Study On The Anoxic-contact Oxidation Process For The Treatment Of Dyeing Wastewater

In the development of the technology of domestic printing and dyeing enterprises, the printing process has made some progress such as the development of waterless printing process. However, in the actual production of enterprises, the production of low-grade products and extremely serious environmental pollution result in a large amount of waste of resources and the appearance of factors harmful to the sustainable development. Nowadays, the regulatory system of environmental protection is not sound enough to carry out its function and the sewage treatment processes are varied. But there are some deficiencies in most sewage treatment process, especially in the traditional A/O process. For example:in denitrification process, microorganisms involved in denitrification are vulnerable to inhibited because of changing oxygen conditions; Advanced microbial denitrification is not adequate; pollutant removal efficiency is not high, and so on. The study conducted on dyeing wastewater treatment technology applications, is still a valuable and practical research issues.This study have investigated the wastewater treatment effect of " Anoxic processes-contact oxidation" process combination with the use of a new biofilm filler in the treatment of dyeing waste water from plant. The results indicated the good treatment effect. The analysis of Chemical Oxygen Demand(CODcr), the content of ammonia nitrogen, total nitrogen and total phosphorus indicated that Anoxic processes-contact oxidation" process exhibited good effect on removal.The removal rate for CODcr, ammonia nitrogen, total nitrogen and total phosphorus was92.2%、86.9%、84.8%and69.6%, respectively. The system effluent reached the demand of "Discharge Standard of Main Water For Municipal Wastewater Treatment Plant and Key Industries of Taihu Area (DB32/1072-2007)"Identified by comparison of experiments improved after several important parameters of the reactor, the total HRT=28h; the mounting density of the filler10cm*10cm*45cm; a mixture of a reflux ratio of200%; contact oxidation tank of the gas-water ratio of20:1. In this condition, the reactor can be obtained relatively good removal effect.During the engineering practice, the expected transformation was made in a textile printing and dyeing enterprise in Jiangsu Province. The operation of the treatment process of was stable and its effectiveness was investigated. The removal rate of CODcr was about90%, Average reactor effluent CODcr is about45mg/l; and the removal rate of ammonia nitrogen was above90%, Average reactor effluent ammonia nitrogen is about3mg/l; The pH of the waste water was6-7and the removal rate of total phosphorus was80%, Average effluent total phosphorus is about0.2mg/l.