CHEMICAL AND BIOLOGICAL TREATMENTS OF THE WASTEWATER FROM DYEING INDUSTRY

Abstract

Textile wastewater is full of many pollutants that render water color, high COD, BOD and TDS. Also, such water can't be used or recycled as it is. Because of this many trials were carried out to treat textile wastewater. The aim of this work was to compare the treatment efficiency of these trials in reducing COD, BOD and TDS. Textile wastewater samples were collected from 18 textile dyeing workshops. Samples were analyzed according standard methods. Treatment methods varied from the use of balance tank, sedimentation tank, balance + settling tanks to the use of aeration lagoons in addition to the aforementioned facilities. Treatment efficiency achieved was 5.9-26.5% and 18.2-38.9% in BOD and COD, respectively, upon the use of sedimentation tank, while it was 50.4-97.5, and 60.5-96.7%, respectively, upon the use of aeration lagoon/balance/settling tanks. The treatment system included one type of reactors (FBR) that were run aerobically, with effective volume of 30 l. Small plastic (polyethylene) tubes of 1.5 cm diameter were used as the supporting material in the reactor. Different samples were taken from the reactor, at the end of each HRT. It is clear from experiment that the reduction of the organic dye as seen from SS, COD, and BOD values increases with the time that organic dye present in the treatment bed. The highest reduction was found to be 1 day after which it decreased and the organic matter increased in the effluent after treatment with failer of the bacteria and wash out of the bacteria out of the bed.