From Big Medical Encyclopedia

NEUTRALIZATION OF WATER - impact on various impurity, harmful to an organism, which are in water for the purpose of their elimination.

In an extreme antiquity it was noted that developing of nek-ry diseases is connected with the use of water. Further the role of the water contaminated by bacteria in emergence inf was evidence-based. diseases. Development of the industry promoted pollution of water sources the drain waters containing various substances, harmful to an organism.

There was a need of creation of special treatment facilities for water handling of the population and the organization a gigabyte. control of quality of water.

Depending on a type of pollution various ways O. of century are applied. So, at pollution of water fighting OV, toxic industrial wastes apply methods decontaminations (see), at radiocontamination of water, in particular products of nuclear explosion — methods deactivations (see), at infection of water with pathogenic viruses, bacteria or protozoa — methods of disinfection (see. Disinfecting of water ). Neutralization of the water contaminated by industrial, agricultural and household wastes — see. Drain waters .

An opportunity and spontaneous O.'s speed of century depends on the chemical nature, physical condition, hydrolytic stability and amount of the poison which got to a reservoir. OV, hydrolysis to-rykh proceeds quickly and with formation of non-toxic products, practically do not cause infection of water (phosgene, diphosgene). Slowly hydrolyzed OV, e.g. iprita, V-gases. give steady and long infection. Landlocked small reservoirs (lakes, ponds, especially wells) can be infected with OV for the term estimated for weeks and months. Infection of large and quickly current rivers, big lakes and water reservoirs with dangerous concentration of these substances is difficult feasible. Infection of OV of artesian water sources and water in tubular wells is improbable because of a deep bedding of a water-bearing layer and good sealing of the place of a water intake.

In case of detection in a reservoir of OV, products of nuclear explosion or poisons it recognize unsuitable for water supply of the population and troops about what the corresponding mark on site of water use becomes. For providing people with water other safe water sources shall be found or if those close do not appear, it is necessary to establish tubular, to dig out mine wells or to drill artesian wells. Temporarily, before receiving local subsoil or well water, it is necessary to organize delivery of high-quality water land or air transport.

Century resort to O. only as a last resort when receiving high-quality water on site is impossible, and its delivery is complicated. The lake of century shall be made only on points of water supply, with use of organic means and under control of health service.

At pollution of water small concentration of phosgene, hydrocianic to - you, and also OV, hydrolysates to-rykh are not toxic and have no off-flavor, for neutralization boiling is used. The lake of century, OV contaminated by considerable concentration, carry out by the method based on ability of the substances applied to neutralization to adsorb poisons. The most effective adsorbent is karboferrogel, exempting water from OV, including from a lewisite, to-ry at boiling does not lose the toxicity.

Scheme of operation of the TUF-200 filter: 1 — tanks for the purified water; 2 — the manual pump; 3 — the fabric-coal filter; 4 — a tank for treated water.

As technical means for O. by century organic filters — the mechanized autofiltration plant with a productivity of 6000 l/hour (MAFS-6000), the fabric-coal filter (TUF-200) with a productivity of 200 l can be used! hour (fig.), and also universal wearable filter with a productivity of 30 l/hour (UNF-30), etc. It is necessary to boil the filtered water at negative analysis findings on the maintenance of OV before the use during the 2nd hour. The water contaminated by big concentration of yperite before filtering needs to be subjected to chlorination with the subsequent coagulating by green vitriol.

Apply the following methods to O. century contaminated by radioactive materials: 1. Filtering of water through the ion-exchange resins capable to exchange the ions for ions of the substances dissolved in water (see. Ion exchange reactions ) — at first through a layer of cation exchanger, then through a layer of anion exchanger. Each layer of an ionite shall have thickness of 45 — 50 cm. Ionites are replaced in 10 — 15 hours of work. 2. Coagulating of water (see. Coagulation ) with the subsequent upholding and filtering through karboferrogel. 3. Coagulating of water with afterfiltration via fabric-coal filters or filters from make-shifts (sand, an anthracitic crumb, etc.). 4. Distillation of water — a method rather effective, but considerably conceding on productivity the above-mentioned.

The lake of century, contaminated by bacteria and toxins, is carried out by chemical methods with the subsequent boiling of water. Neutralization of an individual deposit of moisture (in flasks) is made by means of special tablets. Botulinum toxins of types A, B, E are characterized by rather high heat stability unlike toxins of the types C and D which are rather easily collapsing during the heating. All 5 types of botulinum toxin collapse in water under the influence of active chlorine, iodine and potassium permanganate. A well-tried remedy of destruction of these toxins is rechlorination of water with the subsequent its dechlorination and filtering.

Neutralization of the mine wells contaminated by OV is carried out by processing of a felling and walls by lime chloride with the subsequent full pumping out of water, cleaning of a bottom, triple washing of walls and repeated pumping out of water. Cleaning of the mine wells contaminated by products of nuclear explosion is carried out by washing of walls and quadruple full pumping out of water.

Control of O.'s quality of century is exercised by medical and chemical services. The medical service makes water analysis and draws the conclusion about its suitability to the use. The applied methods O. of century with use of organic means give the chance to exempt water from all OV, products of nuclear explosion, bacteria and toxins. Quality of the conditioned water shall answer a gigabyte. to requirements imposed to drinking water (see. Water, sanitary and hygienic requirements, hygienic control ).

At decontamination, deactivation and disinfecting of water it is necessary to observe safety measures: to use individual means of protection, after work to undergo sanitary cleaning and radiation control.

See also Water treatment .

Bibliography: V. D.'s white hares and E. G Bug. The manual on military hygiene and epidemiology, M., 1978; The Penalty to the h and e in N. I. Toksikologiya OV and protection against nuclear and chemical weapon, Tashkent, 1978; R. V. Queens. Sanitary and chemical examination of water and foodstuff, page 74, M., 1971; Krotkov F. G. Textbook of military hygiene, page 69, M., 1962; With ter lean R. N., Yemelyanov V. I. and Zimin V. I. Chemical weapon and protection against it, M., 1971.

H. N. Savchenko, X. G. Yakubov.