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Ore-mining industry produces a waste, which belongs to the main sources of potentially toxic elements (PTEs). One of the initial steps necessary for remediation project of contaminated sites is the research of PTEs mobile forms that are very capable to enter trophic chain mainly through plants. Great abandoned copper deposit São Domingos (Portugal) was selected as a representative area since the presence of high PTEs contents was proved there in previous research activities.The presented work is focused on efficiency of natural sorbents on the immobilisation of PTEs in copper-polluted soil developed on tailings taken from the mine district, and to compare the treated soils as habitats of vascular plants. Several natural sorbents were selected for the adequate realization of experimental part: bentonite, charcoal, calcium carbonate, phosphate, chicken manure, and organo-zeolitic substrate (mixture of perlite, chicken manure, and calcium carbonate; 5:1:3).From the whole area of the mine-dump, 10 sites were chosen as the representatives of not-so-heterogenic soil conditions, where the sampling itself was realized. As the representative PTEs; Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Sb were chosen. The sorbents were added to composite soil sample. Ex situ experiments were realized from 1st of June to 30th of September 2020. At the end of experiments, a soil sample from each pot were taken, dried and grained into the fine powder. For assessment of total concentration of elements, microwave digestion was performed, with 100 mg of grained powder dissolution in aqua regia. For the purpose to assess the forms of PTEs with the ability to be assimilated by plant roots, the extraction from 1 g of sample was executed in the sequence: I. deionized water; II. 1M ammonium acetate solution by pH 7 (both mixed for 12 hours); 0.01M citric acid solution (mixed for 2 hours). First two fractions can be referred as mobile / exchangeable. The prcessed soil solutions were measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS).The technosol was contamined mainly by As, Cu, and Zn. Obtained results show that neither As nor Sb are present in inverstigated francions, whereas the concentrations of Cr is also very low. The other PTEs are contained in significat concentrations, mostly in mobile fraction, especially Co (36 %); Mn (27 %); Cu (25 %); and Cd (15 %). Among the natural sorbents, the only ones efficient in reducting the mobile forms were charcoal and organo-zeolitic substrate. These pots were also the only suitable habitats for mixture of grass species. In both cases, the mobile contents of Ni, Cu, and Zn were practically reduced to zero since the mobile contents of Co, Mn and Cd decreased to minimum. For better understanding of habitat-suitability after application of those sorbents, the plant-nutrient characterisation should be included in further research. Based on those results, both natural sorbents could be considered for application in remediation techniques aimed on those PTEs.

Second-generation biofuel crop miscanthus is one of the most promising plants tested for phytomanagement of contaminated sites. In this preliminary pot case study, the most used hybrid Miscanthus x giganteus was cultivated in three different real contaminated soils: agricultural soil contaminated with Cd, post-military soil slightly contaminated with Zn, Pb and Cd, and soil contaminated by petroleum industry with metals and hydrocarbons. The stress response of plants and soil microbial communities was monitored to receive data that are important for successful phytomanagement application. With metals only, the plant grew well, and chlorophyll fluorescence measurement proved their good vitality. Changes in leaf anatomy (leaf thickness and sclerenchyma cells area) were additionally determined in post-military soil compared to agricultural. On the contrary, in petroleum-contaminated soil, the biomass yield was too reduced and also physiological parameters were significantly decreased. The response of microbial communities also differed. In agricultural soil, no microbial stress was determined. In post-military soil, it became reduced during the experiment, and in petroleum contamination, it increased year-on-year. It could be concluded that miscanthus is suitable for cultivation in metals contaminated soils with potential for microbial communities support, but in soil contaminated by the petroleum industry, its application did not seem meaningful.

