HU214089B - Process for increasing "pot life" of solutions used in the method for surface-improvement by elimination of organic contaminations - Google Patents

Abstract

(57) EXTRACT The present invention relates to a method for increasing the use time of surfactants on the surface by eliminating organic pollutants, which are used in the bristle admirable nylon polymer, which according to the present invention acts upon contacting the organic impurity material with the electrolyte containing the organic impurities, b) the organic d) and then rinse with water, e) treated with aqueous alkaline oil, and f) then rinsed with water in the given case. ŕ

Description

FIELD OF THE INVENTION The present invention relates to a process for increasing the useful life of solutions used in the surface dressing process by eliminating organic contaminants using an adsorbent polymer.

Solutions used in surface finishing processes, electrolyte solutions, preferably in the electroplating industry, and in the manufacture of printed circuit boards, preferably chemical, autocatalytic and galvanic treatment solutions for coating metals, non-conductive supports and guides.

Electroplating solutions of heavy metals are used in the galvanic production of metal coatings and metal films to which various organic compounds can be added to achieve specific surface properties (luminosity, ductility, tensile strength, etc.). These organic materials undergo chemical transformation during the deposition process, which results in contaminants that would lead to process failures in the case of lossless process control or to the complete recycling of the electrolyte from the process. The concentration of organic pollutants in electrolyte solutions may also be increased by the addition of a pollutant.

DD 280 560 discloses a solution for the removal of organic pollutants which involves adsorption on activated carbon and oxidation using hydrogen peroxide or potassium permanganate. However, this solution does not remove all the organic pollutants from the active bath.

Further disadvantages of the use of activated carbon are the heavy heavy metal losses and the adsorbent losses up to 20% by weight during the regeneration process. Filled activated carbon is a special waste due to its heavy metal fill and difficult regeneration. In many cases, the use of oxidants can also lead to an increase in the concentration of the pollutant.

Another process for removing organic contaminants from galvanic electrolyte solutions starts with opening the internal material stream and includes the following process steps: precipitation of heavy metal as hydroxide in rinse water, dewatering of heavy metal hydroxide sludge, dewatering with sulfuric acid, recycling to a galvanic process bath or recovery electrolysis, cathode selection and recovery of heavy metals in recovery electrolysis, recovery of sulfuric acid to dissolve the sludge. Organic contaminants remain in the filtrate after precipitation of the heavy metal and sludge separation, so that an increase in concentration in the electroplating electrolyte can be avoided (Galvanotechnik 71 (1980) 7, 712 720).

Another method also starts from the opening of the internal material cycle and involves a combination of an ion exchange electrolysis process. The electrolyte rinse water passes through the ion exchanger to the organic and heavy metal ions separating stage. Organic materials remain in the enriched rinse water and are thus removed from the electrolyte solution while the heavy metal ion exchange eluates are either returned to the electrolyte solution or are recovered on the metal by recovery electrolysis (Acta hydrochim et hydrobiol. 12: 183.202 (1984)). The disadvantage of all the above mentioned regeneration processes is that they result in too much material loss and thus do not represent a solution to the problem of providing poor process technology in the harmful material.

It is an object of the present invention to provide a method for eliminating organic contaminants from electrolyte solutions to increase the life of the electrolyte solutions and to minimize wastewater and waste. The removal of contaminants is to be achieved using regenerable adsorbent polymers, where organic solvents are excluded from the regenerative agents applicable to charged adsorbent polymers.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of using regenerable adsorbent polymers to increase the lifetime of electrolyte solutions by eliminating organic contaminants. After removal of contaminants by adsorption, the electrolyte solution should be of unlimited further use. A crucial condition for the application of the process is to ensure that the adsorbent polymers are fully recoverable with aqueous solutions.

In order to solve this problem, a process has been devised to increase the useful life of solutions used in the surface breeding process by eliminating organic contaminants using an adsorbent polymer, which comprises:

a) contacting the adsorbent polymer with an electrolyte solution containing organic pollutants,

b) rinsing the adsorbent polymer filled with organic contaminants with water, and

c) thereafter treated with an aqueous solution of an oxidizing agent,

d) followed by rinsing with water, if appropriate,

e) treated with an aqueous alkaline solution, and

f) optionally rinsing with water thereafter.

It is preferred that the adsorbent polymer filled with organic contaminants and rinsed with water is treated with an aqueous alkaline solution of an oxidizing agent and subsequently rinsed with water.

The oxidizing agent is preferably an aqueous solution containing hydrogen peroxide and / or peroxosulfates or peroxodisulfates.

Further, it is preferable to use sodium or potassium alkali in the concentration range of 2 to 10% by weight as the aqueous alkaline solution.

It is further preferred that the desorbed organic contaminants be re-mineralized by treatment with ultraviolet light / oxidant to reuse the organic matter-containing regenerates formed during regeneration of the adsorbent polymers.

