Fouling of membranes for RO and ultra-filtration is a major cost. AFM® reduces fouling because it does not contain free silica to prevent silicate blockage. Sand filters are biofilters and constantly discharge bacteria into the product water to foul the membranes. AFM® resists biofouling and does not become a biofilter.
AFM® will remove many heavy metals from the water, and is particularly effective for arsenic and ferric. Contaminated water is usually ground water which must be strongly aerated for a period of at least 30 minutes prior to filtration. If arsenic needs to be removed additional ferric may be added to achieve a ratio of 10:1 (ferric:arsenic) to facilitate oxidation and co-precipitation.
Chromium is occasionally found in ground water in trace amount from 1 to 10 ug/l however the occurrence of chromium is usually associated with pollution from industries such a leather tanning, wood preservation and textiles. Polluted ground water may have much higher concentrations.