“…Under alkaline conditions, the iron coagulant easily hydrolyzes to Fe(OH) 3 , and the negatively charged [Fe(OH) 4 ] À reduces the role of electric neutralization, adsorption bridging and net trapping and sweeping. 57,58 The result is a decrease in the removal effect of PS. In general, it showed that the change in floc densities at different pH also applies to the change in PS removal rate.…”