Industrial Wastewater Treatment Project Profile:
Industrial Wastewater Treatment Industrial waste water refers to waste water, sewage, and waste liquids produced in industrial production processes, which contain industrial production materials, intermediate products, and products that are lost to water, and contaminants produced during the production process. With the rapid development of industry, the types and quantities of waste water have increased rapidly, and pollution of water bodies has become increasingly widespread and serious, threatening human health and safety. For the protection of the environment, the treatment of industrial wastewater is more important than the treatment of municipal wastewater.
Industrial Wastewater Classification:
The first classification is based on the chemical properties of major pollutants contained in industrial wastewater. Inorganic wastewater is mainly inorganic wastewater, and organic wastewater is the main organic pollutant. For example, wastewater from electroplating wastewater and mineral processing is inorganic wastewater; wastewater from food or petroleum processing is organic wastewater.
The second classification is based on the products and processing objects of industrial enterprises, such as metallurgical wastewater, papermaking wastewater, coking coal wastewater, metal pickling wastewater, chemical fertilizer wastewater, textile printing and dyeing wastewater, dye wastewater, tannery wastewater, pesticide wastewater, power station wastewater, etc. .
The third type is classified according to the main components of pollutants contained in wastewater, such as acidic wastewater, alkaline wastewater, cyanide-containing wastewater, chromium-containing wastewater, cadmium-containing wastewater, mercury-containing wastewater, phenol-containing wastewater, aldehyde-containing wastewater, oil-containing wastewater, Sulfur-containing wastewater, organic phosphorus wastewater, and radioactive waste water.
The first two classification methods do not involve the main components of the pollutants contained in the wastewater, nor can they harm the harmfulness of the surface wastewater. The third classification method clearly indicates the composition of the main pollutants in the waste water and can indicate the certain hazard of the waste water.
In addition, starting from the difficulty of wastewater treatment and the hazards of wastewater, the main pollutants in wastewater are grouped into three categories:
The first type is waste heat, which mainly comes from cooling water. Cooling water can be reused.
The second category is conventional pollutants, ie substances that are not readily toxic and are readily biodegradable, include biodegradable organic compounds, compounds that can be used as bionutrients, and suspended solids;
The third category is toxic pollutants, that is, substances that are toxic and not easily biodegradable, including heavy metals, toxic compounds, and organic compounds that are not easily biodegradable.
Industrial wastewater treatment principles:
The effective treatment of industrial wastewater should follow the following principles:
1 The most fundamental thing is to reform the production process and eliminate as much as possible the production of toxic and hazardous waste water during the production process. Replace poisonous materials or products with non-toxic materials or products.
2 In the production process of using toxic raw materials and producing toxic intermediates and products, reasonable process procedures and equipment are used, and strict operations and supervision are implemented to eliminate leakage and minimize the amount of losses.
3 Wastewater containing highly toxic substances, such as wastewater containing some heavy metals, radioactive substances, high concentrations of phenols, cyanide, etc., should be separated from other waste water in order to facilitate the disposal and recovery of useful substances.
4 Some high-volume and light-polluting wastewater, such as cooling wastewater, should not be discharged into sewers so as not to increase the load on urban sewers and sewage treatment plants. This type of wastewater should be recycled after proper treatment in the factory.
5 The organic waste water with components and properties similar to urban sewage, such as papermaking wastewater, sugar wastewater, food processing wastewater, etc., can be discharged into the urban sewage system. Large-scale sewage treatment plants should be constructed, including easy-to-use processing facilities such as bio-oxidation ponds, sewage reservoirs, and land treatment systems that can be constructed according to local conditions. Compared with small-scale sewage treatment plants, large-scale sewage treatment plants can not only significantly reduce the cost of capital construction and operation, but also have stable water volume and water quality, and can easily maintain good operating conditions and treatment effects.
6 Some biodegradable toxic waste water, such as phenol and cyanogen wastewater, can be discharged into the urban sewers according to allowable discharge standards after treatment in the factory, and the sewage treatment plant can further conduct biological oxidative degradation treatment.
