With environmental protection is more and more big, the water treatment industry, sludge industry become hot, today the value of several million industry report, free to send you, please call me Lei Feng!

[sludge]
Sludge is a by-product of sewage treatment, and it is a kind of sediment and floating substance produced by different treatment processes in water supply and wastewater treatment. Whether activated sludge and its derivative technology, or membrane treatment technology, in the process of sewage sludge will produce.
The composition and properties of sludge mainly depend on the composition, properties and processing technology of the treated water. Sludge composition is complex, including pathogenic microorganisms, parasite eggs, toxic and harmful heavy metals and a large number of refractory substances, such as improper handling, easy to cause environmental pollution two. At the same time, the sludge also contains a lot of rich nutrients, after appropriate treatment can be used as fertilizer, improve soil, promote the growth of plants; processed to produce biogas can be used as energy sources to solve the energy problem, some.
The sludge moisture content of the sewage treatment plant in the city is 75%-99%, and the organic matter in the sewage is close to 1/3, which is transformed into the sludge. In addition, as part of the industrial waste water is discharged into the urban sewage treatment plant, resulting in sludge containing heavy metals and other toxic substances difficult to degrade, the difficulty of processing a substantial increase.
1 what is sludge treatment
In principle, sludge treatment refers to the process of reduction, materialization and harmlessness. From the process, it is the process of thickening, conditioning, dewatering, stabilizing, drying and incineration of sludge. From the results, refers to the treated sludge or sludge products in the environment or in long-term use to achieve long-term stability, the final consumption mode and does not produce harmful effects on human health and ecological environment.
Sludge treatment is a part of the sewage treatment, but the latter is more perfect, the permeability is high, the professional treatment of sludge is quite backward.
2 sludge classification
According to the source, there are three kinds of domestic sewage sludge, industrial wastewater sludge and dredged sludge.
According to the composition and property of sludge, it can be divided into organic sludge and inorganic sludge.
According to the separation process of sludge from water, can be divided into sludge (including primary sedimentation sludge, sludge and chemical sludge) and biological treatment (sewage sludge produced in the two grade treatment process of sludge, sludge digestion including humic sludge and activated sludge method biofilter, biological rotating disc method). Most of the sludge in modern sewage treatment plant is the mixed sludge. The primary sedimentation sludge, excess sludge and humic sludge are the main objects of the treatment.

According to the different stages of sludge treatment, it can be divided into biological sludge, concentrated sludge, digested sludge, dewatered sludge, dry sludge and sludge incineration ash. According to market segments, divided into industrial and municipal sludge.
Industrial sludge dewatering, processing equipment, and the appearance of similar municipal facilities, but because of heavy metal sludge, or corrosive substances, the need to use a special filter cloth. Municipal sludge can be treated by landfill and incineration. After industrial sludge dehydration, most of the landfill treatment, incineration is not much, mainly low calorific value.
3 sludge characteristics
Sludge characteristics and characterization:

(1) harmful (decision processing)
The content of organic matter and heavy metals in sewage sludge is high in china. High content of organic sludge makes easy to breed bacteria, and rancid; heavy metal content exceed the standard, use will affect the sludge soil. Without the formal treatment of sludge disposal, the two pollution of the environment is even greater than the harm of the sewage itself. This forced environment is the basis for the introduction of relevant supporting policies, China's two sewage sludge has come to face, seize the time to rectify.
Note: some of the sludge, the toxicity is too large, in fact, hazardous waste, so some of the sludge should be classified as hazardous waste

