I. Sewage treatment background China is a country with severe drought and water shortage. The total amount of freshwater resources is 2.8 trillion cubic meters, accounting for 6% of global water resources. It ranks fourth in the world after Brazil, Russia and Canada, but its per capita is only 2,300 cubic meters, which is only 1/4 of the world average. One-fifth of the United States, ranked 121 in the world, is one of the 13 countries with the poorest water resources in the world.
According to monitoring, groundwater in most cities in the country has been polluted to a certain extent by punctate and surface pollution and has been increasing year by year. The increasingly serious water pollution has not only reduced the use of water bodies, further exacerbated the contradiction of water resources shortage, and had a serious impact on the sustainable development strategy being implemented in China. It has also seriously threatened the drinking water safety of urban residents and the people. Health.
With the acceleration of urban modernization in the future, shortage of water resources will affect urban water supply. Sewage is a kind of stable and reliable water resource that can be recycled and reused. It is an important way to solve the problem of water shortage in cities. After advanced treatment, the sewage can be reused for industrial and mining enterprises, municipal sanitation, landscaping and urban river landscapes.
Second, the status of sewage treatment technology The current sewage treatment generally uses the traditional sewage treatment process, the use of flocculation and sedimentation, sand filter system, designed to add ferric chloride agent in the A2/O system, the final sedimentation pool with water wells, strengthen biological phosphorus removal Reduce the concentration of phosphorus in the effluent of the final sedimentation tank. After the sedimentation, the effluent passes through the lift pump station to the sand filter tank, and the air-water backwash filter tank is used. After filtration, the water is sent to the clear water tank and the water is pressurized to enter the reuse water pipe network.
In a conventional sewage treatment system, a sedimentation tank is used for the coagulation of the sewage, which does not form a good condition for particle agglomeration, and does not generate agglomerated floc, resulting in a low solid-liquid separation efficiency.
Third, new sewage treatment technology - granulation fluidized bed sewage treatment technology 1, the basic concept of fluidized bed When a fluid up through the particle bed at different speeds, the following situations may occur. Fixed bed - when the fluid When the velocity is low, the fluid flows only through the gap between the stationary particles. This bed is called a fixed bed. Initial or critical fluidized bed - When the flow rate of the fluid increases to a certain degree, the particles begin to loosen, the position of the particles is also adjusted within a certain interval, the bed is slightly expanded, but the particles are still not free to move. The layer is in an initial or critical fluidized state. Fluidized bed - If the flow rate of the fluid rises until all the particles are just suspended in the upward flowing gas or liquid and can perform random motion, the friction between the particles and the fluid is just balanced with its net gravity. The height of the bed will then increase with the increase of the flow rate. This bed is called a fluidized bed. Dilute phase transport bed - if the flow rate rises again to reach a certain limit value, the interface on the fluidized bed disappears and the particles are dispersed to be suspended in the gas stream and taken away by the gas stream. This bed is called a dilute phase transport bed.
2.Features of the fluidized bed The gas-solid motion in the fluidized bed is very much like a boiling liquid and shows liquid-like properties in many aspects. The fluidized bed has a liquid-like flow behavior and solid particles can be ejected from the orifices of the vessel wall. And like a liquid, flows from one container to another; for example, objects less dense than the bed can be easily pushed into the bed, and when released, it springs up and floats on the surface of the bed; When the vessel is tilted, the upper surface of the bed remains horizontal, and when the two beds are in communication, their bed surfaces are self-adjusted to the same level; the pressure variation between any two sections in the bed is approximately equal to the area between the two sections. Gravity of layers.
