Re-use of Textile Effluent - An Experimental Study of Color Removal

Abstract

Textile wastewater treatment is a great concern worldwide. Due to its uneven water quality parameter, it is difficult to handle using tradition treatment methods. Besides, huge amount of water usage plays a vital role on depleting ground water level. Rainwater harvesting system does not show any significance contribution in this purpose. Thereby comes the necessity of reusing of effluent after proper treatment. In Bangladesh's textile industry, ensuring proper and effective wastewater treatment has become a difficult task. Adsorption is one of the most common and effective methods for dye removal. In this experimental work, the study shows how well Powdered Activated Carbon (PAC) as adsorbent with Lime or Ca(OH)2 as an aid works for removal of color, TDS (Total Dissolved Solid), turbidity and pH. Freundlich and Langmuir are two common models of adsorption to achieve the particular carbon dosage for maintaining any particular range of color. In this study, between Freundlich and Langmuir type of isotherm Freundlich shows a clear trend with determining parameters. After collecting the samples, jar test procedure was followed to achieve the optimum dosage. Jar test method is a laboratory process for estimating the dosage to achieve certain water quality goals. The optimum dosage of PAC was obtained 5-6 gm with adding 1.5 gm Ca(OH)2 and the equilibrium time was 12 hours for color removal. The removal efficiency obtained from the test was 99.3% for color, 99.87% for TDS and 97.8% for turbidity. The results suggest that the combined use of PAC and Ca(OH)2 can be useful as dye removal from textile wastewater. A feasibility study can help to check economic perspective of effectiveness of implementing this process in industry.