🗊Презентация Hygiene of water supply

Role in support of osmotic pressure Role in support of osmotic pressure and acid-base balance. Participation in heat exchange and thermoregulation. Transportation function – delivery of nutrients to cells with blood and lymph, removal of waste products from the organism with urine and sweat. As a component of dietary intake and a source of macro- and microelements supply to organism.

Water can participate in spread of infections in the following ways: Water can participate in spread of infections in the following ways: As transfer factor of pathogens with the fecal-oral transfer mechanism: enteric infections of bacterial and viral origin (typhoid, cholera, dysentery, salmonellosis). As a transfer factor of pathogens of the skin and mucous membrane diseases (when swimming or having another contact with water) trachoma, leprosy, anthrax. As the habitat of disease carriers – anopheles mosquitoes.

Simultaneous appearance of big number of enteric infected people. Simultaneous appearance of big number of enteric infected people. People who used the same water source. Morbidity level will stay high for the long period of time to the extent of water contamination and consumption. After the taking of antiepidemic measures the outburst fades away and morbidity goes down drastically.

Sanitary-hygienic and domestic functions of water include: Sanitary-hygienic and domestic functions of water include: Water usage for cooking and as a part of dietary intake. Usage of water as means of keeping body, clothes, utensil, residential and public premises and industrial areas, settlements clean. Watering of the green areas within settlements. Sanitary-transport and disinfection functions of water – disposal of residential and industrial waste through sewer system, waste processing on plants, self-purification of water reservoirs. Fire fighting, atmospheric pollution clearing (rain, snow).

Water supply sources are divided into ground and surface: 1. Middle waters with pressure (artesian) and without pressure. Middle waters are characterized by not very high, stable temperature (5-12°С), constant physical and chemical composition, steady level and considerable flow. 2. Underground waters that are located in aquifers above the first impermeable layer of soil and therefore.

Surface waters are divided into flowing (running) and stagnant waters.

The main source of pollution of surface water reservoirs are sewage waters that are created as the result of the water use in private life, industry, poultry and cattle factories. The main source of pollution of surface water reservoirs are sewage waters that are created as the result of the water use in private life, industry, poultry and cattle factories.

Technique of sanitary inspection of water-supply sources Sanitary inspection includes three main stages: Sanitary-topographic inspection of water source environment. Sanitary-technical inspection of condition of water source equipment. Sanitary-epidemiological inspection of area of water source location.

The purpose of sanitary - technical inspection is to give a hygienic assessment of condition of technical equipment of hydraulic works at water source.

During water sampling from open reservoir or a well the temperature of water is measured by a special thermometer (fig. 1).

There are centralized and decentralized water supply systems. There are centralized and decentralized water supply systems. Centralized system (water pipeline) includes: source of water, water intake facility, water-lifting facility, main facilities of water supply station, where water clearing, discolour, disinfection are executed, and sometimes there also takes place special water treatment (fluorination, defluorination, deferrization) to improve water quality. Most often decentralized (local) water supply is realised using shaft or tube wells, and more rarely using groundwater intake structures (catchments). Underground (subterranean) water, which accumulates in waterbearing aquifer over the first water-holding horizon, is used in wells. Such water laying depth amounts to some dozens of meters.

Water of I-class ground sources totally meets the concept of the good drinking water quality, it’s quality is totally compliant with those for drinking tap water according to SS 2874-82. Water of I-class ground sources totally meets the concept of the good drinking water quality, it’s quality is totally compliant with those for drinking tap water according to SS 2874-82. In this case water-supply diagram looks as follows:   where: 1 – ground source of water–supply (artesian or not-artesian middle waters) 2 – artesian well 3 – lifting pump І 4 – disinfection 5 – pure water reservoir 6 – lifting pump station ІІ 7 – water-supply network. Kutsak A.V. ZSMU

There are 3 basic groups of methods: There are 3 basic groups of methods: Methods of water cleaning - removal from mechanical impurity and improvement оrganoleptic parameters of water (turbidy, colouring). Methods disinfecting of water - microflora in water. Special methods improvement quality of water – distillation, dechlorination, fluorization, defluorization, deodorization, decontamination, deactivation water. Kutsak A.V. ZSMU

Methods water cleaning. Methods water cleaning. Water cleaning will be carried out by upholding and filtration water through filters (slow and fast filters). For acceleration cleaning used coagulation water - adding salts Al or Fe - are formed flakes with salts Са or magnesium in water. Now use flocculants – polyacrylamid.

Methods disinfecting of water and their hygienic estimation Methods disinfecting of water and their hygienic estimation There are 2 groups of methods of disinfecting: 1) Physical 2) Chemical Kutsak A.V. ZSMU

Chemical methods disinfecting of water: Ozonization - action of atomic oxygen - good bactericidal effect. The big power consumption. It is improved water organoleptics. Full destruction of toxic substances in water. Action ions of silver. «Sacred water» in churches. Ions of silver has bactericidal effect. Dearly method. Chlorination water - most wide used method in view of cheapness.

