![<?echo $_SERVER['SERVER_NAME'];?>](/template/twentyseventeen/skin/images/header.jpg)
Abstract: During the process of coal chemical industry, a large amount of wastewater, waste gas and waste residue are generated, causing serious chemical and environmental pollution. This is extremely unfavorable to the construction of a green and environmental protection society. This article will analyze the sources and characteristics of wastewater in the production of coal chemical industry and introduce several technologies for wastewater treatment.
Key words: coal chemical industry chemical wastewater treatment
1 coal chemical wastewater sources and characteristics
Coal is the main raw material of coal chemical industry, using a series of technical means to convert coal into fuel and chemical products. In the production of coal chemical industry, there are many processes are prone to wastewater, such as: blast condensation, desulfurization, ammonia and so on. Coal chemical wastewater contains large amounts of phenol and ammonia, as well as tar, phenol, cyanide, sulfide, COD and other pollutants, with strong toxicity. If effective measures can not be taken to dispose of wastewater, the quality of the soil will be reduced, with unpredictable negative impacts on the environment.
The main features of coal chemical wastewater are the following aspects.
First, it is difficult to be degraded. Coal chemical industry wastewater contains a large amount of organic substances, such as: quinoline, isoquinoline, biphenyl, the structure of these organic compounds is extremely stable, it is difficult to be degraded, to coal chemical wastewater treatment has brought great difficulties.
Second, the color is dark, high degree of pollution. Coal chemical industry in the production, all aspects of a certain amount of waste can be generated, into the industrial wastewater. This has caused the composition of industrial waste water complex, a variety of pollutants mixed together, it is particularly dirty.
Third, the pollution components are complicated. Coal chemical production process is very complicated, with multiple production processes. Pollutants are produced in these environments. These pollutants are concentrated in the wastewater and have complex components. This greatly increases the difficulty of wastewater treatment and increases the requirements for wastewater treatment technologies.
2 coal chemical wastewater treatment technology
2.1 pretreatment
2.1.1 flotation method
This method is mainly for the removal of oil and wastewater substances and recovery. The main working principle is: through the air into the small bubbles of air to promote small bubbles and water droplets of oil particles attached together, and then use special methods to bubble out from the water to achieve the role of separation of oil composition. Flotation method for the treatment of suspended matter effect is significant, and the resulting scum is easy to transport and reuse. However, the flotation method only has a significant effect on the oil, so often with other methods used in conjunction.
2.1.2 coagulation precipitation method
The coagulation sedimentation method is to remove suspended organic matter in the wastewater for subsequent biological treatment. This method is mainly the use of gravity to make the suspended solids in the water sink, thus separated from the liquid. In industrial wastewater coagulant, such as: aluminum salts, iron salts, polyaluminum, polyiron and polyacrylamide, to strengthen the precipitation effect. The use of coagulation sedimentation method, according to the different composition of the wastewater, different pH values ​​to use different types and dosage of coagulant. The advantage of this method is that the process is simple, the cost is low, and the high-volume wastewater treatment can be realized. The disadvantage is that it has little effect on the removal of COD and easily generates a large amount of sludge which is difficult to be dehydrated.
2.1.3 MAP chemical precipitation method
MAP chemical precipitation method is to remove ammonia and nitrogen in coal chemical wastewater. As the double salts containing ammonia and nitrogen, such as: ammonium magnesium phosphate, zinc ammonium phosphate, etc., is not easy to dissolve in water, so, to the wastewater by adding phosphate ions and some metal ions, with high concentrations of ammonia and nitrogen Precipitate for separation. At present, the treatment of wastewater containing ammonia nitrogen, which is mainly to put magnesium chloride and disodium hydrogen phosphate. Since the resulting precipitate is abbreviated as MAP, this method is called MAP chemical precipitation. MAP chemical precipitation for the removal of ammonia and nitrogen in wastewater is high, the process is not complicated, the precipitation reaction will not be affected by temperature and water toxins, the resulting sediment nor subsequent pollution.
2.1.4 dissolution extraction phenol removal method
By dissolving and extracting wastewater, the phenol content of the waste water can be recovered. The solubility of phenol in some specific solvents is greater than the solubility in water, a property that is the basis for dissolution-de-phenolysis. The industrial wastewater containing phenol and the phenol-soluble extractant are put into an extraction device together, and then the phenol and the extractant are separated through the rectification tower to obtain the extractant and the phenol removal waste water which can be recycled continuously, so as to reach the extraction wastewater The purpose of the phenol. Processed phenol removal wastewater can flow to the next wastewater treatment section via the solvent recovery column.
2.2 biochemical treatment
2.2.1 SBR process
The SBR process is a new technology that emerged in the 1970s and is mainly suitable for biodegradation and nitrogen and phosphorus removal. SBR process includes five workflows, both water, reaction, precipitation, drainage, idle and so on. This process method can realize the functions of biodegradation, sedimentation, homogenization and final sedimentation, and is controlled by high-tech equipment automatically without the need to set the sludge return system. SBR process reaction tank has good biochemical reaction capacity and sewage treatment capacity, can effectively resist the impact of sludge expansion, stable work.
2.2.2 Immobilized biotechnology
Knitted Sneakers
This knitted sneaker not only continues the sweat absorption and deodorant characteristics of traditional sneakers, but it is also more comfortable on the basis of traditional sneakers. It is very light and suitable for sports.
We adopt the latest technology design, so that the sole is not only light, but also has excellent cushioning ability, bringing a comfortable foot feel. At the same time, we also provide good breathability, bring high-quality cushioning effect and bring a comprehensive running experience for runners.
Yacheng Knitting Co., Ltd. can mass produce customized high-quality knitted garments, including sweaters, Custom Knit Sweaters, Knitted Pants, Knitted Skirt , Knitted Shoes, Knitted Scarves and Knitting Blanket. If you need to order knitted products, please contact us.
Knitted Sneakers,Women Knit Sneakers,Knit High Top Sneakers,Stretch Knit Women Shoes
DongGuan Yacheng Knitting Co., Ltd , https://www.dgoemknittingyc.com