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Sedimentary deposition and reflux of phosphorus (P) in the Eastern Gotland Basin and their coupling with P concentrations in the water column

Hille S., Nausch G., Leipe T.

Oceanologia

2005

No. 47 (4)

663-679

In order to describe the role of sedimentary processes for the phosphorus (P) cycle in the open Baltic Proper, P deposition and reflux were quantified for the predominately anoxic sediments of the Eastern Gotland Basin. The study is based on investigations of 53 surface sediment samples and pore water samples from 8 sediment cores. The average P deposition rate was estimated at 0.20 g š 0.18 g -2 yr-1, the fluctuation being due to variable bulk sediment deposition rates. P refluxes were estimated by applying Fick's First Law of Diffusion. A fairly good positive correlation between sedimentary P deposition and P release was obtained. P release from sediments by diffusion exceeds net P deposition by a factor of 2. This suggests that 2/3 of the deposited gross P is recycled in the sediments and released back into the water column; only 1/3 remains in the sediment permanently. A budget calculation demonstrates that the released dissolved inorganic phosphorus (DIP) accounts for the observed increase in DIP concentrations in the deep water during periods of stagnation, which is noticeable even at the surface P concentrations. Under such conditions and with the present remediation conditions it is not possible to freely manage P concentrations in the water column on short time scales.

Oczyszczanie ścieków ze składowisk odpadów - przegląd stosowanych metod

Surmacz-Górska J.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Śląska

2003

z. 48

369-382

W pracy przedstawiono podstawowe pojęcia z zakresu ekotoksykologii. Omówiono znaczenie wskaźników określanych podczas badań toksykologicznych jak LCso, EC50, NOEC itp. Przedstawiono także ogólny algorytm procedury szacowania zagrożenia środowiskowego oraz metody określania stężenia nie wywołującego szkodliwych efektów w środowisku (PNEC). Wśród prezentowanych metod na szczególną uwagę zasługuje metoda Aldenberga i SI oba ze względu na najniższe prawdopodobieństwo przeszacowania wartości PNEC.

Ecotoxicology is a relatively young science, and has a truly applied and interdisciplinary character. Its origin can be considered unique as compared to classical natural sciences. The motivation to undertake ecotoxicological research was based on the recognition that anthropogenic chemicals may affect nontarget organisms, populations and communities in unexpected, extended and in particular hazardous ways. As a result ecotoxicology has been developed. In the paper basic vocabulary within the domain of ecotoxicology was presented. It contains also accounts of current test strategies, test organisms as well as perspectives for an environmental risk assessment. It reviews also current methods to characterize and predict adverse effect on organisms.