A New Wastewater Treatment Technology And Its Application In A Textile Wastewater Treatment System

Textile wastewater is a kind of industrial wastewater that is of large quantity and difficult to treat. It is a very serious pollution for the environment. In view of the pressure of ecological environment on the treatment of textile wastewater, a lot of treatment projects have been built. But up to date, these projects have not reached the requirements of treatment. Therefore, the upgrading and regeneration are needed.The general situation of textile wastewater treatment systemincluding the water supply/method of printing and dyeing/drainage/design and run of the wastewater treatment and equipment existed and so on in a printing and dyeing factory was investigated. We have proposed an engineering technology transformation plan on the base of intensive survey and analysis in original wastewater treatment system as well as the current domestic and foreign experience in textile wastewater treatment, i.e., the combined technology of anaerobic hydrolysis pond+convective exchange aeration oxidation pond+re-oxidation of biological carbon adsorption filter. It adopts some biological and chemical processing equipments on the base of the technology of original textile wastewater treatment. The operation results before and after transformation demonstrate that after regeneration of textile wastewater treated by the combined process, the content of COD in effluent water drops from original over441mg/L to below51mg/L; the content of BOD in effluent water drops from original223mg/L above to below14mg/L; the content of color in effluent water drops from original over205to below29; the average removals for COD, BOD and color in effluent water are improved from72.5%to95.6%,55.4%to96.8%, and75.7%to96.1%, respectively.The upgrading of wastewater processing technology of printing and dyeing industry to the combination processing technology of "physicochemical and biochemical" from the original single physico-chemical treatment enhances the quality of effluent wastewater, and increases the removal rates of COD, BOD and color in effluent water, respectively, to23.1%,41.4%, and20.4%. However, there is little improvement in the removal rate of SS with about90%. Hence, the upgrading of textile wastewater treatment technology reduces the total discharge of pollutants greatly as well as protects the water environment for human survival.