Introduction:
chemical wastewater refers to the wastewater produced in the process of producing products in chemical plants, such as the oily wastewater produced in the production of ethylene, polyethylene, rubber, polyester, methanol, ethylene glycol, oil tank farms, air separation and air compressor stations, etc. After biochemical treatment, it can generally meet the national secondary discharge standard. Due to the shortage of water resources, the water that meets the discharge standard needs to be further treated to meet the requirements of industrial water replenishment and reused.
Features
◆ The composition of water quality is complex, there are many by-products, and the reaction raw materials are often solvent substances or compounds with ring structure, which increases the difficulty of wastewater treatment;
◆ High pollutant content in wastewater, which is caused by the incomplete reaction of raw materials and the entry of a large amount of solvent media used in raw materials or production into the wastewater system;
◆ There are many toxic and harmful substances, and many organic pollutants in fine chemical wastewater are poisonous and harmful to microorganisms. Such as halogen compounds, nitro compounds, dispersants or surfactants with bactericidal effect, etc.;
◆ There are many biodegradable substances, low B/C ratio, and poor biodegradability;
◆ The chromaticity of wastewater is high.
Solution
Micro-electrolysis technology is an ideal process for treating this kind of sewage. This process can not only greatly reduce COD and chroma, but also improve the biodegradability of wastewater when used in the treatment of high-salt, refractory, and high-color wastewater.
This technology is to use the micro-electrolysis filler filled in the micro-electrolysis equipment to produce the "primary battery" effect to treat the wastewater without electricity. When water is passed through, countless "primary batteries" with a potential difference of 1.2V will be formed in the device. The "primary battery" uses wastewater as an electrolyte, and generates an electric current through discharge to perform electrolytic oxidation and reduction treatment on wastewater to achieve the purpose of degrading organic pollutants.
The new ecology [·OH], [H], [O], Fe2+, Fe3+, etc. produced during the treatment process can undergo redox reactions with many components in wastewater, for example, it can destroy the color of colored substances in colored wastewater group or auxochrome group, or even chain breakage, to degrade and decolorize; the generated Fe2+ is further oxidized to Fe3+, and their hydrates have strong adsorption-flocculation activity, especially after adding alkali to adjust the pH value. Ferrous hydroxide and ferric hydroxide colloidal flocculants, their flocculation ability is higher than that of ferric hydroxide colloid obtained by hydrolysis of general medicaments, and can flocculate a large number of tiny particles, metal particles and organic macromolecules dispersed in water. Its working principle is based on electric Combination of chemical, oxidation-reduction, physical and flocculation-sedimentation.
The process has the advantages of wide application range, good treatment effect, low cost, short treatment time, convenient operation and maintenance, low power consumption, etc., and can be applied to pretreatment and advanced treatment of industrial wastewater.