Abstract
The removal of dissolved manganese ions from groundwater by ultrafiltration (UF) membranes was investigated through the addition of chelating poly(acrylic acid) (PAA) polymers of different molecular weight (MW) at various values of pH. An improved degree of removal of manganese was achieved upon the addition of PAA into feedwater during UF. The manganese rejection efficiency depended on the dosage of PAA, but not on the MW of PAA, indicating that the interactions of manganese with the carboxyl groups in PAA was independent of the length of the polymer chain. Sulfate ions present in the feedwater resulted in lower manganese rejection efficiencies as a result of Donnan exclusion, while hardness competed with manganese significantly in the chelation reactions with PAA. An equilibrium model developed in this study made it possible to predict the manganese rejection efficiency at different PAA dosages and values of pH. The UF flux did not always decrease with higher PAA dosages, possibly because of coagulation and restabilization of PAA in the presence of divalent metals (e.g., manganese and hardness).
| Original language | English |
|---|---|
| Pages (from-to) | 163-169 |
| Number of pages | 7 |
| Journal | Journal of Industrial and Engineering Chemistry |
| Volume | 13 |
| Issue number | 2 |
| State | Published - Mar 2007 |
Keywords
- Chelation
- Manganese removal
- Polyfacrylic acid
- Ultrafiltration