3. Granulation type fluidized bed wastewater treatment technology The self-granulation fluidized bed is a new type of water treatment technology that is based on the principle of quasi-steady state operation in chemical engineering and reaction engineering theory combined with the practical experience of the coagulation project. The main technical specifications of this technology are as follows:
§ The initial chemical coagulation reaction is completed in the hydraulic mixer, and the hydraulic retention time is less than 1 min;
§ The self-granulation reaction is completed in the upward flow mechanical stirring device, the mechanical stirring strength (G value) is about 30s-1, and the hydraulic retention time is 10-20 min;
§ Solid-liquid separation is completed in the solid-liquid separation zone on the top of the fluidized bed of the self-granulation fluid, and the hydraulic retention time is 5-10 min;
§ When the sludge is separated, the process of concentration is completed automatically. With the inorganic suspended particles as the main system, the water content of the separated sludge can reach 80% to 85%, and the organic components and inorganic suspended matter coexist in the system. The water content of the separated sludge is 90. ~95%;
§ The concentration of SS in the separated water is usually less than 5mg/L, and the concentration of SS in the separation water after separating the enhanced separation aid is usually less than 1 mg/L;
§ Scope of application: Raw water (sewage, waste water) SS concentration 1,000-20,000 mg/L, COD not more than 1,000 mg/L.
The technology is implemented in specially designed integrated devices. Its main features are short hydraulic retention time, small size, small footprint, wide applicability, flexible use, high processing efficiency, and simultaneous solid-liquid separation and sludge concentration.
The technology can be widely used for high turbidity water treatment, high suspended solids wastewater treatment and reuse, water plant and municipal sewage sludge concentration, construction site wastewater treatment, disaster relief water treatment.
4. Industrialization prospect of granulation type fluidized bed sewage treatment technology In the process of actively implementing the "National Ecological Environment Construction Plan", comprehensive utilization of water resources, water resources regeneration, and water pollution control are particularly important links. Therefore, the market capacity of water treatment equipment will greatly increase, and market competition will be the competition of technology level, applicability and price. The series of equipment adopting this technology has the characteristics of advanced technology, small size and low cost, and can be produced in accordance with the requirements of users. It will be highly competitive in the environmental protection equipment market. The main users of the equipment will be the industrial water treatment, wastewater treatment, industrial water recycling, small and medium-sized water supply and wastewater treatment plant sludge treatment of small and medium-sized industrial enterprises.
The technology has successively been in the Garden of Yellow River Garden in Zhengzhou (high turbidity water treatment), Dengjiacun sewage treatment plant in Xi'an (digestion sludge dewatering), Shaanxi Lueyang Iron and Steel Plant (gas scrubber wastewater and beneficiation wastewater treatment), Shenzhen Water Company (precipitation The semi-productive experiment was conducted on the pool mud treatment. On this basis, the equipment was repeatedly improved and the invention patent for the High-Efficiency Solid-Liquid Separator was applied. At present, it has successfully passed the invention patent examination, and the technology has been recognized by the State Patent Office. protection. The patented technology has so far been used in Xi'an Xijiao Thermal Power Plant for the recovery and reuse of ash-washing wastewater. The Beishiqiao Wastewater Treatment Center in Xi’an City is used for the separation of activated sludge mixture and sludge concentration in Qujiang Water in Xi’an City. The plant, the Zaozhuang City Water Supply Company of Shandong Province and the Binzhou City Water Supply Company of Shandong Province were used for the regeneration and reuse treatment of production wastewater, and achieved good practical application results. Therefore, this technology has a huge market and industrialization prospects.
Fourth, the research status of granulation fluidized bed technology for wastewater treatment has been developed and applied in recent years from my granulation fluidized bed in the water treatment process, especially the sludge dewatering and high turbidity raw water, high concentration of waste liquid The research of granulation fluidized bed for the purpose of solid-liquid separation has attracted the attention of the water treatment industry at home and abroad. Many experts and scholars abroad have begun to conduct in-depth research on this technology, and there have been many research results. However, the technology started late in the country and still needs to be improved!
