Characteristics of chemical wastewater:
1、 The amount of wastewater discharged is large. Chemical production cannot do without water, which requires a large amount of water as a solvent, absorbent, and circulating coolant during the production process, resulting in a large amount of wastewater discharge.
2、 There are many types of pollutants. The discharged water will contain some raw materials, by-products, etc. from production, which will make the composition complex and diverse. 3、 Pollutants are highly toxic and not easily biodegradable. In chemical production, most of the toxic pollutants emitted are nitro compounds, dispersants, and halogenated compounds. Although these compounds have a small proportion, their high toxicity results in highly toxic water emissions.
4、 The amount and quality of chemical wastewater vary greatly depending on the raw material route, production process, and production scale.
5、 The scope of pollution is wide.
Common treatment methods for chemical wastewater
1. Physical Law
Physical processing methods include centrifugal separation, filtration, air flotation, and emulsion breaking. The filtration method refers to the interception of impurities in water through a porous granular filter layer, mainly to reduce suspended solids in the water; The air flotation method refers to the process of introducing air into water to generate large bubbles that adhere to impurity particles, forming a float with a lower specific gravity than water. Under buoyancy, it rises to the surface of the water to achieve solid-liquid separation; Emulsification is mainly used to treat oily wastewater, destroy the stable emulsion layer at the droplet interface, and separate oil and water. These methods have simple processes and do not change the physical properties of the water before and after treatment. They can only remove some insoluble suspended solids, so they have significant limitations.
2. Chemical method
Chemical treatment is a wastewater treatment method that separates and removes dissolved or colloidal pollutants from wastewater through chemical reactions, or converts them into harmless substances. It also plays an important role in the deep treatment of wastewater. The main chemical treatment methods include coagulation, neutralization, chemical precipitation, and redox methods.
3. Biological treatment of wastewater is a process that utilizes the metabolic action of microorganisms to convert organic matter in wastewater into simple inorganic substances. In short, it is a method that uses the life activities of microorganisms to transform pollutants and ultimately achieve harmless results. This method can be divided into aerobic biological treatment and anaerobic biological treatment based on the types of microorganisms involved.
4. Physical and chemical treatment methods include adsorption, ion exchange, electrodialysis, etc. A new treatment process for chemical wastewater: 1. Micro electrolysis technology involves the contact of metals (non metals) with electrode unit differences in wastewater with good conductivity, forming a primary battery effect or undergoing electrolytic reactions to treat wastewater, also known as electrolysis, iron chip filtration, zero valent iron, etc. Micro electrolysis technology is commonly used for the pretreatment of difficult to degrade wastewater containing high concentrations of salts and organic matter.
2. MBR technology MBR wastewater treatment technology is a new technology that combines biological treatment technology with membrane separation technology. It replaces the traditional secondary sedimentation tank in the process and can efficiently perform solid-liquid separation to obtain stable reclaimed water for direct use. This new process is applied in the specific operation of treating wastewater, with a small land area and good effluent quality, and generally does not require tertiary treatment for reuse. It has the advantages of simple process and convenient operation, and can achieve fully automatic operation and management throughout the entire process.
