Treatment of Waste Water Effluent from Coffee Industry using Anaerobic Mixed Culture Pseudomonas Florescence and Escherichia Coli Bacteria and with Gypsum: A Case in Dilla- Ethiopia

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Addis Ababa University


Coffee processing industries generate huge amount of wastewater. The effluent is characterized by a lot of sludge, high amount of organic load and acidic nature due to fermentation process. Due to this, it contains high value of COD, BOD, TS and other contaminants. This effluent when disposed in natural water, it contaminates aquatic animals and plants environment. So, care has to be taken to ensure the quality of the releasing waters should be reduced below the prescribed standards. There are many physical and chemical treatment methods available for the removal of pollutants but all these methods have problems associated with secondary effluent, hazardous and harmful end products, high energy consuming, non-economic etc. These problems can be overcome by the use of biological treatment methods which are simple, eco-friendly and efficient where complete removal of the pollutants is possible. Cognizant of this, the researcher was initiated to study the treatment of wastewater effluent from coffee industry in the specific area by using anaerobic Pseudomonas florescence and Escherichia coli bacteria as mixed culture and with gypsum (CaSO4.2H2O). In this study, the wastewater value of BOD5, COD, TS and neutralization of the PH reduction was achieved. The results show that the treatment reduced BOD5, COD and TS from its initial concentration of 320.26 mg/l, 1261 mg/l, and 3545 mg/l to 35.66 mg/l, 97 mg/l and 68 mg/l respectively. The treatment in the study shows 87.74% reduced of BOD5 load, 92.02% reduced of COD and 98.01% reduced of TS from the initial load using optimization of the treatment method. Therefore, it can be concluded that mixed culture bacteria of Pseudomonas florescence and Escherichia coli in combination with gypsum as a new effective treatment having potential for BOD5, COD and TS reduce from the effluent treated. The mixed culture of microorganisms is capable to reduce the contaminants that made the approach cost effective, time saving compared with other results found by other authors without mixed culture. The microorganisms included in the study can be applied for the treatment of effluents containing the multiple contaminants.



Effluent, Treatment, Anaerobic Microorganism, Mixed culture, Gypsum