From Big Medical Encyclopedia

DRAIN WATERS — effluent of household and production activity of the person.

By origin S. century conditionally divide on household, industrial, agricultural, etc. The structure them is various. They may contain mineral and organic substances in the weighed and dissolved state, the poisonous and possessing intensive smells and smacks chemical connections, the substances exerting preferential impact on processes of self-cleaning of reservoirs, and also pathogenic and saprophytic microflora, causative agents of parasitic diseases. Pages of century characterize by such quantitative and quality indicators as existence and amount of suspended matters and floating impurity, began to smell, coloring, temperature, pH, mineral composition, the amount of oxygen necessary for biochemical oxidation of the century of organic matters which are contained in S. (see. BPK ), existence of activators inf. diseases, toxic agents.

The most frequent way of removal of S. of century — their dumping into reservoirs that is the main reason for pollution of these reservoirs. S.'s dumping into the soil can be century the cause of pollution of underground waters. The main measures of pollution control of the environment drain waters consist in their cleaning, disinfecting, utilization, including use for irrigation of page - x. grounds, the organization of drainless productions, use of the century cleared by S. in water recirculation, etc.

There are various methods of cleaning of S. of century: reagentless, mechanical (sediment, filtering, aeration, averaging, oil and zhiroulavlivany etc.); reagent, chemical by means of coagulants, oxidizers, extragents, adsorbents, and also physical and biological methods. For cleaning of drains the stations of aeration including a complex of constructions — lattices, sand traps, settlers, aerotanks or biofilters, methane-tanks and so forth serve in the large cities (see. Bioscrubbling , Bacteria beds , Paul of irrigation ). For biol. S.'s cleanings with century of small settlements apply compact installations of factory production of various power. Apply septic tanks (percolation pits) representing the horizontal settlers detaining to 70% of suspended matters to S.'s cleaning with century of certain buildings. Depending on S.'s expense of century septic tanks can be one - two - and trekhkakhmerny. The villages of century which passed septic tanks demand additional biol. cleanings, napr, on fields of underground filtering, in the filtering trenches or the filtering wells. More modern settler, in Krom unlike a septic tank fermentation of a deposit happens without release badly of the smelling gases, the two-story settler — a so-called emshersky well is. Its bottom where silt collects, is separated from upper, in a cut there is a sediment of waste liquid.

Due to the presence at S. of century of causative agents of infectious, especially intestinal diseases, they after cleaning shall be exposed to disinfecting (see. Disinfecting of water ).

In development of methods of cleaning of S. of century the big merit belongs to the Soviet scientist S. N. Stroganov.

The state control of water objects is exercised by bodies for regulation of use and protection of waters, the state dignity. supervision — bodies and institutions sanitary and epidemiologic service (see). Constant overseeing by operation сооруя^е-ний on neutralization and S.'s disinfecting of century shall be provided with the water user, S. of century to-rogo are dumped in a water object. The order of control is coordinated with bodies for regulation of use and protection of waters, bodies and institutions of sanitary and epidemiologic service taking into account local conditions on a water object, the nature of its use, degree of harm of S. of century, types of constructions and features of processing of S. of century.

For protection of reservoirs from pollution and for increase in productivity of nek-ry pages - x. cultures household S.' use on agricultural fields of irrigation is recommended century (see. Paul of irrigation ); besides, the cleared household S. even more often are used century in industrial reverse water supply.

Industrial sewage — the effluent of industrial production containing various chemical substances. A variety of industrial productions defines многокомпонентное^ S.'s structure of century. Presence at S. of century of chemical connections inherent to this industry is characteristic of each industry. Contain thousands of chemical substances, to-rye there can be in S. a century. Among them there are mineral and organic compounds of various classes — salts, acids, alkalis, alcohols, aldehydes, ketones, chlorine - phosphorus - and metalloorganic compounds etc. The most widespread chemical substances coming to S. century are mineral fertilizers (see), pesticides (see), synthetic detergents (see), oil products (see. Oil ), etc. On action on an organism they can possess all-toxic, oncogenous, allergenic, mutagen, teratogenic, gonadotoksichesky, embriotoksichesky and other effects. In addition to chemical substances, century of nek-ry productions may contain S. biol. types of pollution, naira, yeast, proteins, antibiotics, enzymes, microorganisms.

Industrial S. century contain large amounts of chemical substances, differ from household drain waters in sizes of chemical oxygen consumption (HPK) and big size of a ratio of HPK from the military industrial complex showing degree biol. stability of the sum of the organic matters which are contained in drains. Presence at industrial S. of century of the substances, most harmful to a human body, napr, compounds of mercury (see), lead (see), arsenic (see), cyanides is especially dangerous (see. Cyanic connections ), oncogenous connections. Degree of harm of industrial S. of century is defined by the substances which are contained in them, their concentration, volume, way of removal, efficiency of their cleaning, character of a reservoir, in to-ry they arrive.

