апрель 2017

Bottom sediments as a potential environmental problem

Cymer M. , Szymczyk S.
Химия и современные технологии
Abstract / Full Text

The study was aimed at verifying the impact of different types of catchments and how small water reservoirs can be used for bottom sediment respiration, methane and carbon dioxide production.

The purpose of the study was to investigate the impact of various types of catchments and the use of small water bodies on the accumulation of organic matter, the respiratory activity of sediments, and the intensity of methane production and carbon dioxide from bottom sediments, in the case of the oxygen content of the reservoir.

The research problem is the influence of the method of development of water reservoirs with small surface area for macronutrient accumulation, biological degradability of the original substance residue (AT4 respiratory activity) and the production of methane and carbon dioxide under reduced oxygen conditions in tanks. The large variety of chemical composition of water in ponds is one of their characteristics. This composition is dependent on many factors such as: internal hydrochemical transformation, levels of water and solids from the catchment, and how they are managed (eg breeding ponds). In No-flow tanks, the concentration of components is increased and therefore they provide a good biogeochemical barrier in the protection of larger hydrological facilities (lakes, rivers).

Despite many important environmental functions, these small water bodies are constantly exposed to negative influences, mainly of anthropogenic origin, and deterioration is observed from one year to another. Gradual degradation, which can lead to complete disappearance, is the greatest threat to ponds.

The eutrophication process causes great changes in aquatic ecosystems. In eutrophic waters there is a lush development of phytoplankton and its seasonal blooms. Sinice causes turbidity in the surface layer, which limits the development of shallow vegetation due to lack of light. Phytoplankton dying falls to the bottom. With a sufficient supply of oxygen, this biomass decomposes and is transformed into inorganic compounds, which again become a source of food. Lack of adequate oxygen needed to decompose biomass leads to deposition of organic matter on the bottom. In addition, anaerobic gases emit toxic gases – hydrogen sulphide and methane and amines and other amino acid decomposition products. The accumulation of more and more sludge leads to the reservoir's sinking and muddying. Oxygen deficiency leads to increased mortality of many fish species.