Optimization And Application Of Centralized Disposal Process Of Printing And Dyeing Wastewater

The management mode of medium or small enterprises entering the industrial park, gives birth to the form of centralized collection and treatment with printing and dyeing waste water. But also leads to the class of mixed wastewater presents water quality fluctuation, regularity difference features, combined with stricter emissions standards, the traditional, single printing and dyeing wastewater treatment process is difficult to meet the requirements of governance.Subject to the centralized treatment of printing and dyeing wastewater sewage treatment plant as the research object, according to the effluent discharge requirements and raw water quality current situation, analysis should be "focused on the removal of COD, both nitrogen and phosphorus removal process design requirements ".Through the feasibility demonstration, combined with domestic sewage treatment of printing and dyeing wastewater with successful experience, the choice of physical chemical treatment and biological treatment technology combined with the comprehensive management of route, and based on the design of pilot and listed a number of dynamic and static test, to determine the process parameters and the optimization of the design. Ultimately determine the " adsorption precipitation+hanging membrane hydrolytic acidification and A2/O nitrogen and phosphorus removal chemical precipitation " printing and dyeing wastewater treatment technologies and its main technical parameters, after engineering test, the printing and dyeing industrial park wastewater emissions of COD, BOD and SS can reach ’centralized sewage treatment plant integrated wastewater discharge standard’. Sewage plant Ⅱ standard, ammonia nitrogen and phosphorus discharge value can also be achieved by "textile dyeing and finishing industrial water pollutant discharge standard " in the grade I standard enterprise.1.On the comprehensive analysis of project quality, drainage and feasibility on the basis of factors such as physical, chemical and biological treatment combined with management line, put forward’with hydrolytic acidification and biological nitrogen and phosphorus removal process’as small, pilot core technology. The first factory wastewater hydrolysis acidification pretreatment, improve wastewater biodegradability, the BOD5/CODcr index of more than0.3, BOD5/TN index of0.4or more, to keep the BOD5/TP index in20above. The main technology of A2/O biochemical reaction, through anaerobic, anoxic and aerobic three links, COD degradation and biological removal of nitrogen and phosphorus target; 2. Through the three stages of the test, the treatment process of printing and dyeing wastewater biochemical treatment unit and processing unit is optimized. Design of the bacterium culture and start test, main technology test and additional test3test phases and process device, through static and dynamic experiments show: process setting difficulty should be placed on COD removal, while considering the removal of nitrogen and phosphorus and decolorization of requirements; hydrolysis acidification pool technology key to total nitrogen ammonification, BOD5/CODcr value improvement, chroma removal; pilot two sedimentation effluent CODcr can reach130～190mg/1, proved "pretreatment+primary settling+hydrolysis+A2/O+dosing two sedimentation process" the setting is reasonable; in order to stabilize the standards must be considered after dosing measures, polyferric sulfate coagulant is suitable, the better the dosage is20-50ppm;3. Through the preliminary design, optimum design and experiment, to determine the " adsorption precipitation+hanging membrane hydrolytic acidification and A2/O nitrogen and phosphorus removal chemical precipitation " core technology. Industrial application show that, the front section of the pretreatment, realize the biodegradability enhancement and color removal, the biological response to treatment of A2/O three section type setting, to better achieve the COD, BOD and other organic matter removal, the average removal rates were77.7%and88.5%, taking into account the requirement of the nitrogen and phosphorus removal after; period of feeding links, to ensure that the SS discharge standards, but also reflects the polymerized ferric sulfate is more appropriate, practical coagulant.