Transcription of ATP-binding cassette (ABC) transporters has been evaluated in cell lines and primary cultures from gilthead seabream and European sea bass teleost fish exposed to methylmercury (MeHg), arsenic, cadmium or lead. The mRNA expression levels showed abcb1, abcc2 and abcc5 constitutive gene expression in all seabream tissues analyzed; however, we were unable to detect any constitutive transcription of abcb1 in many of the sea bass tissues. Furthermore, ABC mRNA expression levels were all affected by metal exposure, especially in the case of fish cell lines and erythrocytes, and greatly depended on cell type and fish species. Thus, while ABC transcription was up-regulated in the seabream cell line it was down-regulated in the sea bass cell line, while the opposite occurred in the primary cultures. All these data point to the importance of ABC transporters in metal detoxification and in the differential regulation in seabream and sea bass cells.

The present multiproxy investigation of marine sediment cores aims at: 1) Identifying dispersion of petroleum exploration related drill cutting releases within the Goliat Field, Barents Sea in 2006/07 and 2) Assessing past and present influence of drill cuttings on the marine environment. The cores were recovered 5, 30, 60, 125 and 250m from the drill site in the eastward downstream direction.Downstream dispersion of drill cuttings is evaluated by examining sediment grain size distribution and barium (Ba), heavy metal, total organic carbon and sulphur concentrations. Dispersion of drill cuttings was limited to <125m east from the drill site. Influence of drill cutting releases on the marine environment is assessed via microfaunal analysis of primarily calcareous benthic foraminifera. The findings suggest contemporaneous physical smothering at ≤30m from the drill site, with a natural fauna reestablishing after drilling cessation indicating no long-term effect of drill cutting releases.

Metal contamination is a serious environmental concern in the Middle East. Herein, geochemical fractionation distribution and potential sources of thirteen metals (Fe, Al, Mn, Zn, Cu, Co, Cr, Ni, V, As, Hg, Pb and Cd) were investigated in sediments from ten coral reef Islands in the Persian Gulf, Iran. To properly assess availability and mobility of elements, enrichment factor (EF), pollution load index (PLI), pollution index (PI), contamination index (CI), sediment pollution index (SPI) and ecological risk assessment were provided. Sediment grain size showed an outstanding role in controlling the levels of potentially toxic inorganic elements (PTIEs). The highest values of total organic matter (TOM) were detected in Kharg and Lavan Islands. Different metals fractionation distribution was found across sites. As was noticed in carbonate (F2), exchangeable (F1), Fe-Mn oxy-hydroxide (F3), organic (F4) and residual (F5) fractions, Hg primarily associated with F2 and F1, whereas Pb and Cd with F2, followed by F1, F3, F5 and F4. Conversely, Ni and V accumulated in F1, suggesting their high mobility and bioavailability, and thus environmental risk to aquatic biota. All metals (except Al, Fe and As) had geological and anthropogenic sources. Based on modified risk assessment analysis, the sediments from Kharg, Lavan, Siri and Lark Islands showed medium adverse effects. Overall, results from this study corroborate that petroleum industry is the main source of pollution of PTIEs in the Persian Gulf, and offer a scientific basis for monitoring and preventing metal pollution in the environment.

The American slipper limpet Crepidula fornicata is an invasive, non-native species (INNS) abundant along the European coast. Its further distribution may be facilitated by activities such as dredging and spoil disposal, and the aim of this study was to assess whether C. fornicata is able to survive sediment burial. The slipper limpet was found attached to hard substratum in intertidal areas, but it was absent at a nearby subtidal dredge spoil site. In laboratory experiments 22% of C. fornicata emerged when buried under a 2 cm sediment-layer; only half of them survived. When buried under ≥6 cm none re-surfaced or survived. The results provided evidence that C. fornicata is poorly adapted to adjust its vertical position in sediment and is killed by sudden burial underneath 2 to 6 cm of sediment. The combined laboratory experiments and field surveys suggested that C. fornicata has limited scope to survive the dredge spoil disposal process.

Osmotic membrane bioreactor (OMBR), which integrates forward osmosis (FO) with biological treatment process, has been recently developed to advance wastewater treatment and reuse. During OMBR operation, driven by osmotic pressure gradient, biologically treated water transports from the mixed liquor, through a semi-permeable FO membrane, into a highly concentrated draw solution. Compared to conventional MBR, OMBR has several advantages, including better product water quality, lower fouling propensity, and higher fouling reversibility. OMBR can be operated in the osmotic dilution mode when the draw solution, such as liquid fertilizers or seawater, can be reused or discharged directly. In most cases, OMBR is integrated with an additional process, commonly including reverse osmosis, membrane distillation, and electrodialysis, to form hybrid systems for sustainably reconcentrating draw solutions and producing clean water for reuse. In addition, several membrane processes, such as microfiltration, ultrafiltration, and electrodialysis, are combined with OMBR to address its inherent issue, salinity build-up in the bioreactor, and achieve resource (e.g., nutrients and energy) recovery. This review aims to provide a comprehensive understanding on the performance of OMBR and its hybrid systems in wastewater reuse and resource recovery. OMBR analogs and their performance are also systematically introduced. Key technical challenges and their potential solutions to the further development of OMBR and its hybrid systems are highlighted. This review sheds light on future research for the further development of OMBR and its hybrid systems.

