With the development of industries such as pharmaceuticals, chemicals, and dyes, there is an increasing amount of high concentration and difficult to degrade wastewater. At the same time, with the improvement of living standards and the enhancement of environmental awareness, people are paying more and more attention to the migration and changes of difficult to degrade organic matter in the environment. However, the treatment of high concentration and difficult to degrade organic pollutants is a difficult point in wastewater treatment, and it is difficult to use conventional processes (such as coagulation and biochemical methods) to treat them. This is because firstly, the pollution of such wastewater is due to the high concentration of such wastewater, with COD generally reaching tens of thousands of mg/l, and some even reaching more than 100000 mg/l; Secondly, the pollutants contained in it are mainly aromatic compounds with low BOD/COD, generally below 0.1, which are difficult to biodegrade; Thirdly, pollutants are highly toxic, with many substances being listed on environmental blacklists, such as aniline Nitrobenzene, etc; Fourthly, the content of inorganic salts is high, reaching tens of thousands or even over 100000. Therefore, it is urgent to develop effective treatment technologies for high concentration and difficult to degrade organic wastewater.
The use of chemical oxidation to treat high concentration refractory organic wastewater is currently one of the most effective methods.
Our company's technical personnel have absorbed and borrowed advanced technologies from both domestic and foreign sources, combined with the actual situation in China, and closely cooperated with relevant scientific research units. After extensive experimental research, we have successfully developed a complete set of equipment for treating high concentration, difficult to degrade organic industrial wastewater using three-phase catalytic oxidation method. It adopts the current advanced catalytic oxidation technology internationally, and its treatment effect has reached a satisfactory level. It has been evaluated by authoritative experts in the environmental protection industry as an international advanced, domestically pioneering, and major breakthrough in the field of environmental protection.
1、 Scope of application:
Suitable for treating various chemical organic wastewater, coking, dye, dye intermediate wastewater, pharmaceutical and pesticide intermediates, and other fine chemical wastewater.
2、 Characteristics:
Low investment, good results, low operating costs, short process flow, easy operation, normal temperature and pressure, can operate intermittently or continuously. No sediment or mud is generated, and there is no secondary pollution to the environment.
3、 Introduction to Basic Principles and Methods:
The principle of the new high-efficiency catalytic oxidation is to use a strong oxidant - chlorine dioxide - to catalyze the oxidation of organic pollutants in wastewater at room temperature and pressure in the presence of surface catalysts. Organic pollutants can be directly oxidized or large molecule organic pollutants can be oxidized into small molecule organic pollutants, improving the biodegradability of wastewater and effectively removing organic pollutants. In the process of degrading COD, the double bond chromophores in organic molecules, such as azo groups, nitro groups, sulfurized hydroxyl groups, carboimines, etc., are broken to achieve decolorization, while effectively increasing the BOD/COD value, making it easy to biodegrade. In this way, the catalytic oxidation reaction of chlorine dioxide serves as a bridge between conventional physical and chemical pretreatment and biochemical treatment in high concentration, high toxicity, and high salt content wastewater.
The core of this technology is three-phase catalytic oxidation. These three phases are: compressed air (gas phase) sent into the tower by the fan, high-efficiency oxidant (liquid phase) generated by the chemical generator, and catalyst (solid phase) adsorbed on the carrier. The catalyst is a composite precious metal compound developed by us. It is the role of this catalyst that allows oxygen in the air to participate in the reaction as an oxidant, thereby reducing the consumption of liquid-phase oxidant, lowering treatment costs, improving treatment efficiency, and greatly accelerating the reaction rate, shortening the residence time of wastewater in the tower. After pre-treatment to remove impurities from the wastewater, it enters the catalytic oxidation tower. Organic pollutants in the water are decomposed by oxidants under the action of catalysts, and benzene rings and heterocyclic organic compounds are opened and broken. Large molecules become small molecules, which are further oxidized into carbon dioxide and water. This significantly reduces the COD value in the wastewater, and the color is basically faded. At the same time, it increases the ratio of BOD: COD, reduces the toxicity of the wastewater, improves the biodegradability of the wastewater, and creates conditions for subsequent biochemical treatment, enabling the wastewater to meet discharge standards after treatment.
4、 Main technical performance:
COD removal efficiency: ≥ 60%
Chromaticity removal efficiency: ≥ 95%
BOD: COD ratio of effluent: above 45%
coking industry
Phenol:<0.5mg/l
Cyanide:<0.5mg/l
Sulfide:<1.0mg/l
5、 Processing ability:
The processing capacity of prefabricated equipment in the factory is divided into 1m3/h, 2m3/h, and 4m3/h. The processing capacity of on-site production equipment and structures can be determined according to the processing capacity.
6、 Preprocessing
Adjust the pH of the wastewater to 6.5-7.5.
2. Control the turbidity of the wastewater entering the catalytic tower below 10 degrees.
3. According to the process requirements, increase the pre-treatment appropriately to improve the overall processing efficiency.