(2) moisture content (core technology)
Water content is the percentage of water content in sludge, and the corresponding solid content is the percentage of solid or dry sludge. In the case of high water content and sludge flow, the volume of sludge was inversely proportional to the solid content: V1/V2 = Ps1 / Ps2 = (100- Pw2) / (100- Pw1). In the formula: V1, V2 is the moisture content of Pw1 (solid content of Ps1), Pw2 (solid content of Ps2) when the volume of wet sludge.
From this formula, we can easily deduce that when the water content of the sludge from 99.5% down to 98.5%, the volume of sludge reduction into raw sludge is about 30%, and further decreased to 95% (including 5% fixed rate), the volume of sludge reduction into raw sludge is about 10%. Thus, the decrease in water content for the reduction effect is obvious, which also determines the core means of treatment dehydration.
How to reduce the water content of the sludge? Usually original sludge water content above 98%, a primary filter, can be reduced to 80%, with subsequent chemical conditioning, filter press dewatering depth, or physical drying methods, the water content was below 50%.
(3) sludge ratio (market space)
Sludge than that of sewage sludge production rate, the general use of thousands of tons of water to calculate the number of tons of dry mud. According to the experience, than in case about sludge in natural water, municipal sludge sludge ratio is between three - million, in case of industrial sludge, sludge ratio at about five. Sludge ratio determines the market space of the three segments.
Other remarks: the wet sludge production rate per ton of domestic sewage is 5/10000 ~ ~ 8/10000, and the wet sludge needs to be added 0.3~0.5 kg per ton of wet sludge
4 key points:
Sludge is a by-product of sewage treatment, sewage treatment process is added, compared to foreign Chinese sludge sludge, organic matter and heavy metals content is high, processing more difficult; sludge harmful decision strength, water content and core technologyOperation, sludge ratio determines the market space.
Investment logic and national policy
1 heavy water light mud, the treatment rate is not matching, water treatment forced sludge treatment speed (supply vs demand side)
We have achieved remarkable results in the field of environmental protection water treatment, the total amount of sewage treatment and treatment rates have achieved rapid improvement. Sludge is one of the most important processes in the process of wastewater treatment, and most of the pollutants are transferred to the sludge.
If you do not control the sludge treatment, pollution transfer or two pollution. In 2015, China's average sludge disposal rate of less than 30% (Note: 30% is a harmless sludge disposal, the remaining 70% may have been disposed of, just or harmful, or directly steal row), over 70% of the domestic sludge disposal into the environment without security, has become the bottleneck problem of sludge sewage treatment industry the development of the problem has been put on hold for a long time, development lags behind.
Figure: at the end of 2015, the national urban sewage treatment plant 6000-7000 block, sewage treatment capacity of 217 million cubic meters / day. City and county sewage treatment rate reached 92% and 85%.





2 industry policy
(1) strong willingness to policy
Environmental protection industry is the core driving force of the government will force the sewage treatment plant to strengthen sludge treatment is the most important symbol of the industry started. There is no single sludge industry planning, the more important the two planning is "&ldquo 12th Five-Year; ” national urban sewage treatment and recycling facilities construction plan", "the State Council on the issuance of energy-saving emission reduction in 12th Five-Year “ ” planning notice" and "&rdquo & ldquo; 13th Five-Year; the use of facilities planning and construction of urban sewage treatment and regeneration (Draft)". The notice will reduce the sludge disposal rate from 80% to 70%. This is not only the reverse of the policy support efforts, planning more pragmatic, but the country will strongly respond to the criticism of sludge disposal will.


(2) lack of existing subsidies, “ water ten ” or bring a turn for the better
Sewage treatment costs in the collection of sludge treatment costs is a trend, but from the current situation, there is a greater resistance to disposal costs. Sewage treatment fees in our current charge is low, still unable to ensure the normal operation of sewage treatment plant, the implementation of adding sludge treatment and disposal fees in the sewage treatment fee, and will increase the economic burden imposed in a certain extent. Therefore, in the future for a long period of time, subsidies will be the main source of sludge treatment and disposal of funds.
At present, there are some cities in China to give subsidies for sludge treatment and disposal, due to different treatment programs and other factors caused by different standards, the sludge treatment industry is difficult to profit, running heavily dependent on government subsidies. At the same time, subsidies coverage is obviously insufficient.
” water ten ” may be a clear opportunity for sludge treatment and disposal subsidy policy. Water pollution prevention action plan is expected to total investment of more than 2 trillion. In addition to the transformation of water treatment, operation brought huge market, “ water ten ” or in the sludge treatment and disposal to give more tilt. On the technical level, it is very likely to change the landfill disposal route in the past, on the economic level, or will require subsidies for sludge treatment and disposal in the country to promote, while clearly subsidies.

