The aim of this study was to evaluate the Zn sensitivity of Euplotes vannus, Euplotes crassus, and their naturally associated bacteria sampled from sediments in the northwest and east regions of Guanabara Bay. The unexposed ciliates and bacteria did not appear to be negatively affected by 96 h of assay. In the control group, E. vannus exhibited an increase in the biomass content from 2.3 × 10²to 2.3 × 10³ μg C cm⁻³between 0 and 96 h, and E. crassus increased up to 7.07 × 10² μg C cm⁻³at 48 h. The maximum biomass was pointed by E. crassus (1.33 × 10³ μg C cm⁻³) in the presence of 0.005 mg Zn L⁻¹and E. vannus was naturally associated bacteria (2.40 × 10⁻¹ μg C cm⁻³) in the presence of 1.0 mg Zn L⁻¹(96 h). The growth of E. vannus from the northwest region showed concentration-dependent manners, and it is more sensitive to zinc than E. crassus from the southeast. Naturally associated bacteria showed better adaptation to increasing concentrations of Zn, and the Dunnett test showed that previous environmental selection is important. These results show that new bioremediation tools are necessary.

Olive mill wastewater is considered as one of the most polluting effluents of the food industry and constitutes a source of important environmental problems. In this study, the removal of pollutants (chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), polyphenols, turbidity, color, total suspended solids (TSS), and oil and grease) from olive oil mill processing wastewater by peroxi-electrocoagulation/electrooxidation-electroflotation process with bipolar aluminum electrodes was evaluated using a pilot continuous reactor. In the electrochemical unit, aluminum (Al), stainless steel, and RuO₂/Ti plates were used. The effects of pH, hydrogen peroxide doses, current density, NaCl concentrations, and reaction times were studied. Under optimal conditions of pH 4, current density of 40 mA/m², 1000 mg/L H₂O₂, 1 g/L NaCl, and 30-min reaction time, the peroxi-electrochemical method yielded very effective removal of organic pollution from the olive mill wastewater diluted four times. The treatment process reduced COD by 96 %, BOD₅by 93.6 %, total, polyphenols by 94.4 %, color by 91.4 %, turbidity by 88.7, suspended solids by 97 % and oil and grease by 97.1 %. The biodegradability index (BOD₅/COD) increased from 0.29 to 0.46. Therefore, the peroxi-electrocoagulation/electrooxidation-electroflotation process is considered as an effective and feasible process for pre-treating olive mill wastewater, making possible a post-treatment of the effluent in a biological system.

Environmental palladium levels are increasing because of anthropogenic activities. The considerable mobility of the metal, due to solubilisation phenomena, and its known bioavailability may indicate interactions with higher organisms. The aim of the study was to determine the Pd uptake and distribution in the various organs of the higher plant Pisum sativum and the metal-induced effects on its growth and reproduction. P. sativum was grown in vermiculite with a modified Hoagland’s solution of nutrients in the presence of Pd at concentrations ranging 0.10–25 mg/L. After 8–10 weeks in a controlled environment room, plants were harvested and dissected to isolate the roots, stems, leaves, pods and peas. The samples were analysed for Pd content using AAS and SEM-EDX. P. sativum absorbed Pd, supplied as K₂PdCl₄, beginning at seed germination and continuing throughout its life. Minimal doses (0.10–1.0 mg Pd/L) severely inhibited pea reproductive processes while showing a peculiar hormetic effect on root development. Pd concentrations ≥1 mg/L induced developmental delay, with late growth resumption, increased leaf biomass (up to 25 %) and a 15–20 % reduction of root mass. Unsuccessful repeated blossoming efforts led to misshapen pods and no seed production. Photosynthesis was also disrupted. The absorbed Pd (ca. 0.5 % of the supplied metal) was primarily fixed in the root, specifically in the cortex, reaching concentrations up to 200 μg/g. The metal moved through the stem (up to 1 μg/g) to the leaves (2 μg/g) and pods (0.3 μg/g). The presence of Pd in the pea fruits, together with established evidence of environmental Pd accumulation and bioavailability, suggests possible contamination of food plants and propagation in the food chain and must be the cause for concern.

