Evaluation of the ecological state of bottom sediments in chosen small water reservoirs

As follows from a number of scientific works, water reservoirs are subjected to sedimentation at a higher or lower intensity requiring in consequence, after a time, desedimentation and renovation. There are several ways of desedimentation but the problem remains what to do with the sediments removed fro the bottom. This depends on the quality of bottom sediments, their ecological state and, first of all, of their chemical properties (especially of heavy metal content). Chemical properties of sediments may depend on the reservoir location whether in anthropogenic transformed territories or in ecologically undisturbed ones. In the paper results of works on chemical composition of sediments of some chosen small water reservoirs were compared. Subsequently these compared with fish pond and granulometric composition and its variability on bottom area, content of organic particles and presence of six basic heavy metals and their distribution in reservoir were examined. An attempt at mathematical relation between granulometric composition and heavy metals and between the percentage relation between organic particles and heavy metals was undertaken. The possibility of agricultural utilization of sediments after removal from the bottom was determined on the basis of the tables of permissible chemical soil pollution. ...

bottom sediment, agriculture purpose, pot experiment, macronutrients, trace elements, maize

The aim of study was to assess the effect of bottom sediments on the concentration of macronutrients (K, P, Na, Mg, Ca) and trace elements (Zn, Cd, Pb, Cr, Ni, Cu) in the plant test. The experimental design comprised 6 treatments: soil (control), soil + 5% of sediment, soil +10% of sediment, soil + 30% of sediment, soil + 50% of sediment and sediment (100%) in relation to the soil dry mass. The test plant - maize was harvested after 70 days of vegetation. Bottom sediment added to soil had a positive effect on maize biomass in the lowest dose, i.e. 5%. Higher doses of the sediment caused a reduction in maize yield. Bottom sediment positively affected concentration of nutrients: N, Mg, Na, K, Ca, Zn, Ni, Cu of maize shoots. However, the shoot biomass did not meet for fodder with respect to quality. Applied bottom sediment, has high content of sandy fractions, acid reaction and low concentration of organic carbon, nitrogen, phosphorus and potassium, can not be used as a fertilizer. Using bottom sediment from Narożniki reservoir in plant cultivation, one should take into consideration a necessity of application of supplementary NPK fertilization due to low concentration of these ...