Reverse osmosis systems are composed of a semi-permeable, thin porous membrane. The reverse osmosis membrane is composed of extremely fine pores along its surfaces and the size of these pores is the primary factor that determines what substances will be filtered. If water has to be forced through this membrane, it's smaller in molecular size. goes through the membrane and other pollutants that are larger in size are filtered out and thus separated in the absence of water. Please visit https://www.huamofilter.com/ for more detail.