Method for treating nuclear fuel element production process wastewater by utilizing vacuum membrane distillation

Abstract

The invention discloses a method for treating nuclear fuel element production process wastewater by utilizing vacuum membrane distillation, and particularly relates to a method for treating organic low-level radioactive process wastewater generated in preparation of a high-temperature gas cooled reactor element core by utilizing vacuum membrane distillation, which comprises the following steps: introducing wastewater subjected to ammonia distillation filtration pretreatment into a constant-temperature water heater, heating the wastewater to 70-90 DEG C, and introducing the wastewater into a high-temperature water heater; introducing the wastewater into the hollow fiber membrane component by using a peristaltic pump, and carrying out heat and mass transfer in membrane holes; introducing cold water with the temperature of 5-20 DEG C into a condensing device connected with the membrane component by utilizing a constant-temperature cold water tank, so that a temperature difference is formed inside and outside the fiber membrane; a circulating water vacuum pump is used for vacuumizing and used for increasing the pressure difference between the cold side end and the hot side end of the membrane assembly, water vapor in the wastewater migrates from the inner side to the outer side of the fiber membrane, enters the outer side of the fiber membrane, is condensed and discharged when encountering cold air on the outer side, and flows into a distillate receiving bottle. And the membrane flux is improved by controlling the feeding flow rate, the wastewater temperature, the device vacuum degree, the condensate water temperature and the like, so that ammonia nitrogen, organic matters and uranium in the wastewater can be well purified and treated, and the desalination rate is improved. The removal rate of uranium is 99.99%, the removal rate of organic matters reaches 80%, the removal rate of nitrate nitrogen is 99.9%, and the removal rate of ammonia nitrogen reaches 97.6% after the pH is adjusted.

Description

technical field [0001] The invention relates to the technical field of organic radioactive waste water treatment, in particular to a method for treating organic low-level process waste water produced by the core preparation of high-temperature gas-cooled reactor elements by using vacuum membrane distillation. Background technique [0002] The production of nuclear fuel elements is one of the key technologies of high-temperature reactors. During the core preparation process of high-temperature gas-cooled reactor elements, a large amount of organic low-level radioactive waste liquid containing high COD (caused by organic matter), high salt, and high ammonia will be produced. Organic low-level radioactive waste has the characteristics of complex composition, high organic content, high chroma, and refractory biodegradation. The organic low-level radioactive process wastewater produced by the core preparation of high-temperature gas-cooled reactor components is different from con...

AI Technical Summary

Problems solved by technology

Therefore, for organic low-radioactive wastewater with a more complex system, it is difficult to remove impurities and ions in the wastewater with traditional methods, the treatment efficiency is low, the system performance is unstable, and "near-zero" discharge cannot be achieved.

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