There are various technical solutions to achieve zero emissions of coking desulfurization waste liquid, and the following are some of the main technical paths:
1、 Advanced treatment and reuse technology for coking wastewater
1. Double membrane+salt extraction deep treatment:
Process flow: After biochemical treatment, coking wastewater enters a dual membrane system (such as reverse osmosis, nanofiltration, etc.) for deep desalination treatment, while extracting salts such as sodium sulfate and sodium chloride.
Effect: The treated water can meet the standard of circulating water and be used as makeup water for circulating water, achieving zero discharge of wastewater. The extracted salts can be sold as industrial qualified products to the outside world, avoiding being treated as solid waste.
2. Multiphase catalytic oxidation+membrane biological combination technology:
Principle: Utilizing multiphase catalytic oxidation technology to improve the biodegradability of wastewater, and further removing organic matter through membrane bioreactors.
Advantages: This combination technology can efficiently remove organic matter from wastewater at room temperature and pressure, with a small equipment footprint and low investment and operating costs.
2、 Collaborative treatment technology for coking wastewater and coke oven flue gas
1. Coke oven flue gas desulfurization and denitrification absorption of coking wastewater:
Process flow: open a hole at the proper position of the large flue of the coke oven, draw out the flue gas of the coke oven by bypass, use the waste heat boiler to recover steam, and spray the coking wastewater into the spray drying tower for desulfurization and denitrification treatment.
Effect: The organic toxic components in coking wastewater undergo thermal decomposition and oxidation under the high temperature of flue gas, transforming into harmless substances. At the same time, pollutants such as sulfur dioxide and nitrogen oxides in coke oven flue gas are also removed, achieving dual purification of wastewater and flue gas.
Advantages: This technology solves the problem of high cost in coking wastewater treatment and can recover resources such as waste heat and water vapor from flue gas.
3、 Specialized coagulation+conversion precipitation technology
Principle: Special coagulants and conversion precipitants are used to treat pollutants such as S2- and CN - in desulfurization waste liquid, converting the pollutants into insoluble solid substances and precipitating them.
Effect: Effectively remove toxic and harmful substances from desulfurization waste liquid and reduce wastewater toxicity.
Subsequent processing: After sedimentation, the sludge can be dehydrated and mixed with coking coal for reuse; The supernatant enters the subsequent processing system for further purification.
4、 Other Technologies
Ozone catalytic oxidation: utilizing the strong oxidizing properties of ozone to oxidize and decompose organic matter in wastewater.
Electrolytic oxidation: The process of producing strong oxidants (such as hypochlorous acid) through electrolysis to oxidize wastewater.
Advanced oxidation techniques, such as Fenton oxidation, utilize strong oxidants such as hydroxyl radicals to oxidize and decompose recalcitrant organic compounds in wastewater.
There are various technical solutions for achieving zero discharge of coking desulfurization waste liquid, and enterprises can choose the appropriate technical path based on their actual situation and wastewater characteristics. Meanwhile, with the continuous improvement of environmental protection requirements and technological advancements, more efficient and economical wastewater treatment technologies will emerge in the future.
