Study On The Pretreatment Of Textile Wastewater By Biological Treatment

Dyeing wastewater is the main pollutant resource of the textile industry in 2003There are over 900 dyeing enterprises in JiangSu province in 2003, which provide wastewater 700 to 800 thousand tons per day. The colourity and organic content in dyeing wastewater is high and it's hard to dispose. Hence it is a problem to treat dyeing wastewater more efficiently with less money.To solve this problem, a lot of domestic and abroad studies have been carried out ,which mainly deal with physical treatment, chemical treatment and the biological treatment. But the appliance of biological treatment only could not meet the need of the national for dyeing wastewater.This subject study is contained in the environmental protection technology developing project"study on the treatment methods and demonstration projects of dyeing and textile wastewater to meet (2003075)"of Jiangsu province. According to the time limit assured by the meeting of dyeing wastewater drainage by the first class drainage criterion in Jiangsu province, the 570 dyeing enterprises in Tai Hu lake basin should lift their drainage criterion from second class to first class before June 30,2005.And by the end of 2007,all the dyeing enterprises in the province should lift their drainage criterion from second class to first class.Through the study, conclusions as follow can be achieved:1.The hydrolysis pond is more suitable for the pretreatment of dye wasterwater contained acid dyes and reactive dyes than the low dissolved oxygen pond.2.After the treatment of the hydrolysis pond/SBR, the pollutants in the wastewater are reduced considerably.1) After the treatment of the hydrolysis pond, The BOD5/COD value of the wastewater is promoted from 0.22 and 0.23 to 0.32 and 0.34.2) After the treatment of the SBR, the COD value of the wastewater is reduced 80.9% to 81.1%, and that of BOD5 is 84.1% to 88.2%.