Three short sediment cores from inner continental shelf of the southern South China Sea (5–50 km) off Terengganu were analyzed for lipid contents (i.e., homologous aliphatic compounds and sterols) using gas chromatography-mass spectrometry. The concentrations of the total aliphatic hydrocarbons (TAHs) ranged from 0.152 to 6.91 μg/g dry weight. The n-alkane distribution was from nC₁₃to nC₃₆, with a carbon preference index (CPI₁₃–₃₅) from 1.08 to 4.28 and a carbon number maximum (Cₘₐₓ), depending on a sample, at 31 or 18. In addition, a strong odd-to-even carbon number predominance was observed in nC₂₅–nC₃₅range. The distribution of the n-alkanoic acids and n-alkanols in all samples exhibited an even-to-odd carbon number predominance and ranged from C₁₀to C₂₆and from C₁₂to C₃₄, respectively. The n-alkanols were dominated by the long-chain homologs with Cₘₐₓat 22; on the other hand, the n-alkanoic acid distributions showed a predominance of short-chain homologs with a Cₘₐₓat 16. The total sterol concentrations ranged from 0.41 to 3.57 μg/g dry weight. Cholesterol was most abundant at the offshore stations, whereas sitosterol was dominant at near-shore station. Pentacyclic triterpenoids such as friedelin and taraxerol α- and β-amyrins, which are known biomarkers for higher plants, were detected at all stations with a dilution trend offshore. In conclusion, the marine sediments off southern Terengganu can still be considered uncontaminated, where the compound sources are biogenic from terrestrial plants superimposed with a marine productivity input.

Energetic characterization of biomass allows for assessing its energy potential for application in different conversion processes into energy. The objective of this study is to physicochemically characterize pineapple crown leaves (PC) for their application in energy conversion processes. PC was characterized according to ASTM E871-82, E1755-01, and E873-82 for determination of moisture, ash, and volatile matter, respectively; the fixed carbon was calculated by difference. Higher heating value was determined by ASTM E711-87 and ash chemical composition was determined by XRF. The thermogravimetric and FTIR analyses were performed to evaluate the thermal decomposition and identify the main functional groups of biomass. PC has potential for application in thermochemical processes, showing high volatile matter (89.5 %), bulk density (420.8 kg/m³), and higher heating value (18.9 MJ/kg). The results show its energy potential justifying application of this agricultural waste into energy conversion processes, implementing sustainability in the production, and reducing the environmental liabilities caused by its disposal.

The subcellular localization and chemical forms of copper in castor (Ricinus communis L.) seedlings grown in hydroponic nutrient solution were identified by chemical extraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The wild castor seeds were harvested from an abandoned copper mine in Tonglu Mountain, Daye City of Hubei Province, China. The results revealed that (1) the seedlings grew naturally in MS liquid medium with 40.00 mg kg⁻¹CuSO₄, in which the seedling growth rate and biomass index were 0.14 and 1.23, respectively, which were the highest values among all the treatments. The copper content in castor seedlings increased along with elevated CuSO₄concentration in the medium, reaching a maximum value of 16 570.12 mg kg⁻¹(DW) when exposed to 60.00 mg L⁻¹CuSO₄, where 91.31 % of the copper was accumulated in roots. (2) The copper existed in various chemical forms in the roots of the castor seedlings. Copper of 67.66 % was extracted from the components of cell walls, such as exchangeable acidic polar compounds, cellulose and lignin, protein and pectin, and less concentrated in cell cytoplasm and nuclei. (3) Furthermore, the root cell walls were thickened when the castor seedlings exposed to CuSO₄, with a large amount of high-density electron bodies, attached to the thickened cell walls. In the cell walls, most copper was bound to the carboxyl (−COOH) and hydroxyl (−OH) groups of acidic polar compounds, cellulose, hemicellulose, and polysaccharides. The conclusion showed that castor exhibited a strong tolerance to copper, the copper were accumulated mainly in the root cell, the root cell walls of castor were the major location of patience and detoxification in copper stress.

