The content of selected elements (Al, As, Ca, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S, Ti, V and Zn) was measured in samples of the lichen Evernia prunastri exposed for 30, 90 and 180 days around a cement mill, limestone and basalt quarries and urban and agricultural areas in SW Slovakia. Lichens transplanted around the investigated quarries and the cement mill rapidly (30 days) reflected the deposition of dust-associated elements, namely Ca (at the cement mill and the limestone quarry) and Fe, Ti and V (around the cement mill and the basalt quarry), and their content remained significantly higher throughout the whole period (30–180 days) with respect to the surrounding environment. Airborne pollutants (such as S) progressively increased in the study area from 30 to 180 days. The magnetic properties of lichen transplants exposed for 180 days have been characterized and compared with those of native lichens (Xanthoria parietina) and neighbouring bark, soil and rock samples, in order to test the suitability of native and transplanted samples as air pollution magnetic biomonitors. The magnetic mineralogy was homogeneous in all samples, with the exception of the samples from the basalt quarry. The transplants showed excellent correlations between the saturation remanent magnetization (Mrs) and the content of Fe. Native samples had a similar magnetic signature, but the values of the concentration-dependent magnetic parameters were up to two orders of magnitude higher, reflecting higher concentrations of magnetic particles. The concentrations of As, Ca and Cr in lichens correlated with Mrs values after neglecting the samples from the basalt quarry, which showed distinct magnetic properties, suggesting the cement mill as a likely source. Conversely, Ti and Mn were mostly (but not exclusively) associated with dust from the basalt quarry. It is suggested that the natural geological characteristics of the substrate may strongly affect the magnetic properties of lichen thalli. Taking this into account, the results of this study point out the suitability of lichens as air pollution magnetic biomonitors.

Application of modified sintering ferric-carbon ceramics (SFC) and sintering-free ferric-carbon ceramics (SFFC) based on coal ash and scrap iron for pretreatment of tetracycline (TET) wastewater was investigated in this article. Physical property, morphological character, toxic metal leaching content, and crystal component were studied to explore the application possibility of novel ceramics in micro-electrolysis reactors. The influences of operating conditions including influent pH, hydraulic retention time (HRT), and air-water ratio (A/W) on the removal of tetracycline were studied. The results showed that SFC and SFFC were suitable for application in micro-electrolysis reactors. The optimum conditions of SFC reactor were pH of 3, HRT of 7 h, and A/W of 10. For SFFC reactor, the optimum conditions were pH of 2, HRT of 7 h, and A/W of 15. In general, the TET removal efficiency of SFC reactor was better than that of SFFC reactor. However, the harden resistance of SFFC was better than that of SFC. Furthermore, the biodegradability of TET wastewater was improved greatly after micro-electrolysis pretreatment for both SFC and SFFC reactors.

The Büyük Menderes River (BMR) is one of the largest rivers in Turkey. This river irrigates efficient farmlands and includes tributaries of other rivers and streams and many populated towns within its limits in the Ege region. Both the estuary and Işıklı Lake serve as a sanctuary for various waterbirds. Therefore, the BMR plays a critical role both for the inhabitants and for the ecosystem organisms in its environs. In the present study, we analyzed levels of metals including iron, barium, zinc, vanadium, cobalt, chromium, cadmium, copper, nickel, aluminum, arsenic, manganese, antimony, silver, selenium, boron, mercury, titanium, and lead in river water, sediment, fish (Cyprinus carpio; common carp), and in various waterbird (Fulica atra, Euroasian coot; Larus michahellis, yellow-legged gull; Ardea cinerea, grey heron; Larus melanocephalus, Mediterranean gull; and Pelecanus crispus, pelican) samples. Analyses were performed using an inductively coupled plasma–mass spectrometry (ICP-MS) instrument after sample preparation. Comparing metal concentrations among different sample types, it was found that barium, aluminum, and zinc are the major metals in river water, and zinc in common carp muscle, while iron, aluminum, and manganese are the major metals in sediments. Iron, zinc, copper, and aluminum were the highest in waterbird muscle tissue. Iron and barium were found to be the major metals in eggshell, while iron and zinc are the major metals in egg samples. A simple “worst-case scenario” model of risk assessment revealed that some of the analyzed metals may pose a risk for human health through consuming fish.

