Study On Nitrogen And Phosphorus Removal For Domestic Wastewater Treatment Appling Kmts Craft

Eutrophication becomes one of the most important issues of water pollution in recent years. Although the rate of sewage treatment is rising, the efficiency in removing nitrogen and phosphorus is very low and the standard of phosphorus and nitrogen concentration is overrun. Then improving the efficiency of removing nitrogen and phosphorus is an efficient way to resolve the problem of eutrophication and it is the fundamental way to control the quality of water.As the problem of eutrophication become more and more seriously, lots of study is focused on it and a lot of techniques have been put forward at home and abroad. The technology of removing nitrogen or phosphorus has been developed rapidly, form removing nitrogen or phosphorus separately to removing nitrogen and phosphorus simultaneously, from the original method of biological activated sludge to multi-function with the oxidation ditch technic, SBR craft, A2/O craft, as well as improved A2/O craft, and so on. The technic named KMTS is an efficient method as one of them.Lots of improvement on KMTS technic has been done by Kunming Ship's Company sewage treatment station because of its outstanding advantages, such as shorter process, ecnomics grounds, smaller project reform, lower cost, less investment and flexibility for operation and management.As a new biological nitrogen and phosphorus removal process developed during improving project, KMTS has its unique characteristics. When it is carred out, the process was divided into four follow parts:anaerobic process, hypoxia process, anaerobic process and then aerobic process, which avoid that the PAO from not adequately discharge phosphorous under the influence of nitrate.Besides those, KMTS has its own characteristics, which are four regurgitation design:mixture regurgitation, regurgitation between anaerobic sludge pond and ramp sedimentation tank, regurgitation between and aerobic sludge pond and ramp sedimentation tank and regurgitation of the leachate in Sludg drying tank. Regurgitating leachate is used to avoid no reaching the standard and then there is no need to resolve the problem.The mechanism of traditional biological nitrogen and phosphorus removal technique is introduced and simply analysis on mechanism of KMTS has been done in this paper. The charactersitc in KMTS process is described in details, which is constantly replenishing the mixture of nitration bacteria and PAO repeat to absorb phosphorus when sludge of aerobic tank is regurgitating.In this paper, the various parameters of KMTS are optimized. Considering the characteristics of KMTS, some experiments are done and discussed.First of all, different mixture regurgitations(20%,40%,75% and105%) are chosen to investigate whose influence to the rate of nitrogen and phosphorus remove and the Concentration of pollutants changing each section under different conditions was monitored.Then the mixture regurgitation of 40% is chosen to obtain the best effect of nitrogen and phosphorus remove.Secondly, the relationship between different regurgitation rate and nitrogen and phosphorus removal results is investigated by adjusting the regurgitation between and aerobic sludge pond and ramp sedimentation tank. And the pollutants concentration in each reaction section under different conditions is also observed. Then the regurgitation between and aerobic sludge pond and ramp sedimentation tank is chosen to be 35% to obtain best effect of nitrogen and phosphorus remove.Finally, the relationship between different regurgitation rate and efficiency of nitrogen and phosphorus remove is experimental discussed in different of regurgitation between anaerobic sludge pond and ramp sedimentation tank. Experiment results showed that the efficiency of nitrogen and phosphorus remove is obtained when the regurgitation between anaerobic sludge pond and ramp sedimentation tank is 45%.From now on, the optimized parameters of KMTS have been gotten in experiments. Using these optimized experiment parameters, the rate of removing nitrogen and phosphorus reached 75.5 percent and 88.9 percent are obtained separately. The final effluent quality can meet the national wastewater discharge standard. These experiment results give some reference significance to Wastewater Treatment Processes using KMTS.