Alicja Zawadzka

Energy Willow From Experimental Plantation as a Potentially Clean Energy Source

Abstract Energy willow as a species with broad adaptation possibilities, large production capacity and a wide range of applications, takes a special place among the plants grown for energy production. In this work an analysis was conducted in respect of the usefulness of this type of wood from experimental plantations as a clean source of energy generated in the combustion process. The heat of combustion and net calorific value of dry matter of energy willow wood, including selected sorts and classes of thickness were determined. Energy willow has a natural ability to accumulate heavy metals which are oxidized during the combustion process or remain in the ash, and consequently repollute the environment. In order to determine the environmental impact the content of heavy metals was examined in energy willow wood and in the soil of the experimental plantation. Metal concentrations were determined by the Atomic Absorption Spectrometry method (AAS). Results of the tests confirmed a close relationship between the heat of combustion, calorific value and wood thickness as well as its location in the tree structure. Furthermore, very large differences were found in the content of heavy metals in the samples of both willow wood and soil. The levels of heavy metal content in the wood of energy willow determine the agricultural use of ashes produced during combustion.

The influence of selected factors on leaching of metals from sewage sludge

AbstractIn Poland, the amount of municipal sewage sludge that contains both organic and inorganic pollutants increases steadily. As a result of penetration of atmospheric precipitations through sludge layers, products of biochemical decomposition of organic matter and soluble mineral compounds are washed away and form contaminated leachates (Arain, J. Hazard. Mater. 154:998–1006, 2008; Fang, J. Hazard. Mater. 310:1–10, 2016; Ignatowicz, Environ. Res. 156:19–22, 2017). Metals contained in these leachates may be particularly burdensome and dangerous, which is due to the toxic nature that disturbs the natural biological balance (Fytili and Zabaniotou, Renew. Sust. Energy Rev. 12 (1): 116–140, 2008). In order to check bio-availability of metals in sewage sludge and find out resulting risks to the environment and human health, apart from the determination of total metal content, speciation analysis is often used. It makes possible a quantitative determination of various chemical forms of metals which are bound in the sewage sludge and finding which of them poses the greatest threat to the environment (Amir, Chemosphere 59:801–810, 2005; Ciba, Waste Manage. 23:897–905, 2003; Hei, Procedia Environ Sci 31:232–240, 2016; Liu, Chemosphere 67(5):1025–1032, 2007).The degree of immobilization of selected metals in sewage sludge has been determined using one of the sequential extraction methods designed to identify groups of compounds with which the metal is bound. Such a method is the Tessier procedure (Janas, Pol J Environ Stud 26(5A):37–41, 2017). Results of this research were used to assess the threat resulting from the increase in the amount of sewage sludge; the management of which is subject to constant restrictions (storage of sewage sludge has been prohibited since January 1, 2016).As a result of the conducted research, it was found that metals in sewage sludge, which undergo various transformations, are very difficult to immobilize. The addition of calcium oxide and an agent supporting the composting process to the sludge does not affect radically the increase of leaching of the analyzed elements from the sludge. Graphical abstractThe schema of proceedings in leaching of heavy metals from sewage sludge after various modifications.

THE IMPACT OF INDUSTRIAL WASTE LANDFILL ON THE ENVIRONMENT

The aim of the study is to assess the environmental impact of a shut down industrial waste landfill. A detailed analysis of the quality of groundwater around the landfill in the years 1995–2016 was conducted. Assessment of the status of groundwater in the landfill area was made based on the results of monitoring tests. It includes the measurement of pH, specific electrical conductivity (SEC) and the content of chlorides, sulfates, phosphates, heavy metals: copper (Cu), lead (Pb), chromium (Cr) and a number of other pollution indicators. The analysis confirms that the landfill during the operation did not constitute a threat because of a number of employed security measures and sealing layers. Only in recent years, the industrial waste landfill which is already out of operation has become an extremely serious environmental threat. The results of water analyses from the piezometers clearly indicate that there is a problem of groundwater contamination. There was a significant increase in the value of some of the analyzed indicators (such as chlorides and sulfates), mainly in the piezometers located on the flow line of groundwater in the landfill area. The observed situation is probably a result of damage to the sealing layers and leaching of pollutants from waste deposited in the landfill by rain water.