| Since the18th Century, various environmental issues were aroused due to the dump of a great amount of water laden with industrial and daily waste, and corresponding treatment technologies were constantly appeared during this period. In1893, the activated sludge wastewater treatment, which the British engineers indulged in, was named as primary treatment. Then the second treatment using microorganism was introduced in later years. Since the1870s, sewage treatment turned into the resource stage. In1972, the convening of the Stockholm Conference on the Human Environment made significant changes in the world environment, led great advancements in wastewater treatment technology, achieved changing development from discharging standard to clean water, and made great advance in sewage treatment and clearly put forward the concept of energy saving. Recently, formal sewage treatment technology has been finalized. Scientists had concentrated on the organic treatment and the improvement of traditional method. Sewage treatment technology research focused on three aspects:①to improve the traditional activated sludge process and technology;②to alter the conventional activated sludge process and technology;③to research the urban wastewater reuse technology.This passage use the second phase of Wudalianchi municipal sewage treatment as an example to discuss and analysis the selection of existing water treatment process, the impact on environment and environmental protection measures. Municipal wastewater treatment plant collects wastewater from urban sewage and industrial emissions, the conventional activated sludge process, oxidation ditch, A/O、A2/O、SBR、 CWSBR. Activated sludge method suited to deal with the wastewater containing high organic matter, but it could not remove nitrogen and phosphorus completely. Although modified activated sludge process can reduce the content of nitrogen and phosphorus, the increased circulating pipeline and amplified pool content increased not only the capital and land occupation. but also the difficulty of regulation. A2/O, with longer application history, can remove organic matter and nutrient at the same time; The removal effect of oxidation ditch to delete nitrogen and phosphorus is limited; SBR method which have a better purification effect can effectively remove organic matter and nitrogen. phosphorus in wastewater; CWSBR can effectively remove organic matter, nitrogen and phosphorus. and the purification effect is better. Each method has its advantages, in order to achieve the sewage treatment purpose, a combination approach is required. The passage cited the advantaged drainage treatment plant of Wudalianchi which adopted the CWSBR and ion odor deodorizing method.The feasible method is decided by comparing the site selection and process of the second sewage treatment phase. Through the analysis and monitoring results of many evaluating methods. the use of different factors and reasonable method to evaluate certain specific method. and then to predict the environmental impact and proposed environmental protection measures. The conclusions as below:the project location is reasonable, which is located in the downwind of the prevailing wind direction. under the downstream, at the end of urban drainage system. The flat, open, easy surrounding and the reasonable layout are suitable for long-term expansion. Low noise equipment with acoustic packages in the foundation design, is suitable for Sound environment, Aeration equipment should be installed with silencer in tuyere and the damping facilities. building sound insulation and green barriers noise reduction should be adopted On the route of transmission, so that noise at boundary of industrial enterprises can reach the standard of discharge. After efficient multi-tube dust catcher treatment, Air flue gas discharged through30m let-off pipe can satisfy the boiler air pollutant emission standard of the second zone Ⅱ time standards.Stench adopts the ion deodorization method, which can purify various indoor harmful gas pollution generated at any time, and does not need additional material. The system can be flexibly installed in any convenient location, and can work normally in environment temperature from-30～60℃without restriction. In water environment, the management should be enhanced, sludge should be cleaned regularly, excessive emissions should be prevented, and on-line monitoring should be adopted. As to Solid waste, temporary storage area, which is treated by Seepage, should be constructed, grid slag and living garbage collection should be sent to urban garbage treatment center, Grit can be sold as building materialsThis passage discussed the development of drainage treatment, the advancement of the dealing process and the selection of the second phrase method of Wudalianchi, the main environmental impact and the adoption of environmental protection. Providing theoretical foundation and technical basis to the similar domestic... |
PDF Full Text Request