Method for deeply treating, desalting and recycling industrial wastewater with high salt content

Abstract

The invention relates to the field of industrial wastewater treatment processes and provides a method for deeply treating, desalting and recycling industrial wastewater with high salt content. The method comprises the following steps: 1) carrying out efficient coagulation treatment on the industrial wastewater with high salt content to obtain supernatant; 2) carrying out chemical precipitation on the supernatant obtained in the step 1) to remove high valence ions with valence higher than bivalence in the wastewater; 3) carrying out catalytic ozonation treatment on the supernatant subjected to chemical precipitation in the step 2); 4) carrying out multi-media filtration, precise filtration and membrane filtration treatment on the wastewater subjected to catalytic ozonation in the step 3) in sequence; and 5) carrying out electrodialysis reversal treatment on the effluent obtained after membrane filtration in the step 4). By adopting the method, organic matters, bacteria, colloids, suspended particles, Ca<2+>, Mg<2+> and high valence ions, other soluble inorganic salts and the like in the industrial wastewater with high salt content are removed by utilizing the coupling and synergistic effects of different unit technologies, thus achieving deep treatment, desalting and recycling of the industrial wastewater with high salt content.

Description

technical field [0001] The present invention relates to the technical field of industrial wastewater treatment, in particular, the present invention relates to the realization of advanced treatment and desalination reuse of high-salt industrial wastewater through the coupling and synergy of physicochemical method and membrane technology. Background technique [0002] High-salt industrial wastewater refers to wastewater with a total salt content of more than 1%. High-salt industrial wastewater is produced in a wide range of ways, and the amount of water is increasing year by year, mainly from steel, coal chemical, textile, paper, oil and natural gas and other production and processing industries. This waste water contains a variety of substances (including inorganic salts, oil, organic matter and heavy metal ions, etc.). According to different production processes, the chemical composition, types and properties of organic matter in high-salt industrial wastewater are quite d...

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Problems solved by technology

Among them, the thermal concentration process is to use thermal energy to concentrate the solid in the liquid state at a high rate, which generally has the problems of large equipment and high energy consumption, and the corrosion of the equipment by chloride ions and the scaling of calcium and magnesium ions in the process of thermal concentration of wastewater will cause maintenance costs. High, and increase the investment and operation risk of the enterprise; such as chemical precipitation method used to remove Ca in wastewater 2+ , Mg 2+ and other high-valent ions, but it has no effect on other soluble inorganic salts; the ion exchange method is only suitable for low-concentration saline wastewater, and the treatment of high-saline industrial wastewater will cause the ion exchange resin to quickly saturate and need to be regenerated repeatedly, which also produces secondary Wastewater; the problems of reverse osmosis in the treatment of high-salt industrial wastewater are that high reverse osmosis pressure will lead to increased energy consumption, low concentration will lead to large discharge of concentrated water, and serious membrane pollution; electrodialysis is used in industrial The main problem in wastewater desalination is due to Ca 2+ , Mg 2+ Membrane fouling caused by ion scaling and organic matter adsorption on the membrane surface makes it difficult for the electrodialysis system to operate stably for a long time

There are also several reports on patents on reverse osmosis, electrodialysis, etc. used in the treatment of saline wastewater. Due to the high content of organic matter and impurities in high-salt industrial wastewater, it will lead to serious membrane pollution in the water treatment process.

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