Table 1.
Summary of estimated 50% and 70% removal times
| System a | Sample fraction | 50% Removal time (d) b | 70% Removal time (d) b |
|---|---|---|---|
| Cazenovia Lake | Total | ||
| July 1977 addition | 9.6 | 70% removal not observed in 23 d | |
| August 1977 addition | 2.0 | 14.1 | |
| September 1977 addition | 50% removal not observed in 22 d | 70% removal not observed in 22 d | |
| Lake Mathews | Total | 15.6 (9.2–52.3) | 27.2 (16.0–90.8) |
| Lake Courtille | Dissolved | 9.0 (6.5–14.7) | 15.6 (11.2–25.6) |
| St. Germain les Belles Reservoir | Dissolved | 4.1 (2.2–28.3) | 7.1 (3.8–49.1) |
| Catfish pond | Dissolved | 0.11 | 0.88 |
| Total | 0.48 (0.38–0.66) | 0.84 (0.66–1.1) | |
| IME microcosms c | Dissolved | ||
| 5 µg/L | 2.3 (1.2–15.5) | 4.0 (2.2–26.9) | |
| 10 µg/L | 1.8 (1.1–6.1) | 3.1 (1.8–10.6) | |
| 20 µg/L | 3.6 (1.3–na) d | 6.3 (2.3–na) | |
| 40 µg/L | 3.3 (2.0–8.8) | 5.7 (3.5–15.3) | |
| 80 µg/L | 3.7 (1.6–na) | 6.3 (2.7–na) | |
| 160 µg/L | 1.4 (0.90–3.0) | 2.4 (1.6–5.2) | |
| Novosibirskoye Reservoir mesocosms e | Dissolved | ||
| Dark, 1st addition | 7.5 (7.1–7.8) | 13.0 (12.4–13.6) | |
| Dark, 2nd addition | 7.3 (6.8–7.8) | 12.7 (11.9–13.6) | |
| Light, 1st addition | 5.0 (4.6–5.3) | 8.6 (8.0–9.3) | |
| Light, 2nd addition | 4.5 (4.0–5.2) | 7.8 (6.9–8.9) | |
| Dark, 1st addition | Total | 8.7 (8.6–8.9) | 15.1 (14.9–15.4) |
| Dark, 2nd addition | 8.3 (8.0–8.8) | 14.5 (13.8–15.2) | |
| Light, 1st addition | 5.8 (5.6–5.9) | 10.0 (9.8–10.2) | |
| Light, 2nd addition | 6.2 (6.0–6.5) | 10.8 (10.4–11.3) | |
| MELIMEX mesocosms | Dissolved | 76.2 | 130 |
| TICKET‐UWM (empirical K D) | Dissolved | 2.7 | 4.7 |
| TICKET‐UWM (calculated K D) | Dissolved | 1.6 | 2.7 |
Sources: Lake Courtille and St. Germain les Belles Reservoir: van Hullebusch et al. (2002, 2003a, 2003b); IME Mmcrocosms: Schäfers (2001); Novosibirskoye Reservoir: Smolyakov et al. (2010a, 2010b); Lake Matthews: Haughey et al. (2000); catfish ponds: Liu et al. (2006); Cazenovia Lake: Effler et al. (1980); MELIMEX: Di Toro et al. (2001b); Gächter (1979); TICKET‐UWM: present study.
Numbers in parentheses denote the 95% confidence interval of 50 or 70% removal times. This interval was developed from the 95% confidence interval of the first‐order loss rate constant fit to the copper concentration data for each study. For the catfish pond dissolved copper data and Cazenovia Lake total copper data, application of a first‐order model was not supported. Removal time values were interpolated from plots of fraction remaining versus time. Removal times for MELIMEX were calculated from the first‐order loss rate constant of 0.0091 day‒1 determined by Di Toro et al. (2001b). No information was provided on the uncertainty associated with this rate constant.
Removal times were determined for each nominal copper dosing concentration in the IME microcosms.
Upper 95% confidence limit of the first‐order rate constant was positive, indicating an increase in copper. An increase in dissolved copper concentration between consecutive samples occurred in the 20‐ and 40‐µg/L test systems but for only 1 of the 2 duplicates.
Removal times were determined for each treatment (light, dark) and copper addition (first and second) separately in the Novosibirskoye Reservoir study.
IME = Fraunhofer Institute for Molecular Biology and Applied Ecology (Schmallenberg, Germany); MELIMEX = MEtal LIMnological Experiment; TICKET–UWM = tableau input coupled kinetic equilibrium transport–unit world model; na = not available.