Industrial S. century, as well as other drains, exert the greatest impact on a dignity. condition of reservoirs. To their descent in reservoirs are shown a dignity. - a gigabyte. the requirements regulated «By rules of protection of surface waters from pollution by drain waters» (1974). Industrial S. the century which are especially strongly contaminated often undergo prerefining on local treatment facilities, and then, as a rule, are exposed to cleaning at city stations of aeration together with household S. century. As chemical substances in certain concentration can break processes biol. cleanings, damaging microorganisms of active silt, requirements for the level of contents in them chemical substances are imposed to cleaning of the industrial drains arriving on city treatment facilities, a row from to-rykh is listed in construction norms and rules. For strengthening of control of prokhmyshlenny S.' dumping of century into reservoirs development is necessary for each separate enterprise of tolerance level of contaminants in S. the century coming to reservoirs (so-called marginal dumpings — PDS), on the basis a gigabyte. requirements to S.'s descent of century in reservoirs and standards of quality of water.

One of features of control and sanitary inspection (see) behind industrial S.' descent century in reservoirs the systematic routine control over structure of drains and efficiency of their cleaning which is carried out by the central factory laboratories to-rye in cases of non-compliance with rules of protection of reservoirs is (see. Sanitary protection of reservoirs) shall inform water management bodies of the enterprise that they took necessary measures. Main objective dignity. bodies control of overall performance of treatment facilities, observance a gigabyte is. standards of quality of water of reservoirs in the closest points of water use.

Drains of page - x. productions, especially large livestock complexes, differ in the high content of organic matters, microflorae, in presence of eggs of helminths. Such S. are neutralized century by hl. obr. in the way biol. cleanings are also used for fertilizer of fields.

Household sewage — the effluent of household economic activity of the person which is formed as a result of use of water in residential, production and public buildings on vessels, in trains etc. for personal hygiene, cooking, washing of linen, washing of ware, floors etc. It defines features of structure and a dignity. - a gigabyte. household S.' characteristics of century, to-rye contain bigger amount of organic matters and salts, including metabolic products in a human body, the remains of food, soap, synthetic detergents and other products of household chemicals. Pollution microflora, in hl is characteristic of household S. century. obr. living in intestines of the person: colibacillus, other saprophytic bacteria; perhaps also pollution by causative agents of dysentery, typhoid, paratyphus, gastroenteritis, viral diseases, parasitic diseases (amoebic dysentery, nek-ry helminthoses), etc. Presence of pathogenic microorganisms at S. of century is connected with their allocation with excrements of patients or carriers of causative agents of diseases.

Household S. are characterized century by an intensive smell, a considerable turbidity and coloring, presence of a large amount of suspended matters and floating impurity, low transparency, availability of foam, high sizes BPK (see) and a coli-index (see. Coli-index, coli-index ). At receipt in reservoirs they exert adverse impact on physical. - chemical and organoleptic indicators of quality of water, worsening conditions economic and household, recreational and other types of water use. Therefore to household S.' descent century in reservoirs «Rules of protection of surface waters from pollution by drain waters» (1974) impose additional requirements. Quality of water in reservoirs, in to-rye is lowered by household S. century, in the next (especially in remote) from the place of descent points of water use shall satisfy to standards: content of suspended matters — no more than 0,25 — 0,75 mg/l (depending on category of water use); on a water surface there have to be no floating films, spots of oil and other.; a smell and smack — no more than 2 points; coloring of a column of water of 10 — 20 cm is not admissible; pH — within 6,5 — 8,5; the general mineralization on a solid residue — no more than 1000 mg/l; amount of the dissolved oxygen — not less than 4 mg/l; BPK poln — 3 — 6 mg/l; the maintenance of causative agents of diseases, toxic agents shall not exceed acceptance limits etc. For the purpose of observance of these requirements household S. century shall be exposed full biol. to cleaning and disinfecting.

Bibliography: Goncharuk E. I., etc. Hygienic bases of soil sewage treatment, M., 1976, bibliogr.; Sh at-to about in A. I., Mongayt And. JI. and Rod-zil of l of e r I. D. Methods of an echistka of production drain waters, M., 1977, bibliogr.; G. P marks. Health control of overall performance of treatment facilities of household drain waters, M., 1977; Marzeev A. N. and JK Abo-tinsky V. M. Utility hygiene, page 313, M., 1979; Methods of the analysis natural and drain waters, under the editorship of M. M. Xie-nkvina, M., 1977; Re-using of the purified drain waters, methods of cleaning and a problem of hygienic safety, WHO, It is gray. tekhn. dokl., No. 517, M., 1975, bibliogr.; R and z at m about in with to and y E. Page, M e d r and sh G. L. and Kazaryan V. A. Cleaning and disinfecting of drain waters of small settlements. M, 1978, bibliogr.; Sergeyev E. P. and M about and-e in E. A. Sanitary protection of reservoirs, M., 1979; Modern methods and constructions on purification of city sewage, under the editorship of E. S. Razumovsky, M., 1979, bibliogr.; T and at to and the p. L. and d river. Construction of sewer treatment facilities in rural areas, Kiev, 1976; Hummer M. D. Technology of processing natural and drain waters, the lane with English, M., 1979; Cherkinsk and y S. N. Sanitary conditions of descent of drain waters in reservoirs, M., 1977, bibliogr.

E. A. Mozhaev.