Study On The Treatment Of Papermaking Wastewater By The Combined Process Of Intensified AAO Process With Advanced Oxidation Technique

The papermaking industry is an important part of the national industrial system.China's papermaking industry developes rapidly and its volume is huge.The papermaking wastewater generated during the papermaking process is the main source of industrial pollution in China,and its emissions account for more than 30%of the total industrial wastewater discharge.At the same time,papermaking wastewater has high COD and high chromaticity.If papermaking wastewater is discharged without treatment or simple treatment,it will inevitably cause serious harm to the natural environment.Therefore,the selection of appropriate treatment technology and the in-depth treatment of papermaking wastewater have an important role in the health and sustainable development of the papermaking industry and the construction of ecological civilization.In this paper,the papermaking wastewater of a township papermaking enterprise in Qianjiang City is taken as the research object.In order to enhance the removal effect of nitrogen and phosphorus,it has reached the first-level A emission standard of the "Sewage Discharge Standard for Urban Sewage Treatment Plants"and reduce COD in water as much as possible.The enhanced AAO process combined with AOP technology is selected and analysed to treat the papermaking wastewater.Based on the traditional AAO process,a moving bed membrane bioreactor(MBBR),a vertical flow sedimentation tank and an enhanced coagulation sedimentation tank are integrated to strengthen the traditional AAO process.The study discusses removal effect and influencing factors of this enhanced AAO process on conventional pollutants.Then taking the strengthened AAO process effluent as the object,the AOP technology is used to further remove COD and chromaticity in the water,and the effects and factors of pollutant removal by AOP technology is investigated.Through practical engineering applications,enhanced AAO combined with AOP technology is used to the advanced treatment of papermaking wastewater,the feasibility of the combined technology is further verified.The engineering investment and water treatment costs is also analyzed.This paper obtains the following research results:1.Through laboratory test research,it was obtained that the average removal rate of COD,ammonia nitrogen,total nitrogen and total phosphorus by the enhanced AAO process under the optimal operating conditions SRT 10d and HRT 19h was 79.63%,88.39%,70.48%,84.21%;2.The self-made catalytic ozonation experimental device was used to study the treatment performance of the enhanced AAO process effluent.The optimal operating conditions of the AOP process were:ozone concentration 6mg/L,initial pH 7.8-8.2,catalyst filling amount 50g,and reaction time.60min.Under these conditions,the average removal rates of COD,chroma,and UV254 by the process are 62.30%,75.68%,and 82.38%,respectively;3.According to the above test results,the enhanced AAO and AOP combined process was applied to a papermaking wastewater treatment plant in Qianjiang,and the effluent water quality after treatment reached the first level "A" in the " Sewage Discharge Standard for Urban Sewage Treatment Plants "(GB 18918-2002).The whole treatment process has a compact structure,a small footprint,strong impact load resistance,convenient maintenance and management,and a cost of 1.57 yuan per ton of water treatment.Comprehensive analysis believes that strengthening the AAO process can better reduce various pollutants in papermaking wastewater and provides a good operating environment for the subsequent operation of the AOP process.The combined process has good effects in practical engineering,and various indicators of the factory water meet the emission requirements.This project has good economic and environmental benefits,and can provide a reference for similar small village and town industrial wastewater treatment projects.