Agnieszka Baran

The effect of low-temperature transformation of mixtures of sewage sludge and plant materials on content, leachability and toxicity of heavy metals

The aim of the study was to determine the influence of the process of low-temperature transformation and the addition of plant material to sewage sludge diversifying the content of mobile forms of heavy metals and their ecotoxicity. The experimental design included: sewage sludge+rape straw, sewage sludge+wheat straw, sewage sludge+sawdust, sewage sludge+bark and sewage sludge with no addition. The mixtures were subjected to thermal transformation in a chamber furnace, under conditions without air. The procedure consisted of two stages: the first stage (130°C for 40 min) focused on drying the material, whereas in the second stage (200°C for 30 min) proper thermal transformation of materials took place. Thermal transformation of the materials, caused an increase in total contents of heavy metals in comparison to the material before transformation. From among elements, the cadmium content changed the most in materials after thermal transformation. As a result of thermal transformation, the content of water soluble form of the heavy metals decreased significantly in all the prepared mixtures. Low toxicity of the extracts from materials for Vibrio fischeri and Lepidium sativum was found in the research, regardless of transformation process. L. sativum showed higher sensitivity to heavy metals occurring in the studied extracts from materials than V. fischeri, evidence of which are the positive significant correlations between the content of metals and the inhibition of root growth of L. sativum.

Assessment of heavy metals mobility and toxicity in contaminated sediments by sequential extraction and a battery of bioassays

The aim of this study was to assess heavy metals mobility and toxicity in sediments collected from a dam reservoir in the conditions of intensive human impact by using chemical fractionation and a battery of bioassays. In the studies, the test organisms were exposed to substances dissolved in water (Microtox, Phytotestkit) as well to substances absorbed on the surface of solid particles (Phytotoxkit, Ostracodtoxkit F). The studies showed that sediments from the Rybnik reservoir are toxic, but the tested organisms showed different sensitivity to heavy metals occurring in the bottom sediments. The sediment samples were classified as toxic and very toxic. Moreover, the studies showed a higher toxicity in solid phases and whole sediment than in pore water. The lowest sensitivity was observed in H. incongruens (solid phases) and V. fischeri (pore water, whole sediment). The studies revealed that the toxicity of the sediments is caused mainly by heavy metal forms associated with the solid phase of the sediments. The studies did not confirm the metals occurring in fraction I (exchangeable) to be bioavailable and toxic to living organisms because most correlations between the metal concentration in fraction I and the response of the organisms were negative. The highest mobility from the bottom sediments was found in zinc, average mobility—in copper, cadmium and nickel, and low mobility—in chromium and lead. Organic matter is likely to be the most important factor controlling metal distribution and mobility in the studied sediments.

Assessment of respiration activity and ecotoxicity of composts containing biopolymers.

The research was conducted to determine if introducing biodegradable polymer materials to the composting process would affect selected biological properties of mature compost. Determination of biological properties of composts composed of testing their respiration activity and toxicity. Respiration activity was measured in material from the composting process by means of OxiTop Control measuring system. The ecotoxicity of composts was estimated by means of a set of biotests composed of three microbiotests using five test organisms. Introduction of polymer materials caused a decrease in respiration activity of mature compost. Similar dependencies as in the case of mass loss were registered. Compost to which a biodegradable polymer with the highest content of starch was added revealed the smallest difference in comparison with organic material composted without polymers. Lower content of starch in a polymer caused lower respiration activity of composts, whereas microorganism vaccine might have accelerated maturing of composts, thus contributing to the smallest respiration of compost. In composts containing biopolymers the following were observed: an increase in germination inhibition--2.5 times, roots growth inhibition--1.8 times, growth inhibition of Heterocypris incongruens--four times and luminescence inhibition of Vibrio fischeri--1.6 times in comparison with the control (compost K1). Composts containing biopolymers were classified as toxicity class III, whereas the compost without polymer addition as class II.

Strategy of Cr detoxification by Callitriche cophocarpa

AbstractThe present work focused on the qualitative and quantitative analysis of Cr detoxification strategy of aquatic cosmopolitan plant Callitriche cophocarpa. This plant species has just been described in the context of its unusual accumulation potential of Cr. The emphasis of the work was placed on the redox reaction Cr(VI)→Cr(III) which is considered to be remediation mechanism of highly reactive and mobile Cr(VI) ions. Plants were immersed for 5 days in 1 mM of Cr(VI) (potassium dichromate) or 1 mM of Cr(III) (chromium sulphate) solutions in semi-natural conditions. Cr was effectively removed from the solution up to the extent of ca.58% or 35% of the starting amount, in the case of Cr(III) and Cr(VI), respectively. No plant-induced Cr(VI) reduction accompanying Cr accumulation was observed in Cr(VI) solutions except from the apparent one, noticed at the fourth day of incubation. On the contrary to these results, according to the method of electron paramagnetic resonance spectroscopy (L-band EPR), biphasic signal of Cr(V) attending Cr(VI) to Cr(III) reduction was detected inside the plant tissue every day of investigations. Our results show that phytoextraction but not phytostabilization is the main strategy of Cr detoxification by C. cophocarpa in aquatic systems.