Surprisingly, it has been found that charged adsorbent polymers, through oxidative pretreatment, e.g. with dilute hydrogen peroxide solution,

They are structurally altered such that reliable, complete regeneration of the adsorbent polymers can then be achieved by using an alkaline solution, such as dilute sodium hydroxide, in only one regeneration step. The treatment may also be carried out in one step by contacting with an aqueous alkaline solution of an oxidant. In addition to hydrogen peroxide solutions, water-soluble peroxosulfates or peroxodisulfates such as ammonium, potassium or sodium salts may also be used as oxidizing agents. The concentration of the oxidizing agent is 1-7 weight ⁰ / »range.

Example 1

Nickel electrolyte (Total Organic Carbon (TOC) = 25.5 gc / l, nickel concentration = 95.9 g / l) contaminated with organic contaminants, which was no longer functional due to high organic matter concentration, was regenerated using adsorbent polymers. The adsorption regeneration of the galvanic nickel electrolyte with adsorbent polymer (ethyl vinylbenzene / divinylbenzene copolymer without polar groups (Wofatit EP 61)) was carried out in a column chromatography at a flow rate of about 2.5 m / h. The column had an internal diameter of approximately 3 cm and a fill height of the adsorbent polymer of approximately 70 cm. Undiluted electrolyte and electrolyte diluted 1: 5 by volume (electrolyte: water = 1: 5) were tested. The adsorption column was filled until the total volume of organic matter (GVK) was utilized. By all organic materials is meant the sum of the organic materials of the pad and the organic materials formed or introduced, expressed as gc / l in the adsorbent as organically bound carbon. GVK is determined by evaluating breakthrough curves under the condition that the adsorption column is loaded until the inflow TOC equals the outflow TOC. The following results were obtained: GVK: about 63 gc / l adsorbent for the recovery of undiluted electrolyte, and GVK: about 37 gc / l adsorbent for the regeneration of electrolyte diluted 1: 5 by volume.

By regenerating the electrolyte, the TOC was reduced from 25.5 gc / l to 10.4 gc / l.

After the electrolyte has been regenerated, the organic matter loaded has been corrected according to the company's formula. Subsequent tests in the HULL cell showed that the electrolyte had become usable again.

Example 2

Non-functional galvanic nickel electrolyte (TOC) into a column packed with ethylene-vinylbenzene / divinylbenzene copolymer (without polar groups) with adsorbent polymer (Wofatit EP61) (inside column: 0.9 cm, loading height of adsorbent polymer: 16 cm) = 4.8 gc / l, nickel concentration = 78.1 gc / l), with a downward flow rate of approximately 2.5 m / h until the GVK was reached.

The regeneration of the charged adsorbent polymer in the same column was performed as follows:

1. Rinse the column with water until nickel is no longer present in the rinse water (flow rate: 3 m / h).

2. Treatment of the adsorbent polymer with 2.5% by volume of hydrogen peroxide corresponding to 5 times the volume of adsorbent in the adsorption column, providing downstream flow and flow (flow rate: approximately 1.7 m / h; duration: 1 / h). .

3. Wash with water until no hydrogen peroxide is detected in the wash water.

4. Treating the adsorbent polymer with a volume corresponding to five times the volume of the adsorbent in the adsorption column, ca. With 6% w / w caustic soda, providing downward flow and circular flow (flow rate: approximately 1.7 m / h, duration: max 1 / h).

5. Wash with water until the wash water is alkaline free. Thereafter, the adsorbent polymer is refilled. The GVK remained constant over the five cycles tested and was at all times approximately 16 gc / l adsorbent.

Example 3

In Example 2, hydrogen peroxide was added to a 3 gc / l TOC-containing soda lime solution obtained during regeneration and exposed to ultraviolet light. The amount of hydrogen peroxide was 200% of the theoretical amount of total carbon. The ultraviolet light source used was a low-pressure mercury waveguide with a wavelength of 254 nm. During the process, the TOC content was reduced to below 0.5 g _c / l. The thus-recovered sodium hydroxide can be recycled without loss of capacity for regeneration of the adsorbent polymer.

Claims (5)

PATENT CLAIMS CLAIMS 1. A method for increasing the useful life of a solution used in a surface breeding process by eliminating organic contaminants, wherein the adsorbent polymer is used. a) contacting the adsorbent polymer with an electrolyte solution containing organic pollutants, b) rinsing the adsorbent polymer filled with organic contaminants with water, and c) thereafter treated with an aqueous solution of an oxidizing agent, d) followed by rinsing with water, if appropriate, e) treated with an aqueous alkaline solution, and f) optionally rinsing with water thereafter. 2. The process of claim 1, wherein the organic adsorbent polymer-filled adsorbent polymer is treated with an aqueous alkaline solution of an oxidizing agent and subsequently rinsed with water. The process according to claim 2, wherein the oxidizing agent is an aqueous solution containing hydrogen peroxide and / or peroxosulfates or peroxodisulfates. 4. A process according to claim 2, wherein the aqueous alkaline solution is sodium or potassium in a concentration of 2 to 10% by weight. HU 214,089 Β 5. A process according to claim 1, wherein the desorbed organic contaminants are re-mineralized by treatment with ultraviolet light / oxidant to reuse the organic matter-containing regenerates formed during the regeneration of the adsorbent polymers.