In this study, the bacterial and archaeal communities along with their functions of activated sludge from three wastewater treatment plants were investigated by Illumina MiSeq Platform. The treatment processes were modified A/A/O, DE oxidation ditch and pre-anaerobic carrousel oxidation ditch, respectively. The taxonomic analyses showed that Proteobacteria was the predominant bacterial phylum, and Nitrosospira was the dominant nitrification genus. Candidatus Accumulibacter was abundant in DE oxidation ditch process, and the main archaea communities were methanosaeta-like species which had the capability to anaerobic ammonia oxidation. The results illustrated that anaerobic ammonium oxidation played an important role in the nitrogen metabolism and there might be other unknown phosphate-accumulating organisms (PAOs) performing phosphorus removal in activated sludge. The predicted function analyses indicated that both bacteria and archaea were involved in nitrification, denitrification, ammonification and phosphorus removal processes, and their relative abundance varied metabolic modules differed from each other.

Poor microbial water quality jeopardizes the health and safety of food produced by aquaculture farms. Three fish farms and transect sites in Singapore were assessed for microbial water quality and antimicrobial resistance determinants. Of the 33 multidrug resistant E. coli isolated from surface waters of the Johor Straits, 81.8% were ESBL producers. The relative abundance of sul1, qnrA and intI1 genes were higher in sediments than surface waters. Among the surface water samples, higher concentrations (10−1−101) of beta-lactamases (blaSHV, blaOXA, blaCTX-M) were detected in the transect sites. This study highlights a potential antimicrobial resistance transmission chain from environmental waters, to animal carriers and humans.

Proteome response of plants is an important process that enables them to cope with environmental stress including metal stress. In this study, the proteome of Gracilaria lemaneiformis exposed to lead was investigated. Two-dimensional gel electrophoresis analysis revealed 123 protein spots, among which 14 proteins were significantly differentially expressed and identified using MALDI-TOF MS. Two of the up-regulated proteins were identified and predicted to be involved in photosynthesis and signal transduction, while eleven down-regulated proteins were functionally grouped into five classes including photosynthesis, energy metabolism, protein metabolism, carbohydrate transport and metabolism, and antioxidation proteins. There was also an up-regulation in superoxide dismutase, peroxidase, glutathione s-transferase, and heat-shock protein 70 upon Pb exposure. Proteomic studies provide a better picture of protein networks and metabolic pathways primarily involved in intracellular detoxification and defense mechanisms.

Although organic UV filters (OUVFs) benefit human health by preventing skin burns and cancer, several studies revealed that organic UV filters can induce developmental and reproductive toxicity to aquatic organisms. Discharge of OUVFs occurs predominantly at marine recreational hotspots, such as Lac Bay, Bonaire, and is predicted to increase significantly due to growing tourism worldwide. Unfortunately, there is no insight what the current and future discharge of OUVF at Lac Bay is. Therefore, this study aimed to 1) measure concentrations and estimate the risk of specific OUVFs to different nursery habitats at Lac Bay, and 2) compare measured and predicted concentration based risk assessment outcome. Results showed that at least one of the three nurseries at Lac Bay had a potential for adverse effects. Furthermore, predicted environmental concentrations of UV filter discharge can be applied to gain more insight in the order of extent of OUVF discharge by marine tourism.

Seawater and brackish water desalination has been a practical approach to mitigating the global fresh water scarcity. Current large-scale desalination installations worldwide can complementarily augment the global fresh water supplies, and their capacities are steadily increasing year-on-year. Despite substantial technological advance, desalination processes are deemed energy-intensive and considerable sources of CO₂ emission, leading to the urgent need for innovative low carbon desalination platforms. This paper provides a comprehensive review on innovations in membrane processes and membrane materials for low carbon desalination. In this paper, working principles, intrinsic attributes, technical challenges, and recent advances in membrane materials of the membrane-based desalination processes, exclusively including commercialised reverse osmosis (RO) and emerging forward osmosis (FO), membrane distillation (MD), electrodialysis (ED), and capacitive deionisation (CDI), are thoroughly analysed to shed light on the prospect of low carbon desalination.