There are mainly two aspects of the research on granulation fluidized bed technology. One is to study from experiment or practice, mainly on the application of granulation fluidized bed technology in practice. For example, Prof. Wang Xiaochang's “Test Measurement of Particle Flow in Self-Pelletizing Fluidized Beds†and Pan Yongzhang’s “Experimental Study on the Treatment of Car Washing Wastewater in Granulated Fluidized Bed Technologyâ€, etc.; the other is to carry out theoretical research. This is mainly to study the mechanism of particle flocculation in fluidized bed and simulate the solid-liquid flow in fluidized bed. For example, Prof. Huang Tinglin's "Balanced Fluidized Bed Movement Balance" and Professor Wang Xiaochang's "Kinetic study of fluidized pellet bed process. Development of a mathematical model". However, in general, at present, China's research on this technology mainly remains in experimental research.
5. Application Status of Granulation Fluidized Bed Technology for Wastewater Treatment Since the granulation fluidized bed technology can efficiently perform solid-liquid separation, it is widely used for high turbidity water treatment, high suspended solids wastewater treatment and reuse. Sludge enrichment in water plants and municipal wastewater plants, wastewater treatment in construction sites, disaster relief water treatment, etc.
The use of granulation-type high-efficiency solid-liquid separation technology to treat high suspended solids concentration industrial wastewater is superior to traditional treatment processes in the following aspects:
(1) The processing efficiency is high and the effect is good. The hydraulic retention time of the main equipment of the high-efficiency solid-liquid separation device is about 9 min. With the mixing of the front Water Pump and the pipeline, the total hydraulic retention time is within 10 min, which is much shorter than the required residence time of the traditional treatment process. After such a short treatment time, the effluent turbidity of the device has met the industrial water quality requirements. And the required amount of inorganic coagulant is lower than traditional coagulation sedimentation process.
(2) The separation sludge has a low moisture content and does not require special concentration treatment. Separation sludge of high-efficiency solid-liquid separation equipment has very good dewatering performance. After staying in the mud storage area for more than 1 h, the moisture content of the sludge is reduced to less than 85%, and the final sludge treatment can be performed without special concentration.
(3) Operational flexibility is strong enough to meet different processing needs. High-efficiency solid-liquid separation equipment can not only perform continuous treatment of wastewater, but also can perform intermittent treatment, and has strong anti-impact load capability, and it is also basic if it exceeds the rated load by 50%. Can guarantee the treatment of water quality.
The following describes the application of fluidized bed in the treatment of industrial wastewater by taking the application of granulation fluidized bed technology in the treatment of car wash wastewater as an example:
With the continuous improvement of people's living standards, the number of cars is also rising, so the car wash industry has a huge market demand. Now, car wash yards of different sizes are scattered all over the country. However, most of the car wash sites do not have wastewater treatment and recycling facilities. The car wash water is simply discharged into municipal pipelines after being precipitated. This not only wastes water resources, but also Urban water environment caused a certain amount of pollution.
In view of the current status of water pollution and water waste in the car wash industry, various types of car wash wastewater reuse equipment have emerged on the market in recent years. Some are based on multi-media filters, ceramic adsorption filters, ultrafiltration system retention, adsorption, screening principle to achieve reuse after car wash wastewater treatment; some use conventional oil precipitation, filtration, disinfection methods. Although the effluent treated by these equipments can meet the requirements for the quality of car wash wastewater, its common shortcomings are large floor space, high construction and operating costs, and many difficulties in launching the market.
However, when the granulation fluidized bed technology is used to treat the car wash wastewater, after the car wash wastewater is treated by the fluidized bed device, the quality of the effluent water can reach the discharge standard of the car wash back water. The moisture content of the sludge produced by the granulation fluidized bed method is significantly lower than that produced by the conventional coagulation sedimentation method, and no sludge concentration equipment is required. In addition, the granulation fluidized bed method has the advantages of small occupied area, simple equipment structure, and low investment and operating costs compared with the traditional treatment process, so it is used in the reuse treatment of car wash wastewater, and has a broad market prospect. .
According to monitoring, groundwater in most cities in the country has been polluted to a certain extent by punctate and surface pollution and has been increasing year by year. The increasingly serious water pollution has not only reduced the use of water bodies, further exacerbated the contradiction of water resources shortage, and had a serious impact on the sustainable development strategy being implemented in China. It has also seriously threatened the drinking water safety of urban residents and the people. Health.
