海水淡化术语表（Glossary of desalination terms）.doc

海水淡化术语表（Glossary of desalination terms） Glossary of desalination terms Glossary Acre (AF): a unit of measurement of water volume. An acre foot is equal to 325851 gallons (an area of one acre, a depth of one foot of water) or 1233 cubic meters. One million gallons equals 3.07 acres - feet. . Bar: a unit of measurement of pressure. 1 bar = 14.5 psi = 0.99 ATM Biocide: a chemical substance (such as Sodium Bisulfite) used to kill living organisms. Brackish water: water containing less than 10000 ppm salt - more salt than fresh water but less salt than sea water. Concentrated brine: water containing more than 50000 ppm of salt. Concentrated brine discharged from the desalination unit also contains the chemicals added during the pretreatment process. BTU (British unit of heat): the standard unit of measurement of heat. Electricity, gas, or any other energy can be measured by BTU. A BTU is the amount of heat required to raise 1 pounds of water at sea level by 1 degrees fahrenheit. 1000 BTU equals 0.29 kwh. Condensation: a pretreatment process used in some desalination plants. Add a substance (such as ferric chloride) to a solution to condense the suspended particles and form larger particles that are easier to remove from the solution than the smaller particles. Cogeneration: cogeneration. A power plant aims to save energy by using residual heat in power generation for another purpose, such as thermal desalination, or heating of SWRO water. Degassing: removal of oxygen. A pretreatment process used to reduce corrosion and fouling in a desalination plant. Air flotation (DAF): a pretreatment process used in desalination plants to remove solids and organisms. Distillation: a desalination device for heating incoming water to produce steam. The steam is then condensed into a low concentration of finished water. Efficiency: energy transfer efficiency is expressed as the ratio of the sum of energy flowing out to the inflow in the PX device or device column, calculated using the fo