Quality-divided resourceful treatment method for coal chemical industry high-salt-content wastewater

Abstract

The invention discloses a quality-divided resourceful treatment method for coal chemical industry high-salt-content wastewater. The coal chemical industry high-salt-content wastewater enters an electrolytic oxidation device, a part of COD extremely difficult to degrade is removed, loop opening and chain scission are conducted on macromolecular organic matter, electrolytic oxidation device effluent enters an ozone catalytic-oxidation device to further remove the organic matter, ozone catalytic-oxidation device effluent enters a buffer pool to decompose residual ozone, wastewater in the buffer pool enters a nanofiltration device for separation, a main component on the nanofiltration produced water side is NaCl, main components on the nanofiltration concentrated water side are NaCl and Na2SO4, the nanofiltration produced water is further concentrate and reused through reverse osmosis, the concentrated water crystallizes by adopting a hot method, industrial-grade NaCl is recovered, and 'hot-method crystallization + freezing crystallization' is conducted on the nanofiltration concentrated water to recover industrial-grade Na2SO4. The quality-divided resourceful treatment method facilitates resource recovery, is stable and reliable in treating effect and moderate in construction, operation and maintenance cost.

Description

technical field [0001] The invention relates to a method for treating waste water with high salt content in coal chemical industry by quality and resource, and belongs to the technical field of environmental protection waste water treatment. Background technique [0002] my country is rich in coal resources, but oil and gas resources are relatively scarce. Therefore, developing the modern coal chemical industry, using coal as raw material to synthesize and produce clean energy products, partially replacing petrochemical products and fuel oil, will relieve the pressure of insufficient oil and gas resources in my country to a certain extent. The construction of modern coal chemical projects usually requires supporting large-scale coal bases of billions of tons, while the per capita water resources and water resources per unit land area of ​​my country's major coal producing areas are only 1 / 10 of the national level. Large-scale coal chemical projects consume more than ten ton...

AI Technical Summary

Problems solved by technology

Another feature of the wastewater is that the CODcr concentration is high, reaching 500-2000mg / L, and the composition is complex, mainly composed of organic substances such as alcohols, alkanes, amines, indole, pyrimidine, ketones, acids, and lipids. An organic compound containing a chromogenic group makes the wastewater highly chromatic

The above water quality characteristics bring difficulties to the crystallization operation, the crystallized salt has low purity and whiteness, and the quality is poor, so it cannot be reused

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