Removal of Arsenic from Aqueous Solution by Adsorbing Colloid Flotation
| Autor: | Felicia F. Peng, Pingkuan Di |
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| Rok vydání: | 1994 |
| Předmět: | |
| Zdroj: | Industrial & Engineering Chemistry Research. 33:922-928 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie00028a020 |
| Popis: | Adsorbing colloid flotation (ACF) with ferric hydroxide as the coprecipitant, anionic surfactant sodium dodecyl sulfate (SDS) as the collector, and nitrogen microbubbles has been shown to be effective in removing arsenic from low concentration of arsenic aqueous solution ([approximately]10 mg/dm[sup 3]). Experiments were conducted to assess the effects of pH, dosages of SDS and Fe(III), gas flow rate, foreign anions including NO[sub 3][sup [minus]], SO[sub 4][sup 2[minus]], and PO[sub 4][sup 3[minus]], and Al(III) addition on the efficiency of the arsenic removal by ACF. When pH is at the range of 4--5, 99.5% arsenic removal efficiency can be achieved. The optimal operating conditions are 35 ppm SDS, 80 ppm Fe(III), 40 cm[sup 3]/min gas flow rate, 500 rpm rotary speed of stirrer, and 5 min ferric hydroxide floc formation time. The analysis results indicate that foreign anions SO[sub 4][sup 2[minus]] and PO[sub 4][sup 3[minus]] have an inhibiting effect on the removal of arsenic, while AI(III) additions can compensate for the effect. An actual mine wastewater sample containing 10.4 ppm arsenic(V), 0.76 ppm chromium(VI), and 0.55 ppm lead was tested by adsorbing colloid flotation at the optimal operation conditions. The residual arsenic, chromium, and lead are 0.07, 0.06, and 0.04 ppm, respectively.more » The interaction mechanisms between Fe(OH)[sub 3]-bearing arsenic floc and SDS were analyzed and interpreted by means of [zeta]-potential, infrared spectra analysis, and molecular orbital theory. The adsorption of SDS can occur physically and chemically on Fe(OH)[sub 3] at the pH range of 4--5.« less |
| Databáze: | OpenAIRE |
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