Treatment Research On Flotation-Hydrolytic Acidification-Biological Contact Oxidation Process In Treating Paint Wastewater

In the paper,the experimental studies on Aqueous paint wastewater,the wastewater has a high organic content,biodegradable,poor biodegradability characteristics.The quality indicators of wastewater main are: concentration of COD6000¹2000 mg/L,concentration of BOD₅1600³400mg/L,concentration of SS600²400mg/L,concentration of NH₃-N18³5mg/L,respectively.If the water are directly emissioned,it can cause great harm to the environment.The combined process of flotation-hydrolysis acidification-biological contact oxidation combined technology has been adopted to deal with waste water.through the process of laboratory research,combined with engineering commission is conducted,studying the reliability and stability of the system operation,make the effluent meet the integrated wastewater discharge standard?GB8978-1996?secondary emission standard.?1?Through the screening of coagulant by the experiment,the PAC and PAM have determined as coagulant,and the optimum dosage is 125mg/L,7mg/L,respectively;Through the results inflotation pretreatment,its removal rate of COD,SS are 64.8%,90.1%.Effluent after Flotation mixed with sewage as inflow of a biochemical pool.The quality index of Mixed wastewater are:concentration of COD₅00¹400mg/L,concentration of BOD₅250⁴50mg/L,concentration of SS120¹90mg/L,concentration of NH₃-N28⁴5mg/L.?2?Hydrolysis acidification reactor remained stable after 25 days of the start,microbial growth is good and the volume load from 0.9kgCOD/?m3·d?to 2.6kgCOD/?m3·d?.By analyzing changes in the indicators found with removal rate of HRT,COD,SS increases with HRT extended until HRT=8h,then removal rate of COD,SS is34.3%,51.4%,determined HRT=8h water used in the present experiment hydrolysis acidification reactor residence time of the wastewater treatment paint.After hydrolysis acidification,the B/C of wastewater value raised from 0.33 to 0.41.?3?After Acclimation and vaccination,about 30 days' biological contact oxidation reactor starts successfully.Aration time,DO and volume loading are Site commissioned,the results show that HRT =14h,DO =2³mg/L,volumetric loading is 2.1kg COD/?m3·d?,this time on the removal rate of COD,NH₃-N,SS are80.1%⁸6.8%,60%⁸2%,80%⁸4%.After the joint operation of "Flotation-hydrolysis acidification-contact oxidation process",wastewater effluent water quality indicators: concentration of COD 92mg/L,concentration of BOD₅ 25.4mg/L,concentration of SS 14.3mg/L,concentration of NH₃-N 8.44mg/L,respectively.The water indicators are stable and achieve the integrated wastewater discharge standard?GB8978-1996?secondary standards.