Papers by Keyword: Municipal Sewage

Abstract: The experiment uses municipal sewage as the research object and runs SBR reactor in completely aerobic conditions. Through controlling different of DO concentration and COD concentration, we study spreading comparison. The results show that when DO concentration was 1mg/L, the removal effect of aerobic granular sludge process in SBR treating municipal sewage was best, the average removal rate of COD, ammonia nitrogen, total nitrogen and phosphorous was 90.12%,98.95%,87.65% and 83.74% respectively. When COD concentration of influent was about 400mg/L, the treatment effects of aerobic granular sludge for COD, ammonia nitrogen, total nitrogen and phosphorous were all better, the average removal rate was up to 92.33%,98.83%,88.17% and 80.25% respectively.

Abstract: With the development of urbanization and industrialization in China, the output of municipal sewage gradually increase, which imposes great pressure to the sustainable development of environment. Effective microorganisms (EM) technique has been considered as cheap and effective technique to apply in sewage treatment and gradually attracted scientists much attention also due to its environmentally friendly nature. This paper is aimed to draw a conclusion about the applications of EM technique in municipal sewage treatment and offer proposals to promote the intensive development of EM technique.

Abstract: A laboratory, jar-test type study was conducted to investigate the effect of operational parameters on coagulation efficiency when PACl and ferric chloride are used. Under the same dosages, TP removal by ferric chloride was more effective than that of PACl with municipal fresh sewage, while PACl was superior to ferric chloride in case filtered municipal fresh sewage was used as feed. Zeta potential is believed to be a feasible parameter for the determining of appropriate coagulant dosage. Optimal pH for TOC removal was about 6.0, which is slightly lower than that for turbidity and color removal. There are no significant difference in the removal of TOC, turbidity and color over the range of GT values 12,780~112,800.

Abstract: The process parameters and running effect of A²O-high density sedimentation tank-filter tank process applied in the treatment of municipal sewage were introduced，aiming to provide technical basis for broad application of A²O-high density sedimentation tank-filter tank process. An engineering case was taken as example to describe process flow, process parameters and the size of the structures. The character of the designing was explained along with the discussion of the running effect. The running effort shows that municipal sewage treated by A²O-high density sedimentation tank-filter tank process can meet the requirements of Grand A of Primary standard of Discharge standard of pollutants for municipal wastewater treatment plant（GB189118—2002）.

Abstract: Contamination can change the physical properties of soil, reduce the strength of cemented soil foundation, and then induce the instability or disruption of buildings. This study explored the relationships among the age, electrical resistivity, unconfined compression strength, contamination of municipal sewage concentration. Firstly, we mixed the silty clay with municipal sewage of five different concentrations to form the contaminated soil. Then, mixed the contaminated soil with ordinary portland cement to form the cemented soil blocks. Finally, measured the unconfined compression strength and electrical resistivity of these blocks. The results show that the unconfined compression strength and electrical resistivity increase linearly with the increase of the logarithm of age, and decrease exponentially with the increase of municipal sewage concentration. The unconfined compression strength of cemented soil has a linear relationship with its resistivity. The municipal sewage concentration and age can be use to predict the unconfined compression strength of cemented soil.The predicted values correlate well with the experimental values.

Abstract: The process parameters and running effect of baffled-submerged bio-film process applied in the treatment of sewage wastewater were introduced, aiming to improve the broad application of baffled-submerged bio-film process in the wastewater treatment in small towns. An engineering case was taken as an example to describe the process flow, process parameters and sizes of the structures. The character of the designing was explained along with the discussion of the running effect. The running effect shows that sewage wastewater treated by baffled-submerged bio-film process can meet the requirements of Grand B of Primary standard of Discharge standard of pollutants for municipal wastewater treatment plant (GB18918).

Abstract: To solve the problem of huge investment and high difficulty of individually treating landfill leachate, the experiment adopted A²O simulated wastewater treatment plant to treat landfill leachate combined with municipal sewage.Under the conditions of 11h HRT, 1.0-2.0mg/L DO concentration, 200% mixture reflux proportion, 80% sludge reflux proportion and 20d sludge age, adding langdfill leachate to municipal sewage with the proportion of 1:1500, 1:1000 and 1:600, the effluent concentration can achieve the first order A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant. When the proportions come to 1:400 and 1:200,the effluent quality can’t reach the standard. After a comprehensive consideration of water quality and landfill leachate treatment amount in practice, we can draw a conclusion that the 1:600 proportion is the most suitable one of adding landfill leachate to municipal sewage.

Abstract: The result showed that, after addition of a suitable content zeolite to A/O tank, the zeolite sludge had a low resistance and a high membrane flux. The heavy metals in municipal wastewater were inactivated and types of organic matter were adsorbed by the sludge containing zeolite, while sludge compressibility was decreased. It also changed the chemical composition of the sludge and added the inorganic substances such as silicon, aluminum, potassium and sodium, which obviously influenced the way the sludge could be reused.

Abstract: This paper mainly studied on using activated sludge process with zeolite to upgrade the traditional secondary treatment plants. In this process, zeolite acted as ammonian sorbent and microbial carrier firstly, and then composed zeolite and biological complex to improve denitrification of anaerobic zone and nitrification of oxic zone. In the anaerobic zone, the influent contained a lot higher ammonian concentration. The zeolite adsorbed ammonian, it increased carbon nitrogen ratio and facilitated denitrification. While in the oxic zone, adsorbate concentration of mixed liquid decreased owing to biodegra dation by the action of salinity and microorganism. Thus, it striked a balance between adsorption and desorption of zeolite with ammonium, and zeolite with ammonium released constantly ammonian to renew.

Abstract: This paper mainly studies the use of the activated sludge process with zeolite to upgrade the traditional secondary water treatment plants. With the addition of an appropriate amount of zeolite, the living environment of several micro-organisms in the activated sludge can be improved, thus raising the activity and number of micro-organisms and increasing the level of nitrification. Simultaneously, it also can improve size distribution and structure of sludge particles, the settling property, thus reducing the specific resistance of sludge. However, excess doses of zeolite will increase the viscosity of the sludge, which will reduce the compression performance in sludge thickening. This is not favorable to the operation of the secondary sedimentation tank and the pipeline transport of sludge. Therefore, we suggest the further study of the lower doses of zeolite, to find the optimum effect and eliminate the negative ones.