Zero-drainage technology of biochemical effluent water deep treatment and resource recycling of coal chemical industry wastewater

Abstract

The invention relates to a zero-drainage technology of biochemical effluent water deep treatment and resource recycling of coal chemical industry wastewater. The zero-drainage technology comprises the following steps of adding a coagulant and a sterilizing agent into biochemical effluent water, sending into a settling and clarifying tank and a multi-medium filter, and removing small-particle suspension and oil; sending into a resin adsorbing tank 1 and a nanofiltration membrane module; sending resin adsorbing liquid into a ceramic membrane nanofiltration membrane module, thickening, and mixing with an additive, so as to obtain a water-coal-slurry finished product, wherein the water filtered by the ceramic membrane nanofiltration membrane module is used as a desorbing agent for the next resin desorption; enabling the water produced by the nanofiltration membrane module to pass through a reverse osmosis membrane module 1, a reverse osmosis membrane module 2, a resin adsorbing tank 2, a resin adsorbing tank 3 and a membrane distiller, sending the produced water as boiler water into a boiler, and sending the concentrated water to perform multi-efficiency evaporation treatment and quality-divided crystallization, so as to obtain NaCl (sodium chloride) and Na2SO4 (sodium sulfate) industrial salts. The zero-drainage technology has the advantages that the secondary pollution is avoided, the cost is low, the energy consumption is low, and the long-term running is realized.

Description

Technical field [0001] The invention belongs to the field of wastewater treatment, and in particular relates to a zero-discharge process for advanced treatment and resource recovery of biochemical effluent from coal chemical wastewater. Background technique [0002] my country's coal resources and water resources are in a reverse distribution state. Coal chemical technology consumes huge amounts of water. The rapid development of coal chemical projects has caused an imbalance between regional water supply and demand. Water shortages and wastewater pollution have become key issues restricting the development of coal chemical industries. The organic pollutants contained in coal chemical wastewater include phenols, polycyclic aromatic compounds, and heterocyclic compounds containing nitrogen, oxygen, and sulfur. It is a typical industrial wastewater containing refractory organic compounds. The state has put forward strict requirements and restrictions on the discharge of water and w...

AI Technical Summary

Problems solved by technology

[0004] Chinese patent CN 101857331 A uses flocculation sedimentation, activated coke adsorption, ultrafiltration, nanofiltration and reverse osmosis processes to treat coal chemical wastewater, and the concentrated water of the multi-stage membrane system is added with CaCO 3 / CaO is used as a desulfurizer. This process achieves the goal of zero discharge, but does not consider the impact of organic matter in the wastewater on the life of the membrane system, and a large amount of salt in the concentrated water will cause corrosion to equipment and pipelines, increasing production costs. Therefore, The method also has the problem that the activated coke with adsorption saturation is difficult to handle.

This method achieves the goal of zero discharge of concentrated brine in the coal chemical industry, and has a higher reuse rate of concentrated brine, but compared with the treatment process described in this patent, the equipment investment is large, the acid and alkali adjustment is required, the operation is complicated and the treatment cost is high, and The impact of organic matter in high-concentration wastewater on membrane life and treatment effect is not considered. The crystalline salt produced after evaporation and crystallization of concentrated brine contains organic matter and heavy metals, which is a hazardous waste. The cost of hazardous waste treatment is high and it is easy to cause secondary pollution.

In addition, this method also has problems such as the difficulty of regeneration of deactivated activated carbon, which can only be incinerated, and the processing cost is high.

[0006] Chinese patent CN104150718 A adopts ultrafiltration + RO + SUPER RO + MVR process to treat biochemical effluent. After the wastewater is treated, it meets the requirements of reclaimed water reuse. A large amount of salt and organic residues after MVR evaporation treatment are incinerated or landfilled. , but this method does not consider the problem of membrane pollution by organic matter in the biochemical effluent, and the salts after multi-effect evaporation and crystallization contain a large amount of organic matter and heavy metals, which are hazardous wastes, and the treatment cost is very high

Images