Abstract
Effluent copper concentrations from a pilot-scale conventional activated-sludge system (control) were compared with those from a conventional pilot treatment process that also integrated bioferric/selector units. The bioferric/selector units employed iron coagulation within the activated-sludge basin and also provided storage of activated sludge in a nonaerated selector for a period of 18-24 h. During pseudo-steady-state operation over a 30-day period, the systems employing the bioferric/selector treatment consistently yielded lower effluent copper concentrations than did the controls. Although influent copper concentration ranged from 126 to 723 ppb (228 ppb average), the two bioferric/selector units achieved an average effluent copper concentration of 22 ppb, whereas the two conventional controls achieved an average of 40 ppb. The difference in copper concentrations between the bioferric/selector units and the controls was statistically significant to the 99.5% confidence level when comparing effluent copper concentrations as a function of mixed-liquor volatile suspended solids (MLVSS). For both conditions, lower effluent copper corresponded to higher MLVSS, and for equal levels of MLVSS, the bioferric/selector units statistically achieved lower effluent copper concentrations than did the controls. Likewise, Freundlich isotherm plots indicated that the MLVSS (or MLSS) that had undergone the bioferric/selector treatment achieved statistically greater capture of copper than did their control counterparts.
Original language | English (US) |
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Pages (from-to) | 470-478 |
Number of pages | 9 |
Journal | Journal of Environmental Engineering |
Volume | 125 |
Issue number | 5 |
DOIs | |
State | Published - May 1 1999 |
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Civil and Structural Engineering
- Environmental Chemistry
- General Environmental Science