Chlorination water. Chlorination water. At entering chlorine in water there is a hydrolysis of chlorine and formation hydrochloric and chlorinewatic (HOCl) acids, dissociates to ions Н + and ions OCl- bactericidal effect. The scheme of chlorination: 90 % of chlorine contacts with various substances in water and inactivated (chlorine absorbing), there is residual or free chlorine - for sufficient bactericidal effect it should be 0,3-0,5 mg/l (below - there is no bactericidal effect, is higher - change a smell of water more than 2 points).

Organoleptic properties of water are divided into 2 subgroups: Organoleptic properties of water are divided into 2 subgroups: Physical and organoleptic – combination of organoleptic characteristics that are perceived by sense organs and are evaluated according to the strength of perception Chemical and organoleptic – content of particular chemical substances, which can irritate receptors of corresponding analyzers and cause one sense or another. Kutsak A.V. ZSMU

Give to water salty smack - in the big concentration - change taste of water more than 2 points. Give to water salty smack - in the big concentration - change taste of water more than 2 points. At increasing chlorides in water it is violations of water-electrolit exchange and function of kidneys. «The Salt hypertension» - in areas with salty water arterial hypertension meets in 4 times more often. At concentration chlorides more than 500 mg/l - oppression secretion and acidity of gastric juice. It is the indirect parameter of organic pollution water by household sewage - chlorides is a lot in urine. Kutsak A.V. ZSMU

Give to water bitter smack more than 2 points. Give to water bitter smack more than 2 points. At increase - oppression gastric secretion, break intestinal absorbtion, can be reflex dyarrea. Also it is indirect parameter organic pollution – many sulfates in faecal masses.

Criteria of safety according to chemical composition – are indices of maximum allowable concentrations of chemical substances (MAC), which may Criteria of safety according to chemical composition – are indices of maximum allowable concentrations of chemical substances (MAC), which may have negative impact on people health causing progress of different diseases.

Sanitary and microbiological crit eria of epidemic safety of water All over the world the following parameters microbe pollution of water are used: 1. Total number of microorganisms in water. 2. The contents intestinal stick (E.Coli) as constant inhabitant of sewage and relative steadier microbe, than others, to disinfecting water - shows efficiency of disinfecting water. Total microbes number (TNM) - up to 100 in 1 ml (amount microbe colonies at crop 1 ml of water at Petri’s cup at 37ºС in 24 hours). Coli - index - up to 3 in 1 l. Quantity intestinal sticks in 1 l waters. Coli - titr - not less than 300. Quantity water in ml in which 1 intestinal stick is found. Kutsak A.V. ZSMU

Epidemiological value of water Water factor plays the leading part in occurrence some infectious diseases

Straight indexes - deterioration bacteria parameters of water, presence pathogenic microbes Straight indexes - deterioration bacteria parameters of water, presence pathogenic microbes Indirect - deterioration organoleptic parameters, growth chlorides, sulfates, nitrogenous substances, oxidability water.

Attributes of water epidemic (epidemic with water-way transmission): Quick mass flash the same infectious diseases. Territorial connection flash of diseases with the certain water source. After realization antyepidemic measures in the center (prohibition using water source, disinfecting water) - sharp decrease amount of diseases, are registered only separate cases («epidemic tail»). The hot season - better conditions for duplication activators, besides the person consumes a lot of liquid - is reduced acidity of gastric juice - barrier to microbes.

Sanitary and chemical criteria of epidemic safety of water: Oxidability of water and biochemical consumption of oxygen (BCO). The important parameter of amount of organic substances in water - for their oxidation is required more О2. In norm oxidability of water - 2-4 mg О2/l. Dynamics oxidability for 5 or 20 day - BCO - criterion of oxygen mode of a reservoir - is studied at normalization pollutants in water of reservoirs. Dissolved oxygen — is quantity of oxygen that is available in 1 litre of water. Kutsak A.V. ZSMU

Nitrogen substances (ammonia, nitrites, nitrates). Nitrogen substances (ammonia, nitrites, nitrates). Ammonia and nitrites in water practically should not be, nitrates - up to 10 mg / l (in recalculation on nitrogen). As it is final parts disintegration proteins, on them it is possible to make prescription about organic pollution: if in water is only ammonia - fresh pollution, only nitrates - old, all nitrogenous substances - proceeding pollution. It is indirect parameter organic pollution of water. At the increased contents nitrates and nitrites (the reason: organic pollution of reservoir or going in it nitric fertilizers) it is possible special illness - water-nitrate methaemoglobynaemya (are especially dangerous to children of the first months of life).

Sanitary inspection of centralized water supply is subdivided into preventive one and regular. Sanitary inspection of centralized water supply is subdivided into preventive one and regular.