Application of geochemical and ecotoxicity indices for assessment of heavy metals content in soils / Zastosowanie wskaźników geochemicznych i ekotokysycznych w ocenie zawartości metali ciężkich w glebach

Abstract The research aimed to use chemical, geochemical, and ecotoxicity indices to assess the heavy metals content in soils with different degrees of exposure to human pressure. The research was conducted in southern Poland, in the Malopolska (Little Poland) province. All metal contents exceeded geochemical background levels. The highest values of the Igeo index were found for cadmium and were 10.05 (grasslands), 9.31 (forest), and 5.54 (arable lands), indicating extreme soil pollution (class 6) with this metal. Mean integrated pollution index (IPI) values, depending on the kind of use, amounted to 3.4 for arable lands, 4.9 for forests, and 6.6 for grasslands. These values are indicative of a high level of soil pollution in arable lands and an extremely high level of soil pollution in grasslands and forests. Depending on the type of soil use, Vibrio fischeri luminescence inhibition was from -33 to 59% (arable lands), from -48 to 78% (grasslands), and from 0 to 88% (forest). Significantly the highest toxicity was found in soils collected from forest grounds. Celem badań było wykorzystanie wskaźników chemicznych, geochemicznych i ekotoksycznych w ocenie zawartości metali ciężkich w glebach o zróżnicowanym stopniu narażenia na antropopresję. Badania prowadzono na terenie Polski Południowej w województwie Małopolskim. Punkty poboru prób wyznaczono metodą równych kwadratów o boku kwadratu równym 7,5 km przy wykorzystaniu urządzenia GPS (Garmin 62s, dokładność +/- 2 m). Łącznie wyznaczono 76 punktów w których pobrano próby glebowe z poziomu 0-10 cm. Średnia zawartość poszczególnych metali ciężkich w glebach gruntów ornych (GO) wyniosła w kolejności malejącej: 107,52 mg Zn; 44,47 mg Ni; 23,23 mg Pb; 12,30 mg Cu; 1,21 mg Cd ∙ kg-1 s.m. Na użytkach zielonych (UZ) średnia zawartość metali tworzyła szereg malejący (mg ∙ kg-1 s.m): Zn (428,04) > Pb (76,35) > Ni (20,93 mg) > Cu (19,60) > Cd (2,38). W glebach leśnych (L) przeciętna zawartość cynku wyniosła 149,33 mg, ołowiu 97,76 mg, miedzi 13,32 mg, niklu 13,03 mg oraz kadmu 2,18 mg ∙ kg-1 s.m. Spośród badanych metali największe wartości wskaźnika Igeo wykazano dla kadmu: 10,05 (UZ); 9,31 (L); 5,54 (GO), co świadczy o ekstremalnym zanieczyszczeniu (klasa 6) gleb tym pierwiastkiem, niezależnie od rodzaju użytkowania terenu. Średnie wartości zintegrowanego współczynnika zanieczyszczenia wyniosły: 2,8 (GO); 5,3 (L) oraz 6,4 (UZ). Wartości te świadczą o wysokim stopniu zanieczyszczenia gleb na gruntach ornych oraz ekstremalnie wysokim na użytkach zielonych i lasach. Inhibicja luminescencji Vibrio fischeri w zależności od sposobu użytkowania gleb wyniosła od -33 do 59% (GO), od -48 do 78% (UZ) oraz od 0 do 88% (L). Istotnie największą toksycznością charakteryzowały się gleby pobrane z użytków leśnych.

SEWAGE SLUDGE BIOCHARS MANAGEMENT – ECOTOXICITY, MOBILITY OF HEAVY METALS AND SOIL MICROBIAL BIOMASS

Production of biochar from sewage sludge may be a promising solution for sewage sludge management and improvement of soil properties, including carbon dioxide sequestration. The aim of the present study was to compare the effects of biochars derived from different sewage sludges on soil physicochemical and biological properties, ecotoxicity, and plant yield. Three biochars (produced at a temperature of 300 °C) were applied into sandy acid soil in doses of 0.5, 1, and 2% (w/w). Depending on the type and dose, the application of sewage sludge biochars into the soil caused diverse effects on the parameters of soil biological activity (microbial biomass [Cmic], soil respiration, and value of metabolic quotient). No correlation between the applied dose of biochars and inhibition of Vibrio fischeri luminescence was observed. The factor with a stronger impact on the activity of V. fischeri was the type of biochar. The use of the OSTRACODTOXKIT F test (MicroBioTests) showed that the addition of sewage sludge biochar (regardless of its dose) reduced the soil toxicity to Heterocypris incongruens compared with the control soil. A significant increase of Poa pratensis L. biomass was obtained in soils with 1 and 2% additions of each of the biochars. The addition of biochars in doses of 1 and 2% to the soil had greater effect on the content of mobile forms of Cu, Pb, and Cd than the 0.5% dose compared with the control. Environ Toxicol Chem 2018;37:1197-1207.

