coking wastewater is a typical toxic and difficult-to-degrade organic wastewater. Mainly from the production water and steam condensation wastewater in the primary cooling and coking production process of coke oven gas . Pollutants in wastewater contain dozens of inorganic and organic compounds, among which inorganic compound is mainly a large number of ammonium salts , thiocyanide, sulfide, cyanide, etc.; organic compounds include phenols, monocyclic and polycyclic aromatic compounds, and heterocyclic compounds containing nitrogen, oxygen, and sulfur. They are typical industrial wastewater containing difficult-to-degrade organic compounds.
characteristics of wastewater
① The concentration of pollutants in coking wastewater is high and difficult to degrade. Due to the existence of nitrogen in coking wastewater, the excess of nitrogen source required for biological purification, which brings great difficulties to the treatment standards;
② The wastewater discharge is large, and the water consumption per ton of coking is greater than 2.5t;
③ The wastewater is very harmful. polycyclic aromatic hydrocarbon in coking wastewater is not only difficult to degrade, but is usually a strong carcinogen, which causes serious pollution to the environment and directly threatens human health.
Wastewater source
Coking plant mainly produces chemical products such as coke , commercial gas, ammonium sulfide and light benzene . The plant's tar recovery system adopts ammonium sulfide process, and the tar processing adopts tube furnace two towers continuous distillation, and the industrial production process is dual furnace and double tower continuous distillation, washing and refining. During the coke oven gas cooling, washing, crude benzene processing and tar processing, industrial wastewater containing phenol, cyanide, oil, ammonia and a large amount of organic matter is generated.
focuses on industrial wastewater and provides high-value solutions and key equipment
For many years, Longantai Environmental Protection has continuously learned experience and systematically summarized it to form a set of high-value water treatment solutions specializing in the treatment of various types of industrial wastewater, providing customers with a series of water treatment services including "project consultation, water quality analysis, solution design, project construction, equipment production, water operation" and other water treatment services. At the same time, by deeply digging out the pain points, water quality conditions and key needs of coal coking and gas purification production industries, and reshaping a complete solution to the wastewater in this industry, the coking wastewater treatment project of a Shanxi energy technology company is one of the typical cases.
Shanxi Energy Technology Coking Wastewater Treatment Project
Shanxi Energy Manufacturing Enterprise is a Shanxi energy production enterprise is a project to build coke manufacturing and chemical product production, and distribute: raw coal, medium coal , coal slime , electric coal, refined coal , coke, iron ore, bauxite , chemical raw materials and products (excluding hazardous chemicals, easy-to-toxic chemicals, Fireworks and Firecrackers , monitoring chemicals, civil explosives), steel, environmental engineering equipment, pig iron, refractory materials, working conditions accessories; building materials, civil building materials (excluding logs, river water and sand); hardware and electrical equipment, auto parts, tires, lubricating oil, daily necessities, labor protection supplies, electronic products, instruments, wires and cables; solar energy, wind energy, and biomass energy application technology research and development; cargo and technology import and export business; construction, operation and management of electric vehicle charging piles; waste recycling and utilization of coking plants (projects that require approval according to law can only be carried out after approval by relevant departments). The design water requirements are better than the emission standards of Table 3 in the "Coking Chemical Industry Pollutant Emission Standard" (GB16171-2012).
Wastewater comes from wastewater discharged during coking production, among which the wastewater generated during ammonia vaporization is the wastewater discharged after the coking wastewater is distilled. The easily degradable organic compounds in coking ammonia distilled wastewater are mainly phenolic compounds and benzene compounds. Azolium, naphthalene, furan and silazoles are degradable organic compounds. The main organic substances that are difficult to degrade include arsenic, carbazole , biphenyl , terphenyl , etc.
Longantai Environmental Protection attaches great importance to this project, carries out special research, set up a coking sewage treatment project team, and specializes in studying and designing the wastewater project technology.For the coking chemical wastewater produced by the enterprise, the high and low COD wastewater generated in each section is classified and collected and processed by laying pipelines in each section. After multiple rounds of expert demonstration and technical route comparison, many small and pilot experiments are carried out. Taking into account the land use, reduction, harmlessness, nearby influence, social stability and other factors, it was finally determined to use the process of using "oil-interference gas float + LYO pre-oxidation device + biochemical water inlet regulation tank + AAO biochemical process + two sedimentation tank + mixed sedimentation tank + sand filter tank + LCO ozone catalytic oxidation + LBAF aerated biological filter tank " as the main body to achieve the standard emission of sewage and far below the required emission standards.
