Biotests for environmental quality assessment of composted sewage sludge

The quality of sewage sludge-based products, such as composts and growth media, is affected by the contamination of sewage sludge with, potentially, hundreds of different substances. Therefore, it is difficult to achieve the reliable environmental quality assessment of sewage sludge-based products solely based on chemical analysis. In the present work, we demonstrate the use of the kinetic luminescent bacteria test (ISO 21338) to evaluate acute toxicity and the Vitotox? test to monitor genotoxicity of sewage sludge and composted sewages sludge. In addition, endocrine-disrupting and dioxin-like activity was studied using yeast-cell-based assays. The relative contribution of industrial waste water treated at the Waste Water Treatment Plants led to elevated concentrations of polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins and -furans (PCDD/F) in sewage sludge. The effect of elevated amounts of organic contaminants could also be identified with biotests able to demonstrate higher acute toxicity, genotoxicity, and potential for endocrine-disruptive properties. Additional extraction steps in kinetic luminescent bacteria test with DMSO and hexane increased the level of toxicity detected. Composting in a pilot-scale efficiently reduced the amounts of linear alkylbenzensulphonates (LASs), nonylphenols and nonylphenolethoxylates (NPE/NPs) and PAH with relative removal efficiencies of 84%, 61% and 56%. In addition, decrease in acute toxicity, genotoxicity and endocrorine-disrupting and dioxin-like activity during composting could be detected. However, the biotests did have limitations in accessing the ecotoxicity of test media rich with organic matter, such as sewage sludge and compost, and effects of sample characteristics on biotest organisms must be acknowledged. The compost matrix itself, however, which contained a high amount of nutrients, bark, and peat, reduced the sensitivity of the genotoxicity tests and yeast bioreporter assays.     

Accelerating the deployment of carbon capture and storage technologies by strengthening the innovation system

In order to take up the twin challenge of reducing carbon dioxide (CO₂) emissions, while meeting a growing energy demand, the potential deployment of carbon dioxide capture and storage (CCS) technologies is attracting a growing interest of policy makers around the world. In this study we evaluate and compare national approaches towards the development of CCS in the United States, Canada, Norway, the Netherlands, and Australia. The analysis is done by applying the functions of innovation systems approach. This approach posits that new technology is developed, demonstrated and deployed in the context of a technological innovation system. The performance assessment of the CCS innovation system shows that the extensive knowledge base and knowledge networks, which have been accumulated over the past years, have not yet been utilized by entrepreneurs to explore the market for integrated CCS concepts linked to power generation. This indicates that the build-up of the innovation system has entered a critical phase that is decisive for a further thriving development of CCS. In order to move the CCS innovation system through this present difficult episode and deploy more advanced CCS concepts at a larger scale; it is necessary to direct policy initiatives at the identified weak system functions, i.e. entrepreneurial activity, market creation and the mobilization of resources. Moreover, in some specific countries it is needed to provide more regulatory guidance and improve the legitimacy for the technology. We discuss how policy makers and technology managers can use these insights to develop a coherent policy strategy that would accelerate the deployment of CCS.     

Impact of physical factors on the society and environment

In 1988 I published a paper “Electromagnetic fields—a new ecological factor” (Markov 1988). There was no internet and very few cell phones were available. It was not even fear from the hazard of the power lines. However, I want to cite the beginning of this paper: “The contemporary conditions of life put man in dependence of the complex of physical influences on the environment and in the first place—of the electromagnetic fields. The rapid development of science and technology has resulted in the introduction of many new devices and technologies in industry, agriculture, and everyday life. On the other hand, during their phylogenetic and ontogenic development, the living organisms are continuously exposed to the influence of different biotic and abiotic factors. The physical factors are included in the first group, and the entire evolution of life is connected with an adaptation to the action of these factors.” Could I repeat this statement nearly a quarter of century later? Sure, I will. The only difference would be that I will speak not only for electromagnetic fields, but for green-house effects, global warming, volcano eruption, and radiation disasters. I would also discuss the noise and vibration to which people are exposed from early days to the very end of their life traveling with private vehicles or public transport.     

Fractionation of natural radionuclides in soils from the vicinity of a former uranium mine ?irovski vrh, Slovenia

As a result of former uranium mining and milling activities at ?irovski vrh, Slovenia, 0.6 million tons of uranium mill tailings (UMT) were deposited onto a nearby waste pile Boršt. Resulting enhanced levels of natural radionuclides in UMT could pose threat for the surrounding environment. Therefore, sequential extraction protocol was performed to assess mobility and bioavailability of ²³⁸U, ²³⁴U, ²³⁰Th and ²²⁶Ra in soils from the waste pile and its surrounding. The radionuclides associated with exchangeable, organic, carbonate, Fe/Mn oxides and residual fraction, respectively, were determined. Results showed that the highest activity concentrations for the studied radionuclides were on the bottom of the waste pile. In non-contaminated locations, about 80% of all radionuclides were in the residual fraction. Considering activity concentrations in the UMT, ²³⁸U and ²³⁴U are the most mobile. Mobility of ²²⁶Ra is suppressed by high sulphate concentrations and is similar to mobility of ²³⁰Th.     

