“…Various approaches have been presented in the literature which have taken up this challenge: diatomaceous earth (DE) modified with polyelectrolytes, 5-7 DE modified with salts/hydroxides of aluminum, iron, magnesium and calcium, 5,6,8 fiberglass and cellulose modified with salts of Al, Fe, Mg and Ca, 9 fiberglass and cellulose modified with alumina-coated colloidal silica, 10 sand modified with Fe-and Al-hydroxide, 11 and granular anthracite and granular activated carbon coated with nanoporous Al 2 O 3 . 12 These and other studies of electropositive filter media 13,14 generally show that the strongest contribution to the adsorption process is made by electrostatic forces, i.e.…”