Equipment For Water Treatment Plants

Dual media filters or multi media filters comprise off sand and anthracite as filtering media and polishing media respectively. Internally it is fitted with inlet distributor and a bottom collecting system. Externally, it is fitted with frontal pipe work and isolation valves. Sand is used for removing the suspended particles and anthracite removes the odor and colour etc to make the water fit for various application. Pebbles and gravels are provided to support to both the media. This filter is to be backwashed after accumulation of suspended solids; however, before carrying out the backwash, air scouring is also to be done for loosening of dirt and suspended solids. Limit for the backwash in these filers is governed by differential pressure across the filter.

Where water has to be clarified through addition of flocculants and where design considerations demand, clariflocculators provide an optimum solution by giving high efficiency and economy of space and operation. In Akar clariflocculators, effluent mixed with flocculants is guided to the flocculation chamber. In the flocculation chamber rapid settling flocs are formed. The clariflocculator is designed as to cater to the capacity requirement both in terms of quantity of effluent as well as the flocs settling time consideration.

Chlorine dosing system is the simplest and most commonly used disinfection system worldwide. Chlorine is also the oldest disinfectant. Chlorine is simple to dose, easily available and very efficient as a disinfectant. There is a wide variety of chlorine dosing systems available. Normally diaphragm pumps are used to dose chlorine. In addition to them plunger and some other types of pumps are also used. Care needs to be taken to ensure that chlorine dosed water remains in static contact with chlorine for some time. Chlorine contact tanks are also therefore desired in some cases. Chlorine is available in two types viz. liquid chlorine (called Hypo-Chlorite) and Gaseous chlorine. Method of dosing each is different.

Ozone plays an important role in nature's life cycle. It is formed in the upper atmosphere through high-energy radiation of sunlight, breaking up the oxygen molecules. Ozone is applied to oxidize water to disinfect the same from Bacteria and other harmful genes in water and wastewater and is widely used in water and wastewater treatment, which results in a variety of effective applications. One of the most important characteristics of ozone is its beneficial impact on the environment. In all applications to date, there have been no damaging effects to systems or the environment, nor have any toxic by-products been formed. On the other hand chlorination and some other disinfection processes involve handling of hazardous chemicals and costly materials. Ozonation is very economical, since it is produced on site, and only in the amount needed; therefore, hazardous transportation and storage are not required. Hence, ozone technology has proven itself to be the preferred technological method of water treatment for the future of our environment.

Of all available systems of water purification in the world today, ultra violet disinfection systems are considered to be quite comprehensive, effective, reliable and safe. Chlorination and other chemical disinfection techniques once assumed to be safe and harmless are more cumbersome and involve handling problems. Ultraviolet light system, whose effectiveness has recently been improved with the development of more intense Ultraviolet Lamps. Ultraviolet rays are part of the light that comes from the sun. UV is known to be an effective disinfectant due to its strong germicidal (inactivating) ability. UV has been used commercially for many years in the pharmaceutical, cosmetic, beverage and electronic industries. UV radiation has disinfection properties that inactivate bacteria, viruses, spores, cysts etc. UV is effective only if the light intensity reaches the organism in question, therefore nothing should be present in the water that shields the organism from radiation.