The product water after desalination characteristically has very low mineral content, hardness, alkalinity, and pH. The water has an unpleasant taste so it must be conditioned prior to final supply and use. The main purposes of remineralization are
a. Provide protection to the distribution system to prevent corrosion
b. Add minerals that are essential to human dietary needs.
c. To facilitate the secondary use of the desalinated water, for example, irrigation.
Dosages of 60 to 120 mg/L as CaCO3 of calcium containing chemicals like lime, calcite, calcium, hypochlorite, or calcium and magnesium containing chemicals like dolomite are added to the desalinated water. this is important for the water distribution …show more content…
During treatment of water using RO system, there could be the occurrence of scale deposition and corrosion. These could cause pollution of the treated water, increase in energy consumption during transportation of water, and the life span if the pipes could reduce (W. Fang, 2004). Water that has problems with corrosion has a relation to pH, alkalinity, hardness, temperature, TDS,CO2. Other physical, chemical and biological factors could be related to corrosive water. when water has high level of NaCl, there will be increase in the conductivity of the water causing corrosion which could be accelerated by high flow rates (Salvato;J.A, etal, 2003). Depending on the chemistry of the water been treated in the RO system, the water could promote scaling or corrosion or both. One of gthe most critical issues associated with desalination processes especially RO systems is …show more content…
It approximates the base 10 logarithm of the level of calcite saturation. The Langeleir saturation examines the saturation concept using pH as the main determinant. The LSI obtained can be explained as the pH required to bring the water to equilibrium. Water that indicates LSI of 1.0 is one pH unit above saturation. Also, a reduction of pH by one unit will bring the water to equilibrium. This occurs as a result of the portion of total alkalinity present as CO32- increases as pH as increases according to the equilibrium describing carbonic acid dissociation. LSI is an equation that shows the effects of pH, calcium, total alkalinity, dissolved solids, and temperature, as it relates to the solubility of CaCO3 of water especially between the pH ranges of 6.5-