Bioenergy crops such as Miscanthus x giganteus are foreseeable as an alternative source to replace fossil fuel and reduce greenhouse gas emissions. They are also assessed as an environment-friendly solution for polluted, marginal and low-quality agricultural soils. Several studies had been launched on soil organic carbon sequestration potentials of miscanthus culture along with its impacts on restoring soil functionality, most of which focus on the long-term basis of the plant’s cultivation. Nevertheless, information concerning the short term impacts as well as the situation in Czechia is still scarce. In this context, a field experiment was launched in 2017 in a poor-quality agricultural land in the city of Chomutov (North-Western Czechia) to compare the impacts of the perennial C4 miscanthus with an annual C3 forage crop (wheat) on the soil carbon stocks as well as enhancing its functionality. Results through the 0–30 cm soil profile examination showed that miscanthus plants played a role in improving the studied soil physico-chemical (bulk density and soil organic carbon concentrations) and biological (Phospholipid fatty acids stress indicator, basal respiration and fluorescein diacetate hydrolytic activity) parameters. The naturally occurring δ13C concentrations were used to evaluate the direct plant contribution to the total soil organic carbon (SOC) stocks and revealed considerable miscanthus contribution all over the detected soil layers (1.98 ± 0.21 Mg C. ha−1 yr−1) after only 3 growing seasons. It is thus suggested that the C4 perennial miscanthus possess remarkable prospects for SOC sequestration and restoring degraded lands.

Miscanthus × giganteus proved good phytostabilization potentials in heavy metals-contaminated soils. However, the coexistence of multiple pollutants (heavy metals and organic) in soil is very common and renders remediation more complicated. The aim of the current work was to investigate the impacts of miscanthus crop on enhancing the health and quality of agricultural soils contaminated by single (heavy metals, polycyclic aromatic hydrocarbons and total petroleum hydrocarbons) and/or multiple pollutants. Ex situ experiment was established by cultivating miscanthus in soils spiked by gradient concentrations of single and/or multiple contaminants. The experiment lasted for a period of 5 months, which corresponds to a complete miscanthus growing season. The results demonstrated high plant resistance and growth yields against the various contaminants, as well as a remarkable decrease in metals availability and organic pollutants concentrations in the cultivated soils. In addition, miscanthus plants boosted the soil biological parameters (acid phosphatase, laccase, urease, basal respiration, fluorescein diacetate hydrolytic activity and microbial biomass). This outcome confirms the crop’s capacity to proliferate well and enhance the quality of agricultural soils polluted by single/multiple contaminants. However, these results should be validated under real contaminated field conditions.

Magnetic sorbents represent very promising materials for environmental applications due to their simple synthesis, separability in a magnetic field, low toxicity, wide range of possible modifications, and usability in heterogeneous systems. We report on the synthesis, characterization, and application of magnetically separable Fe3O4/SiO2 sorbent surface-modified with octadecyl chains (C18). Preparation of Fe3O4 cores by co-precipitation from Fe2＋ and Fe3＋ chlorides in an alkaline aqueous solution was followed by SiO2 shell synthesis and functionalization with C18. Fe3O4, Fe3O4/SiO2, and Fe3O4/SiO2-C18 samples were characterized by SEM, TOC, XRD, BET, and tested for purification of water contaminated by various polycyclic aromatic hydrocarbons (PAHs). Since PAHs are formed as by-products of pyrolysis, a rapidly evolving technology for transformation of waste into green chemicals, there is a need for efficient sorbents suitable for PAHs removal from the environment. The use of Fe3O4/SiO2-C18 for adsorption of 16 different PAHs has not yet been reported. The adsorption was examined by gas chromatography with mass spectrometry and studied using molecular modeling. Comparison of adsorption efficiency η for Fe3O4, Fe3O4/SiO2, and Fe3O4/SiO2-C18 revealed a positive effect of C18. When averaging all Fe3O4/SiO2-C18 doses tested (1–8 g/L), η > 80% and > 90% was found for 14 and 7 PAHs, respectively, out of a total of 16 tested PAHs. The highest η values were found for medium-heavy PAHs (178.2–228.2 g/mol). Exhibiting high efficiency and average capacity of ∼ 1 μ g/g, the Fe3O4/SiO2-C18 is suitable for pre-concentration purposes of PAHs in analytical sample extractions from water.

