Coking wastewater treating process with zero discharge

Abstract

The invention discloses a coking wastewater treating process with zero discharge. The coking wastewater treating process with zero discharge comprises the following steps: carrying out biochemical treatment, adsorbing by activated carbon, softening crystals, filtering by an ultrafiltration membrane, filtering by a reverse osmosis membrane, carrying out spray evaporation and the like. The coking wastewater treating process with zero discharge is simple in process, convenient in operation and management, high in automation degree and low in running cost, is capable of not generating secondary pollution, effectively treating coking wastewater, basically realizing wastewater zero discharge, completely eliminating environment disruption caused by organic matters, ammonia nitrogen, salts and the like in the wastewater and reusing all the wastewater with high quality, can be used as a wastewater treating full flow process of a newly-built coking enterprise and can also be abutted to the wastewater treating process of the traditional coking enterprise.

Description

technical field [0001] The invention relates to wastewater treatment, in particular to a coking wastewater zero-discharge treatment process. Background technique [0002] Coking wastewater is wastewater containing a large amount of aromatic and condensed ring compounds and heterocyclic compounds (phenols\cyanides) produced in the process of coal coke, gas purification and coking product recovery. It has large discharge, high salt concentration, It has the characteristics of high hardness, high concentration of organic matter and ammonia nitrogen, poor biodegradability, complex organic matter composition, and difficult treatment. It belongs to high-salt organic wastewater that is difficult to biodegrade. [0003] At present, the treatment methods of coking wastewater mainly include dilution biochemical method, chemical agent treatment method and direct use in wet coke quenching. Due to the high salt content of coking wastewater itself, a large amount of process water must be...

AI Technical Summary

Problems solved by technology

However, this disclosed method has the following disadvantages: (1) the process is complex, the flow process is tedious, the operation is cumbersome, the management is difficult, and the actual engineering investment and operating costs are huge so that the enterprise is unbearable; (2) nanofiltration and reverse osmosis are in addition to Affected by organic pollution, it is also often limited by inorganic factors such as total salt and hardness, but no corresponding effective hard removal pretreatment measures are set in this method; (3) the nanofiltration concentrated water and reverse osmosis concentrated water It is not feasible because it will cause the total salt, hardness and undegraded organic matter in the system to circulate in the system and be enriched rapidly, which will eventually lead to the nanofiltration and reverse osmosis membrane system due to excessive osmotic pressure. High or membrane fouling, severe fouling and paralyzed outage; (4) The use of wastewater treatment facilities that have been put into operation in the existing coking plant is not considered

But they have common problems: (1) The pretreatment measures to prevent fouling of the membrane system are not considered, and the coking wastewater has high salinity and high hardness, which will inevitably cause fouling and fouling of the membrane during the process of membrane concentration and filtration, resulting in Flux attenuation, life shortening, etc.; (2) There is no way to explain the way out of reverse osmosis or nanofiltration concentrated water, which is a pollutant-enriched liquid, or to use it for blast furnace slag cooling, slag flushing water, coal yard dust suppression, etc.

However, this method will consume a large amount of oxidant, the cost of chemicals is high, and the energy consumption of evaporation is high. There are no measures for removing high hardness in coking wastewater to prevent fouling and fouling of reverse osmosis membranes and evaporators, and the impact of residual organic matter on evaporation is not considered. coking effect

Images