摘要：Manganese is considered as an undesirable ion and it should be removed from water. Dendrimers have various applications in pharmaceutical and medicine, water treatment and industrial wastewaters. The aim of this study was to evaluate the impact of G4 poly-amidoamine dendrimer (G4-PAD) as a coagulant aid on the performances of poly-aluminum chloride (PAC) coagulant in manganese (Mn) removal from aqueous solutions. The effect of various factors on Mn removal (monitored by ICP) via coagulation-flocculation process were studied by response-surface methodology (RSM). Initial Mn concentration (in the range 0.5 to 6.5 mg/L), PAC concentration (0 to 20 mg/L), pH (2 to 12) and G4-PAD concentration (0.02 to 0.26 mg/L) were studied as effective factors on process efficiency. Design Expert 7.0.0 software and central composite design method were utilized for experimental design. Optimum amounts of Mn, pH, PAC concentration and G4-PAD concentration were 3.5, 9.5, 10 and 0.14 mg/L, respectively. Mn removal efficiency under optimal conditions after coagula-tion-^occulation process was 82.1%. It also showed that the use of G4-PAD concentration and PAC in coagulation-flocculation process for decreasing the Mn content from aqueous solutions were effective. Compared to conventional methods in pollutants removal, the use of G4-PAD as a coagulant illustrated therefore to be efficient; its relevance should be subsequently confirmed in terms of economic considerations.
