Browsing by Author "Kiros, Solomon(PhD)"

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    Removal Efficiency of Blended Coagulants in Textile Wastewater Treatment
    (Addis Ababa University, 2016-06) Hagos, Abadi; Kiros, Solomon(PhD)
    Textile industry plays an important role in the economic development of developing countries including Ethiopia. In the other hand textile industry is one of the main sources of pollution worldwide. Textile effluent is characterized by high BOD and COD loads, suspended solids, minerals, oils and residual dye. During the dyeing process 2-20% is directly discharged as aqueous effluents into different environmental components which results in environmental pollution. This indicated urgent need to develop cost effective and efficient treatment method. The overall objective of this study was to treat textile waste water and evaluate the removal efficiencies of blended inorganic and natural coagulants namely alum and Moringa Stenopetala. The evaluation of removal efficiency of the blended coagulants were done for COD, BOD, TDS, TSS, Turbidity and light absorbance of the textile waste water before and after treatment. The raw textile wastewater was collected from Ayka Addis Textile and Investment group. The treatment process was carried out using a jar test at different dose and pH values. The coagulant dose and pH were the two factors considered in the treatment process. The dose of the coagulants were 15, 20, 25 g/l where as pH was set at 3, 7, 11.The pH was adjusted using Nitric acid (1M). The experimental result of textile wastewater after treatment was analyzed using the design-expert 6.0.8 portable software by the general factorial design with factors of coagulant dose and pH. Three levels of each factor with three times replication were used. Before treatment, the value of The turbidity, suspended solid , total dissolved solid found in the waste water , chemical oxygen demand (COD), biological oxygen demand (BOD) and light absorbance of the textile waste water effluent was 63.4 FNU,78 mg/l,37600mg/l,1700 mg/l and 630 mg/l,100% respectively. The maximum removal efficiency of the blended coagulant for turbidity, TDS, suspended solid, COD, BOD and light absorbance was obtained at coagulant dose of 25 g/l and pH of 3 and the removal efficiency was 83.9%, 76.2, 79.8, 72.6, 88%, 3.2% respectively. Keywords: Alum, coagulation, Jar Test, Moringa stenopetala, Textile Waste Water