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Low Carbon Desalination by Innovative Membrane Materials and Processes Full text
2018
Duong, Hung Cong | Ansari, Ashley J. | Nghiem, Long D. | Pham, Thao M. | Pham, Thang D.
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.
Show more [+] Less [-]Seagrass ecosystem trajectory depends on the relative timescales of resistance, recovery and disturbance Full text
2018
O'Brien, Katherine R. | Waycott, Michelle | Maxwell, Paul | Kendrick, Gary A. | Udy, James W. | Ferguson, Angus J.P. | Kilminster, Kieryn | Scanes, Peter | McKenzie, Len J. | McMahon, Kathryn | Adams, Matthew P. | Samper-Villarreal, Jimena | Collier, Catherine | Lyons, Mitchell | Mumby, P. J. (Peter J.) | Radke, Lynda | Christianen, Marjolijn J.A. | Dennison, William C.
Seagrass ecosystems are inherently dynamic, responding to environmental change across a range of scales. Habitat requirements of seagrass are well defined, but less is known about their ability to resist disturbance. Specific means of recovery after loss are particularly difficult to quantify. Here we assess the resistance and recovery capacity of 12 seagrass genera. We document four classic trajectories of degradation and recovery for seagrass ecosystems, illustrated with examples from around the world. Recovery can be rapid once conditions improve, but seagrass absence at landscape scales may persist for many decades, perpetuated by feedbacks and/or lack of seed or plant propagules to initiate recovery. It can be difficult to distinguish between slow recovery, recalcitrant degradation, and the need for a window of opportunity to trigger recovery. We propose a framework synthesizing how the spatial and temporal scales of both disturbance and seagrass response affect ecosystem trajectory and hence resilience.
Show more [+] Less [-]Non-native marine bryozoans (Bryozoa: Gymnolaemata) in Brazilian waters: Assessment, dispersal and impacts Full text
2018
Miranda, Adélia A. | Almeida, Ana C.S. | Vieira, Leandro M.
Bryozoa is a phylum of aquatic invertebrates widely distributed around the world, including harbor areas. They have association to artificial structures as main mechanism of dispersal, including ships, which facilitates their introduction to new environments. The detection of exotic species is important to prevent new introductions and to propose management strategies of marine areas. Thus, after analyzing and discussing local and global criteria of exotic species, an account of exotic bryozoans from Brazil is presented, including 12 classified as exotic (six established and six detected) and 17 classified as potentially exotic (cryptogenic). Three species have been reported causing economic or environmental impacts worldwide. Of those, Membraniporopsis tubigera is known to cause economic impacts on the Brazilian coast. Hull fouling is the main dispersal mechanism for exotic bryozoans. The lacking of reliable data did not allow inferring on the exotic status on some fouling bryozoan species in Brazil.
Show more [+] Less [-]Operational modelling of bigeye tuna (Thunnus obesus) spatial dynamics in the Indonesian region Full text
2018
Lehodey, P. | Senina, I. | Wibawa, T.A. | Titaud, O. | Calmettes, B. | Conchon, A. | Tranchant, B. | Gaspar, P.
With INDESO, Indonesia has implemented a system for the monitoring and management of its tuna resources. Despite increasing catch, very few is known about the dynamics and real abundance of tuna species in the Indonesian waters and adjacent oceanic regions. The SEAPODYM model was implemented in an operational chain of production for the Indonesian region to simulate tuna spatial dynamics in realtime. This challenging objective imposed developing a global scale model at coarse resolution to provide initial and boundaries conditions of the regional model. A parameter optimization approach was used to provide the best solution fitting several hundreds of thousand catch observations, over a long historical simulation at coarse resolution. Then downscaling method and regional modelling at high resolution (1/12°x day) were validated to produce realtime and forecast on a weekly basis. The architecture of this application, the approach for its parameterization and some key results are presented and discussed.
Show more [+] Less [-]Osmotic Membrane Bioreactor and Its Hybrid Systems for Wastewater Reuse and Resource Recovery: Advances, Challenges, and Future Directions Full text
2018
Li, Yun | Zhang, Bangxi | Li, Guoxue | Luo, Wenhai
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.
Show more [+] Less [-]Study on the bacterial and archaeal community structure and diversity of activated sludge from three wastewater treatment plants Full text
2018
Qin, Hui | Ji, Bin | Zhang, Shufei | Kong, Zehua
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.
Show more [+] Less [-]Microbial water quality and the detection of multidrug resistant E. coli and antibiotic resistance genes in aquaculture sites of Singapore Full text
2018
Ng, Charmaine | Chen, Hongjie | Goh, Shin Giek | Haller, Laurence | Wu, Zhixin | Charles, Francis Rathinam | Trottet, Aurore | Gin, Karina
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.
Show more [+] Less [-]Proteome responses of Gracilaria lemaneiformis exposed to lead stress Full text
2018
Du, Hong | Liang, Honghao | Jiang, Yang | Qu, Xiaoxiao | Yan, Haibo | Liu, Xiaojuan
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.
Show more [+] Less [-]An environmental risk assessment of three organic UV-filters at Lac Bay, Bonaire, Southern Caribbean Full text
2018
Schaap, Iris | Slijkerman, Diana M.E.
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.
Show more [+] Less [-]Exposure of Belgian florists to pesticide residues during their professional activities Full text
2018
Toumi, Khaoula | Joly, Laure | Vleminckx, Christiane | Schiffers, Bruno