(3) the effect of the payment mechanism
Although there are many provisions of the sewage treatment fee should include the cost of sludge treatment, sludge disposal fees but will now be incorporated into the sewage fee only for Beijing City, Jiangsu province Taihu District, Changzhou City, Guangzhou City, and the proportion is low.

(4) summary of key points:
In 2015 the sludge disposal rate of less than 30%, the rest is not really harmless or unaccounted for; the quantity of sewage and sludge production does not match the serious, forced sludge treatment accelerated water treatment; policy support, pragmatic intention, treatment rate of 90%, the city 50% towns, 70% county sewage sludge, and clear the charging mechanism; payment mechanism obstacles the governance effect, general price does not include the cost of sludge treatment.
[technology line]
1 basic circuit
Generally speaking, the sludge treatment and disposal programs need to be pretreated, sludge thickening and dewatering, three main links of the back-end treatment. Among them, the sludge pretreatment and dehydration can be said to be all kinds of back-end disposal programs must go through the process, and the back-end disposal program needs to be based on a comprehensive consideration of various factors.
(1) pretreatment of sludge
The pretreatment of sludge mainly includes collection, conditioning, concentration, dehydration and related auxiliary facilities management. Sludge treatment technology is mainly digestion, fermentation.

(2) sludge thickening and dewatering
Sludge treatment is the core of the reduction, according to our understanding of the sludge moisture content can be concluded that the reduction of the core of dehydration.
Sludge dewatering is an important part of the sludge treatment process, its purpose is to reduce the moisture content of sludge, reduce the volume of sludge, to create the conditions for the final disposal of sludge. In order to separate the sludge liquid phase and solid phase, the binding force between them must be overcome. Sludge dewatering and drying include natural dehydration, mechanical dehydration and heat treatment drying. At present, sludge thickening and dewatering technology in China, including sludge thickening and dewatering, plate and frame filter press dewatering, centrifugal dewatering and so on.
Commonly used dehydration methods as well as dehydration technology, ultrasonic dehydration technology, flocculation dehydration technology.
At present, the dehydration rate is 60Between -80%. With the introduction of 60% indicators can be filled with domestic waste, the depth of the increasingly strong demand for dehydration, and the most common way of deep dehydration is the use of diaphragm filter press.

