Sludge disposal is moving towards reduction, decontamination, resource recovery and stabilization, and the initial sludge dewatering is an indispensable step. At present, the sludge dewatering method has been widely accepted. In this paper, some discussions are made on the sludge disposal methods. The main technologies and application prospects of sludge dewatering are emphatically introduced.
Deep dewatering technology widely accepted Sludge disposal process and then high
Sludge is an inevitable result of sewage treatment. Accompanied by the sludge generation is getting larger and larger, the impact of sludge on human living environment and economic development has become increasingly prominent. How to treat and dispose the sludge reasonably and effectively, reduce its impact on the environment, and realize the resource utilization of the sludge is an important topic of sludge disposal and environmental protection.
First, the sludge disposal situation and problems
1, the situation of sludge treatment
Over the past 30 years of reform and opening up, China has made remarkable achievements in economy and its economy ranks second in the world. However, behind the rapid economic growth, it is a serious environmental damage.
At present, 90% of the country's surface water is subject to different degrees of sludge, of which 60% are seriously polluted. The water crisis has become the biggest threat to our country's economic development. Therefore, sewage treatment has become the top priority of China's "12th Five-Year Plan" and "13th Five-Year Plan", and has risen to a long-term national development strategy.
Sludge is the final product of sewage treatment, enriching the sewage of organic matter, salt and a large number of phosphorus, nitrogen and other viruses and viruses, parasites eggs, heavy metals and other toxic and harmful substances, it can be said that the sewage sludge pollution The concentration of things off, with considerable environmental hazards.
During the "12th Five-Year Plan" period, the scale of urban sludge treatment and disposal within the national planning scope is 25 million tons / year, equivalent to 5,181,100 tons / year of dry sludge. How to treat and dispose of these sludge reasonably and effectively is an important challenge before us. Our government attaches great importance to the treatment and disposal of sludge and has promulgated a series of rules and measures in an effort to solve the problem of sludge on environmental sludge at the policy and technical levels. However, due to the sluggish and weak foundation of our country in terms of sludge treatment and disposal as well as the conservative and backward concepts, the problem of sludge disposal and disposal remains quite serious. There is still a long way to go in the future.
2, different treatment methods and problems faced
At present, sludge disposal in China has a variety of ways, did not form a unified understanding. According to the "Guidelines for Best Practicable Technical Guidelines for the Prevention and Control of Sludge Disposal in Municipal Sewage Treatment Plants (Trial)" released by the Ministry of Environmental Protection in February 2010, the treatment of sludge mainly refers to the pretreatment methods such as concentration and dewatering of sludge, Disposal mainly refers to the land use of sludge and incineration. This guideline basically includes all the existing sludge treatment and disposal methods in our country. Although there is a certain description on the priority, it still faces considerable problems in the actual implementation.
(1) The existing sludge treatment methods of China's sewage treatment plants are still concentrated by belt-type filter press dewatering or centrifugal dewatering. A considerable part of the wastewater treatment plants do not even have facilities for concentration or dehydration. Survey shows that the water content of sewage sludge factory effluent are generally more than 80%, the average close to 90%, that is, the sludge moisture is nearly 9 times the dry sludge. Sewage treatment plants are not only lagging behind in sludge dewatering technology, but more serious dumping of sludge after dewatering, resulting in the waste of land resources and serious environmental pollution.
(2) Sludge disposal methods The main recommended ways of land use, including the use of sludge for agriculture, landscaping, or soil improvement, are certainly an ideal way of disposal and the disposal costs are relatively low. However, the main problem is the limited capacity of land digestion, especially in cities and areas where economic development occurs. There is an order of magnitude difference in sludge production and land use. Another problem is that the sludge must be strictly identified and controlled for land use, otherwise the sludge will have serious consequences on soil, groundwater and air pollution.
(3) Direct landfill after sludge pretreatment As a transitional approach for sludge disposal in China in the near term, it is still very common in our country at present, especially in underdeveloped areas. Of course, according to China's actual national conditions, with land resources increasingly tight and improve understanding of sludge disposal, sludge landfill will be banned gradually.
(4) The use of sludge incineration has become the mainstream of the current sludge disposal routes. However, due to the different disposal processes, the economic value and environmental effects of sludge incineration vary. Typical incineration routes are where sludge with high moisture content is directly mixed with coal or incinerated by a heat source (steam, electricity or flue gas), which is incinerated and incinerated or exchanged for primary energy or high-grade heat Sludge thermal energy is not only economically unreasonable, but also inevitably lead to greater energy consumption, secondary pollution problems.
(5) A new route of sludge dewatering method, which is also an intermediate step of sludge treatment and disposal, has been gradually recognized and recognized in the field of sludge disposal. Depth of sludge dewatering technology not only for the convenience of subsequent disposal, but also take into account the balance of the sludge treatment and disposal process of economic and environmental balance, is suitable for China's new approach to sludge disposal.
Second, the depth of sludge dewatering technology and technology
Deep sludge dewatering refers to the higher moisture content of the sludge after chemical tempering treatment, and then squeezing high-pressure dehydration to a moisture content of 60% or less, not only in reducing the number of more than 50%, more importantly, the sludge Subsequent disposal approach is more extensive. Deep dehydration sludge has a certain calorific value, can be used as power plant low-grade fuel and cement clinker in the production process, to achieve stable, harmless disposal and resource utilization. Even if landfill, but also significantly reduce land occupation and environmental pollution.
deutz Water Cooled Diesel Engine are common used for water pumpp and generator set , industial , Vehicle and argrialculture .
we do business all over the world. we are mainly in deutz Water Cooled Engine , and we are good in quality and competitive in price. We can supply you variouse power engine .
and they are often used in different aplication . if you need any of them , please feel free to contact us for free .
Deutz Diesel Engine,Industrial Diesel Engine,3 Cylinder Diesel Engine,Water Cooled Diesel Engine
Shijiazhuang Houfeng Trading Co.,Ltd , https://www.hfdieselengine.com