A zero-discharge treatment method and device for high-ammonia-nitrogen wastewater resource recycling by membrane aeration and membrane absorption coupling process

Abstract

The invention discloses a high-ammonia-nitrogen wastewater reutilization zero-discharge treatment method and device of a membrane aeration and membrane absorption coupling technology and belongs to the field of environmental engineering. About 60% of ammonia nitrogen in ammonia-nitrogen wastewater is removed first in a membrane aeration mode, then about 99% of remaining ammonia nitrogen in the wastewater is removed in a membrane absorption multistage ammonia removal mode, and thus the high-ammonia-nitrogen raw water can be directly discharged after being treated; ammonia gas separated out from a membrane aeration system is directly introduced into an absorption liquid tank for the membrane absorption process to react with and remove excess acid in the absorption liquid tank; treated absorption liquid is introduced into a by-product recovery system to treat high-concentration absorption liquid. When the operating capability is reduced to 70% the original operating capability or long-time shutdown is needed, it is needed to start a cleaning-air purging system to maintain and clean the systems so that the systems can be kept stably operating for a long time.

Description

technical field [0001] The invention belongs to the field of environmental engineering, and relates to a technology for recycling ammonia-containing wastewater, in particular to a zero-discharge treatment method for recycling industrial high-ammonia-nitrogen wastewater by applying a coupling process of membrane aeration and membrane absorption. Background technique [0002] my country is seriously short of water resources, and the per capita fresh water resources are only a quarter of the world's average level. The main rivers, lakes and groundwater in the country are polluted to varying degrees, and the pollution is still intensifying. According to monitoring by the environmental protection department, ammonia nitrogen is one of the main pollutants. The main harm of ammonia nitrogen to the environment is that after entering the water body, it becomes a nutrient element for algae and other organisms, causing toxic organisms in the water body to multiply in a short period of ...

AI Technical Summary

Problems solved by technology

More than 70% of the deammonization process adopts the ammonia distillation method, but the ammonia distillation method has the disadvantages of high energy consumption, high treatment cost (about 25 yuan / ton), serious scaling of equipment, etc. The ammonium magnesium phosphate precipitation method has the disadvantage of a large amount of sediment , so there is an urgent need to develop cost-effective new high-ammonia nitrogen treatment and recovery technologies and equipment

[0007] However, the membrane absorption process currently has the following problems that must be solved in industrial applications. One is the problem of hydrophilization of the membrane module; The concentration is low and the pH value is low, so it cannot be directly used as fertilizer, and the "evaporation-crystallization" salt production technology has the problem of high treatment cost; the third is that the waste liquid with high ammonia nitrogen is recycled instead of continuous Operation will bring many problems such as increased floor area and construction cost, long operation time, and high energy consumption. There are many restrictions in industrial applications, which is not conducive to large-scale industrial applications; The problem of the volume expansion of the absorption liquid caused by the osmotic distillation of the water on the high ammonia nitrogen raw liquid side caused by the poor activity

[0008] The authorized announcement number is CN103086453B "A Method for Ammonia Nitrogen Wastewater Membrane Deamination" invention patent and the authorized announcement number applied at the same time is CN203065287U "A Ammonia Nitrogen Wastewater Membrane Integrated Deamination Device" utility model patent, using vacuum deamination Coupling with membrane absorption process to treat high ammonia nitrogen wastewater, the existing problem is that the cost of vacuum deamination system is high and the process requirements are complicated. In addition, the vacuum deamination system is a static system, and the single-step residence time is 2-5 hours. Subsequent membrane absorption The deamination system is a cyclic deamination system with a treatment time of 1-3 hours. Due to the slow treatment time, a large-scale industrial water treatment system requires a large footprint, and the prospect of industrial practical application is very small.

[0010] Application No. 201310535302.4 "A Zero Discharge Method for High Salt and High Ammonia Nitrogen Wastewater" invention patent and its simultaneous application No. 201310535284.X "A Zero Discharge Device for High Salt and High Ammonia Nitrogen Wastewater", and the application No. 201310349390.9 "A Process for Treating High-Ammonia Radioactive Wastewater by Membrane Absorption Method" avoids by-products such as ammonium sulfate and ammonium chloride obtained by membrane absorption and deamination. Due to low concentration and low pH value, it cannot be directly used as Fertilizers are used, and the "evaporation-crystallization" salt production technology has the problem of high processing costs

[0011] In summary, the hydrophilization of the membrane module, the treatment of the absorption liquid, and the batch cycle operation mode are still bottlenecks restricting the industrialization of the membrane absorption process.

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