Browsing by Subject "ecotoxicity"

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Access status: Open Access ,
Geochemistry indices and biotests as useful tools in the assessment of the degree of sediment contamination by metals
(Wydawnictwa AGH, 2023) Koniarz, Tomasz; Tarnawski, Marek; Baran, Agnieszka
Ecological and geochemical indicators have been widely accepted as tools with the potential for rapid risk assessment of metal contamination of bottom sediments. In this study we propose a selection of such indicators to characterize the potential ecological risks stemming from metal contamination of the bottom sediments of the Chechło reservoir (S Poland). The Chechło reservoir is located in an area formerly occupied by zinc and lead ore mining and processing industry. High amounts of metals, especially zinc (39.37–4772.00 mg/kg d.m.), cadmium (0.37–21.13 mg/kg d.m.) and lead (4.50–434.49 mg/kg d.m.) have been found in the bottom sediments. Both geochemical (CD – contamination degree) and ecological indices (mean PECQ) were indicative of bottom sediment contamination and their potential toxicity to living organisms. Most of the bottom sediment samples (71%) examined were toxic for <i>Heterocypris incongruens</i>, while only 9% of the samples were toxic to Sinapis alba. However, no significant correlations between the metal content and the response of the test organisms were observed. Correlation and principal component analyses (PCA) showed that silt and clay fractions were the key factors influencing the metal content in the sediments. Our study makes a contribution to building evidence of the need to integrate several indices for the assessment of environmental risks related to the presence of metals in bottom sediments rather than relying on a single one.
Access status: Open Access ,
The effect of different additives on the immobilization of heavy metals, the stability of organic matter, and the ecotoxicity of municipal sewage sludge
(Wydawnictwa AGH, 2026) Gondek, Krzysztof; Baran, Agnieszka; Siudek, Michał
There is an ongoing search for the most environmentally friendly use of various materials as additives to improve sludge properties. The aim of this study was to analyze the effect of additive type and dose of biochar (BC), dolomite (DL), bentonite (BN) or diatomite (DT) on heavy metal immobilization, organic matter stability, biochemical activity and ecotoxicity of municipal sewage sludge (SS). Risk Assessment Code (RAC) and Ecological Risk Factor (ERF) values indicated low risk associated with heavy metal (HM) mobility. Higher non-hydrolyzing C contents, compared to SS control, were found in SS to which 1% BC (by 3.6%), 1% DL (by 38.0%), 1% BN (by 25.5%) and 1% DT (by 20.6%) were added. Higher ratio C humic acids/C fulvic acids (Ckh/Ckf) values (more than 30% on average) were obtained when 1% BC, DL or BN were added compared to the 3% addition. Compared to the SS, the Ckh/Ckf values in SS with the addition of BC, DL or BN were on average more than 19% higher. The least varied values of dehydrogenase activity and respiration activity of SS (within dose) were obtained after the application of DT and BC, while the values of both parameters differed the most when BN was added to SS. Based on the results, it is not possible to clearly state which of the applied additives had the most significant effect on reducing the biochemical activity of SS. Sewage sludge and its mixtures generally showed low phytotoxicity to Sorghum saccharatum and Lepidium sativum, as root growth inhibition was 8–56% and 17–48%, respectively.