Power Plant Industries
Water is the lifeblood of a power
plant. Needed in vast quantities to produce steam and for cooling purposes, U.S.
thermoelectric power producers use more than 70 trillion gallons of water per
year. To effectively use water within a plant, it must be treated to meet each
individual site's needs, which vary with the influent source water quality; type
of boiler, discharge requirements and whether or not "used" water is recycled
within the plant.
Technologies used in Power plants are:
1. Cooling Tower
DM Plant is an Ion exchange technology used to remove salts (cations and anions) from water. Soluble chemical compounds, when dissolved in water, become ionized; that is their molecules dissociate into positively and negatively charged components called ions. Consider common table salt, sodium chloride. In its solid form, this compound consists of one sodium atom (Na) and one chlorine atom (Cl) tightly coupled together (NaCl). When dissolved in water, however, the compound splits into two ions Na+ and Cl- A Typical two-bed DM Plant consists of two FRP vessels connected in series along with its internal fittings. The first unit consists of high capacity strongly acidic cation exchange resin, which converts positive ions of salt and replaces them with hydrogen ions to form respective acids, which are absorbed in next vessel by strongly basic anion exchange resin. The water obtained by this process shows conductivity less than 30 µS/cm and Total Dissolved Solids less than 10 ppm.Further high purity water can be achieved by Mixed Bed Deionizers, which are designed to produce high purity treated water. They can be used as polishing units after two beds DM Plant to obtain high purity water.
A Conventional Method
• Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled and floating materials are removed and the remaining liquid may be discharged or subjected to secondary treatment.
• Secondary treatment removes dissolved and suspended biological matter. Secondary treatment is typically performed by indigenous, water-borne micro-organisms in a managed habitat. Secondary treatment may require a separation process to remove the micro-organisms from the treated water prior to discharge or tertiary treatment.
• Tertiary treatment is sometimes defined as anything more than primary and secondary treatment. Treated water is sometimes disinfected chemically or physically (for example, by lagoons and microfiltration) prior to discharge into a stream, river, bay, lagoon or wetland, or it can be used for the irrigation of a golf course, green way or park. If it is sufficiently clean, it can also be used for groundwater recharge or agricultural purposes.
B Ozonation Method
A sewage transfer pump will transfer the raw effluent into a manual self cleaning filter, and then pressure sand filter & then onward to an ozonator. Ozone will be injected into the raw sewage and mixed in to a contact chamber / holding tank. The ozone will oxidize the organics present in the sewage, thereby reducing the BOD / COD levels of the sewage to acceptable limits.
4. River water treatment –
Water purification is a process of removing undesirable chemicals, materials, and biological contaminants from raw water. The goal is to produce water fit for a specific purpose. Water purification may also be designed for a variety of other purposes, including meeting the requirements of medical, pharmacology, chemical and industrial applications. In general the methods used include