Biomonitoring of heavy metals in fish from the Danube River

The Croatian part of the Danube River extends over 188 km and comprises 58 % of the country’s overall area used for commercial freshwater fishing. To date, the heavy metal contamination of fish in the Croatian part of the Danube has not been studied. The main purpose of this study was to determine heavy metal levels in muscle tissue of sampled fish species and to analyze the measured values according to feeding habits of particular groups. Lead ranged from 0.015 μg^?1 dry weight in planktivorous to 0.039 μg^?1 dry weight in herbivorous fish, cadmium from 0.013 μg^?1 dry weight in herbivorous to 0.018 μg^?1 dry weight in piscivorous fish, mercury from 0.191 μg^?1 dry weight in omnivorous to 0.441 μg^?1 dry weight in planktivorous fish and arsenic from 0.018 μg^?1 dry weight in planktivorous to 0.039 μg^?1 dry weight in omnivorous fish. Among the analyzed metals in muscle tissue of sampled fish, only mercury exceeded the maximal level (0.5 mg kg^?1) permitted according to the national and EU regulations determining maximum levels for certain contaminants in foodstuffs, indicating a hazard for consumers of fish from the Danube River.     

Formation of PFOA from 8:2 FTOH in closed-bottle experiments with brackish water

The formation of perfluorooctanoate (PFOA) from 1H,1H,2H,2H-perfluorodecanol (8:2 FTOH) was studied for the first time in laboratory experiments with brackish water. The water samples were collected from the Baltic Sea, which is one of the largest brackish water areas in the world and is polluted with PFOA and other perfluorinated compounds. The formation of PFOA was studied in closed-bottle experiments at different water temperatures. As a reference experiment, a modified OECD 310 test was conducted with sludge from a wastewater treatment plant and with brackish water. The PFOA and 8:2 FTOH were concentrated from water samples by solid-phase extraction (SPE) and were analysed using liquid chromatography–mass spectrometry. The effect of oxygen concentration on the formation of PFOA was studied using surface water samples with high and low oxygen contents. Other experiments were performed with oxygen-rich surface water and oxygen-deficient bottom water. The formation of PFOA was observed in all experiments; it was higher in the trial performed with brackish water than in the reference test carried out with sludge. Clear temperature dependence was observed in the formation of PFOA in brackish water tests; after a 30-day test period, a sixfold increase was observed in the amount of PFOA in surface water between the temperatures of 15 and 20 °C. Microbes were suggested as the major cause of the formation of PFOA, but other environmental characteristics, such as oxygen, could also affect the formation potential of PFOA.     

Catalytic gasification of tars from a dumping site

The work deals with catalytic gasification, pyrolysis and non-catalytic gasification of tar from an industrial dumping site. All experiments were carried out in a vertical stainless steel gasification reactor at 800 °C. Crushed calcined dolomite was used as the gasification catalyst. Parameters such as addition of water and air, and the influence of the catalyst in regard to the composition of the process gas were investigated. The catalytic gasification experiment in the steady state produced process gas with the composition: 56 % of H₂, 9 % of CO, 11 % of CH₄ and 12 % of CO₂ (mol.%). Concentration of the C₂ fraction was lower than 1 mol.%. Volume flow of air was later changed from 120 to 230 ml min^?1 reducing the amount of hydrogen to 51 mol.% and that of methane to 10 mol.%. Process gas created in a non-catalytic gasification process contained 26–30 mol.% of methane, 13–15 mol.% of carbon monoxide and 15–17 mol.% of the C₂ fraction and lower amounts of hydrogen (20 mol.%) and carbon dioxide (2–3 mol.%). The highest apparent conversion of tar was reached in the catalytic gasification processes. A higher rate of catalyst deactivation can be observed when water or air is not added.     

(210)Po and (210)Pb activity concentrations in Mytilus galloprovincialis from Croatian Adriatic coast with the related dose assessment to the coastal population

Activity concentrations of ²¹⁰Po and ²¹⁰Pb in the species Mytilus galloprovincialis from Croatian Adriatic coast were determined. The samples were collected in thirteen sampling places which are also a part of Croatian Mediterranean mussel watch project. The results of ²¹⁰Po and ²¹⁰Pb activity concentrations were found to vary between (22.1 ± 2.5)-(207 ± 21) Bq kg⁻¹ fresh weight and (2.8 ± 1.4)-(9.3 ± 0.7) Bq kg⁻¹ fresh weight, respectively. ²¹⁰Po/²¹⁰Pb ratio ranged between 6.2 and 30.7. The highest measured activities were found in the enclosed basins of the Neretva channel, where the majority of Croatian mussel cultivation is taking place. The estimated consequent average total annual effective ingestion dose due to ²¹⁰Po and ²¹⁰Pb from mussel consumption in Croatian coastal region is 202 ± 99 μSv with 96% contribution of ²¹⁰Po to the total effective dose.