| Title |
The Treatment of dyeing effluents by Al ( 3 ) and Fe-Al coagulants and their physico - chemical properties |
| Authors |
이상화(Sang Wha Lee),이기세(Ki Say Lee),곽종운(Jong Woon Kwak) |
| Abstract |
Fe-Al dual salts were prepared by blending poly aluminium silicate chloride, Hi-PAX, and polyferric sulfate, PFS. Both AI-based (Hi-PAX, Fe/Al=0) and Fe-Al based (Fe/Al=0.1) coagulants were used to investigate the removal efficiency of turbidity, SS, and COD from dyeing effluents. At 40℃, Fe-Al coagulant maintained high removal efficiency of turbidity and SS at pH7∼9, whereas Hi-PAX exhibited a maximum coagulation efficacy at pH6∼7 followed by a rapid decrease of coagulation efficacy over pH7. Therefore, Fe-Al coagulant is expected to be effective for the treatment of basic wastewater possibly due to enhanced sedimentation contributed by Fe(III) and improved coagulability contributed by Al(III). Fe-Al coagulant was also characterized by the analysis of zeta-potential, size distribution, and FTIR spectrum. Hi-PAX exhibited a distinct decrease of zeta-potential with rising pH, while Fe-Al exhibited a gradual decrease of zeta-potential with rising pH. From the size distribution of coagulating species, Fe-Al was confirmed to have average size groups of 20∼50 ㎚ and 80∼200 ㎚, respectively. FTIR spectrum indicated some possible interaction between AI and Fe components in the blended salts. |