Previous research found that the water-level fluctuating zone (WLFZ) of the Three Gorges Reservoir (TGR) was an Hg-sensitive area. However, little research has been conducted on the distribution of Hg-methylating microorganisms in this area. The goal of this research was to provide an initial description of the distribution of the dsrB (for sulfate-reducing bacteria) and hgcA (one gene confirmed for Hg methylation) genes. Different types of soil were selected to analyze the abundance of the dsrB and hgcA in different periods, in inundated soil (SI, ≤155 m, which becomes sediment during the wet period, SS) and in non-inundated soil (≥175 m, SN) from Shibao, a typical WLFZ of the TGR. A significant positive correlation was observed between dsrB and hgcA abundance and MeHg concentrations, suggesting that microorganisms with these genes contribute to Hg methylation. Principal component analysis (PCA) indicated that dsrB diversity was highest in SI, followed by SS; SS had the highest diversity of hcgA. Six phylogenetic trees were constructed and showed that more strains were present in SI than in SS. HgcA sequences in SS were confined to three evolutionarily distant clades, δ-Proteobacteria, a methanogen group, and a Clostridia group, which was relatively rare among most clades.

Solar photo-Fenton represents an innovative and low-cost option for the treatment of recalcitrant industrial wastewater, such as the textile wastewater. Textile wastewater usually shows high acute toxic and variability and may be composed of many different chemical compounds. This study aimed at optimizing and validating solar photo-Fenton treatment of textile wastewater in a semi-pilot compound parabolic collector (CPC) for toxicity removal and wastewater reclamation. In addition, treated wastewater reuse feasibility was investigated through pilot tests. Experimental design performed in this study indicated optimum condition for solar photo-Fenton reaction (20 mg L⁻¹ of Fe²⁺ and 500 mg L⁻¹ of H₂O₂; pH 2.8), which achieved 96 % removal of dissolved organic carbon (DOC) and 99 % absorbance removal. A toxicity peak was detected during treatment, suggesting that highly toxic transformation products were formed during reaction. Toxic intermediates were properly removed during solar photo-Fenton (SPF) treatment along with the generation of oxalic acid as an ultimate product of degradation and COS increase. Different samples of real textile wastewater were treated in order to validate optimized treatment condition with regard to wastewater variability. Results showed median organic carbon removal near 90 %. Finally, reuse of treated textile wastewater in both dyeing and washing stages of production was successful. These results confirm that solar photo-Fenton, as a single treatment, enables wastewater reclamation in the textile industry. Graphical abstract Solar photo-Fenton as a revolutionary treatment technology for “closing-the-loop” in the textile industry

Phenol hydroxylases (PHs) play a primary role in the bacterial degradation of phenol and alkylphenols. They are divided into two main classes, single-component and multi-component PHs, having distinctive catalytic subunits designated as PheA1 and LmPH, respectively. The diversity of these enzymes is still largely unexplored. Here, both LmPH and pheA1 gene sequences were examined in activated sludge from oil refinery wastewaters. Phenol, p-cresol, or 3,4-dimethylphenol (3,4-DMP) supplied as extra carbon sources were rapidly mineralized by the microbial community. Analysis of LmPH genes revealed a wide range of sequences, most of which exhibited moderate similarity with homologs found in Proteobacteria. Moreover, the LmPH diversity profiles showed a dramatic shift upon sludge treatment with p-cresol or 3,4-DMP amendment. This resulted in an enrichment in sequences similar to LmPHs from Betaproteobacteria and Gammaproteobacteria. RT-PCR analysis of RNA extracted from wastewater sludge highlighted LmPH genes best expressed in situ. A PCR approach was implemented to analyze the pheA1 gene diversity in the same microbial community. Retrieved sequences fell into four clusters and appeared to be distantly related to pheA1 genes from Actinobacteria. Altogether, our results provide evidence that phenol degraders carrying LmPH are more diverse than PheA1 carrying bacteria and suggest that PHs with best adapted substrate specificity are recruited in response to (methyl)phenol availability.

