A novel PCR-free DNA-based assay was developed for the detection of Vibrio spp. A sandwich hybridization format using an immobilized capture probe and a labeled signal probe was selected and combined with chemiluminescent method for the detection of the RNA target. In a first step, probes were validated using positive controls (PCs). A linearity was observed between 0.1 and 2.5 nM of PC, and detection limit was determined as 0.1 nM. In a second step, specificity was checked by using RNA extracted from a panel of 31 environmental bacterial strains. Detection limit of 5 ng μL⁻¹ of total fragmented RNA was obtained, and the assay allowed a good discrimination between the 21 Vibrio and the 10 non-Vibrio strains tested. Finally, the DNA-based assay was successfully applied to analysis of spiked and natural environmental samples. Stability and analysis time of the DNA-based assay were also investigated to optimize working conditions. We demonstrated that microplates can be coated beforehand with capture probe and stored at 4 °C without any buffer in wells for at least 30 days. The use of the pre-made plates enables the assay to be completed in 2 h. The developed assay appeared as an interesting tool to determine the presence of bacteria in environmental samples.

Veterinary antimicrobials are emerging environmental contaminants of concern. In this study, the sorption of enrofloxacin (ENR) onto humic acids (HAs) extracted from three Brazilian soils was evaluated. HAs were characterized by elemental analysis and solid ¹³C nuclear magnetic resonance spectroscopy. The sorption of ENR onto HAs was at least 20-fold higher than onto the soils from which they were separated. Ionic and cation bridging are the primary interactions involved. The interactions driven by cation exchange are predominant on HAs, which appear to have abundant carboxylic groups and a relatively high proportion of H-bond donor moieties with carbohydrate-like structures. Interactions explained by cation bridging and/or surface complexation on HAs are facilitated by moieties containing conjugated ligands, significant content of oxygen-containing functional groups, such as phenolic-OH or lignin-like structures. HAs containing electron-donating phenolic moieties and carboxylic acid ligand groups exhibit a sorption mechanism that is primarily driven by strong metal binding, favoring the formation of ternary complexes between functional groups of the organic matter and drugs.

The present work described that tertiary ammonium surfactants containing bromide ion as novel metal-free catalysts were innovatively coupled with peroxymonosulfate (PMS) to build a simple catalytic oxidation system, possessing outstanding catalytic ability with organic dye Reactive Red M-3BE (RR M-3BE) as the target pollutant. Furthermore, cetyltrimethylammonium bromide (CTAB), a representative of cationic surfactant, was selected to further investigate the catalytic oxidation performance. It is found that at the critical micelle concentration (CMC) of CTAB, the oxidation efficiency of the CTAB/PMS system was optimal due to the strong electrostatic attraction between the CTA⁺ micelle and reactive anions (Br⁻ and HSO₅ ⁻), concentrating HSO₅ ⁻ and Br⁻ at the micellar surface, which accelerated the catalytic oxidation reaction between Br⁻ and HSO₅ ⁻, generating a mass of highly active reactive species. A hybrid method that combined radical scavenger (methanol) with electron paramagnetic resonance (EPR) technology was adopted for the investigation of reactive species, and the results indicated that hydroxyl radical (•OH) was generated and had a major role in the process. The findings from this work provide a practicable pathway for highly efficient PMS activation in wastewater treatment, and also initiate a promising research area of surfactants in the field of environmental catalysis.

Insect repellents are widely applied to various materials and to both human and animal skin to deter mosquitoes and ticks. The most common deterrent compounds applied are DEET, EBAAP and icaridin (picaridin, Bayrepel). Due to their extensive application, these repellents are frequently detected in surface waters in considerable concentrations. As these compounds are designed to alter invertebrates’ behaviour rather than to intoxicate them, we hypothesised that insect repellents have the potential to modify the natural behaviour of non-target invertebrates in natural freshwater bodies. To test this, we used a well-established laboratory assay designed to quantify the odour-mediated foraging behaviour of freshwater gastropods and the great pond snail Lymnaea stagnalis (Linnaeus, 1758) as a model organism to test for potential deterrent effects of insect repellents on aquatic snails. Using a wide concentration range from the picogramme per litre to microgramme per litre range (and by far exceeding the range of concentrations reported from natural waters), we found no evidence for a deterrent effect of either of the three repellents on foraging L. stagnalis. Our data and other recent studies give no indication for undesirable behavioural alterations by common insect repellents in surface waters.