main process introduction
air floater
For some clean water after treatment, the gas float pipeline pump , pressurized water inlet dissolved gas tank and mixed with air, and the air dissolved into the water, and the dissolved gas efficiency reaches more than 80%. The air in the dissolved gas tank is provided by the air compressor and is automatically replenished into the dissolved gas tank. The dissolved gas water from the dissolved gas tank is released through the releaser , so that the dissolved gas water pressure is released to reduce the pressure of the dissolved gas water to zero or negative pressure, and the air dissolved in the water is released from the water, forming micro bubbles with particle sizes of 20 microns to 50 microns. The micro bubbles are combined with the suspended substance in the sewage, and some micro bubbles grow directly in the suspended substance, making the specific gravity of the suspended substance in the sewage decrease until it floats on the surface of the water. A large amount of scum is formed, and a chain foam scraper installed on the float tank is scraped into the collection barrel and lifted to the sludge concentration tank through the pump. After the clean water at the bottom of the air float pool passes through the water outlet and enters the air float pool, except for the part as refluxed dissolved gas water, the rest enters the latter stage of treatment equipment.
LYO pre-oxidation device
LYO pre-oxidation system uses the LYO supporting treatment reaction device produced by our company to pre-treat wastewater, effectively degrade compounds such as rings, phenyl, chelators, etc., and finally catalytically oxidize the organic macromolecule into small-molecular organic matter. The small-molecule organic matter is directly oxidized into carbon dioxide and water, realizing the degradation of organic matter in wastewater at a lower treatment cost.
AO Biochemical System
A-A-O Biotin nitrogen removal and phosphorus removal process is a combination of traditional activated sludge process, bionitrification and denitrification process and biological phosphorus removal process. In this process, BOD, SS and nitrogen and phosphorus present in various forms will be removed together. The process flow is as follows: In the activated sludge of this system, the bacterial flora are mainly composed of nitrifying bacteria, denitrifying bacteria and polyphosphate bacteria . The obligate anaerobic and general obligate aerobic bacteria are basically eliminated by the process. In the aerobic section, nitrifying bacteria converts the inflow ammonia nitrogen and ammonia nitrogen formed from organic nitrogen through biological nitrification to nitrate ; in the hypoxic section, denitrifying bacteria will convert the nitrate brought in in the reflux into nitrogen through biological denitrification, nitrogen into the atmosphere, thereby achieving the purpose of nitrogen removal; in the anaerobic stage, lphosphine releases phosphorus and absorbs low-grade fatty acids and other easily degradable organic matter; in the aerobic section, lphosphine bacteria absorbs phosphorus in excess and removes phosphorus through the discharge of residual sludge.
LCO ozone catalytic oxidation process
In the traditional ozone oxidation process, the utilization rate of O3 is not high (at room temperature, the solubility of in water is about 10 mg/L), and the efficiency of thoroughly mineralizing organic matter needs to be improved. In order to improve the efficiency of ozone catalytic oxidation, improve the utilization rate of O3, reduce the operation cost of ozone oxidation, and further improve the efficiency of pollutant removal, our company uses a high-efficiency ozone catalytic oxidation process to treat wastewater. By adding a catalyst supported by transition metal ions to the oxidation system, it can produce a significant catalytic effect on ozone oxidation, which can catalyze the self-decomposition of O3 in water, increase the concentration of OH produced in water, and thereby improve the ozone oxidation effect.
oxidized ozone catalytic oxidation filler key innovation points
① Use composite porous high-strength aluminum metasilicate as the catalytic support, doping it is not easy to lose catalytic components, and improving the stable performance of catalyst . The carrier preparation uses special adhesive materials, which have high mechanical strength and long service life.
② Carefully screen the carrier and active components of catalytic filler, and use transition metals, rare metals, and rare earth metals as effective catalytic components to ensure that the ozone oxidation effect continues to be efficient.
③ Use at least three or more metal oxides as catalytic components to enhance the adaptability of the catalyst to different wastewaters while improving catalytic activity. High-temperature sintering technology ensures high utilization rate and high adhesion of active components, while reducing the catalytic filler loss rate and preventing secondary pollution.
④Catalytic filler strength ≥100N/piece, specific surface area ≥280m2/g, and catalytic filler has no loss and no regular injection is required.
⑤ can catalyze the self-decomposition of ozone in water, increase the concentration of OH produced in water, thereby improving the ozone oxidation effect, and the oxidation efficiency is 2 to 4 times higher than that of pure ozone oxidation.