With the acceleration of urban modernization in the future, shortage of water resources will affect urban water supply. Sewage is a kind of stable and reliable water resource that can be recycled and reused. It is an important way to solve the problem of water shortage in cities. After advanced treatment, the sewage can be reused for industrial and mining enterprises, municipal sanitation, landscaping and urban river landscapes.
Second, the status of sewage treatment technology The current sewage treatment generally uses the traditional sewage treatment process, the use of flocculation and sedimentation, sand filter system, designed to add ferric chloride agent in the A2/O system, the final sedimentation pool with water wells, strengthen biological phosphorus removal Reduce the concentration of phosphorus in the effluent of the final sedimentation tank. After the sedimentation, the effluent passes through the lift pump station to the sand filter tank, and the air-water backwash filter tank is used. After filtration, the water is sent to the clear water tank and the water is pressurized to enter the reuse water pipe network.
In a conventional sewage treatment system, a sedimentation tank is used for the coagulation of the sewage, which does not form a good condition for particle agglomeration, and does not generate agglomerated floc, resulting in a low solid-liquid separation efficiency.
Third, new sewage treatment technology - granulation fluidized bed sewage treatment technology 1, the basic concept of fluidized bed When a fluid up through the particle bed at different speeds, the following situations may occur. Fixed bed - when the fluid When the velocity is low, the fluid flows only through the gap between the stationary particles. This bed is called a fixed bed. Initial or critical fluidized bed - When the flow rate of the fluid increases to a certain degree, the particles begin to loosen, the position of the particles is also adjusted within a certain interval, the bed is slightly expanded, but the particles are still not free to move. The layer is in an initial or critical fluidized state. Fluidized bed - If the flow rate of the fluid rises until all the particles are just suspended in the upward flowing gas or liquid and can perform random motion, the friction between the particles and the fluid is just balanced with its net gravity. The height of the bed will then increase with the increase of the flow rate. This bed is called a fluidized bed. Dilute phase transport bed - if the flow rate rises again to reach a certain limit value, the interface on the fluidized bed disappears and the particles are dispersed to be suspended in the gas stream and taken away by the gas stream. This bed is called a dilute phase transport bed.
2.Features of the fluidized bed The gas-solid motion in the fluidized bed is very much like a boiling liquid and shows liquid-like properties in many aspects. The fluidized bed has a liquid-like flow behavior and solid particles can be ejected from the orifices of the vessel wall. And like a liquid, flows from one container to another; for example, objects less dense than the bed can be easily pushed into the bed, and when released, it springs up and floats on the surface of the bed; When the vessel is tilted, the upper surface of the bed remains horizontal, and when the two beds are in communication, their bed surfaces are self-adjusted to the same level; the pressure variation between any two sections in the bed is approximately equal to the area between the two sections. Gravity of layers.
3. Granulation type fluidized bed wastewater treatment technology The self-granulation fluidized bed is a new type of water treatment technology that is based on the principle of quasi-steady state operation in chemical engineering and reaction engineering theory combined with the practical experience of the coagulation project. The main technical specifications of this technology are as follows:
§ The initial chemical coagulation reaction is completed in the hydraulic mixer, and the hydraulic retention time is less than 1 min;
§ The self-granulation reaction is completed in the upward flow mechanical stirring device, the mechanical stirring strength (G value) is about 30s-1, and the hydraulic retention time is 10-20 min;
§ Solid-liquid separation is completed in the solid-liquid separation zone on the top of the fluidized bed of the self-granulation fluid, and the hydraulic retention time is 5-10 min;
§ When the sludge is separated, the process of concentration is completed automatically. With the inorganic suspended particles as the main system, the water content of the separated sludge can reach 80% to 85%, and the organic components and inorganic suspended matter coexist in the system. The water content of the separated sludge is 90. ~95%;
§ The concentration of SS in the separated water is usually less than 5mg/L, and the concentration of SS in the separation water after separating the enhanced separation aid is usually less than 1 mg/L;
§ Scope of application: Raw water (sewage, waste water) SS concentration 1,000-20,000 mg/L, COD not more than 1,000 mg/L.