7 Wastewater containing toxic pollutants that are difficult to biodegrade should not be discharged into urban sewers and transported to sewage treatment plants, but should be treated separately.
Industrial wastewater treatment technology:
With people's rising demand for wastewater treatment and recycling, people are increasingly concerned about new technologies for industrial wastewater treatment. At present, the main industrial wastewater treatment technologies are the following.
(1) Coagulation and precipitation method. The coagulation and sedimentation method is a method of using a coagulant to purify industrial wastewater. Coagulants are generally composed of inorganic polymer flocculants, organic polymer flocculants and biopolymer flocculants. At present, polyaluminum salts and complex polyaluminum salts in inorganic polymer flocculants are most widely used in water treatment.
(2) adsorption method. Adsorption is the use of adsorbents to treat wastewater. The most widely used adsorbents in industry today are magnesium hydroxide, activated cellulose carbon (ACF) and novel adsorbent-chitosan and its derivatives. Magnesium hydroxide has a wide range of applications as an acidic industrial wastewater treatment agent, and can be used for papermaking and printing and dyeing wastewater, urban domestic wastewater, electroplating wastewater, fluorine-containing wastewater, etc., and is safe and reliable.
(3) Biodegradation. At present, printing and dyeing and papermaking wastewater are the two major factors that cause environmental pollution. Most of the dyes used today are synthetic macromolecular aromatic compounds, which have complex structures and are difficult to be degraded. The color of the dye industrial wastewater is dark. Although the dye processing wastewater treated by physical methods has a large degree of reduction in chroma, the removal rate of COD is poor, and The treatment cost is high, and it is easy to cause secondary pollution. The use of chemically synthesized organic substances will cause water poisoning. The use of biodegradation can not only overcome the above problems, but also has the following advantages: 1 No need to pretreat the pollutants; 2 has antibacterial effect on other microorganisms; 3 can deal with heavy pollution and toxic pollutants; 4 degradants have a broad spectrum. White rot fungi and yellow-celled primordium pupae are two very good strains that can be degraded with essential pigment printing and dyeing wastewater.
(4) Ion exchange resin method. Ion exchange resin (IER) is a kind of synthetic functional polymer material containing reactive groups, which is formed by introducing different ion exchange groups into crosslinked polymer copolymers. Ion exchange resins have exchange. The functions of selection, adsorption and catalysis are mainly used in industrial wastewater treatment to recover heavy metals and noble metals, purify toxic substances, and remove organic or acidic organic substances such as phenols, acids and amines in organic wastewater.
(5) Membrane separation technology. In industrial wastewater treatment, membrane separation technology can be used to treat a variety of wastewater. Treating oily wastewater with an ultrafiltration membrane can achieve a grease removal rate of 97%-100%. A gradient alumina tube and an inorganic membrane-bioreactor were used to treat domestic wastewater. The removal rate of BOD was 83%, and the removal rates of COD, NH3-N, and turbidity exceeded 96%, 95%, and 98%, respectively, for SS. The removal rate reaches 100%. The use of acid-alkali inorganic membranes to treat alkaline papermaking black liquor does not require adjustment of the pH value. Different pore size membranes can be used to recover useful components such as cellulose and lignin. The treated water quality can be used for cooking and pulping, and the closed-circuit of papermaking wastewater can be realized. Recycling: The mud-film mixing process was used to treat tannery wastewater. The removal rates of CODCr, S2-, and Cr6+ were 86.14%, 88.39%, and 54.5%, respectively. In addition, the use of membrane technology can also handle restaurant wastewater, pharmaceutical and chemical wastewater, dye wastewater and so on.
Main technique:
UASB reactor anaerobic treatment is a relatively complex biochemical process. It mainly relies on the combination of hydrolytic acidogenic bacteria, hydrogen-producing acetogenic bacteria, and methanogenic bacteria to decompose organic matter in wastewater into methane in an anaerobic environment. And carbon dioxide and other material processes.
