CS260811B1 - Method of waste waters' salinity reduction - Google Patents

Abstract

The solution lies in the field of reduction salinity of wastewater from galvanization, hardening, PCB production and everywhere where in the manufacturing process the increased salinity of wastewater. Currently with it solves the reduction of salinity considerably expensive largely imported. They are ion exchanger, reverse osmosis, electrodialysis and evaporators with varying degrees of evacuation. In all of these methods, they are problematic liquidate eluates. Way reducing salinity removes these drawbacks. Phosphoproteides are used to reduce salinity in partially condensed form s formaldehyde under catalytic action lactic acid directly in the wastewater. The phosphoproteid used is initially partially dissolved, then catalyst a followed by formaldehyde and the resulting solution stirring until a clot forms. This the precipitate is allowed to settle. After completion of sedimentation with water over the precipitate draining - decanting - according to salinity, if the salinity complies with the sewer system the order, released into the sewer, they were not the procedure is repeated. The resulting sediment with the remaining water is pumped into the filter press storage tank then the sludge is trapped.

Description

SUMMARY OF THE INVENTION The present invention provides a method for reducing the salinity of wastewater by adsorption of partially condensed phosphoproteins. It collects wastewater salts from galvanizing, hardening and similar plants after pre-disposal / toxic substances by oxidation, reduction and neutralization processes. Remaining soluble salts in waste water, such as chlorides, sulphates, phosphates, nitrates and nitrites, are the cause of pollution of other waters and therefore cause intervention of sanitary and water authorities against their discharge.

Currently, salinity reduction is being solved by relatively expensive equipment, largely from imports. They are reverse osmosis, electrofrdialysis of evaporators with different degrees of evacuation and ion exchange. These devices are mostly combined to /

reducing the energy required. All of these processes give rise to problematic liquidated eluates. Although it is currently proposed to use casein, it is present in its bulk-semolina form, which is sparingly soluble and thus cannot achieve the sorption effect as freshly precipitated mycels of partially condensed casein. The pH is also decisive for the action of mycelial casein in a given type of wastewater. At pH lower than 4.5 the casein becomes insoluble.

The drawbacks of the prior art are solved by a method of reducing the salinity of waste water from metal surface treatment, heat treatment of metals according to the invention, which consists in treating the waste water with a colloidal solution of formaldehyde partially condensed phosphoproteids under the catalytic action of lactic acid. The salinity of the waste water can be reduced by the action of a colloidal phosphoproteid solution (casein) with the addition of a lactic acid condensation catalyst. With stirring, a formaldehyde solution is added after 20 seconds. Its reaction with phosphosporide produces a partially condensation product, which results in

260 811 colloidal precipitates in the pH range of 7.5 - 9, optimally at pH 8. The resulting precipitate has a considerable adsorption capacity. It adsorbs dissolved salts in the waste water from 18 to 20 percent for each cycle. By repeating the efficiency of 90 #, the adsorption-saturated precipitate can then be separated by coagulation, sedimentation and filtration. Acceleration of packing of the precipitate can be achieved by adding flocculant - eg, polyacrylamide. Waste water can be depleted in several cycles by salting so that it is possible to re-use it or discharge it into a watercourse.

By repeating the above process, it is possible to economically eliminate a substantial part of the salinity of the discharged water & at the same time to create a waste-free technology. The high salinity reduction efficiency is due to the casein being treated to its maximum utilization (up to 90 percent). Necessary substances are commonly manufactured and cost-effective in Czechoslovakia. The device can be made from standardized devices,

The technical casein solution is metered into the waste water which is fed to the reaction tank with motor or pressurized mixing. 1.25 to 2.50 kg of casein per 1 m ^{J of} waste water are needed. To dissolve technical casein, 0.2 L of triethanolamine or 0.1 L of concentrated ammonium hydroxide in 50 to 60 L of waste water is required. After stirring for 2 minutes, 0.2 L of 60% lactic acid was added, followed immediately by 0.1 L of formalin (30%). The supernatant water is pumped out after 20 minutes - decant - and according sclno $ tii _t If the salinity compliant according sewer, discharged into the sewer (streams). If the satisfactory salinity is not yet reached, the water is pumped to the next reaction tank, where the whole process is repeated.

The laboratory test result using sodium chloride saline was as follows;

A 5 g / l NaCl solution was prepared for the laboratory test, and its concentration was determined by titration with 0.1N AgNO4.

260 811

After sorption and separation of the precipitate with respect to volume changes, gradually decreasing NaCl concentration was also found by titration

15.8 ml of 0.1N AgNO4 = 4.617 g / l NaCl

14.5 Hall 0.1N AgNO ₃ = 4.237 g / L NaCl

11.8 ml of 0.1N AgNO4 = 3.448 g / l NaCl

9.2 and 0.1N AgNO4; 2.688 g / l NaCl

The most efficient sorption was at pH 8.5 using a solution of 5g casein / 250 [mu] l with the addition of 2 ml of formaldehyde (30 and 1 ml of hydrochloric acid (62%)).

The invention can be applied as replenishment equipment downstream of wastewater treatment stations from galvanizing plants, hardening shops, printed circuit boards, and, wherever the production process for increasing the salinity of the wastewater arises. Separate precipitate can be used either as an additive to compound feed for poultry, pig or compost for waste-free technology ·

Claims (2)

P S B D E T LY LILBZU 1 · Way to reduce salinity! waste water from galvanizing, hardening, printed circuit board production and wherever the production process results in increased wastewater salinity, characterized in that the waste water is treated with a colloidal solution of formaldehyde and partially condensed phosphoproteids under the catalytic action of lactic acid. 2. A process according to claim 1, characterized in that the desalination is carried out at a pH of 7.5 to 9, preferably a pH of 8.