Performance Evaluation of Textile Effluent Treatment Plant: Bangladesh Perspective

The present study was undertaken to evaluate the performance efficiency of an Effluent Treatment Plant (ETP) of a Textile industry located at Tongi, Bangladesh with biological treatment (BT) and Membrane Bio-Reactor (MBR) with an average inflow of 300 m3/hr. The effluent samples were collected from the inlet and outlet of the ETP on a weekly basis for a 4 weeks’ period and were analysed for key parameters such as colour, temperature, total suspended solids (TSS), Total Dissolved Solids (TDS), pH, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD). In this study, it was observed that the colour of the effluent in the inlet was dark blue and after multiple unit treatments of the colour’s final outlet the discharge, water colour was very light purple. The temperature was varied from 32.2⁰C to 34.33⁰C. The TDS was varied from 1252.5 mg/l to 1087.5 mg/l and the percentage removal efficiency of TDS was varied from 21.47% to 42.7%. The TSS was varied from 4 mg/l to 4.5 mg/l and the percentage removal efficiency of TSS was varied from 98.48% to 98.21%. The pH value was varied from 6.48 to 7.63. The DO value in the inlet was varied from 6.47 mg/l to 6.775 mg/l. The BOD was recorded from 12.75 mg/l to 17.75 mg/l and the percentage removal efficiency of BOD was varied from 89.92% to 87.24%. The COD was varied from 33.75 mg/l to 34.25 mg/l and the percentage removal efficiency of COD was varied from 91.11% to 90.5%. It is conjectured that the values of the measured parameters are seen to be within the permissible limit as per the standard of the Department of Environment (DoE) of Bangladesh.

Green Gold from Dairy Industry: A Self-Sustained Eco-Friendly Effluent Treatment Plant

The major bottleneck of dairy effluent treatment plant operation is the generation of 10 m3 of nutrient rich wastewater per m3 of milk processed resulting in an annual production of 7.93 tons of carbon dioxide equivalent (CO2 e) gas during treatment in a 7–8 step process. It is an expensive, non-ecofriendly, laborious process which is often not adoptable by the small segment installations. A carefully selected tailor-made bacterial consortium in biofilm reactor within 4 h of incubation in a single step operation under ambient condition could transform the total volume of wastewater into ammonia rich liquid biofertilizer generating 0.79 tons/year CO2 e gas. This biofertilizer replaces the use of fresh water and chemical fertilizer for agriculture, producing economic crops at par with chemical fertilizer. In certain cases, the production of crops is increased substantially over chemical fertilizer based growth. It reduced carbohydrate content of tuber crops. The generated liquid biofertilizer can overcome the shortage in fodder production without using chemical fertilizer and fresh water, hence solving one of the major concerns for sustaining the expansion of dairy industry, hence making dairy effluent treatment plant (ETP) operation an eco-friendly, self-sustainable operation.

Chromium bioremediation potential of indigenous Bacillus pumillus isolated from river water of Bangladesh

Bangladesh has achieved rapid industrialization in recent years. However, many of these industries lack proper effluent treatment plant and discharge untreated effluent laden with different heavy metals into the major rives that surround these industries, affecting the environment as well as human and animal health. Aiming to develop a sustainable effluent treatment plant, a heavy metal tolerant Bacillus pumillus isolated from polluted river water of Bangladesh was studied for its chromium bioremediation potential. Reduction of hexavalent chromium using the Sdiphenylcarbazide (DPC) method showed that whole cells of the Bacillus pumillus reduced 89.5%, 75%, 73% and 45% of 1.0, 2.5, 5 and 10mg/L Cr(VI) to Cr(III), respectively. This bacterium reduced 100% of 20mg/L Cr(VI) to Cr(III) within 8 hours, in a growth associated pattern. A 20kb plasmid was detected in this Bacillus pumillus, and loss of this plasmid did not cause complete impairment of chromium tolerance capacity, though the tolerance efficiency was reduced. The Bacillus pumillus studied in the current study therefore shows its potential to develop a sustainable chromium bioremediation method. Bangladesh J Microbiol, Volume 38, Number 1, June 2021, pp 27-30

Textile Industry Wastewaters From Jetpur, Gujarat, India, Are Dominated by Shewanellaceae, Bacteroidaceae, and Pseudomonadaceae Harboring Genes Encoding Catalytic Enzymes for Textile Dye Degradation

Textile industries play an important role in uplifting the national economies worldwide. Nevertheless, they generate a huge amount of intensive colored effluent, which is a serious threat to the environment. The microbial communities present in these highly polluted environmental sites help in remediating pollutants naturally. However, little is known about their genes and enzymes in the textile wastewater systems. In this study, we explored the microbial community structure and their functional capability in three different wastewater systems, i.e., industry sites, effluent treatment plant (ETP), and common effluent treatment plant (CETP). Our findings based on shotgun metagenomics highlight the varied bacterial diversity at the three industry sites. Overall, the major dominant phyla in the industry site and CETP samples were Proteobacteria and Bacteroidetes, while in the ETP site, Firmicutes, Cyanobacteria, and Proteobacteria were predominant. The final discharge sample site was having a higher proportion of the Proteobacteria and Bacteroidetes. Aeromonas caviae, Desulfovibrio desulfuricans, Klebsiella pneumoniae, Pseudomonas stutzeri, Shewanella decolorationis, Shewanella oneidensis, Shewanella putrefaciens, and Vibrio cholera were the abundant species across the three sites. Furthermore, this research study identified the key microbial genes encoding enzymes having a known role in textile dye and aromatic compound degradation. Functional annotation of the shotgun metagenome samples indicates the presence of reductase, azoreductase, nitrate/nitrite reductase, and oxidoreductase enzyme encoding genes. Our findings provide the shotgun metagenomics-based approach for mining the textile dye degrading genes and genomic insights into the bioremediation of textile industrial effluent.

Study of Change in Physico-Chemical Parameters by Treatment of Sludge from Common Effluent Treatment Plant (CETP) with Earthworms

One of the most vital problems of environmental protection concern is that of solid waste disposal. This problem continues to grow with the growth of population and the development of industries. The Common Effluent Treatment Plant (CETP) already establishes itself as a service to society at large, contributing towards a cleaner environment. However, the inappropriate disposal of CETP’s hazardous sludge can cause serious environmental problems. The sludge if sent for landfilling may cause groundwater contamination, changing the soil fertility parameters as well. The research presented here is carried out to explore the ability of an epigeic earthworm Eudrilus eugeniae to transform the sludge produced from CETP into a value-added product i.e., vermicompost. In this study, six samples of feed mixture were used with different ratios of CETP sludge, cow dung, and sawdust. Physico-chemical parameters such as pH, Electrical Conductivity (EC), Volatile Solids (VS), Total Nitrogen (TN), Nitrate Nitrogen (NO3--N), Ammonium Nitrogen (NH4+-N) were characterized to analyze the quality of the compost formed. All these parameters are in the agreement with recommended standards of mature compost. The result shows that vermicomposting technique when used, epigeic earthworm Eudrilus eugeniae can work as a favorable alternative solution for the disposal of CETP sludge.