The upflow anaerobic sludge blanket reactor, referred to as the UASB reactor, has no carrier in the sludge bed reactor and is a suspended growth type digester. It consists of a reaction zone, a precipitation zone, and a gas chamber. The waste water enters from the bottom of the sludge bed and is mixed with the sludge in the sludge bed. The microorganisms decompose the organic matter in the waste water to produce biogas. Due to the strong agitation of rising bubbles, a suspended sludge layer forms on the top of the sludge. The mixture of gas, water, and mud rises into the three-phase separator. When the biogas bubble hits the reflector in the lower part of the separator, it is folded into the air chamber and is effectively separated and discharged; the sludge and water enter the three-phase separation through the channel. In the sedimentation zone of the device, under the action of gravity, the water and mud are separated and the supernatant is discharged from the upper part of the precipitation zone. The sludge in the lower part of the precipitation zone is returned to the reaction zone along the inclined wall.
SBR process
SBR is an abbreviation for sequential batch reactor. The SBR process is a reactor operating in a time-sequential batch operation. Main features: complete mixing in space, full push-in time, high reaction speed, in order to obtain the same treatment efficiency, the reaction tank of SBR method is obviously smaller than the volume of continuous treatment tank. The process flow is simple, the number of structures is small, the area is saved, the cost is low, and the operating cost is low. Static precipitation, solid-liquid separation effect is good, and the quality of effluent is high. The operating mode is flexible and a variety of process routes can be combined.
CASS process
The CASS (cyclic activated sludge system) process is a cyclic activated sludge process. Compared with SBR, the pre-reaction zone is increased and a more rational and optimized bioreactor is designed. The process returns part of the remaining sludge in the main reaction zone to the selector and realizes continuous water intake. CASS tanks can withstand the impact of water, water quality impact, high dilution of industrial waste water; eliminate the initial sedimentation tank, the second settling tank, the process is simple, easy operation and management; mechanical equipment, less, simple, and not easy to appear Faults, less maintenance, simple operation control and automation requirements. Fewer structures, compact biological pool layout, and space saving; better denitrification and phosphorus removal effects; less residual sludge, good sludge stability, good dewatering performance, and excess sludge production as traditional About 60% of the activated sludge process; suitable for industrial wastewater treatment.
Industrial Wastewater Treatment Industrial waste water refers to waste water, sewage, and waste liquids produced in industrial production processes, which contain industrial production materials, intermediate products, and products that are lost to water, and contaminants produced during the production process. With the rapid development of industry, the types and quantities of waste water have increased rapidly, and pollution of water bodies has become increasingly widespread and serious, threatening human health and safety. For the protection of the environment, the treatment of industrial wastewater is more important than the treatment of municipal wastewater.
Industrial Wastewater Classification:
The first classification is based on the chemical properties of major pollutants contained in industrial wastewater. Inorganic wastewater is mainly inorganic wastewater, and organic wastewater is the main organic pollutant. For example, wastewater from electroplating wastewater and mineral processing is inorganic wastewater; wastewater from food or petroleum processing is organic wastewater.
The second classification is based on the products and processing objects of industrial enterprises, such as metallurgical wastewater, papermaking wastewater, coking coal wastewater, metal pickling wastewater, chemical fertilizer wastewater, textile printing and dyeing wastewater, dye wastewater, tannery wastewater, pesticide wastewater, power station wastewater, etc. .
The third type is classified according to the main components of pollutants contained in wastewater, such as acidic wastewater, alkaline wastewater, cyanide-containing wastewater, chromium-containing wastewater, cadmium-containing wastewater, mercury-containing wastewater, phenol-containing wastewater, aldehyde-containing wastewater, oil-containing wastewater, Sulfur-containing wastewater, organic phosphorus wastewater, and radioactive waste water.
The first two classification methods do not involve the main components of the pollutants contained in the wastewater, nor can they harm the harmfulness of the surface wastewater. The third classification method clearly indicates the composition of the main pollutants in the waste water and can indicate the certain hazard of the waste water.
In addition, starting from the difficulty of wastewater treatment and the hazards of wastewater, the main pollutants in wastewater are grouped into three categories:
The first type is waste heat, which mainly comes from cooling water. Cooling water can be reused.
