Technology for using organic contaminated high salinity wastewater to produce industrial refined salt

Abstract

The invention discloses a technology for using organic contaminated high salinity wastewater to produce industrial refined salt. The technology comprises the steps of conducting pretreatment and oil removal on the organic contaminated high salinity wastewater, afterwards, leading the pretreated organic contaminated high salinity wastewater into a secondary evaporation crystallizer in a multiple-effect evaporative crystallization system to be subjected to multiple-effect evaporation, obtaining risky waste salt particles after multiple-effect evaporation dewatering, leading the risky waste salt particles into a multi-stage ring kiln to be subjected to thermal desorption treatment, removing organic matter in the risky waste salt and obtaining solid particles, conducting dissolution and impurity removal on the solid particles, removing carbon dregs, phosphorous, ammonia nitrogen and calcium and magnesium in the solid particles to obtain a saline solution, leading the saline solution again into a primary evaporation crystallize in the multiple-effect evaporative crystallization system, and obtaining the industrial refined salt after evaporative crystallization. According to the technology for using the organic contaminated high salinity wastewater to produce the industrial refined salt, the technology is intact, resource utilization of the organic contaminated high salinity wastewater can be directly achieved, a set of evaporative crystallization device is saved, the problem of waste gas treatment in thermal desorption of the risky waste salt is effectively solved; meanwhile, the whole technological process is simple and automation of an operation can be achieved.

Description

technical field [0001] The invention relates to the technical field of treatment of salty wastewater, in particular to a process for preparing industrially refined salt from organically polluted high-salt wastewater. Background technique [0002] In the pesticide, chemical, printing and dyeing, pharmaceutical and other industries, a large amount of high-organic salt-containing wastewater will be generated, with a salt content of about 10% and an organic concentration of more than 10,000 mg / L. This kind of wastewater is not suitable for microbial growth, so biological treatment technology is not feasible; if it is treated by chemical methods, the high concentration of chloride ions in it will greatly reduce the oxidation effect of oxidants, so the use of chemical oxidation technology is not only expensive, but also the treatment effect is not good. . [0003] At present, the treatment technology for this kind of high-salt and high-organic waste water is to use evaporation cr...

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Problems solved by technology

However, this process produces a new hazardous waste after wastewater treatment, and there is no subsequent treatment process, which does not conform to the concept of environmental protection. The process has huge defects and is not a complete treatment process.

[0007] Patent CN 201610072785.2 discloses an advanced oxidation-salt separation and crystallization combined system for high-salt industrial wastewater. This system discloses a process for treating high-salt wastewater with advanced ozone oxidation, multi-effect evaporation, and freeze crystallization. Can this process be traditional? The biochemical oxidation method is insufficient to remove COD; however, in the actual operation process, the work requirements of the ozone oxidation device are high, and there are certain dangers in the production process, and in the process, the organic matter is removed first, and then the brine without organic matter is treated. In the process of evaporation and crystallization, in the case of incomplete removal of organic matter, a small amount of organic matter will easily remain in the brine, which will affect the purity of the subsequent industrial salt. At the same time, after the treatment is completed, there will be certain pollution in the subsequent treatment.

[0008] Patent CN 201610072782.9 discloses a high-salt industrial wastewater salt-separation zero-discharge system. The system discloses a process for treating high-salt wastewater by using salt-separation nanofiltration, advanced oxidation, evaporation or freeze crystallization. The process mainly uses classification The nanofiltration process grades various inorganic salts in high-salt water, which achieves the characteristics of zero pollution discharge, but the salt-separation nanofiltration process itself is relatively cumbersome, and the efficiency of membrane separation operations for high-salt wastewater is low. ; Because its purpose is mainly to realize the classified treatment of various salts, the treatment effect is poor for organic waste water with only NaCl, and it cannot fully treat organic matter

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