The technology is implemented in specially designed integrated devices. Its main features are short hydraulic retention time, small size, small footprint, wide applicability, flexible use, high processing efficiency, and simultaneous solid-liquid separation and sludge concentration.
The technology can be widely used for high turbidity water treatment, high suspended solids wastewater treatment and reuse, water plant and municipal sewage sludge concentration, construction site wastewater treatment, disaster relief water treatment.
4. Industrialization prospect of granulation type fluidized bed sewage treatment technology In the process of actively implementing the "National Ecological Environment Construction Plan", comprehensive utilization of water resources, water resources regeneration, and water pollution control are particularly important links. Therefore, the market capacity of water treatment equipment will greatly increase, and market competition will be the competition of technology level, applicability and price. The series of equipment adopting this technology has the characteristics of advanced technology, small size and low cost, and can be produced in accordance with the requirements of users. It will be highly competitive in the environmental protection equipment market. The main users of the equipment will be the industrial water treatment, wastewater treatment, industrial water recycling, small and medium-sized water supply and wastewater treatment plant sludge treatment of small and medium-sized industrial enterprises.
The technology has successively been in the Garden of Yellow River Garden in Zhengzhou (high turbidity water treatment), Dengjiacun sewage treatment plant in Xi'an (digestion sludge dewatering), Shaanxi Lueyang Iron and Steel Plant (gas scrubber wastewater and beneficiation wastewater treatment), Shenzhen Water Company (precipitation The semi-productive experiment was conducted on the pool mud treatment. On this basis, the equipment was repeatedly improved and the invention patent for the High-Efficiency Solid-Liquid Separator was applied. At present, it has successfully passed the invention patent examination, and the technology has been recognized by the State Patent Office. protection. The patented technology has so far been used in Xi'an Xijiao Thermal Power Plant for the recovery and reuse of ash-washing wastewater. The Beishiqiao Wastewater Treatment Center in Xi’an City is used for the separation of activated sludge mixture and sludge concentration in Qujiang Water in Xi’an City. The plant, the Zaozhuang City Water Supply Company of Shandong Province and the Binzhou City Water Supply Company of Shandong Province were used for the regeneration and reuse treatment of production wastewater, and achieved good practical application results. Therefore, this technology has a huge market and industrialization prospects.
Fourth, the research status of granulation fluidized bed technology for wastewater treatment has been developed and applied in recent years from my granulation fluidized bed in the water treatment process, especially the sludge dewatering and high turbidity raw water, high concentration of waste liquid The research of granulation fluidized bed for the purpose of solid-liquid separation has attracted the attention of the water treatment industry at home and abroad. Many experts and scholars abroad have begun to conduct in-depth research on this technology, and there have been many research results. However, the technology started late in the country and still needs to be improved!
There are mainly two aspects of the research on granulation fluidized bed technology. One is to study from experiment or practice, mainly on the application of granulation fluidized bed technology in practice. For example, Prof. Wang Xiaochang's “Test Measurement of Particle Flow in Self-Pelletizing Fluidized Beds†and Pan Yongzhang’s “Experimental Study on the Treatment of Car Washing Wastewater in Granulated Fluidized Bed Technologyâ€, etc.; the other is to carry out theoretical research. This is mainly to study the mechanism of particle flocculation in fluidized bed and simulate the solid-liquid flow in fluidized bed. For example, Prof. Huang Tinglin's "Balanced Fluidized Bed Movement Balance" and Professor Wang Xiaochang's "Kinetic study of fluidized pellet bed process. Development of a mathematical model". However, in general, at present, China's research on this technology mainly remains in experimental research.
