Stanislaw Baran

Spatial distribution and risk assessment of heavy metals in bottom sediments of two small dam reservoirs (south-east Poland)

Abstract Sediments of two dam reservoirs in SE Poland, Zalew Zemborzycki (ZZ) and Brody Iłżeckie (BI) were studied. The sediments from both reservoirs were sampled in the transects perpendicular to the shoreline, at the river inflow and the frontal dam. The total concentration of Mn, Zn, Pb, Cd, Cu, Cr and Ni was determined by ICP-EAS method after the sample digestion in the mixture of concentrated HNO3 and HClO4 acids. The statistical analyses: value intervals, mean values, variation coefficient, the median and the skewed distribution were performed. To estimate differences between the means for transects, Tukey’s test was applied with least significant difference (LSD) determination. The maps of the metal spatial distribution were drawn and sediment quality according to the geochemical and ecotoxicological criteria evaluated. Differences between the reservoirs in terms of heavy metals concentration in bottom sediments, and regularities in their spatial distribution were found. In the ZZ sediments the concentration was at the level of geochemical background (Zn, Cr), slightly (Cd, Cu, Ni) or moderately (Pb) contaminated sediments. The metal concentration in the sediments of the BI was up to eight times higher as compared to the ZZ. Moreover, sediments from the BI reservoir showed a greater variability of metal concentration than those from ZZ, which resulted from the dredging operation performed in the part of the reservoir. Metal concentration in sediments of the dredged part was ca. 2–5 times lower than in the undredged one, which indicates that after the dredging operation, accumulation of these metals was slight. The concentrations of Zn, Pb and Cd from the undredged part of BI were at the level of contaminated sediments and exceeded the probable effects level (PEL). In the ZZ, the greatest accumulation of metals occurred in the upper part of the reservoir and at the frontal dam, and the lowest in the middle part of the reservoir. In BI, the lower outflow of water in this reservoir caused a lower metal concentration in the sediments at the frontal dam, as compared with the other sediments in the undredged part of the reservoir. The results indicate that in small and shallow reservoirs, areas of accumulation of heavy metals depend on such factors as a parent river current, reservoir depth, water waving, reservoir shape (narrowing, coves/bays), and type of water outflow.

Influence of sludge-ash composts on some properties of reclaimed land / Wpływ kompostów osadowo-popiołowych na niektóre właściwości rekultywowanego gruntu

Abstract The study was conducted in the area of the impact of sulfur mine in Jeziórko. The aim of the study was to assess changes in pH, cation exchange capacity and content of available phosphorus, potassium and magnesium after 6 years of conducting remediation. In the experiment (plots with an area of 15 m2) degraded soil was rehabilitating by post-floating lime and compost from sewage sludge, sewage sludge and ash from combined heat and power (CHP). Composts at a dose of dry matter 180 t · ha-1 (6%), were determined in accordance with Minister of the Environment Regulation from 2001, applied the following options: control (only native soil limed), compost from municipal sewage sludge, sewage sludge compost (80%) and ash (20%), compost from sewage sludge (70%) and ash (30%). The reclaimed plots were sown with mixture of rehabilitation grass. Single de-acidification, land fertilization and a further 6-year extensive (without fertilization) use had a different influence on the properties of the native soilless substratum. Irrespective of the reclamation manner, after six years land use in the upper layers, observed increase in the average content of available phosphorus, available potassium content does not changed significantly but recorded a tenfold decrease in the content of available magnesium. Badania prowadzono w obszarze oddziaływania kopalni siarki w Jeziórku. Celem badań była ocena zmian odczynu, pojemności sorpcyjnej i zawartości przyswajalnych form fosforu, potasu i magnezu po 6 latach od przeprowadzenia rekultywacji. W doświadczeniu (poletka o powierzchni 15 m2) przeprowadzono rekultywację zdegradowanego gruntu wapnem poflotacyjnym, oraz kompostami: z osadu ściekowego, osadu ściekowego i popiołu z elektrociepłowni. Komposty w dawce suchej masy 180 t · ha-1 (6%), ustalonej w oparciu o rozporządzenie MŚ z 2001 roku, zastosowano w wariantach: kontrola (grunt rodzimy tylko zwapnowany); kompost z komunalnego osadu ściekowego; kompost z osadu ściekowego (80%) i popiołu (20%); kompost z osadu ściekowego (70%) i popiołu (30%). Na zrekultywowanych poletkach zasiano mieszankę traw rekultywacyjnych. Jednorazowe odkwaszenie i nawożenie gruntu i dalsze 6-letnie ekstensywne (bez nawożenia) użytkowanie wywarły zróżnicowany wpływ na kształtowanie właściwości rodzimego utworu bezglebowego. Bez względu na sposób rekultywacji, po sześciu latach użytkowania gruntu, w wierzchnich warstwach, zwiększyła się średnia zawartość przyswajalnego fosforu, zawartość przyswajalnego potasu nie uległa znacznym zmianom natomiast około 10-krotnie zmniejszyła się zawartość przyswajalnego magnezu.