(3) back-end disposal
After pretreatment and dehydration, the sludge should be disposed at the back end, and the disposal methods of the common sludge include sanitary landfill, sludge reclamation, land use, sludge incineration and building materials. There are a lot of practical technical routes
2 main backend solutions (routine)
At home and abroad, the existing back-end disposal methods include sanitary landfill, incineration, land use, construction and so on.
(1) sanitary landfill (no future)
The sanitary landfill method is simple, easy to operate, low cost, the sludge does not need a high degree of dehydration, strong adaptability, is the most convenient sludge disposal program. However, there are many problems landfill, the resistance is increasing.
A landfill leachate will be formed. Leachate is a kind of serious polluted liquid, which will pollute the groundwater environment if the landfill site is selected or run improperly.
Two, the high content of organic sludge will form methane gas, odor, if not taken appropriate measures will cause the explosion and combustion, affect the stability of landfill, prolong the sealing time.
Three, after the dehydration of the sludge is sticky, can not be stacked, will affect the mechanical work of the landfill, resulting in a reduction in the life of landfill.
Four, the sludge is very easy to plug the landfill leachate pipeline, affecting the normal operation of the drainage system.
In recent years, the city landfill faced early filling full field, so the sludge landfill refuse to accept the case It is often seen. The sludge is often improperly disposed, resulting in a huge risk of two pollution. Taking into account all aspects of factors, landfill disposal will gradually be abandoned.
(2) incineration (trend + expensive)
Incineration is the burning of combustible components in the sludge at high temperature, and finally become stable ash. The incineration method has the advantages of high volume reduction, high weight loss rate, fast processing speed, and no pollution.
It is more common to use the wet sludge directly after the incineration, and it is not only difficult to carry out incineration directly without drying sludge, but also is not economical in energy consumption. Sludge treatment method by incineration as the core of the sludge treatment method of the most thorough, it can make all the organic carbonization, kill pathogens, can minimize sludge volume; but its disadvantage is that the processing facilities of large investment, high cost.
In recent years, the incineration process adopts the appropriate pretreatment technology and advanced incineration method to meet the increasingly stringent environmental requirements. Sludge drying and incineration technology has been successfully applied in Europe and the United States, making the sludge drying and incineration technology widely spread in developed countries, has become the most important way of disposal.
In China, although the low level of sludge treatment and disposal, incineration disposal case is relatively small, but in recent years has ushered in a rapid development.
Note: in addition to energy consumption or operating costs, each household will be a little different, the others are similar
(3) land use (no future)
Because of the advantages of low investment, low energy consumption, low operation cost, and organic components can be transformed into soil amendments, the direct land use of sludge is considered to be one of the most promising ways.
Land use will be treated sludge or sludge products used for land as fertilizer or soil improvement materials. Land use in developed countries has achieved good results, mainly with agriculture to achieve close ties.
Sludge for land severe disturbances (such as land mines, forest harvesting field, landfill, serious damage to the surface area to the reclaimed land) in the repair and reconstruction, reduce sludge potential threat to human life, not only treat the sludge and the restoration of the ecological environment.
But in China, the way of land utilization of sewage sludge is extremely difficult due to the previous industrial and domestic sewage treatment for long-term confusion, the risks of heavy metals in sludge, sludge organic fertilizer made of “ ” Ministry of agriculture has been banned from entering the field, can only be used for greening soil, landfill soil and roadbed soil.
(4) use of buildings (no future)
The use of building materials refers to the solidification of sludge, the use of special purpose materials, including the burning of ceramsite or brick, cement based traffic noise reduction materials, landfill cover materials, adsorption materials and building materials, etc..
Building materials used in a low-cost way to appear in the country, but because of the widespread use of poor quality and two pollution phenomenon in practice, it has not been generally recognized by the industry. Successful cases can be found from the developed countries, building materials if you want to do enough security, the cost does not have the advantage. Use of sludge and clay to burn ceramsite and environmental protection brick. Currently there are some provinces, such as Guangzhou need to apply for a license to be able to carry out the production of ceramic tiles and environmental protection.
Land use, building materials and other areas may be used in some areas of individual projects to achieve good results, but a wide range of promotion resistance.



3 backend disposal considerations
There are at least several important factors to be considered in the selection of sludge treatment and disposal technologies in china.
Stability, reduction, harmless priority, attention to the possibility of resources. The problem is how to complete under the premise of low cost, wet sludge dehydration to water content of 60% or less, and to ensure the safety and stability of sludge after treatment.
Cost management capabilities will become a major constraint. Transport conditions, land use and other restrictions. In the sludge treatment technology route link selection, technical route and facility scale sewage treatment plant covers an area will directly restrict the choice of supporting facilities and sewage sludge, from a city into consideration, the sewage treatment plant distribution, transport conditions and other factors have become the choice of sludge disposal routes must be taken into consideration.
In 2010, from the United States and China, 55% of the sludge is used for land use, while China is still the main landfill. But with the advance of TechnologyStep, as well as the scarcity of landfill sites, the future will be the comprehensive utilization of sludge disposal in china. 2010 data are as follows, the data is too old, only for reference.

