Phosphorus balance of Lake Tiefwarensee during and after restoration by hypolimnetic treatment with aluminum and calcium salts

Variations in the aluminum:phosphorus binding ratio and alum dosage considerations for Half Moon Lake, Wisconsin

“…The area-based dosage I considered for Half Moon Lake was high relative to dosages reported in Rydin and Welch (1999), but not unprecedented: Lake Süsser See (Germany) received incremental applications between 1977 and 1992 that totaled 100 g Al/m 2 (Lewandowski et al 2003); Lake Tiefwarensee (Germany) received a dosage of 137 g Al/m 2 (Wauer et al 2009); and Green Lake, Washington, was treated at a dosage of 94 g Al/m 2 (Dugopolski et al 2008). The targeted Al:P ratio generally ranged between 2:1 and >10:1, and all treatments were successful in reducing P in the water column and sediment.…”

Dilemma of Non‐Steady State in Lakes – Development and Predictability of In‐Lake P Concentration in Dimictic Lake Scharmützelsee (Germany) after Abrupt Load Reduction

“…As indirect evidence, we suggest that non-equilibrium phases are identifiable by deviations between measured P lake and R and predictions from empirical models (WAUER et al, 2009). Thus, for Lake Scharmützelsee the switch from modeled under-to overestimation of retention 1987/88 marks the transition between high or increasing loading and the transient phase with decreasing loading (Fig.…”

“…The assumption of a consistent relation between the net sedimentation coefficient (sigma) and P lake may not be valid under non-steady state conditions so that the application of simple one-box models (SAS, 1989;IMBODEN and GÄCHTER, 1978), often used for restoration scenarios (e.g., COOKE et al, 2005;WAUER et al, 2009), is complicated. Lake Scharmützelsee was studied as an example for a lake in non-equilibrium after a long-lasting high loading phase from the 1950s to the 1980s and termination of point sources after German reunification.…”

“…As a consequence, common empirical models (e.g., VOLLENWEIDER, 1976;OECD, 1982;NÜRNBERG, 1984) underestimate the annual mean in-lake phosphorus concentration (NÜRN- BERG, 2009) under non-steady state conditions with varying import, export and potentially high internal load. The assumption of a consistent relation between the net sedimentation coefficient (sigma) and P lake may not be valid under non-steady state conditions so that the application of simple one-box models (SAS, 1989;IMBODEN and GÄCHTER, 1978), often used for restoration scenarios (e.g., COOKE et al, 2005;WAUER et al, 2009), is complicated.…”

Longevity and effectiveness of aluminum addition to reduce sediment phosphorus release and restore lake water quality

“…The monitoring of selected lakes was carried out according to European Water Framework Directive guidelines. Details about Lake Tiefwarensee are presented in Mehner (Mehner et al, 2008;Wauer et al, 2009). …”