Flood effects on phosphorus immobilisation in a river water filled pit lake—Case study Lake Goitsche (Germany)

Abstract

a b s t r a c tBetween 1999 and 2002, a former open-cast mine was filled with river water forming the recent Lake Goitsche. During filling initially acid water was neutralised. Phosphorus (P) imported from Mulde River was nearly completely removed from the water column by co-precipitation with iron (Fe) and aluminium (Al) and deposited in the sediment.During extremely high waters of the Mulde River in 2002, a dike breach facilitated a second high import of P into Lake Goitsche with suspended and dissolved matter. The analysis of total phosphorus (TP), however, showed that P again had been eliminated from the water body a few months after the flood event. Sediment investigations before filling with river water, during filling, and after the flood event were used to analyse the process of P immobilisation in a lake with acid mine drainage history.The ratios of Fe to soluble reactive P (SRP) of sediment pore water were up to three orders of magnitudes higher than in natural lakes and can serve as an indicator for potential internal P loading from sediments. The SRP concentrations at the oxic/anoxic boundary were near or below the limit of quantification (o 0.2 mmol/L). Fe and manganese (Mn) redox cycling were responsible for hindering P dissolution from sediment to lake water.Finally it can be stated, that the risk of eutrophication for such a lake seems to be low.

Water and (bio)chemical cycling in gravel pit lakes: A review and outlook

“…The inflow and accumulation of nutrients into the gravel pit lakes may cause eutrophication with nuisance algal blooms (Section 5) and interferes with metal cycling, see Section 4.4. Organic matter in sediment strongly affects PO 4 adsorption as observed in pit lakes in a former lignite mine (Herzsprung et al, 2010), with the light fraction or ganic matter (LFOM) playing a key role in nutrient cycling. The chemis try and kinetics may change over time: if LFOM is removed, PO 4 adsorption decreases (Wang and Mulligan, 2006).…”

Metal accumulation in an artificially recharged gravel pit lake used for drinking water supply

“…High organic content contributes to metal immobilization on the lake bottom but also provides the base for microbial reduction of iron and manganese and the redox cycling of these metals, trace elements and P between the lake bottom water and sediment (e.g. Herzsprung et al, 2010;Stumm, 2004). The production of organic material in fresh water lakes is high in comparison to coastal environments (Meckler et al, 2004).…”

“…The lakes will also affect the hydrogeochemistry of the surrounding groundwater bodies. This may be beneficial as, for example, in the case where phosphates are retained and nitrates are broken down when contaminated groundwater flows through gravel pit lakes (Herzsprung et al, 2010;Muellegger et al, 2013). Gravel pit lakes may also have a negative influence, for example, by allowing the mobilization of soil-bound compounds like arsenic (Marques et al, 2008(Marques et al, , 2012Mollema et al, in prep;Wallis et al, 2010;Weiske et al, 2013) or the growth of poisonous algae in response to accumulation of nutrients such as P and N and availability of light (Downing et al, 2001;Smith, 2011).…”

Quantifying Lake Water Quality Evolution: Coupled Geochemistry, Hydrodynamics, and Aquatic Ecology in an Acidic Pit Lake

“…126 Future simulations with a sediment diagenesis module 79 activated could be used to investigate the postbreach sediment-water coupling in the lake, and other pit lakes where river inflow and throughflow has occurred. 97,127,128 Environmental Modeling Implications. The numerical modeling approach presented here constitutes an important tool for formulation and desktop testing of alternative scientific hypotheses.…”