The second category is conventional pollutants, ie substances that are not readily toxic and are readily biodegradable, include biodegradable organic compounds, compounds that can be used as bionutrients, and suspended solids;
The third category is toxic pollutants, that is, substances that are toxic and not easily biodegradable, including heavy metals, toxic compounds, and organic compounds that are not easily biodegradable.
Industrial wastewater treatment principles:
The effective treatment of industrial wastewater should follow the following principles:
1 The most fundamental thing is to reform the production process and eliminate as much as possible the production of toxic and hazardous waste water during the production process. Replace poisonous materials or products with non-toxic materials or products.
2 In the production process of using toxic raw materials and producing toxic intermediates and products, reasonable process procedures and equipment are used, and strict operations and supervision are implemented to eliminate leakage and minimize the amount of losses.
3 Wastewater containing highly toxic substances, such as wastewater containing some heavy metals, radioactive substances, high concentrations of phenols, cyanide, etc., should be separated from other waste water in order to facilitate the disposal and recovery of useful substances.
4 Some high-volume and light-polluting wastewater, such as cooling wastewater, should not be discharged into sewers so as not to increase the load on urban sewers and sewage treatment plants. This type of wastewater should be recycled after proper treatment in the factory.
5 The organic waste water with components and properties similar to urban sewage, such as papermaking wastewater, sugar wastewater, food processing wastewater, etc., can be discharged into the urban sewage system. Large-scale sewage treatment plants should be constructed, including easy-to-use processing facilities such as bio-oxidation ponds, sewage reservoirs, and land treatment systems that can be constructed according to local conditions. Compared with small-scale sewage treatment plants, large-scale sewage treatment plants can not only significantly reduce the cost of capital construction and operation, but also have stable water volume and water quality, and can easily maintain good operating conditions and treatment effects.
6 Some biodegradable toxic waste water, such as phenol and cyanogen wastewater, can be discharged into the urban sewers according to allowable discharge standards after treatment in the factory, and the sewage treatment plant can further conduct biological oxidative degradation treatment.
7 Wastewater containing toxic pollutants that are difficult to biodegrade should not be discharged into urban sewers and transported to sewage treatment plants, but should be treated separately.
Industrial wastewater treatment technology:
With people's rising demand for wastewater treatment and recycling, people are increasingly concerned about new technologies for industrial wastewater treatment. At present, the main industrial wastewater treatment technologies are the following.
(1) Coagulation and precipitation method. The coagulation and sedimentation method is a method of using a coagulant to purify industrial wastewater. Coagulants are generally composed of inorganic polymer flocculants, organic polymer flocculants and biopolymer flocculants. At present, polyaluminum salts and complex polyaluminum salts in inorganic polymer flocculants are most widely used in water treatment.
(2) adsorption method. Adsorption is the use of adsorbents to treat wastewater. The most widely used adsorbents in industry today are magnesium hydroxide, activated cellulose carbon (ACF) and novel adsorbent-chitosan and its derivatives. Magnesium hydroxide has a wide range of applications as an acidic industrial wastewater treatment agent, and can be used for papermaking and printing and dyeing wastewater, urban domestic wastewater, electroplating wastewater, fluorine-containing wastewater, etc., and is safe and reliable.
(3) Biodegradation. At present, printing and dyeing and papermaking wastewater are the two major factors that cause environmental pollution. Most of the dyes used today are synthetic macromolecular aromatic compounds, which have complex structures and are difficult to be degraded. The color of the dye industrial wastewater is dark. Although the dye processing wastewater treated by physical methods has a large degree of reduction in chroma, the removal rate of COD is poor, and The treatment cost is high, and it is easy to cause secondary pollution. The use of chemically synthesized organic substances will cause water poisoning. The use of biodegradation can not only overcome the above problems, but also has the following advantages: 1 No need to pretreat the pollutants; 2 has antibacterial effect on other microorganisms; 3 can deal with heavy pollution and toxic pollutants; 4 degradants have a broad spectrum. White rot fungi and yellow-celled primordium pupae are two very good strains that can be degraded with essential pigment printing and dyeing wastewater.