Titania-iron mixed oxides with various Ti:Fe ratio were prepared by homogeneous hydrolysis of aqueous solutions of titanium(IV) oxysulphate and iron(III) sulphate with urea as a precipitating agent. The synthesized samples were characterized by X-ray diffraction, Raman and infrared spectroscopy, scanning and transmission electron microscopy, XRF analysis, specific surface area (BET) and porosity determination (BJH). These oxides were used for degradation of organophosporus pesticide parathion methyl. The highest degradation efficiency approaching

The phospholipid fatty acid (PLFA) content was determined in samples of Paracoccus denitrificans encapsulated in silica hydrogel films prepared from prepolymerized tetramethoxysilane (TMOS). Immediately after encapsulation the total PLFA concentration was linearly proportional to the optical density (600 nm) of the input microbial suspension (R2 = 0.99). After 7 days this relationship remained linear, but with significantly decreased slope, indicating a higher extinction of bacteria in suspensions of input concentration 108 cells/mL and higher. trans-Fatty acids, indicators of cytoplasmatic membrane disturbances, were below the detection limit. The cy/pre ratio (i.e., ratio of cyclopropylated fatty acids (cy17:0 + cy19:0) to their metabolic precursors (16:1ω7 + 18:1ω7)), an indicator of the transition of the culture to a stationary growth-phase, decreased depending on co-immobilization of nutrients in the order phosphate buffer > mineral medium > Luria Broth rich medium. The ratio, too, was logarithmically proportional to cell concentration. These results confirm the applicability of total PLFA as an indicator for the determination of living biomass and cy/pre ratio for determination of nutrient limitation of microorganisms encapsulated in sol-gel matrices. This may be of interest for monitoring of sol-gel encapsulated bacteria proposed as optical recognition elements in biosensor construction, as well as other biotechnological applications.

A new kind of magnetically separable composite consisting of maghemite grains and cerium oxide nanocrystalline surface layer (CeO 2 /γ-Fe 2 O 3 ) was successfully used as so called “reactive sorbent” to decompose certain dangerous organophosphate compounds, including the organophosphorus pesticide parathion methyl and the chemical warfare agents soman and VX. The phosphatase-mimetic behaviour of the sorbent was also demonstrated. A reversed-mode co-precipitation of Fe 3+ /Fe 2+ salts with aqueous ammonia was used to prepare the magnetite core, with the subsequent precipitation of cerous carbonate on the surfaces of the magnetite grains (again in the reversed mode) and its conversion to cerium oxide by calcination in the presence of air. The magnetite was converted to maghemite during calcination. Scanning electron microscopy (SEM), high-resolution transmission microscopy (HRTEM) and electron diffraction (ED) confirmed the presence of the nanocrystalline layer of CeO 2 on the sorbent surface. The CeO 2 /γ-Fe 2 O 3 composite materials prepared at the optimum temperatures of 300–400 °C exhibited the highest degradation efficiency and simultaneously retained good magnetic properties. Very high degradation rates (reaction half-lives of approximately ten minutes or less) were achieved at ambient temperature, with the degree of conversion approaching 100%. The facile separability of the sorbents using, for example, permanent magnets may enable their versatile use in various decontamination strategies.

Soil is a key part of a biotope and microorganisms are dominant components contributing to soil functions. Conversely, established methods for valuation of biotopes according to Natura 2000 rely predominantly on the communities living on the surface. Here, we aimed to assess soil microbial biomass and community structure on five localities with range of biotope values by means of phospholipid fatty acid (PLFA) profiling. PLFA figures were affected both by sampling season (spring vs. autumn) and locality. In spring, the living microbial biomass (estimated by PLFAtot) exhibited poor correlation to biotope values. These were, on the contrary, correlated to trans/cis PLFA, an indicator of microbial stress, (i.e., lower stress in higher-rated biotopes), and fungal/bacterial PLFA (i.e., higher-rated biotopes contained more fungi). The attempt to model biotope values from microbial characteristics explained a maximum of ~50% of the variability; the best predictors were the trans/cis stress indicator, percentage of actinobacterial PLFA, and ratio of PLFA of Gram-positive to Gram-negative bacteria. These results show that soil microbial characteristics present partly new information and indicate the need to amend the procedures of biotope assessment. Soil PLFA profiling could serve as suitable methods for this purpose.