Content of PAHs, activities of γ-radionuclides and ecotoxicological assessment in biochars

Abstract The aim of this research was to determine the effect of thermal conversion temperature and plant material addition to sewage sludge on the PAHs content and the activity of selected γ-radionuclides in biochars, and to conduct an ecotoxicological assessment. The pyrolysis of the mixtures of sewage sludge and plant materials at 300°C and such temperature caused an increase in the contents of 2- and 3-ring hydrocarbons. During the pyrolysis of organic materials at 600°C, the amount of the following compounds was reduced in biochars: benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene. Among γ-radioisotopes of the elements, natural radiogenic isotopes were dominant. 137Cs was the only artificial radioactive isotope. The pyrolysis of the mixtures of municipal sewage sludge and plant materials revealed that isotope 40K had the highest radioactive activity. In the case of other analysed nuclides, activities of 212Pb, 214Pb, 214Bi, and 137Cs were determined after the sample pyrolysis. The extracts from the mixtures of sewage sludge and plant materials were non-toxic to Vibrio fischeri.

Assessment of the use of municipal and industrial wastes in agriculture

Assessment of the use of municipal and industrial wastes in agriculture Agricultural usability of urban and industrial wastes was investigated in 2004 - 2006 in a pot experiment carried out in the vegetation hall. In the first year of the experiment maize was the test plant, oat grass in the second and oat in the third. The experimental design comprised 11 treatments differing with fertilizer and the kind of the supplied fertilizer components. The experiment used: mineral salts, farmyard manure, compost, municipal sewage sludge and industrial sewage sludge in two fertilizer doses. Metal concentrations in the test plants were diminishing in the following direction: oat grass < maize < oat. The lowest concentrations of the analyzed heavy metals were assessed in the plants fertilized with farmyard manure and compost (Zn, Cu). Among the tested plants the highest quantities of Zn, Cu, Ni, Pb and Cd were removed with the yield of the oat grass, then maize and oat. The highest uptake of Zn, Cu, Ni and Pb by plants was registered on a double dose of industrial sludge and Cd on a single dose of municipal sludge.

Assessment of the pollution and ecological risk of lead and cadmium in soils

The aim of the study was to assess the content, distribution, soil binding capacity, and ecological risk of cadmium and lead in the soils of Malopolska (South Poland). The investigation of 320 soil samples from differently used land (grassland, arable land, forest, wasteland) revealed a very high variation in the metal content in the soils. The pollution of soils with cadmium and lead is moderate. Generally, a point source of lead and cadmium pollution was noted in the study area. The highest content of cadmium and lead was found in the northwestern part of the area—the industrial zones (mining and metallurgical activity). These findings are confirmed by the arrangement of semivariogram surfaces and bivariate Moran’s correlation coefficients. Among the different types of land use, forest soils had by far the highest mean content of bioavailable forms of both metals. The results showed a higher soil binding capacity for lead than for cadmium. However, for both metals, extremely high (class 5) accumulation capacities were dominant. Based on the results, the investigated soils had a low (Pb) and moderate (Cd) ecological risk on living components. Soil properties, such as organic C, pH, sand, silt, and clay content, correlated with the content of total and bioavailable forms of metals in the soils. The correlations, despite being statistically significant, were characterized by very low values of correlation coefficient (r = 0.12–0.20, at p ≤ 0.05). Therefore, the obtained data do not allow to define any conclusions as to the relationships between these soil properties. However, it must be highlighted that there was a very strong positive correlation between the total content of cadmium and lead and their bioavailable forms in the soils.

Effect of wheat and Miscanthus straw biochars on soil enzymatic activity, ecotoxicity, and plant yield

Abstract The variety of technological conditions and raw materials from which biochar is produced is the reason why its soil application may have different effects on soil properties and plant growth. The aim of this study was to evaluate the effect of the addition of wheat straw and Miscanthus giganteus straw (5 t DM ha−1) and biochar obtained from this materials in doses of 2.25 and 5 t DM ha−1 on soil enzymatic activity, soil ecotoxicity, and plant yield (perennial grass mixture with red clover). The research was carried out under field conditions on soil with the granulometric composition of loamy sand. No significant effect of biochar amendment on soil enzymatic activity was observed. The biochar-amended soil was toxic to Vibrio fischeri and exhibited low toxicity to Heterocypris incongruens. Application of wheat straw biochar and M. giganteus straw biochar in a dose of 5 t DM ha−1 contributed to an increase in plant biomass production by 2 and 14%, respectively, compared to the soil with mineral fertilisation. Biochars had a more adverse effect on soil enzymatic activity and soil ecotoxicity to H. incongruens and V. fischeri than non-converted wheat straw and M. giganteus straw, but significantly increased the grass crop yield.