Intensive agricultural system with high input of fertilizer results in high agricultural output. However, excessive fertilization in intensive agricultural system has great potential to cause nitrate and heavy metal accumulation in soil, which is adverse to human health. The main objective of the present study was to observe the effects of intercropping and inoculation of endophytic bacterium Acinetobacter calcoaceticus Sasm3 on phytoremediation of combined contaminated soil in oilseed rape (Brassica napus L.). The results showed that with Sasm3 inoculation, the biomass of rape was increased by 10–20 % for shoot, 64 % for root, and 23–29 % for seeds while the nitrate accumulation in rape was decreased by 14 % in root and by 12 % in shoot. The cadmium concentration in rape increased significantly with mono-inoculating treatment, whereas it decreased significantly after intercropping treatment. By denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR analysis, the diversity of bacterial community and the number of nirS and nirK gene copies increased significantly with inoculation or/and intercropping treatment. In conclusion, the endophytic bacterium Sasm3-inoculated intercropping system not only improved the efficiency of clearing cadmium from soil without obstructing crop production, but also improved the quality of crop.

The importance of road traffic, residential heating and meteorological conditions as major drivers of urban PM₁₀ concentrations during air pollution critical episodes has been assessed in the city of Florence (Italy) during the winter season. The most significant meteorological variables (wind speed and atmospheric stability) explained 80.5–85.5 % of PM₁₀ concentrations variance, while a marginal role was played by major emission sources such as residential heating (12.1 %) and road traffic (5.7 %). The persistence of low wind speeds and unstable atmospheric conditions was the leading factor controlling PM₁₀ during critical episodes. A specific PM₁₀ critical episode was analysed, following a snowstorm that caused a “natural” scenario of 2-day dramatic road traffic abatement (−43 %), and a massive (up to +48 %) and persistent (8 consecutive days) increase in residential heating use. Even with such a strong variability in local PM₁₀ emissions, the role of meteorological conditions was prominent, revealing that short-term traffic restrictions are insufficient countermeasures to reduce the health impacts and risks of PM₁₀ critical episodes, while efforts should be made to anticipate those measures by linking them with air quality and weather forecasts.

Low-cost and environmentally friendly mediators could facilitate the application of laccase (EC 1.10.3.2) in variant biotechnological processes. Acetylacetone (AA) represents an inexpensive and low toxic small molecular diketone that has been proven as an effective mediator for laccase in free radical polymerization. However, the potential of AA as a mediator for laccase in pollutant detoxification and/or degradation is still unknown. In this work, the roles of AA in laccase-induced polymerization and transformation were investigated. AA was demonstrated to be a highly efficient mediator in the laccase-induced grafting copolymerization of acrylamide and chitosan. The efficacy of AA in the laccase-induced decoloration of malachite green (MG) was compared with that of the widely used 1-hydroxybenzotriazole (HBT). The laccase-AA system had the highest turnover number (TON, 39.1 μmol/U), followed by the laccase-only system (28.5 μmol/U), while the TON of the laccase-HBT system was the lowest (14.9 μmol/U). The pseudo-first-order transformation rate constant (k ₁) of MG in the laccase-AA system was up to 0.283 h⁻¹ under the given conditions, while the k ₁ of AA caused by laccase was only 0.008 h⁻¹. In the five-cycle run, the concentration of AA remained stable. The larger TON of the laccase-AA system and the stability of AA in the cycling runs demonstrate that AA was more recyclable than HBT in the LMS, leading to a prolonged serving life of laccase. These results suggest that AA might be a potential redox mediator for laccase.

In this study, simulated fly ash containing CuO/CuCl₂ was heated at 350 °C in a flow of N₂ and also in a nitrogen flow containing 10 vol% H₂, to evaluate the influence of hydrogen adding on dioxin formation. The total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) output derived from the CuO sample under N₂ and 10 % H₂ was 7.382 and 0.708 ng/g, respectively. As for CuCl₂, it was 589 and 46.1 ng/g, respectively. The results show that the hydrogen adding has a good inhibition effect on PCDD/F formation; the inhibition rate was higher than 90 % for PCDD/Fs. HCl and NH₃ were detected by Gasmet in the flue gas; the probable inhibition mechanism of hydrogen reaction was proposed, based on our measurements and others’ researches.