Study on Reuse Potential of Textile Effluent in Bangladesh

Abstract

Being a developing country, achieving effective wastewater treatment in textile industry has proven to be a difficult task in Bangladesh. Many industries do not have adequate treatment facilities and untreated or poorly treated wastewater is discharged in nearby lands causing environment pollution. Traditional treatment processes of ETP being costly is one of the main reasons for this. Adsorption is a commonly used method for dye removal. Activated carbon is a widely-used effective low-cost absorbent for treating industrial wastewater. Using Lime or Ca(OH)2 along with activated carbon can further increase its effectiveness. In this research work, the removal of color from Bangladeshi textile industry effluent has been investigated. Both batch and fixed-bed column experiments have been conducted in this study. After multiple trials and errors, the optimal dosage of activated carbon was determined from the batch reaction. Freundlich and Langmuir isotherms were derived for the ease of determining the appropriate dosage of carbon to obtain desired color keeping lime dosage constant. There was reduction of color up until 24 hours in case of batch reactions and up until 6 hours in case of fixed-bed column studies. No significant change in color was found afterwards in both cases. Changes in other parameters such as turbidity, TDS and pH were also noticed. The removal efficiency of color obtained from fixed bed column was 98% for 6-inch bed height and 94% for 3-inch bed height. However, usage of lime has caused an increase in pH value for the treated water. From the results, it is clear that using activated carbon and lime together might be a successful method of reducing color and turbidity from wastewater used in the textile industry.