Water is collected from a channel and transported to next treatment. Along this path, all the particles of type that have a grainy sedimentation rate greater than the rate of climb of current are held in tub. In practice, the sedimentation depends on surface of tub and not by its volume (survival water purification systems). In fact the same flow rate of upward flow (Qa), the greater the surface (S) of tub, the lower the speed of upward flow (Va = Qa / S), the greater the proportion of particles sedimenting.
These sources of supply, due to specific characteristics of waters and / or the degree of pollution, must be subjected to cycles of treatments of filtration necessary to modify the characteristics and improve its quality. Often, this happens even for the deep waters with a high content of organic substances and a high microbial contamination, especially if they are present faecal bacteria (eg. Coliforms).
The filtration is carried out by passing the waters (from rivers or lakes) through various types of implants removal of organic and inorganic material. The removal methods used can be physical, chemical-physical and biological function of type of substances to be eliminated from waters entering the plant.
However, the fact that the waters is by nature a solvent makes it somewhat problematic the effective elimination of many unwanted substances. The waters is entered into a tank head from which it originated the system of waters supply - drinking. The waters containing different types of organic substances and inorganic, hereinafter classified, that must be removed during the purifying treatment. Physical treatments simple: they are articulated in a single step, eliminating the suspended solids and sediments those not coarse sediments (screening and sedimentation) and non-settleable (sieving and filtration).
Physical and chemical treatments normal and driven: they are divided into several phases and eliminate non-settleable suspended solids (flocculation) and correct the chemical characteristics of waters by eliminating the dissolved substances that are incompatible with the use to which the waters is bound (softening, stabilization, removal of iron, manganese, desilication, fluoridation and defluoration, aeration).
Treatments: also divided into several phases, improve the organoleptic characteristics of waters (adsorption on activated carbon) and lower the content of dissolved solids (demineralization). The interventions of this type are provided, when necessary, upstream of treatment processes of filtration real, and allow the removal of materials and substances which by their nature and size are likely to damage the equipment and compromise the efficiency of subsequent treatment stages.
The filters are formed from cylindrical vessels made of reinforced concrete on the bottom of which special shelves, provided with an adequate number of holes, support the filtering mass. The filter bed consists of fine sand / fine or other material minute. The filter bed is supported by an underlying layer of material, also the filter, formed by a layer of coarse gravel and the overlying layers of gravel gradually finer (mattress draining).
The sedimentation is carried out in special tanks, called decanters, within which the waters moves in a laminar flow as possible for a time sufficient to allow the sedimentation of heavier particles. Decanters flow or vertical upward flow are generally circular section. Inse tanks the entrance of waters can be centrally from above; in this case waters, to be able to escape from the tank itself is forced along a tortuous path; in fact must first move vertically downwards in order to pass beneath a baffle concentric, said fireplace, subsequently, passed over the obstacle fireplace, must rise and exceed a weir located along the perimeter of tub.
These sources of supply, due to specific characteristics of waters and / or the degree of pollution, must be subjected to cycles of treatments of filtration necessary to modify the characteristics and improve its quality. Often, this happens even for the deep waters with a high content of organic substances and a high microbial contamination, especially if they are present faecal bacteria (eg. Coliforms).
The filtration is carried out by passing the waters (from rivers or lakes) through various types of implants removal of organic and inorganic material. The removal methods used can be physical, chemical-physical and biological function of type of substances to be eliminated from waters entering the plant.
However, the fact that the waters is by nature a solvent makes it somewhat problematic the effective elimination of many unwanted substances. The waters is entered into a tank head from which it originated the system of waters supply - drinking. The waters containing different types of organic substances and inorganic, hereinafter classified, that must be removed during the purifying treatment. Physical treatments simple: they are articulated in a single step, eliminating the suspended solids and sediments those not coarse sediments (screening and sedimentation) and non-settleable (sieving and filtration).
Physical and chemical treatments normal and driven: they are divided into several phases and eliminate non-settleable suspended solids (flocculation) and correct the chemical characteristics of waters by eliminating the dissolved substances that are incompatible with the use to which the waters is bound (softening, stabilization, removal of iron, manganese, desilication, fluoridation and defluoration, aeration).
Treatments: also divided into several phases, improve the organoleptic characteristics of waters (adsorption on activated carbon) and lower the content of dissolved solids (demineralization). The interventions of this type are provided, when necessary, upstream of treatment processes of filtration real, and allow the removal of materials and substances which by their nature and size are likely to damage the equipment and compromise the efficiency of subsequent treatment stages.
The filters are formed from cylindrical vessels made of reinforced concrete on the bottom of which special shelves, provided with an adequate number of holes, support the filtering mass. The filter bed consists of fine sand / fine or other material minute. The filter bed is supported by an underlying layer of material, also the filter, formed by a layer of coarse gravel and the overlying layers of gravel gradually finer (mattress draining).
The sedimentation is carried out in special tanks, called decanters, within which the waters moves in a laminar flow as possible for a time sufficient to allow the sedimentation of heavier particles. Decanters flow or vertical upward flow are generally circular section. Inse tanks the entrance of waters can be centrally from above; in this case waters, to be able to escape from the tank itself is forced along a tortuous path; in fact must first move vertically downwards in order to pass beneath a baffle concentric, said fireplace, subsequently, passed over the obstacle fireplace, must rise and exceed a weir located along the perimeter of tub.
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