Atrazine and S-metolachlor are two of the most widely used herbicides for agricultural purposes; consequently, residues of both compounds and their metabolites had been detected in ground and superficial waters. Unlike atrazine, the complete degradation of metolachlor has not been achieved. Hence, the purpose of this research is to study the biodegradation of a commercial mixture of atrazine and S-metolachlor in a prototype of a multi-channel packed-bed-biofilm reactor (MC-PBR) designed with the aim of solving the problems of pressure drop and oxygen transfer, typically found on this type of bioreactors.Because the removal efficiency of the herbicides was increased when Candida tropicalis was added to the original microbial community isolated, the reactor was inoculated with this enriched community. The operational conditions tested in batch and continuous mode did not affect the removal efficiency of atrazine; however, this was not the case for S-metolachlor. The removal rates and efficiencies showed a notable variation along the MC-PBR operation.

Harmful algal blooms (HABs) are global threats to marine ecosystems, fisheries, and human health. Therefore, developing effective and accurate methods for identifying causative algae and monitoring seawater quality is urgent. However, traditional, microscopy-based methods are complex, inaccurate, and time-consuming. Here, we present a novel method for effective and sensitive detection of Chattonella marina using hyper-branched rolling circle amplification (HRCA) and HRCA-based strip test (HBST). The large subunit (LSU) ribosomal DNA (rDNA) D1–D2 region of C. marina was firstly sequenced to design a species-specific padlock probe (PLP). The HRCA reaction with two amplification primers and further HBST for C. marina was established. The optimized reaction conditions for HRCA were PLP concentration, 20 pM; ligation temperature, 65 °C; ligation time, 60 min; amplification temperature, 61 °C; and amplification time, 60 min. The developed HBST detection procedure involved HRCA reaction, test strip preparation, hybridization, coloration, and judgment of hybridization by the naked eye. Specificity and sensitivity of the established methods were validated. Moreover, the results showed that the established detection methods were specific and sensitive to C. marina. The detection limits of HRCA and HBST assays were 10 copies and 1 copy μL–¹ of plasmid with LSU rDNA of C. marina, which are of two and three respective magnitude orders higher than conventional PCR. Finally, the protocols were applied to the simulated field samples and the results showed that the developed HBST assay had higher detection sensitivity than HRCA and PCR. In conclusion, the methods presented in this study are promising for sensitive, intuitive, and specific detection of C. marina in field monitoring natural samples and may provide a good detection model for other harmful algae in the future.

In this article, a comparison will be made concerning the advantages and disadvantages of five kinds of coal mine methane (CMM) deoxygenation method, including pressure swing adsorption, combustion, membrane separation, non-metallic reduction, and cryogenic distillation. Pressure swing adsorption has a wide range of application and strong production capacity. To achieve this goal, adsorbent must have high selectivity, adsorption capacity, and adequate adsorption/desorption kinetics, remain stable after several adsorption/desorption cycles, and possess good thermal and mechanical stabilities. Catalytic combustion deoxygenation is a high-temperature exothermic redox chemical reaction, which releases large amounts of thermal energy. So, the stable and accurate control of the temperature is not easy. Meanwhile partial methane is lost. The key of catalytic combustion deoxygenation lies in the development of high-efficiency catalyst. Membrane separation has advantages of high separation efficiency and low energy consumption. However, there are many obstacles, including higher costs. Membrane materials have the requirements of both high permeability and high selectivity. The development of new membrane materials is a key for membrane separation. Cryogenic distillation has many excellence advantages, such as high purity production and high recovery. However, the energy consumption increases with decreasing CH₄ concentrations in feed gas. Moreover, there are many types of operational security problems. And that several kinds of deoxygenation techniques mentioned above have an economic value just for oxygen-bearing CMM with methane content above 30%. Moreover, all the above methods are not applicable to deoxygenation of low concentration CMM. Non-metallic reduction method cannot only realize cyclic utilization of deoxidizer but also have no impurity gases generation. It also has a relatively low cost and low loss rate of methane, and the oxygen is removed thoroughly. In particular, the non-metallic reduction method has good development prospects for low concentration oxygen-bearing CMM. This article also points out the direction of future development of coal mine methane deoxygenation.

