Evaluation of the addition of immobilizing agents on selected physicochemical properties of soil contaminated with heavy metals

This study was aimed at determining effects of increasing simultaneous contamination of soil with Pb and Zn at doses of 200, 400 and 800 mg·kg⁻¹ and with Cd at doses of 5, 10 and 20 mg·kg⁻¹ soil, after the addition of immobilizing agents (zeolite, diatomite, chalcedonite, dolomite, limestone, and activated carbon), on selected properties of soil. In the soil without the immobilizing agents, the highest doses of metals caused a decrease in pH value, total sorption capacity, total exchangeable base cations and saturation of the sorption complex with base cations as well as an increase in hydrolytic acidity and electrical conductivity of the soil. Among the agents applied, dolomite and activated carbon exerted a positive effect on the analyzed properties of soil, as they contributed to an increase in pH value, total exchangeable bases, and total sorption capacity, and to a decrease in hydrolytic acidity of the soil. The addition of zeolite caused soil electrical conductivity to decrease compared to the control pot, at all levels of soil contamination with Pb, Cd, and Zn

Research of the biodegradability of degradable/biodegradable plastic material in various types of environments

Research of the biodegradability of degradable/biodegradable plastic material in various types of environments. Research was carried out in order to assess biodegradability of degradable/biodegradable materials made of HDPE and mixed with totally degradable plastic additive (TDPA additive) or made of polyethylene (PE) with the addition of pro-oxidant additive (d2w additive), advertised as 100% degradable or certified as compostable within various types of environments. Research conditions were: (i) controlled composting environment – laboratory-scale, (ii) real composting conditions – domestic compost bin, (iii) real composting conditions – industrial composting plant and (iv) landfill conditions. The results demonstrate that the materials made of HDPE and mixed with totally degradable plastic additive (TDPA additive) or made of polyethylene (PE) with the addition of pro- -oxidant additive (d2w additive) or advertised as 100% degradable did not biodegrade in any of the above-described conditions and remained completely intact at the end of the tests. Biodegradation of the certified compostable plastic bags proceeded very well in laboratory-scale conditions and in real composting conditions – industrial composting plant, however, these materials did not biodegrade in real composting conditions – domestic compost bin and landfill conditions

Wpływ zielonych dachów na jakość wody deszczowej oraz wybrane problemy ekoploatacyjne - studium przypadku

Shopping centres usually occupy large areas of land development. However, their roofs are rarely used for purposes related to rainwater management and introduction of active biological surfaces. In Bielsko-Biała, thanks to the initiative of the originator and architect, an intense green roof was created on the rooftop of a shopping centre. In addition to the primary role of the roof as a garden that makes the housing estate more attractive, it also collects some of the rainwater and delays its outflow to the sewage system. Plants, shrubs and trees planted on the roof are watered almost exclusively with water collected in a tank located under the building, intended for retaining rainwater. These waters are pretreated before they reach the tank, i.e. they filter through the root layer of plants growing on the roof, and through the biologically active layer (substrate). This paper highlights some of the operating problems of the selected green roof. The authors focused on assessing the toxicity of rainwater flowing down from hardened surfaces on the roof of the shopping centre and the area occupied by the green roof. Relevant toxicity studies on these waters have been carried out in this regard. The research hypothesis that rainwater percolating through the selected soil material is not toxic and stimulates test plant growth was put forward. Tests of semichronic toxicity with the seeds of white mustard (Sinapis alba L.) prove that all the rainwater samples showed a stimulating effect on the test plant. The average root growth stimulation value during the period considered was –125%. It was confirmed that rainwater did not show toxic properties for white mustard seeds (Sinapis alba L.) and can be used for watering the garden constituting the green roof of a selected research facility. In the case of rainwater pH, it was found that the pH is adequate and has no toxic effect on the selected white mustard test plant (Sinapis alba L.). It confirms that the rainwater retained in this way can be used to water the green roof. The selected research facility meets the requirements set for green roofs