organic substances even after the secondary treatment process, which poses many severe environmental and health threats. However, the recalcitrant coloured compounds have not yet been clearly identified. In this study, two bacterial strains DS3 and DS5 capable to decolorize distillery wastewater (DWW) pollutants were isolated and characterized as Staphylococcus saprophyticus (MF182113) and Alcaligenaceae sp. (MF182114), respectively. Results showed that mixed bacterial culture was found more effective decolorizing 71.83% DWW compared to axenic culture DS3 and DS5 resulting only 47.94% and 50.67% decolorization, respectively. The FT-IR and LC-MS/MS analysis of untreated DWW showed the presence of many recalcitrant compounds having different functional groups, but after bacterial treatment, most of compounds get diminished and the toxicity of DWW was reduced significantly. Further, the Nile red staining of Caenorhabditis elegans exposed to untreated and bacteria treated DWW for evaluation of toxicity assay and results revealed that the worms exposed to untreated DWW showed sharp reduction in total fat content having more profound effects, suggesting the diminished nAchR signaling as compare to bacterial treated DWW. Hence, this study revealed that inadequate disposal of untreated DWW may cause transfer of toxic substances into the environment and receiving water bodies.

Evaluation of distillery wastewater treatability in a customized photobioreactor using blue-green microalgae - Laboratory and outdoor study

Treatability of anaerobically digested distillery wastewater is challenging because of its high pollution load of COD up to 40,000 ppm. This research investigates the possibilities of retrofitting the effluent treatment plant (ETP) of a distillery with microalgae treatment step. For this, at first the photobioreactors of capacity 50 L and 500 L were customized for the cultivation of Spirulina sp. under xenon lamp and sunlight. The reactor supported the maximum specific growth rate up to 0.42 ± 0.03 d^-1 in the 50 L reactor at laboratory and 0.10 ± 0.02 d^-1 in the 500 L reactor at the outdoor for Spirulina sp. The treatability of wastewater of COD 30,000 ppm-40,000 ppm was carried out in those reactors with the Spirulina sp. of culture volume fraction 0.8 and 0.93 under xenon lamp and sunlight respectively. The chemical oxygen demand and total dissolved solids reduction were 60-70% in both the volume fractions of the culture. Ion chromatography analysis indicated the reduction of major inorganic pollutants in the wastewater by the Spirulina sp. The algae were sustainable when the culture volume fraction was increased from 0.8 to 0.93. Thus, the phycoremediation was shown the significant pollution reduction in the wastewater. The addition of this step is valuable and it benefits the distillery by not only improving the quality of wastewater but also through the generation of algae biomass that would be appropriate for animal feed or biofuel application. However, the detail biochemical study is needed for the best use of algae biomass and the treatment could be checked for the long run sustainability.

A novel application of Paracoccus pantotrophus for the decolorization of melanoidins from distillery effluent under static conditions

Melanoidin is the hazardous byproduct formed during the production of ethanol in distilleries. In the present study, a highly effective melanoidin decolorizing bacterial isolate, SAG1, was isolated from the effluent enriched soil of a distillery. This strain, identified as Paracoccus pantotrophus, was highly efficient to decolorize melanoidins up to 81.2 ± 2.43% in the presence of glucose and NH4NO3. The effects of autoclaved as well as living cells and inoculums size on decolorization activity were investigated. The results indicated that only living cell showed the decolorization activity i.e. 78.6 ± 2.62%, while, no activity has been observed using autoclaved cells. The inoculums size of 8% v/v, showed maximum activity of 62.9 ± 3.00%. The isolate SAG1 was found to be more efficient in decolorizing the melanoidins from distillery effluent as compared to the reference culture Pseudomonas putida.

Comparison of transport between two bacteria in saturated porous media with distinct pore size distribution

The transport behaviour ofEscherichia coliandKlebsiellasp. was studied under saturated flow conditions to explore the effect of pore size distribution and bacteria cell properties on microbial transport.