Overview Of Survival Water Purification Systems

By Stacey Burt


When the filtering layer begins to clog need cleaning it, which happens every 4 to 6 weeks. The cleaning is manual and involves removing the first layer of sand, sand washing in separate tubs and in reconstruction of filter bed. Quick filters are the most used, particularly in combination with other treatments such as clarification (surface waters) and the removal of iron and manganese (deep waters), and can deal with an input flow rate 40 times higher than that of lens filters (survival water purification systems).

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).

ants: the most used today are the polyelectrolytes. The agitation speed should be neither too low to prevent sedimentation of flakes, or too high to avoid breakage of flake. The slow agitation is achieved by use of mechanical mixers (dynamic system) or by placing a series of baffles in tank (static system).

Filter volume: the filtration takes place by means of a three-dimensional porous matrix said filter bed consisting of discrete materials of small dimensions (eg. Sand); in this case the particles are retained within filter medium. The effectiveness of a filter material depends on certain properties of particles such as size, shape and surface chemistry. The filters lenses are the first filtration system used in filtration, but they are currently little used. The slow filtration can be used in case of turbidity 10 ppm.

The 'sodium aluminate is very expensive and is also used in treatment of lime-soda softening species in case of high hardness and magnesium. In some waters, even with a strong dose of coagulant, are unable to develop a staple of suitable density. Inse cases, adjuvants are added to waters coagulation to promote the densification of micro-flakes.

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.




About the Author:



No comments:

Post a Comment