Cadmium (Cd) transport in overland flow from agricultural soils is potentially important when trying to predict future soil Cd concentrations, but at present there is little information on the magnitude of loss from this pathway. This study measured Cd concentrations and fluxes in overland flow from a catchment where cattle winter-grazed a forage crop (kale) (Brassica oleracea) in year one and measurements continued in year two when the catchment was returned to pasture and grazed by sheep. Flow-weighted mean concentrations (FWMC) of total, particulate and dissolved Cd in overland flow events from the forage crop were 0.49, 0.41 and 0.08 μg L⁻¹, respectively. In contrast, no dissolved Cd was detected in overland flow from pasture, with a FWMC of total Cd of 0.09 μg L⁻¹. In line with the Cd concentrations, total Cd fluxes were greater from the forage crop (0.06 g Cd ha⁻¹ year⁻¹) than from pasture (0.04 g Cd ha⁻¹ year⁻¹). Cadmium losses in overland flow were relatively minor compared with those reported for other pathways such as plant uptake or subsurface flow. Further, compared to the amount of Cd that is currently added to soil in a maintenance application of phosphate fertiliser (30 kg P ha⁻¹ year⁻¹) which is on average 5.5 g Cd ha⁻¹, Cd losses in overland flow represented < 1% of inputs. Measurement of Cd losses in overland flow should be undertaken at other sites to confirm the low Cd losses found in this study, along with the distribution between dissolved and particulate fractions.

Eggshells are good bioindicators of environmental contamination, and therefore, the concentrations of 17 trace elements in 87 eggshells of black-headed gulls, Chroicocephalus ridibundus, were determined in five breeding colonies in an area dominated by farmland in northern Poland. The intra-clutch variability in the eggshell concentrations of heavy metals and other elements was also investigated, and the concentrations of the elements showed the following pattern: Ca > Mg > Sr > Fe > Zn > Al > Cr > Se > Mn > Cu > Pb > As > Ni > Mo = V > Sc > Cd. The concentrations of Fe, Al, and Mn decreased with the order in which the eggs were laid, but Sr concentrations increased. In contrast, the concentration of Cu significantly increased with the laying date. The concentrations of all elements significantly differed among the studied colonies; the highest concentration of eight elements was found in the eggshells from the Kusowo colony, which may have resulted from the intensive use of fertilizers, manure, and slurry in the surrounding agricultural region. The concentrations of Mg, Sr, and Zn in the eggshells from Skoki Duże were higher than those of the other studied colonies, which may have occurred because the gulls were nesting in a functioning gravel pit; soil and the parent rock are natural reservoirs of these elements. The observed element levels indicate that the environment where the black-headed gull eggs were formed, i.e., primarily near the breeding colonies, remains in a relatively unpolluted state, which was reflected by the low levels of Cd, Ni, and Pb and the lack of measurable levels of Hg.

The stable isotopes of δ¹⁸O, δ²H, and ⁸⁷Sr/⁸⁶Sr and dissolved major ions were used to assess spatial and seasonal water chemistry variability, chemical weathering, and hydrological cycle in the Pangani River Basin (PRB), Tanzania. Water in PRB was NaHCO₃ type dominated by carbonate weathering with moderate total dissolved solids. Major ions varied greatly, increasing from upstream to downstream. In some stations, content of fluoride and sodium was higher than the recommended drinking water standards. Natural and anthropogenic factors contributed to the lowering rate of chemical weathering; the rate was lower than most of tropical rivers. The rate of weathering was higher in Precambrian than volcanic rocks. ⁸⁷Sr/⁸⁶Sr was lower than global average whereas concentration of strontium was higher than global average with mean annual flux of 0.13 × 10⁶ mol year⁻¹. Evaporation and altitude effects have caused enrichment of δ¹⁸O and δ²H in dry season and downstream of the river. Higher d-excess value than global average suggests that most of the stations were supplied by recycled moisture. Rainfall and groundwater were the major sources of surface flowing water in PRB; nevertheless, glacier from Mt. Kilimanjaro has insignificant contribution to the surface water. We recommend measures to be taken to reduce the level of fluoride and sodium before domestic use.