5. Application Status of Granulation Fluidized Bed Technology for Wastewater Treatment Since the granulation fluidized bed technology can efficiently perform solid-liquid separation, it is widely used for high turbidity water treatment, high suspended solids wastewater treatment and reuse. Sludge enrichment in water plants and municipal wastewater plants, wastewater treatment in construction sites, disaster relief water treatment, etc.
The use of granulation-type high-efficiency solid-liquid separation technology to treat high suspended solids concentration industrial wastewater is superior to traditional treatment processes in the following aspects:
(1) The processing efficiency is high and the effect is good. The hydraulic retention time of the main equipment of the high-efficiency solid-liquid separation device is about 9 min. With the mixing of the front Water Pump and the pipeline, the total hydraulic retention time is within 10 min, which is much shorter than the required residence time of the traditional treatment process. After such a short treatment time, the effluent turbidity of the device has met the industrial water quality requirements. And the required amount of inorganic coagulant is lower than traditional coagulation sedimentation process.
(2) The separation sludge has a low moisture content and does not require special concentration treatment. Separation sludge of high-efficiency solid-liquid separation equipment has very good dewatering performance. After staying in the mud storage area for more than 1 h, the moisture content of the sludge is reduced to less than 85%, and the final sludge treatment can be performed without special concentration.
(3) Operational flexibility is strong enough to meet different processing needs. High-efficiency solid-liquid separation equipment can not only perform continuous treatment of wastewater, but also can perform intermittent treatment, and has strong anti-impact load capability, and it is also basic if it exceeds the rated load by 50%. Can guarantee the treatment of water quality.
The following describes the application of fluidized bed in the treatment of industrial wastewater by taking the application of granulation fluidized bed technology in the treatment of car wash wastewater as an example:
With the continuous improvement of people's living standards, the number of cars is also rising, so the car wash industry has a huge market demand. Now, car wash yards of different sizes are scattered all over the country. However, most of the car wash sites do not have wastewater treatment and recycling facilities. The car wash water is simply discharged into municipal pipelines after being precipitated. This not only wastes water resources, but also Urban water environment caused a certain amount of pollution.
In view of the current status of water pollution and water waste in the car wash industry, various types of car wash wastewater reuse equipment have emerged on the market in recent years. Some are based on multi-media filters, ceramic adsorption filters, ultrafiltration system retention, adsorption, screening principle to achieve reuse after car wash wastewater treatment; some use conventional oil precipitation, filtration, disinfection methods. Although the effluent treated by these equipments can meet the requirements for the quality of car wash wastewater, its common shortcomings are large floor space, high construction and operating costs, and many difficulties in launching the market.
However, when the granulation fluidized bed technology is used to treat the car wash wastewater, after the car wash wastewater is treated by the fluidized bed device, the quality of the effluent water can reach the discharge standard of the car wash back water. The moisture content of the sludge produced by the granulation fluidized bed method is significantly lower than that produced by the conventional coagulation sedimentation method, and no sludge concentration equipment is required. In addition, the granulation fluidized bed method has the advantages of small occupied area, simple equipment structure, and low investment and operating costs compared with the traditional treatment process, so it is used in the reuse treatment of car wash wastewater, and has a broad market prospect. .
1. Description of GH sand and Gravel Pump
Naipu G series Gravel and sand slurry pump is
designed specifically for continuous pumping of extremely aggressive
slurries, with a wide particle size distribution. Capable of handling
large particles at consistently high efficiencies results in low cost of
ownership. The large volume internal profile of the casing reduces
associated velocities further increasing component life.
Typical Applications---
Slag Granulation
Suction Hopper Dredging
Dredging
Barge Loading
Sand Reclamation
Sugar Beet
2. Construction drawing for Naipu GH sand and gravel pump
3. Select chart of GH sand and gravel pump
4.Performance parameters of GH sand and gravel pumps
Gravel Pump, Sand Pump, High Head Gravel Pump, GH Gravel Pump, Dredging Pump, Sand Gravel Pump
Shijiazhuang Naipu Pump Co., Ltd. , https://www.naipu-pump.com