Analyses of trimethylsilyl-derivatized neutral lipids by gas chromatography coupled to mass spectrometry afford a wealth of information contained in the marine sediments. This information is useful for unraveling the processes associated with past climate changes such as those from glacial and interglacial periods. Studies of samples from the Iberian Margin deposited about 1,300,000–1,400,000 years ago afforded the qualitative identification and quantification of n-alkanes, n-alkan-1-ols, isoprenoids, triterpenoids, sterols, hopanols, alkenones, alkenols, and polycyclic aromatic hydrocarbons. Using this information, the lipidomic approach has allowed to identifying differences in sea surface temperatures, marine productivity, microbial degradation processes, and inputs from continental plants between these periods. Differences in predominant higher plant species related to climate changes have also been observed.

We studied the fate and toxicity of two types of CeO₂ NPs (bare or citrate-coated) in environmentally relevant conditions, using large indoor microcosms. Long-term exposure was carried out on a three-leveled freshwater trophic chain, comprising microbial communities as primary producers, chironomid larvae as primary consumers, and amphibian larvae as secondary consumers. Whereas coated NPs preferentially sedimented, bare NPs were mainly found in the water column. However, mass balance indicated low recovery (51.5%) for bare NPs, indicating possible NP loss, against 98.8% of recovery for coated NPs. NPs were rather chemically stable, with less than 4% of dissolution. Chironomid larvae ingested large amounts of NPs and were vectors of contamination for amphibian larvae. Although bioaccumulation in amphibian larvae was important (9.47 and 9.74 mg/kg for bare and coated NPs, respectively), no biomagnification occurred through the trophic chain. Finally, significant genotoxicity was observed in amphibian larvae, bare CeO₂ NPs being more toxic than citrate-coated NPs. ᅟ

This study evaluated decabromodiphenyl ether (BDE-209) anaerobic debromination and bacterial community changes in mangrove sediment. BDE-209 debromination rates were enhanced with zerovalent iron compared to without zerovalent iron in the sediment. BDE-209 debromination rates in microcosms constructed with sediments collected in autumn were higher than in microcosms constructed with sediments collected in spring and were higher at the Bali sampling site than the Guandu sampling site. The intermediate products resulting from the reductive debromination of BDE-209 in sediment were nona-BDE (BDE-206, BDE-207), octa-BDEs (BDE-196, BDE-197), hepta-BDEs (BDE-183, BDE-184, BDE-191), hexa-BDEs (BDE-137, BDE-138, BDE-154, BDE-157), penta-BDEs (BDE-85, BDE-99, BDE-100, BDE-126), tetra-BDEs (BDE-47, BDE-49, BDE-66, BDE-77), tri-BDEs (BDE-17, BDE-28), and di-BDEs (BDE-15). Fifty bacterial genera associated with BDE-209 debromination were identified. Overall, 12 of the 50 bacterial genera were reported to be involved in dehalogenation of aromatic compounds. These bacteria have high potential to be BDE-209 debromination bacteria. Different combinations of bacterial community composition exhibit different abilities for BDE-209 anaerobic debromination.

Soil salinity is a major abiotic stress that is constraining crop growth and productivity. Greenhouse hydroponic experiments were performed using salt-sensitive (cv. Zhongmian 41) and tolerant (Zhong 9806) cotton seedlings to evaluate how different genotypes responded to salinity stress in the presence of exogenous GSH (reduced glutathione). Cotton plants grown in 150 mM NaCl showed severe reduction in plant height, root length, and shoot and root fresh/dry weight. Salinity also caused reduction in photosynthesis and chlorophyll content, but increase in malondialdehyde (MDA) content. However, the reduction was more in Zhongmian 41 compared to Zhong 9806. Importantly, Sodium concentration was increased in the two genotypes and the induction was more in Zhongmian 41. Calcium and magnesium concentration was decreased in Zhongmian 41; however, in Zhong 9806 there were no significant differences relative to control. Addition of 50 mg L⁻¹ GSH in150 mM NaCl solution (Na + GSH) significantly alleviated salinity stress. Compared with salinity treatment alone (NaCl), Na + GSH increased fresh and dry weight of the root, stem, and leaf, photosynthesis, and chlorophyll content. Obvious ultrastructural alterations were observed in the saline-treated leaf- and root-tip cells. Exogenous GSH greatly ameliorated the salinity-induced damage on the leaf/root ultrastructure, especially in Zhongmian 41.These results advocate a positive role for GSH in alleviation of salinity, which is related to significant improvement in chlorophyll content, photosynthetic performance, and leaf/root ultrastructure.