Different patterns of phosphorus release from lake sediments in laboratory experiments

Abstract

The phosphorus release from surface sediments of eight lakes, mainly shallow lakes in agricultural areas, was studied in laboratory batch experiments with additions of acetate and/ or nitrate. The lake sediments could be separated into three categories. Some sediments did not release phosphorus under any conditions. The second category showed a high phosphorus release rate when acetate was added, in order to stimulate bacterial activity and oxygen consumption. The addition of nitrate, only, stabilized the redox conditions and prevented phosphorus release. This pattern followed the classical theories of Einsele and Mortimer. The third sediment category released phosphorus up to some level which remained constant throughout the experiment, and was independent of acetate and/ or nitrate additions.Several extraction procedures and adsorption-desorption experiments were performed in order to characterize the sediment phosphorus and thus explain the different behaviours of the three sediment categories.

Organic phosphorus in marine sediments : chemical structure, diagenetic alteration, and mechanisms of preservation

“…It has long been recognized that when waters overlying the sediments are oxic, phosphorus is bound in the sediments, and that P is released under reducing conditions. There is disagreement, however, as to whether the mechanism for this P release is physicochemical (Mortimer, 1941;Bostrom & Pettersson, 1982;Doremus & Clesceri, 1982) or due to bacterial activity (Gachter et al, 1988;Hupfer & Uhlmann, 1991;Gachter & Meyer, 1993). In oxic sediments, P can be sorbed to the surfaces of ferric iron minerals.…”

A Simplified Assessment of Factors Controlling Phosphorus Loading from Oxygenated Sediments in a Very Shallow Eutrophic Lake

“…It also increases organic matter mineralization and liberates inorganic phosphates (Boström & Pettersson 1982), although sediment bacteria do not necessarily release P when they mineralize settled organic matter (Gächter & Meyer 1993).…”

“…In release experiments, simulated oxic and anoxic conditions were created with CP5 sediment using methods described by Boström & Pettersson (1982) through the addition of nitrate (5 mg N l -1 ) and acetate (10 mg C l -1 ), respectively. Nitrate produces a redox potential slightly less than that of O 2 and prevents release of phosphorus, while acetate stimulates microbial activity, increasing oxygen consumption and thus lowering the redox potential to a point where iron-phosphate complexes dissolve.…”

Effects of Sediments on the Growth of Algae at Chusori Area in Daechung Reservoir

“…수체로의 영양염류의 증가 는 외부부하(external loading) 또는 내부부하(internal loading) 에 의해 일어난다 (Ahn et al, 2013;Kim, 2002) (Kim, 2002). 퇴적물 로부터 영양염류의 용출은 수온, pH, 용존산소, 유속 등과 같은 물리화학적 환경요인과 저서 미생물 등의 생물학적 요 인에 의해 영향을 받는다 (Bostrὅm and Pettersson, 1982).…”