Chemical plants generate a large amount of wastewater in their daily production processes. Which ones belong to chemical wastewater? For example, wastewater from food processing, papermaking, electroplating, rubber production, synthetic plastics, synthetic fibers, synthetic dyes, paints and coatings, pharmaceuticals, gas plants, petrochemical plants, insulation material factories, and other processes can all be considered as chemical wastewater. This type of wastewater has strong oxygen consumption, many toxic and harmful substances, strong toxicity, strong pollution, high color, difficult decomposition, and poor biodegradability. So these sewage must be treated before being discharged, otherwise it will cause serious pollution to the surrounding ecological environment. How to treat chemical wastewater? Let's take a look together with the editor;

Firstly, the treatment methods are also divided into several types based on the different properties of the wastewater:

1. Physical processing methods: precipitation method, adsorption method, etc.

2. Biological treatment methods: activated sludge, biological turntable, biological drum, and biological contact oxidation method, etc.

3. Chemical treatment methods: neutralization method, coagulation method, oxidation method, etc.

Chemical wastewater is generally treated in three levels:

1. Primary treatment: mainly separates suspended solids, colloids, floating oil or heavy oil in water, and can use methods such as natural precipitation and flotation;

2. Secondary treatment: mainly to remove biodegradable organic solutes and some colloids, usually treated by biological methods;

3. Third level treatment: mainly to remove organic pollutants and dissolved inorganic pollutants that are difficult to biodegrade from wastewater. Common methods include activated carbon adsorption and ozone oxidation.

1. Pre treated aeration tank

According to the provided inflow water quality, the water temperature is as high as around 60 ℃, and the concentration of organic matter is also high. In order to reduce the load of subsequent treatment and ensure that the effluent meets the discharge standards, pre-treatment is considered before physical and biochemical treatment.

Cooling and temperature reduction are achieved through oxygenation and aeration, and some organic compounds such as ammonia nitrogen and phenol are absorbed and released into the atmosphere from the water. At the same time, ferrous sulfate and lime are added to the tank to oxidize and analyze the organic compounds in the wastewater, reducing organic matter.

2. Sedimentation adsorption tank

By adding chemicals, coagulation reaction, precipitation, and adsorption of coal slag layer, the wastewater is purified, and the concentration of some organic compounds such as nitrogen and phenol is reduced, creating conditions for subsequent biochemical treatment.

3. Anaerobic anoxic aerobic biochemical treatment (A2/O method)

The A2/O biological denitrification process is a combination of traditional activated sludge technology, biological nitrification technology, and biological nitrogen and phosphorus removal technology. The microbial community in the activated sludge of the A2/O method is mainly composed of nitrifying bacteria. In the aerobic stage, nitrifying bacteria convert the ammonia nitrogen in the water into nitrate through biological nitrification. In the anoxic stage, denitrifying bacteria transfer the nitrate brought in by internal reflux into nitrogen through biological denitrification and release it into the atmosphere, thereby achieving denitrification. In the anaerobic stage, polyphosphate accumulating bacteria release phosphorus and absorb easily degradable organic matter such as lower fatty acids. In the aerobic stage, polyphosphate accumulating bacteria excessively absorb phosphorus and remove it through the discharge of residual sludge. All three types of bacteria have the ability to remove CODcr, The effect of BOD5, but the concentration of BOD5 further decreases.

4. Air flotation device

This device adopts the principle of dissolved air flotation, which uses chemical reactions to coagulate organic substances in wastewater into hydrophobic particles or flocs. When dissolved water is released, fine bubbles are generated to form a good combination of bubbles and flocs particles, separating the combination from the wastewater.

5. Adsorption filtration (deep treatment)

The purified wastewater from the air flotation device is fed into small particles of coke or coal slag for adsorption and filtration. The untreated organic matter in the purified wastewater is then absorbed into particles such as coal slag for adsorption.

Diphenyl ether manufacturer