In 2016, the sludge treatment processes were as follows: dry incineration (39%), landfill or recycling (24%), anaerobic digestion (21%), aerobic composting (14%), others (2%). Note that in the past 5 years, the number of dry incineration has increased from less than 3% to over 39%.
4.“ drying + incineration ” or ideal solution
On the whole, “ drying + incineration &rdquo is the ideal solution for domestic sludge treatment at the present stage, and the important part is the selection of sludge dewatering and incineration facilities. Accordingly, it is recommended to focus on the dewatering equipment and the total project operation.
With the domestic and foreign research of sludge incineration technology, technology and equipment has been used in practical engineering various new sludge incineration, such as sewage sludge bed incineration process and mixed with domestic waste incineration, the use of existing industrial furnace, sewage sludge incineration power plant mixed incineration process, spray drying and rotary incinerator etc.. The domestic thermal power plant, cement kiln, kiln number, a variety of ways for sludge incineration, can choose according to the actual need.
At least in the following aspects of the development of sludge incineration has a prerequisite:
First, the domestic solid waste treatment capacity is facing greater gap of sludge reduction is put forward higher request;
Two, the domestic thermal power plant, cement kiln, kiln number, sludge after pretreatment and dewatering after initial delivery to the various facilities for incineration, only need to process and equipment of a transformation, without reconstruction of incineration facilities, reduce the scale of investment and financial pressure;
Three, in recent years the rapid development of domestic waste incineration industry, dioxins in fly ash, control has accumulated a lot of experience for the incineration of sludge from treatment effect has reached the EU standards in two important indicators, pollution risk is greatly reduced; four, the existing and expected subsidy policy can significantly improve the profitability of a project.
With the domestic sludge treatment industry is facing all kinds of conditions can be judged: landfill disposal will gradually be abandoned; has a good effect of land use, building materials such as possible in some areas of individual projects, but the promotion of resistance range; &ldquo measure, on the whole; drying + incineration &rdquo is ideal; at this stage the scheme of sludge treatment and disposal.
5 other technical lines
Sludge treatment industry has formed several clear technology roadmap, including “ anaerobic digestion + &rdquo, “ land use; dry ash landfill or building materials using &rdquo + +, “ incineration; industrial furnace incineration and landfill ” “ and other sets of dehydration processing technology.
(1) anaerobic digestion + land use — — is gradually overcome acclimatized (due to the composition of complex, very limited)
Anaerobic digestion is the most used for sludge stabilization and recycling method widely, its stabilization effect, low energy consumption, biogas can achieve energy recovery produced by the digestive process, does not require a large amount of materials and the use of the land resources. Europe and the United States more than 50% of sludge anaerobic digestion treatment, the conversion of methane into electricity to meet the needs of the sewage plant power of 33% ~ 100%.
However, the sludge anaerobic digestion in China is obvious. In our country's construction of about 50 sludge anaerobic digestion facilities, the only stable operation of more than 20 seats. The main reason is that the sludge quality is poor and the operation management level is low. In our country, the sludge contains high sand content, low content of organic matter, poor biodegradability of the sludge, the stability of the operation of the digestion equipment and biogas production rate, and so on. In addition, our country lacks the incentive mechanism of biogas utilization, the investment cost of equipment is high, and the system is complex and difficult to master.
However, in the continuous development and improvement, the technology has been gradually perfect, using alkaline treatment, heat treatment, ultrasonic treatment, microwave treatment and pretreatment of sludge, thus improving sludge hydrolysis rate, improve the performance of sludge anaerobic digestion. And through the accumulation of the experience of the project, enterprises have gradually mastered a more comprehensive operational skills. Therefore, the sludge anaerobic digestion technology in our country is constantly breaking through the bottleneck, the future will be further development, we believe that this will be a major trend in the future.
Anaerobic digestion can eliminate organic harmful bacteria, there is a certain amount of reduction. Some methane may be used, but the value is very small. The land itself will certainly be harmful, at least in municipal gardens.

