SU1628453A1 - Method of removing ammonia nitrogen from sewage - Google Patents

Abstract

The invention relates to methods for purifying wastewater from ammonia nitrogen and can be used in the disposal or conditioning of liquid waste from hydro-metallurgical industries, and such decitrification of drinking water purposes. The purpose of the invention is to increase the efficiency of the process of cleaning waste waste from ammonia nitrogen, reducing the duration of regeneration of the cation exchanger, reducing the consumption of reagents for regeneration. The method is carried out by sorbing ammonia nitrogen from wastewater with, 5 on a carboxyl cathnonite of the brand Cr-III-2 - a copolymer of methacrylic acid and triethyl glycol acrylate with butylacetate. The regeneration of the saturated cation exchanger is carried out with a solution of aetic acid containing Mg and Na of the solution and corresponding to the composition of the regenerates of the H-cation-exchange filters of the plants obvsolivanil water, t sf f-crystals, 1 table. 1 il. -Ia Oh with

Description

The invention relates to methods of cleaning waste water from ammonia nitrogen and can be used in the disposal or conditioning of liquid waste from hydro-metallurgical production, as well as the denitrification of drinking water.

The aim of the method is to increase the efficiency of purification of ammonia nitrogen by using cation exchangers with high exchange capacity, reducing the duration of regeneration of cation exchangers, reducing the consumption of reagents for regeneration. In order to remove ammonia nitrogen from wastewater with a pH of 10.5, a carboxyl cation exchanger of the СГ-1 М2 brand is used;

by copolymerization of methacrylic acid and triethylglycol acrylate in the amount of 8-12% of the mayster of monomers and butpgacetate in the amount of 20-30% by weight of the monomers. The regeneration of the cation exchanger is carried out with a multicomponent nitric acid solution containing Ca4, Mg ++, Na. The proposed cation exchanger has a high exchange rate (capacity with large amounts of free ammonia in wastewater (in terms of N11 up to 2900 mEq / dm). When this cation exchanger is used for r.genergstzchi, this multicomponent acidic nitric acid solution instead of nitric acid is , desorption of ammonia nitrogen proceeds with much more

Јg

O1

speed This is probably due to the additional displacement of ammonium ions from the Ca + Na cations. Presumably, the process of displacement of these ions by ions. NH. occurs in accordance with the election for the carboxyl cationirit jU

the same and the values of the exchange constants of the code vv v MBA v BOTH ... HMW

КНН4-Ай КЖЦ-На The indicated displacement of ammonium nitrogen, together with the existing exchange of ammonium ions by C in the ammonium cation, leads to an additive increase in the rate of regeneration - a reduction in the process time.

The acid regenerates of the desalination plants are the same for almost all desalting plants. Cation content

B

Са ™, the amount of 1.8-2.2 g / dm; 0.450-0.50 g / dm3; 0.9-1.1 g / dm3, respectively, is determined by the total dynamic exchange capacity (PDOE) of the cations used for H-cationic water and it does not seem appropriate to change it. The acidity of regenerates is 2-3%. An increase in the concentration of nitric acid in the regenerating solution of the regenerate, although it provides an initial acceleration of the displacement of ammonia nitrogen from quatnonite, subsequently leads to an increase in the residual capacity, a decrease in the efficiency of regeneration, and does not correspond to the actual acidity in the regenerations of water desalination plants.

Examples of the method.

Example 1. A solution simulating the composition of the condensate of juice vapor D for the production of nitrogen fertilizers and holding L / 1.5 g / dm of ammonia nitrogen (in total) is passed through the SG-Sh2 cationite layer from top to bottom. The transfer rate of the solution is 2 vol / vol, with a volume of the ion exchanger layer of 20 cm3. In parallel, experiments were carried out according to the method of the prototype,

I

The regeneration of saturated cation exchangers is carried out under dynamic conditions in the same columns with a bulk velocity of 5 v / v and 2.5 v / v of SG-1M2 and KU-2x8, respectively. Regenerate is passed through cationic SG-III

H-cationic filter of the water desalination unit, sos.tava: HNO g - 2.1%, 526 mg / d, mg / dm Na - 2007 mg / dm3, through a layer of Ku-2x815% HNO solution. The results are presented in the table.

Example 2: Saturated under static conditions (capacity 2900 mEq / dm by NHt) the cation exchanger SG-1M-2 is brought into contact with the regenerate, corresponding to the composition of the multicomponent solution in Example 1. Graphic results of the dependence of the residual capacity (E OSG) cationite from contact time (F) is shown in the drawing (a, curve 1). In the same place (curve 2), the dependence Eoer f (Ј) is shown during SG-1M-2 regeneration by a two-component solution HZ0-HN03 (20 g / dm3).

Dependence of residual capacity of SG-1M-2 and KU cation exchangers - 2x8 on the time of contact with the regenerating solution.

In the drawing (b), a similar dependence is presented for the cation exchanger KU-2x8 in the prototype method, saturated with Na ions, with its 15% HNOj regenerated. Comparison of dependences in graphs a, b is determined by the ionic equivalence of NH ions. and Na + dl (CU-2).

From the example it can be seen that the use of a multicomponent solution of the indicated composition makes it possible to shorten the regeneration time of a saturated ion exchanger (SG-1M-2) by A compared with the method of the prototype. In addition, the time-to-regeneration of SG-III-2 when using regenerates of H-cation-exchange filters is reduced 5 times in contrast to the use of a solution of 1-SOD.

Thus, in comparison with the known method, the proposed method improves the efficiency of wastewater treatment by increasing the capacity of the cation exchanger used, speeding up the regeneration process, and reducing the consumption of reagents. The use and quality of the regenerating solution of regenerants of H-cation-exchange filters of plants desalted with water accompanying any industrial production will make it possible to exclude the use of specially prepared solutions of mineral acids in the scheme of ion-exchange wastewater treatment from ammonia nitrogen. This will reduce the operating costs of the cleaning process. At the same time, the reduction in the volume of regenerates H-cationite516284

These filters, due to their partial use in other production, also lead to a reduction in the cost of plant i neutralizing reagents used before discharging mixed regenerates (acidic and alkaline) of desalting plants into the hydrographic network.

Claims (1)

1. A method of purifying wastewater from ammonia nitrogen at a pH of% 10.5, including its sorption on katnonite in the H-form, the regeneration of a konnonnt acid, characterized in that, in order to increase the cleaning efficiency by using cation , 0 five P S3b a nitrate with a higher exchange capacity, reduced regeneration time and consumption of regenerating reagent; CP-Sh-2 carboxyl katnonite — Co ™ is a polymer of metal acid and triethylglycol-acrylate with butyl acetate, while regeneration of the cation exchanger is exhausted as catnonite. nitric acid containing calcium, magnesium and sodium ions. 2, the method according to p. 1, about tl and h and y and the fact that as a regenerating reagent use regenerant - # - cation exchanger filters of plants with desalinated water containing, g / dm: HN09 20-30 Ca2 0.450-0.50 Mg2 0.9-1.1 Na 1.8-2.2 100 (Eocfli.,% ABOUT tt 8 iZ W 20 b.min 0 10 20 30 W SO G.mik