ENKI WATER TREATMENT TECH. LTD

Media filter is used to reduce the level of suspended solids (turbidity) in feed water. Suspended solids consist of small particles such as silt, clay, grit, organic matter, algae and other microorganisms. Feed water that is high in suspended solids can cause a high pressure drop and reduce the effectiveness of downstream equipment such as reverse osmosis membranes and ion exchange beds.

When is used an activated carbon filter? Activated carbon filters are very similar to multi media filters and other pressure filters in construction and operation. The purpose of an activated carbon filter is to remove free chlorine, an oxidizing agent that will damage most resins and/or membranes in a water treatment system. A chemical injection system using sodium bisulfite (a reducing agent) can be used in place of an activated carbon filter to remove chlorine. Granular activated carbon is a particularly good adsorbent medium due to its high surface area to volume ratio. One gram of a typical commercial activated carbon will have a surface area equivalent to 850-1.000 square meters. This high surface area permits the accumulation of a large number of contaminant molecules. Some drinking water may be disinfected with chlorine or chloramines.

Reverse osmosis is the finest level of filtration available. The reverse osmosis membrane acts as a barrier to all dissolved salts and inorganic molecules, as well as organic molecules with a molecular weight greater than approximately 100. Water molecules, on the other hand, pass freely through the membrane creating a purified product stream. Rejection of dissolved salts is typically 95% to greater than 99%. Classification of brackish water: • Low salinity brackish waters: up to 5.000 ppm • High salinity brackish waters: between 5.000 - 15.000 ppm • Sea water: up to 45.000 ppm Reverse osmosis is a technology that is used in the production of ultrapure water for use in the semiconductor industry, power industry (boiler feed water), and medical/laboratory applications. Utilizing reverse osmosis prior to ion exchanger dramatically reduces operating costs and regeneration frequency of the Ionen exchanger plant.

A "CO2 degasser" (degassifier) is a relatively simple water treatment device. Incoming water is sprayed into a tower filled with packing material. The drops of water that flow down through the tower strike the packing material and form a thin film on the packing material surface, encouraging the release of excess carbon dioxide. A centrifugal fan creates an updraft of air through the tower to carry away the released carbon dioxide gas. The carbon dioxide gas exits through a vent at the top of the unit.