Study On Sewage Purification Effect And Odor Control By Bio-ecological Coupling Technology

After nearly 40 years of efforts,China’s sewage plant has been greatly developed,and technology has also begun to meet the international standards.But the attendant problems such as high energy consumption,high chemicals consumption and secondary pollution have restricted the improvement of sewage treatment benefit.Aiming at these problems,a sewage treatment plant in Guangdong province uses bio-ecological coupling technology,which has realized the advanced treatment of sewage and the in situ purification of odor.Except for total nitrogen,the effluent quality reaches the requirements of surface water environmental quality standard(GB 3838-2002)class III.In this paper,the role of emergent plants in the technology was studied,and the coupling characteristics between microorganism and plants were revealed.In addition,the water quality and odor are monitored and analyzed,the chemical phosphorus removal in the sewage plant is optimized and the efficiency of energy saving and consumption reduction of the automatic control adding system is calculated.How the sewage treatment plant meets the future development are evaluated from the three aspects of whether the effluent meets the ecological reuse,whether the release of the odor is environmentally friendly,and whether the automatic dosing system can save energy and reduce consumption.The research results show that:(1)The emergent plants used in bioecological coupling technology have good resistance to sewage and have a certain removal effect on pollutants in water.The rhizosphere effect of plant roots enhances the removal of pollutants by technology,and the technology realizes the ecological coupling between microbes and plants.(2)In the effluent of bio-ecological coupling technology,except that total phosphorus occasionally can not be stable to meet the standard because the water concentration is higher the design value,COD,ammonia nitrogen,total nitrogen basically reach the surface water environmental quality standard(GB 3838-2002)class III water quality standard.The effluent of sewage treatment plant basically achieves advanced treatment and meet the ecological reuse requirements.From October to November,the best operating parameters were determined,including internal reflux ratio 300%,sludge reflux ratio 75%,sludge age 14 d.(3)The sewage plant is seriously polluted by antibiotics,and influent and effluent mainly contains quinolones.The sewage plant has a good removal effect on some antibiotics.OTC(Oxytetracycline)and TC(Tetracycline)can be completely removed,and the removal rate of NFX(Norfloxacin),LIN(Lincomycin),DC(Doxycycline),SQX(Sulfaquinoxaline)are also over 60%.The biochemical tank plays a major role in the removal of antibiotics,which is followed by secondary sedimentation tank,and advanced treatment has little effect on it.(4)Ammonia is the malodorous substances mainly releases in sewage,and releases higher concentration in each sewage treatment unit.The release characteristics of TVOC(Total volatile organic compounds)is similar to ammonia,but its release concentration is low compared to ammonia.Hydrogen sulfide is the most concentrated material release concentration,more than 90% released in fine grid room.In months,the release of odor is related to the temperature of water,and the release of each hour in collecting well and fine screens is related to the activities of residents’ water use.The bio-ecological coupling technology not only realizes the integrated treatment of sewage and odor and conforms to the operation concept of low carbon and energy saving,but also has good control effect on the odor.It creates a good plant environment,improves the ecological benefit,and combines the development direction of the environmental friendly sewage plant in the future.(5)On the basis of simultaneous phosphorus removal,after a variety of chemicals compared,it is found that the phosphorus removal of single agent PAC(Polyaluminium chloride)and agent PAC+PAM(Polyacrylamide)has the best effect and are the most economical.In the test range of concentrations,PAC and PAM has little effect on the effluent pH and COD.And in the actual operation of the sewage plant,two schemeS also show good effect of phosphorus removal.(6)The automatic control and dosing system can achieve the goal of stable nitrogen and phosphorus removal by monitoring and feedback to realize the dynamic precision dosing of the carbon source and dephosphorization agent.After applying the phosphorus removal test data to the automatic control system and counting,it is found that using compound PAC+PAM not only cut down the amount of agent,but it lowers the long-term operating cost.Methanol is chose as the carbon source.Under the optimization of the automatic control dosing system,the amount of methanol and the power consumption of biological nitrogen removal have decreased.Therefore,automatic control dosing system can reduce chemicals consumption,energy consumption and operation cost in varying degrees to achieve the purpose of saving energy and reducing consumption,which conforms to the future development direction of the sewage plant.