Advanced treatment recovery technology of coking wastewater

Abstract

An advanced treatment recovery technology of coking wastewater comprises the steps of sequentially implemented air floatation oil removal pretreatment, acidifying treatment, denitrification treatment and biodegradation treatment, and also comprises the following steps: 1, processing biodegraded wastewater by using an inorganic membrane filtering device, reusing parts of the obtained membrane filtrate as mineral separation process water, and allowing the residual membrane filtrate to enter a pollution resistant reverse osmosis membrane device to carry out desalination treatment; and 2, pumping the membrane filtrate obtained in step 1 into the pollution resistant reverse osmosis membrane device to carry out desalination treatment in order to remove COD, NH3-N and inorganic salts in water, and directly reusing the obtained membrane permeation liquid as circulating cooling water. The technology adopting an inorganic membrane to carry out the reverse osmosis pretreatment can solve the problems of no pollution resistance and unlikely dirt obstruction of an ultrafilter membrane, and no flocculating agent or a small amount of the flocculating agent is added by adopting inorganic membrane feeding, so the reverse osmosis pollution degree is reduced, thereby the cleaning period of the RO (reverse osmosis) membrane is prolonged, the cleaning effect is good, and the irreversible dirt obstruction of the RO membrane is avoided.

Description

technical field [0001] The invention relates to chemical production, in particular to an advanced treatment and recovery process of coking wastewater. Background technique [0002] Coking wastewater mainly comes from the high-temperature dry distillation of medium coal in coking production, gas purification and refining of chemical products, of which the residual ammonia water produced in the ammonia distillation process is the main source. The water quantity and water quality of coking wastewater vary depending on the scale of coking production, the gas purification process used and the depth of chemical product processing. However, the average amount of water is about 1.18 to 1.83 tons of waste water per ton of coke produced. The national annual discharge of coking wastewater is about 300 million tons. Coking wastewater has complex water quality and large volume, and is toxic, harmful, highly polluting and difficult to treat industrial wastewater. Being able to treat th...

AI Technical Summary

Problems solved by technology

[0003] The main problems in my country's coking wastewater treatment are: some small coking plants have not yet built sewage treatment facilities; most coking plant wastewater treatment is not up to standard

However, there are still many problems in these projects using membrane technology. The main problems are: MBR membrane fouling is relatively serious, membrane flux declines relatively quickly, the treatment effect of biological aerated filter is not obvious, reverse osmosis membrane fouling is relatively serious, and chemical cleaning is relatively serious. Frequent, large output of reverse osmosis concentrate, easy to pollute the environment when discharged, etc.

Therefore, the use of aerobic effluent to enter the MBR membrane module will easily cause oil and organic matter to pollute the MBR membrane filaments, and it is not easy to clean

After pretreatment by ultrafiltration and other units, the CODc content of reverse osmosis influent water is still 100-150mg / L, which will cause serious pollution to the reverse osmosis membrane and frequent chemical cleaning.

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