(4) Ion exchange resin method. Ion exchange resin (IER) is a kind of synthetic functional polymer material containing reactive groups, which is formed by introducing different ion exchange groups into crosslinked polymer copolymers. Ion exchange resins have exchange. The functions of selection, adsorption and catalysis are mainly used in industrial wastewater treatment to recover heavy metals and noble metals, purify toxic substances, and remove organic or acidic organic substances such as phenols, acids and amines in organic wastewater.
(5) Membrane separation technology. In industrial wastewater treatment, membrane separation technology can be used to treat a variety of wastewater. Treating oily wastewater with an ultrafiltration membrane can achieve a grease removal rate of 97%-100%. A gradient alumina tube and an inorganic membrane-bioreactor were used to treat domestic wastewater. The removal rate of BOD was 83%, and the removal rates of COD, NH3-N, and turbidity exceeded 96%, 95%, and 98%, respectively, for SS. The removal rate reaches 100%. The use of acid-alkali inorganic membranes to treat alkaline papermaking black liquor does not require adjustment of the pH value. Different pore size membranes can be used to recover useful components such as cellulose and lignin. The treated water quality can be used for cooking and pulping, and the closed-circuit of papermaking wastewater can be realized. Recycling: The mud-film mixing process was used to treat tannery wastewater. The removal rates of CODCr, S2-, and Cr6+ were 86.14%, 88.39%, and 54.5%, respectively. In addition, the use of membrane technology can also handle restaurant wastewater, pharmaceutical and chemical wastewater, dye wastewater and so on.
Main technique:
UASB reactor anaerobic treatment is a relatively complex biochemical process. It mainly relies on the combination of hydrolytic acidogenic bacteria, hydrogen-producing acetogenic bacteria, and methanogenic bacteria to decompose organic matter in wastewater into methane in an anaerobic environment. And carbon dioxide and other material processes.
The upflow anaerobic sludge blanket reactor, referred to as the UASB reactor, has no carrier in the sludge bed reactor and is a suspended growth type digester. It consists of a reaction zone, a precipitation zone, and a gas chamber. The waste water enters from the bottom of the sludge bed and is mixed with the sludge in the sludge bed. The microorganisms decompose the organic matter in the waste water to produce biogas. Due to the strong agitation of rising bubbles, a suspended sludge layer forms on the top of the sludge. The mixture of gas, water, and mud rises into the three-phase separator. When the biogas bubble hits the reflector in the lower part of the separator, it is folded into the air chamber and is effectively separated and discharged; the sludge and water enter the three-phase separation through the channel. In the sedimentation zone of the device, under the action of gravity, the water and mud are separated and the supernatant is discharged from the upper part of the precipitation zone. The sludge in the lower part of the precipitation zone is returned to the reaction zone along the inclined wall.
SBR process
SBR is an abbreviation for sequential batch reactor. The SBR process is a reactor operating in a time-sequential batch operation. Main features: complete mixing in space, full push-in time, high reaction speed, in order to obtain the same treatment efficiency, the reaction tank of SBR method is obviously smaller than the volume of continuous treatment tank. The process flow is simple, the number of structures is small, the area is saved, the cost is low, and the operating cost is low. Static precipitation, solid-liquid separation effect is good, and the quality of effluent is high. The operating mode is flexible and a variety of process routes can be combined.
CASS process
The CASS (cyclic activated sludge system) process is a cyclic activated sludge process. Compared with SBR, the pre-reaction zone is increased and a more rational and optimized bioreactor is designed. The process returns part of the remaining sludge in the main reaction zone to the selector and realizes continuous water intake. CASS tanks can withstand the impact of water, water quality impact, high dilution of industrial waste water; eliminate the initial sedimentation tank, the second settling tank, the process is simple, easy operation and management; mechanical equipment, less, simple, and not easy to appear Faults, less maintenance, simple operation control and automation requirements. Fewer structures, compact biological pool layout, and space saving; better denitrification and phosphorus removal effects; less residual sludge, good sludge stability, good dewatering performance, and excess sludge production as traditional About 60% of the activated sludge process; suitable for industrial wastewater treatment.