What Is Wastewater Treatment Engineering?

China's sewage treatment industry has made relatively late progress. (Zhan'er Roots Blower) Since the founding of the People's Republic of China and before the reform and opening up, China's sewage treatment needs have been mainly based on cutting-edge industrial and defense applications.

Sewage treatment project

Sewage treatment is the process of purifying the sewage to meet the water quality requirements for draining a certain water body or reusing it. Sewage treatment is widely used in construction, agriculture, transportation, energy, petrochemical, environmental protection,

Since the late 1990s, China Taigang, Baosteel, and state-owned and joint ventures such as Baoxin and Zhangpu have introduced a series of sewage treatment production lines through introduction and technological transformation. The sewage treatment technology and equipment have reached the international advanced level. Production has begun to take shape. The structure of sewage treatment products has also undergone positive changes, and the quality of sewage treatment products has improved rapidly. Especially domestic sewage treatment

Processes for treating domestic sewage include anaerobic filters, jet aeration, contact oxidation, oxidation ponds, submerged artificial wetlands and other processes.

Anaerobic filter process The principle of this process is to fix a large number of anaerobic microorganisms on the filler of the filter, and use the degradation of anaerobic microorganisms to decompose organic matter into methane, carbon dioxide and other gases to achieve purification.

Anaerobic filter process for sewage treatment project

This process does not require electricity and is suitable for areas where power supply is difficult.

The processing capacity is predicted to be about 50 ~ 70% for COD and BOD removal, about 50 ~ 80% for SS removal, and about 20 ~ 50% for ammonia nitrogen removal.

SBR process SBR is the abbreviation of Sequencing Batch Activated Sludge Process (SequencingBatchReactorActivatedSludgeProcess). It is a kind of activated sludge wastewater treatment technology that operates in intermittent aeration mode, also known as sequential batch activated sludge process. Unlike traditional wastewater treatment processes, SBR technology uses a time-divided operation instead of a space-divided operation. An unsteady biochemical reaction replaces a steady-state biochemical reaction, and a stationary ideal sedimentation replaces a traditional dynamic sedimentation. Its main feature is the orderly and intermittent operation in operation. The core of the SBR technology is the SBR reaction tank, which integrates functions such as homogenization, primary sedimentation, biodegradation, and secondary sedimentation into one pond, and has no sludge return system. The SBR process has the notable characteristics of simple process, flexible and changeable operation methods, multiple process routes, complete mixing in space, ideal push flow in time, impact resistance, high purification efficiency, good effluent quality and prevention of sludge expansion. Enhanced biosorption is a more important advantage. Therefore, it has been paid much attention to in the field of wastewater biological treatment technology, and has been developed and applied widely. There are successful examples of SBR treatment of landfill leachate.

SBR SBR process of sewage treatment project

Contact oxidation process Contact oxidation process, also known as "submerged biological filter", "contact aeration method", "fixed activated sludge method", is a sewage treatment technology pioneered in the early 1970s, and its technical essence Filler is filled in the biological reaction tank. The oxygenated sewage immerses all the filler and flows through the filler at a certain flow rate. The biofilm is covered on the filler, and the sewage is in extensive contact with the biofilm. Under the action of the microbial metabolism on the biofilm, the organic pollutants in the sewage are removed and the sewage is purified.

Contact oxidation process in sewage treatment project

The biological contact oxidation method has the characteristics of both the activated sludge method and the biofilm method. The concentration of biological solids in the pond (5 ~ 10g / l) is higher than that of the activated sludge method and biological filter, and has a higher volume load (up to 2.0). ~ 3.0kgBOD5 / m3.d). In addition, the contact oxidation process does not require sludge backflow, no sludge swelling, simpler operation and management than the activated sludge method, and has a strong ability to adapt to fluctuations in water volume and quality. It is a typical aerobic treatment method, which has the advantages of large aeration, high treatment degree and automatic control.

The processing capacity of this process is predicted to be about 80 to 95% of COD and BOD removal, 70 to 90% of SS removal, and 80 to 90% of ammonia nitrogen removal.

Oxidation pond process Oxidation pond is a general term for structures that use natural purification capabilities to treat sewage. Its purification process is similar to the self-purification process of natural water bodies. Usually, the land is properly artificially trimmed to form a pond, and embankments and impervious layers are set up to rely on microorganisms growing in the pond to treat sewage. The combined action of bacteria and algae is mainly used to treat organic pollutants in wastewater. The stabilization pond sewage treatment system has the advantages of low capital investment and operating costs, simple maintenance and repair, easy operation, effective removal of organic matter and pathogens in sewage, and no need for sludge treatment. In China, especially in dry and arid regions, It is an effective method to implement the utilization of sewage resources, so stabilization of sewage treatment in ponds has become a new technology that China has been promoting.

Oxidation pond process for sewage treatment project

The submerged artificial wetland artificial wetland system is to fill a certain bed (such as soil, gravel, etc.) in a depression with a certain length-to-width ratio and bottom slope to form a bed. , A long growth cycle, beautiful and economically valuable aquatic plants (such as reeds) constitute a unique flora and fauna ecosystem.

Underwater flow constructed wetland for sewage treatment project

Plants growing in artificial wetlands absorb nutrients from waste water into the body through the root system, and transform them into their own components under photosynthesis. Most of the eutrophic substances such as nitrogen and phosphorus in the water are transferred to the plants, so that the sewage resources are converted into useful resources in the plants. When a lot of tiny suspended streams in the water pass through the ecological module, they are intercepted by the "soil" in the module, so that the sewage is purified. The processing effect of this processing unit is predicted as follows: the removal rate of COD and BOD is about 50 ~ 80%, the removal rate of SS is about 70 ~ 80%, and the removal rate of ammonia nitrogen is about 50 ~ 70%.

Since 1990, the global apparent consumption of sewage treatment has increased at an average annual rate of 6%. During the ten years of the 1990s, China s annual average growth rate of apparent consumption of sewage treatment has reached 17.73%, which is the world s average annual growth rate. 2.9 times. In the 21st century, China's sewage treatment industry has grown rapidly. From 2000 to 2004, China's sewage treatment consumption increased from 1.88 million tons to 4.47 million tons, an increase of 2.3 times, and the average annual growth rate was more than 27%. Among them, in 2001, China s apparent consumption of sewage treatment reached 2.25 million tons, surpassing the United States and becoming the world s largest consumer of sewage treatment. At the same time, sewage treatment imports have also increased significantly. In 1998, China imported 1 million tons of sewage treatment, thus becoming the world's largest importer of sewage treatment. Compared with 2004, the average annual growth rate of sewage treatment imports reached 27.14%. It is expected that in 2005, China s apparent consumption of sewage treatment will reach 5 million tons, and imports will remain at about 3 million tons.

Along with the rapid development of the sewage treatment market, China's sewage treatment output has also ended a long period of hovering and achieved rapid growth. China's sewage treatment output increased from 460,000 tons in 2000 to 2.36 million tons in 2004, with an average annual growth rate of 82.6%, and its proportion in domestic market demand also increased from 24.47% in 2000 to 52.80% in 2004. In the same period, the world's sewage treatment output increased at a rate of only about 6%.