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The study assesses the contamination, classification and phytotoxicity of foundry waste. The presented results are a part of the research on the agrotechnical use of foundry waste. Landfilled foundry waste (LFW) and dust samples were taken from one of the Polish foundries. An analysis of the waste and its leachate composition was conducted. Phytotoxicity tests were carried out using Lepidium sativum. The aim of the phytotoxicity study was to evaluate germination and root growth after 72 h and the accumulation of heavy metals after 7 days. LFW was least contaminated with heavy metals and metalloids compared to dust. The composition of the foundry dusts depended on the unit of the foundry, from which it was collected. It was found that electric arc furnace dust (EAFD) was the most polluted by heavy metals among the dust samples. According to the requirements of Polish regulations most of tested waste were classified as non-hazardous, and EAFD as hazardous waste due to high Pb concentration in leachate. Phytotoxicity tests have shown a low phytotoxicity of the leachate from most of the tested waste. The results of the accumulation test showed that an excess of metal and metalloids in leachate was not directly related to its accumulation in plants. A negative correlation between EC, Cu, Co, Fe, Pb, Cr, K, Na, sulfate, fluoride, ammonia, phenol and formaldehyde concentration in leachate and GI was found. It was stated that the Fe, Mn, As and Se in plants was significantly correlated with concentrations in leachate.

This paper presents the comparison of heavy metals accumulation in spider webs from Agelenidae family (Eratigena atrica and Agelena labyrinthica) and lichens Hypogymnia physodes, exposed to pollution for two months. Webs were obtained from the laboratory-reared spiders and stretched on Petri dish while lichens were transplanted from Stobrawa Landscape Park into the study area. Concentrations of Cu, Zn, Ni, Pb and As were determined in both biomonitors and the elevated values indicated the impact of the copper smelter and surrounding roads. Our study revealed that webs were more sensitive than lichens to emissions of pollutants, and for all of the studied elements, the determined concentrations were much higher for spider webs. The results of similarity tests showed a clear difference among the concentrations of Cu, Zn, Ni and As in lichens and spider webs, with the exception of Pb, suggesting that this element could be accumulated in a similar way by both bioindicators. These differences are probably due to their morphological and ecological dissimilarities suggesting that spider webs should be favorably applied where the use of lichens is improper due to the drought, which is an unfavorable condition for accumulation of elements in lichens, or their limited uptake of elements.

This paper determines the impact of the maturation process of composted sewage sludge on the quality of the final product and assesses the stabilization effect. The samples of composted sewage sludge were taken from a wastewater treatment plant located in Pomerania in northern Poland. The sewage sludge was composted in an open windrow composting plant with the addition of straw and wood chips in the turning windrow. The aeration of the sewage sludge mixture was conducted based on two methods. The first phase (intensive degradation phase of 6 to 8 weeks) was characterized by frequently turning; the second phase for maturation used aeration channels (2 to 3 months). In three sampling campaigns samples were taken from the same windrow after 2 (no. 1), 8 (no. 2), and 12 weeks (no. 3) of maturation. Fresh samples were used for analyzing the stabilization parameter as static respiration activity (AT4). Furthermore, the values of pH, organic matter (OM), total organic carbon (TOC), elementary composition, nutrients, total content, and mobile forms of heavy metals were analyzed in the compost samples. A significant decrease was found in the stabilization parameter (AT4) during the maturation of tested materials. In turn, no significant differences were found in the elementary composition. The concentration of most metals increased in the final product. The total content of heavy metals in the final product did not exceed the limit values for the agricultural use of sewage sludge, compost from municipal waste, and for organic fertilizers. There were no significant changes in the percentage of bioavailable and mobile forms of heavy metals during compost maturation. Zinc was characterized by the highest level of mobile and bioavailable forms, which may cause bioaccumulation after the fertilization of soil. The study has shown that the process of maturation of compost from sewage sludge not affects changes in the content of heavy metal forms. The scope of this study has been planned on a wider scale for different variants of sewage sludge composting, in order to evaluate the process.

Abstract. There are a number of leaching test which are used to evaluate the effect of foundry waste disposal on the environment (TCLP, SPLP, ASTM at al.). Because the spent foundry sand are usually deposited at the ground level and they have a similar structure to the soil, survey mobility of metals using the same methods seems appropriate. One-step extraction allows for the evaluation of the mobility and bioavailability of metals in soil and waste. Waste foundry sands have been successfully used as a component in manufactured soils in U.S., but concern over metal contamination must be eliminated before considering this direction of use. The study evaluated the leaching of heavy metals (Cd, Pb, Cu, Zn, Cr, Ni) from deposited waste foundry sands. The overall, as well as heavy metals were extracted by different type of extractants: H 2 O, CH 3 COOH, HCl, EDTA, MgCl 2 and NaCOOH. These extractants are most commonly used to study the mobility and bioavailability of metals in soil and waste. In the present study applicable standards and methodology described in the literature in analysis were used. The results allowed to evaluate the bioavailability of metals leached from those wastes.

The study evaluated the use of Lepidium sativum L. to assess the phytotoxicity of three types of waste such as hazardous waste (slags from zinc to copper smelters) and nonhazardous waste (mineral–organic composite). Previous studies evaluated heavy metal leaching and the environmental impact of the tested waste. The purpose of phytotoxicity studies was to increase knowledge about this waste. Two types of tests were used to assess the phytotoxicity of wastes: germination index and accumulation test. Both tests were carried out for leachate (leachate test) and waste (contact test). The results of both tests were compared to assess the phytotoxic effects of tested waste. Phytotoxicity tests have shown that the mineral–organic composite leachate was stimulated plant growth, copper smelter slag leachate was characterized by no phytotoxicity and zinc slag leachate inhibited the growth of plants. In contrast, contact test showed inhibitory effects from all tested waste. Wherefore, the contact test was indicated as more sensitive in the assessment of phytotoxicity. However, this is not a clear assessment, because the germination index values for both tests were a result of differences of root length for both control samples (deionized water and sand). The study confirmed the usefulness of L. sativum for the assessment of phytotoxicity of various types of waste. Additionally, it was found that L. sativum was resistant to high concentrations of heavy metals in the leachate, without causing any negative physiological effects.

The foundry industry generates various types of waste, depending on the applied technology. This waste includes: spent foundry sands (SFS), molding compounds, furnace slag, sludge or dust from dust collectors as well as other types of waste, e.g., chips, milling and casting scale. It is estimated that the mass of waste generated during foundry production conforms to the total weight of the castings. This means that approximately one ton of molding sand is required to produce each ton of iron or steel casting. According to the Polish classification of waste, foundry waste is listed among several categories of waste, including hazardous waste. In accordance with Polish legislation, more than 75 codes have been attributed to waste derived from foundry production [1, 2]. Some metallurgical waste is a valuable resource for industry, for example, granulated blast furnace slag, due to its high iron content, is used as a mineral additive for cement [3]. The metallic iron from the slag may be used as a raw material for steelmaking or in other technological processes [4-6].