The content of phospholipid fatty acids (PLFA) was determined in samples of polyvinyl alcohol lenses (Lentikats Biocatalyst, LB) with encapsulated Paracoccus denitrificans withdrawn during long-term denitrification experiments. The total PLFA content correlated highly with specific denitrification activities of LB as well as biomass estimation based on image analyses of microscopic photos. The results confirmed the applicability of PLFA determination for estimation of the amount of living encapsulated microbial biomass during biotechnological applications.

At present, there is great demand for new resistant and metabolically active strains of biodegrading bacteria capable of degrading high concentrations of petroleum pollutants. In this study, we undertook a series of pot-based biodegradation experiments on soil from a petroleum refinery lagoon heavily polluted with aliphatic hydrocarbons (81.6 &plusmn, 2.5 g&middot, kg&minus, 1 dry weight) and metals. Periodical bioaugmentation with either a mixture of isolated degraders identified as Bacillus sp. and Ochrobactrum sp. or biostimulation with nutrient medium, singly or in combination, did not produce any significant decrease in hydrocarbons, even after 455 days. Inoculation with Gordonia rubripertincta CWB2 and Rhodococcus erythropolis S43 in iron-limited media, however, resulted in a significant decrease in hydrocarbons 45 days after bioaugmentation. These actinobacterial strains, therefore, show significant potential for bioremediation of such highly polluted soils.

In the Protected Landscape Area “Labské pískovce” (Czech Republic), there are many sandstone caves accessible by permission only and where climbing equipment is commonly required. The tradition of visiting the caves dates back to turn of the 19th and 20th centuries, and visitors traditionally record their visits in log-books. We have gathered attendance data from 12 caves from log-books and via survey (2-year form collection period). The attendance varied from less than 10 to ~650 visitors annually. Signs of inadequate behavior of visitors were observed, especially waste disposal and smoking in the caves. Sediment step-compression increased significantly the ratios of fungi/bacteria and gram-positive to gram-negative (G+/G−) phospholipid fatty acids (PLFA) as well as PLFA of actinobacteria and activities of sediment phosphatases, glucosidases, and peroxidases. The number of visitors was correlated positively with the G+/G− ratio and sediment nutrients but negatively with sediment moisture and the activity of peroxidases. The results indicate a significant effect of attendance on sediment microbial communities, most likely caused by the import of nutrients into caves. Hence, reconsideration of the cave attendance policy is recommended.

Possible enhancement of biodegradation of petroleum hydrocarbons in agricultural soil after tank truck accident (~5000 mg/kg dry soil initial concentration) by bioaugmentation of diesel degradingPseudomonas fluorescensstrain and addition of abiotic additives (humates, zeolite) was studied in a 9-month pot experiment. The biodegradation process was followed by means of analytical parameters (hydrocarbon index expressed as content of C10–C40aliphatic hydrocarbons, ratio pristane/C17, and total organic carbon content) and characterization of soil microbial community (content of phospholipid fatty acids (PLFA) as an indicator of living microbial biomass, respiration, and dehydrogenase activity). The concentration of petroleum hydrocarbons (C10–C40) was successfully reduced by~60% in all 15 experiment variants. The bioaugmentation resulted in faster hydrocarbon elimination. On the contrary, the addition of humates and zeolite caused only a negligible increase in the degradation rate. These factors, however, affected significantly the amount of PLFA. The humates caused significantly faster increase of the total PLFA suggesting improvement of the soil microenvironment. Zeolite caused significantly slower increase of the total PLFA; nevertheless it aided in homogenization of the soil. Comparison of microbial activities and total PLFA revealed that only a small fraction of autochthonous microbes took part in the biodegradation which confirms that bioaugmentation was the most important treatment.

The bioluminescence (BLM) and colony-forming units (CFU) of Pseudomonas fluorescens HK44 were monitored during encapsulation into pre-polymerized Si(OMe)4. The non-induced BLM of free cells was increased in the presence of 0.5–2.5 % MeOH. After mixing silica sol with the cell suspension, both BLM and CFU dropped to 1–3 and 8–18 %, respectively; both remained lowered as long as the silica biofilm contained residual MeOH. The kinetics of MeOH being released from silica biofilms (a thickness of 2–6 mm) were first-order. The decrease of bacterial activity due to encapsulation was proportional to the biofilm thickness. MeOH evolving during encapsulation is probably the principal stress factor but not the only one.