Influent wastewater enters the inside of the drum from one end and flows out through the filtering screen depositing solids on the inner surface of the screen. The screen is continually washed and the solids are collected and returned to the beginning of the treatment system. Pore size in a microstrainer is between 50 and 60 micrometers. The flow rate is maintained between 5 and 10 gallons per minute per, square foot of submerged screen. Extensive and frequent cleaning of mircostraining equipment is required to control these problems.
Ion exchange is the exchange of one type of electrically charged particle for a different type.
A solid material containing exchangeable ions is placed in a bed or column and the wastewater to be treated is then passed through it. Ion exchange systems are used to soften water, selectively remove specific impurities, and recover valuable chemicals lost in industrial waste discharges. Specific applications include the recovery of calcium and magnesium ions from solutions by exchanging them with sodium ions in beds of sodium zeolite, and the removal of ammonia by the use of a natural occurring zeolite material called clinoptilolite. Ion exchange beds have a limited capacity. Activated Carbon a.