(2) aerobic fermentation + land use — — out of misunderstanding
The dual role of aerobic fermentation technology is stable and sterilization, sludge fermented into humus, restricted agricultural, landscape or soil, so as to realize the efficient utilization of sludge organic matter and nutrient elements, low equipment investment, convenient operation and management.
However, for a long time, people have a one-sided understanding of aerobic sludge fermentation technology, such as large area and heavy metal pollution. However, aerobic fermentation engineering can be used efficiently, fast, stable and intensive design, operation mode, can realize the area greatly reduced; in addition, the research indicates that the heavy metal city sewage sludge in China exceed the standard ratio of about 5%, the pollution risk is small, should not become the main obstacle to limit land use of sludge fermentation products. Therefore, in the "urban sewage treatment plant sludge treatment technology guide (Trial)", ‚ “ aerobic fermentation + land use ” also as a recommended technical route. The application of this technology is relatively large in the less developed areas.
Note: anaerobic digestion can eliminate organic harmful bacteria, a certain amount of reduction, does not produce methane. The land itself will certainly be harmful, can be composted, most used in municipal gardens.
(3) drying + incineration + ash landfill or building materials using — — usher in the stage of growth
It can be used to achieve a high degree of reduction and stabilization of sludge, especially when the content of toxic and harmful substances in sludge is high and can not be reduced in the short term. Japan is limited by the limited land resources, widely used sludge incineration technology.
In the process of drying and incineration, sludge drying agent is used to dewater the sludge moisture content from 80% to about 40%. The calorific value of dry sludge can reach 2500-3500kcal/kg, which has the value of energy utilization, and can be mixed with a certain amount of auxiliary fuel for energy recovery. However, the investment of the equipment in the process of drying incineration is large, and the flue gas produced by incineration is seriously polluted, so a perfect flue gas treatment system is needed. Therefore, the dry incineration process is generally applicable to the land and the economically developed areas.
With the deepening of carbon emission reduction and sludge biomass resources, the application range of drying incineration technology in foreign countries began to decrease. However, at present, in our country the sludge anaerobic digestion and aerobic fermentation technology is still immature under the condition of sludge incineration in a certain period of time there may be a growth trend, especially in industrial kiln incineration way.

(4) deep dehydration + landfill '— — the current mainstream, but no future
In the most extensive deep dehydration for our application is using calcium oxide inorganic medicament conditioning as the core, although this technology can realize the reduction of sludge volume, but also accompanied by a substantial increase in the quality of dry sludge, and sludge quality influence, is not conducive to the subsequent processing. Therefore, some enterprises began to explore new ways of deep conditioning, such as electrodialysis dehydration, low temperature vacuum dehydration.
Although ‚ deep dehydration + "is an important way to landfill sludge treatment in China at present, but with in-depth understanding of the drawbacks, the more cautious attitude. Part of the landfill in the Yangtze Delta region of China has rejected the sewage treatment plant sludge; the United States, the European Union and other regions the proportion of sludge landfill is greatly reduced, the EU made provisions on the mechanical properties of sludge into the landfill, and organic matter ratio is less than 5%. In view of this, the future application of the depth of dewatering + landfill will be further reduced, probably as a major emergency treatment.

In general, our current technology of sludge treatment has been basically formed, from the construction investment, the operation effect, in terms of resources, to the anaerobic fermentation and aerobic fermentation and incineration as the main body of the three kinds of technologies will be the mainstream of the future. The gradual maturity of the technical route, the obvious role in promoting the industry.
The short term, deep dehydration + landfill is still a lot of the city's first choice, but will be gradually reduced, replaced; incineration method at this stage have obvious advantages, but the problem of flue gas governance has the strict and high operating cost is a major obstacle, but the technology is still the technology means the fastest development in the short term; long term, anaerobic digestion is the mainstream, with low operating costs, resource recovery rate is high. The advantage of aerobic fermentation lies in its low cost, it will be favored in less developed areas.

Other versions and icons for comprehensive comparison and reference

6 Summary
Drawing lessons from international experience, there are four main approaches to the development of sludge treatment and disposal in the future:
(1) anaerobic digestion technology route for biogas energy recovery and land use;
(2) the technology of aerobic fermentation based on land use;
(3) sludge drying incineration route;
(4) building materials using route processing technology based high sludge dehydration.
Summary of key points:
Sludge treatment involves three main steps: pretreatment, sludge concentration and dehydration, and back-end disposal. Stabilization, reduction, harmless priority, followed by the possibility of recycling
According to local conditions, dry & incineration or ideal solution, anaerobic fermentation, aerobic fermentation and incineration as the main body of the three technical routes will be the mainstream of the future (the most promising) of dry incineration.
Industry chain and value chain distribution
1 profit model (BOT + + plant dehydration, or EPC)
From the profit model, and similar to sewage treatment, sludge treatment and disposal is generally divided into two types of BOT and BOO model. In the process of disposal, originally more common is the 80% sewage treatment plant water content sludge directly to the disposal of the factory, the next step is disposal; more and more enterprises in the factory will be further dehydrated sludge to 50-55% water rate of 80%, then the next step the disposal of sinotrans. The advantage of the latter is obvious, that is, the cost of transportation is saved, and the cost is saved for the sewage enterprises.
Note: some of the price of water signed by the sewage treatment plant and the government will include the sludge handling fee.