⑥ can reduce the reaction activation energy or change the reaction process, thereby achieving the purpose of deep oxidation and maximum removal of organic pollutants.
LBAF biological filter
aeration biological filter is also called a flooded aeration biological filter. It was developed based on the common biological filter , high-load biological filter trough, biological filter tower, biological contact oxidation method and other biological membrane methods. It is called the third generation biological filter filtration. The process principle is to fill a certain amount of granular filter material with a small particle size in the filter tank, and aeration is made on the surface of the filter material. When sewage flows, the sewage is rapidly purified by the oxidation and degradation ability of the high concentration of the biofilm brought by the high specific surface area of the filter material. This is a biooxidation and degradation process; at the same time, when sewage flows, the filter material is in a compact state. Using the small particle size of the filter material and the biological flocculation effect of the biofilm, suspended in the sewage and ensure that the fallen biofilm will not waft out with water. This is an interception effect. After a certain period of operation, due to the increase in the loss of the water head, the filter tank needs to be backflushed to release the intercepted suspended substance and renew the biofilm. This is a backflushing process.
Aeration biological filter technology characteristics
①Aeration biological filter has the functions of biooxidation degradation and filtration, and can obtain excellent effluent water quality;
②Aeration biological filter covers a small area and is invested in infrastructure. Its area is only 1/10-1/5 of conventional processes, and there will be no h afterwards tml1 secondary sedimentation tank , this process has high processing load and short residence time, so the pool capacity is small, and infrastructure investment saves at least 20~30% compared with conventional processes;
③The oxygen transmission and utilization efficiency of the aerated biological filter process is very high, the aerated volume is small, the oxygen supply power consumption is low, and the operating cost is low, and the oxygen utilization efficiency can reach 20-30%;
④The filter material in the aerated biological filter has a high specific surface area, When the organic load increases, the impact load resistance capacity is strong, and the biomass on the surface of the filter material can increase rapidly; on the other hand, it depends on the buffering capacity of the overall aeration biological filter;
⑤ Easy to hang membrane, fast start, and can restore the design processing capacity in a very short time;
⑥ Aeration biological filter adopts a modular structure, which is convenient for later modification and expansion, and does not affect the operation of the existing process;
⑦ The structural form of an aerated biological filter is similar to that of an ordinary fast filter. Its main body consists of the filter pool body, filter material layer, support layer, water distribution system, gas distribution system, backwash system, water effluent system, pipeline and automatic control system;
⑧ The aerated biological filter uses the metabolism of high-efficiency bacterial species to achieve low-cost direct oxidation of small molecule organic matter into carbon dioxide and water, which can greatly reduce the total investment and operation costs of the process system while ensuring that the final effluent meets the emission standards.
has been operating stably, becoming the leading domestic industrial water treatment process
project since its operation, the sewage treatment volume has exceeded 2,400 tons/day, with reasonable operating costs, stable water effluent standards, and friendly production environment, achieving the reduction, harmlessness, stability and resource utilization of sewage. Through continuous improvement in management, it has become a project with a large actual treatment scale, long continuous operation time and low direct operation cost in domestic coking wastewater treatment processes, and has fully achieved the expected goals.
Seven core competitiveness, effectively solving the problems of industrial wastewater treatment
117 Technical precipitation
Longantai Environmental Protection has been deeply engaged in the field of industrial water treatment since its establishment in 2005, with a complete technical R&D team, insisting on technological innovation, having core technology, and accumulating rich water treatment experience in the field of industrial sewage.
2 Perfect quality assurance
Longantai Environmental Protection has its own high-end environmental protection equipment intelligent industrial park, insists on the self-producing of key equipment and catalysts, has a complete quality control management system, and ensures product quality.
3 Professional technical team
Longantai Environmental Protection has 20 years of design, operation and management experience, and has a full-chain professional team service from consulting, planning, planning, engineering construction to operation and management, and uses proprietary technology to achieve customized professional technical support for customers. Ensure the project is implemented reliably.
4 Cloud Intelligence Automatic control
Industrial Internet, Cloud computing , accurate control, energy saving, and high efficiency.
5 Superb security control
provides the security system management of the entire process from design to construction to operation.
6 Solution Systematization
Longantai Environmental Protection is reshaping the complete resources and reusing circular economy industrial chain , while giving full play to its product strength advantages in the field of environmental protection. Through "solution systemization", from the water outlet to the water inlet, coordinate analysis and overall planning, it provides customers with systematic water treatment solutions.
7 Engineering modular
realizes module integration combination and development, providing customers with modular optimal configuration and integration.
