Pretreatment method of low-radioactivity wastewater

Abstract

The invention provides a pretreatment method of low-radioactivity wastewater, which comprises the steps of conducting air flotation deslagging, specifically, introducing air-dissolved water into the bottom of an air flotation tank to form scum on the water surface, and collecting the scum to obtain a first intermediate liquid; conducting primary filtration, specifically, inputting the first intermediate liquid into a filter to obtain second intermediate liquid; conducting secondary filtration, specifically, inputting the second intermediate liquid into a ceramic membrane device, and obtaining a third intermediate liquid after filtration, wherein the filtration size in the secondary filtration step is smaller than that in the primary filtration step; and conducting reverse osmosis treatment, specifically, carrying out reverse osmosis treatment on the third intermediate liquid to obtain a purified liquid. According to the pretreatment method disclosed by the embodiment of the invention, the pollutants are sequentially filtered out according to the sizes of the pollutants from large to small, so that on the one hand, the filtering effect on the pollutants in the wastewater is ensured, and the content of TSS and the content of TOC are reduced; and on the other hand, the probability that the filtering medium is damaged due to excessive pollutants needing to be filtered is reduced.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a pretreatment method for low-radioactive wastewater. Background technique [0002] Nuclear waste reprocessing plants will produce a large amount of non-technical low-level radioactive wastewater during the treatment of nuclear waste. The so-called non-process low-radioactive wastewater refers to the wastewater produced in the reprocessing plant except for the main processes involved in the treatment of nuclear waste, and its radioactive activity is less than 10 6 Bq / m 3 (Becquerel per cubic meter, Becquerel per cubic meter). Sources of waste water include desorption and decontamination liquid from process plants, desorption and decontamination liquid from three-waste plants, ground flushing water in the orange area of ​​process plants, shower water and laundry water, etc. Non-process low-radioactive wastewater has the characteristics of large annual production vo...

AI Technical Summary

Problems solved by technology

However, during the process of evaporating and concentrating wastewater in this treatment process, the evaporator may cause bumping, which makes it difficult to achieve the expected effect of evaporating and purifying radioactive wastewater; suspended solids, colloidal particles and other substances contained in wastewater are likely to block the filter channels and ion exchange channels. Pores, reducing the purification effect; and the soluble complexing agent, salt-free reagent radiolysis products and other substances remaining in the incompletely purified wastewater complex with radioactive elements to form soluble radionuclide species, and the solidification of cement Poor effect, easily soluble in water after contact with groundwater and released from cement, causing pollution

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