Hard water is water that has high mineral content (in contrast with “soft water”). Hard water is formed when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates.
The water softener system is used to remove calcium, magnesium, and certain other metal cations in hard water. The resulting soft water is more compatible with soap and extends the lifetime of plumbing. Water softening is usually achieved using lime softening or ion-exchange resins.
A groundwater is to be partially softened from 275 mg/L down to 150 mg/L of CaCO? hardness. IX has been selected instead of lime softening because of its simplicity and the ease of cycling on and off to meet the water demand.the well pumping capacity is 3.8x10m3/d,and the system must be sized to meet this maximum flow rate.the source water contains only traces of iron;therefore,potential clogging problems because of suspended solids are not significant.In applications where raw water suspended solids would foul the resins,coagulation filtration or filtration pretreatment with dual-or multimedia filters would be required.