2 industry chain
Sludge treatment industry chain is very short, sludge from sewage treatment, after a certain dehydration, by other third party companies to deal with, nothing more than that. There was an article written in “ sludge treatment and disposal must be constructed from a complete industrial chain to deal with the disposal of ” this statement shows that the sludge is not yet complete industrial chain, or simply not feasible. Among them, at the same time to provide engineering construction and operation of sludge disposal solutions are the most competitive, we should look at the enterprise.
Industry chain mainly involved:

Figure: sludge treatment industry chain

3 value chain
Unknown data, and then research, mostly in engineering &.
Summary of key points:
Sludge industrial chain is too short, relying on the upstream sewage treatment plant, the industry is very fragmented, can notEasy out bull stock;
Focus on the ability to provide engineering construction and operation of sludge disposal solutions, the most competitive.
[industry development course]
1 western methods and stages
In the west, the large-scale modern sludge treatment began in the late 60s. According to the time, it can be divided into three stages.

2 national standards

3 lack of relevant policies, funds under pressure
Sludge treatment should be an important part of the close connection with the sewage treatment, but because of the biased domestic environmental protection, the sludge treatment has brought the &ldquo to the wastewater treatment plant; the cost of additional &rdquo. Compared with the cost of sewage treatment in our country, the cost of sewage treatment can not solve the problem of sludge treatment and disposal.
"People's Republic of China water pollution prevention law" stipulates that urban sewage centralized treatment facilities in accordance with the provisions of the state to provide sewage sewage treatment of paid services, collect sewage treatment fees. Sewage treatment fee cost mainly includes the production cost of sewage treatment plants and pipe network maintenance cost, cost management, cost of pumping station upgrade and depreciation, and the sewage treatment plant sewage treatment fee should be the cost of production factors the actual operation consumption sum, but there is no clear sludge disposal costs. According to the actual situation, sludge is a by-product of sewage treatment, sewage treatment should include the disposal of sludge.
The purpose of the protection of sludge treatment and disposal costs is to ensure that the sludge treatment and disposal can be long-term, stable and normal operation, to alleviate the environmental pressure caused by sludge treatment and disposal to the community.
At present, China's sewage treatment fee collection has been more common, but not alone on the cost of sludge treatment. Meanwhile, the level of sewage treatment fees are lower than developed countries. Water consumption and industrial water prices in major cities in the country, the proportion of sewage treatment fees accounted for about 30% of the total price of water, while in developed countries the proportion is about $50%. For the sewage treatment plant, the sewage treatment fee can not even guarantee the normal operation of sewage treatment facilities, can be used for sludge treatment is more stretched.

4 illegal events
The sludge treatment and disposal capacity, backward means of urban sewage treatment in China, a large number of sludge treatment and disposal has not been standardized, directly to the water, soil and air pollution caused “ two, ” not only reduces the effective treatment of sewage treatment capacity, but also pose a serious threat to the ecological environment, great waste at the same time also caused the resources, in recent years there have been illegal dumping of sludge causing environmental pollution incidents are reported. In recent years, sewage sludge pollution inventory.


From the above case is not difficult to find, most cases have a common point: sewage sludge treatment enterprises will be outsourced to third party contractors, and basically do not have the sludge processing capacity, in order to obtain benefit, take the waste rush into danger, eventually causing serious environmental hazards.
Most areas of the country do not meet the relevant standards of landfill for sanitary landfill, there is no dry incineration and other sludge treatment and disposal of industrial and professional treatment agencies, large amounts of sludge unaccounted for.
Summary of key points:
There is no clear policy to pay the cost of sludge treatment of the main body, or not alone on the cost of sludge treatment;
Sewage treatment fees accounted for the proportion of the total water price is too low about 30% (developed countries is 50%), for the treatment of sludge costs more tense;
A large number of sludge whereabouts unknown, frequent vicious illegal events.
This article source: chemical 707;