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Enhancement of life cycle assessment (LCA) methodology to include the effect of surface albedo on climate change: Comparing black and white roofs
2012
Susca, Tiziana
Traditionally, life cycle assessment (LCA) does not estimate a key property: surface albedo. Here an enhancement of the LCA methodology has been proposed through the development and employment of a time-dependent climatological model for including the effect of surface albedo on climate. The theoretical findings derived by the time-dependent model have been applied to the case study of a black and a white roof evaluated in the time-frames of 50 and 100 years focusing on the impact on global warming potential. The comparative life cycle impact assessment of the two roofs shows that the high surface albedo plays a crucial role in offsetting radiative forcings. In the 50-year time horizon, surface albedo is responsible for a decrease in CO₂eq of 110–184 kg and 131–217 kg in 100 years. Furthermore, the white roof compared to the black roof, due to the high albedo, decreases the annual energy use of about 3.6–4.5 kWh/m².
Afficher plus [+] Moins [-]Airborne sensors for detecting large marine debris at sea
2012
Veenstra, Timothy S. | Churnside, James H.
The human eye is an excellent, general-purpose airborne sensor for detecting marine debris larger than 10cm on or near the surface of the water. Coupled with the human brain, it can adjust for light conditions and sea-surface roughness, track persistence, differentiate color and texture, detect change in movement, and combine all of the available information to detect and identify marine debris. Matching this performance with computers and sensors is difficult at best. However, there are distinct advantages over the human eye and brain that sensors and computers can offer such as the ability to use finer spectral resolution, to work outside the spectral range of human vision, to control the illumination, to process the information in ways unavailable to the human vision system, to provide a more objective and reproducible result, to operate from unmanned aircraft, and to provide a permanent record that can be used for later analysis.
Afficher plus [+] Moins [-]Inter-annual variability of wet season freshwater plume extent into the Great Barrier Reef lagoon based on satellite coastal ocean colour observations
2012
Schroeder, Thomas | Devlin, Michelle J. | Brando, Vittorio E. | Dekker, Arnold G. | Brodie, J. E. (Jon E.) | Clementson, Lesley A. | McKinna, Lachlan
Riverine freshwater plumes are the major transport mechanism for nutrients, sediments and pollutants into the Great Barrier Reef (GBR) lagoon and connect the land with the receiving coastal and marine waters. Knowledge of the variability of the freshwater extent into the GBR lagoon is relevant for marine park management to develop strategies for improving ecosystem health and risk assessments. In this study, freshwater extent has been estimated for the entire GBR lagoon area from daily satellite observations of the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2002 and 2010. To enable a reliable mapping of freshwater plumes we applied a physics-based coastal ocean colour algorithm, that simultaneously retrieves chlorophyll-a, non-algal particulate matter and coloured dissolved organic matter (CDOM), from which we used CDOM as a surrogate for salinity (S) for mapping the freshwater extent.
Afficher plus [+] Moins [-]Mapping the pollutants in surface riverine flood plume waters in the Great Barrier Reef, Australia
2012
Devlin, M.J. | McKinna, L.W. | Álvarez-Romero, J.G. | Petus, C. | Abott, B. | Harkness, P. | Brodie, J.
The extent of flood plume water over a 10year period was mapped using quasi-true colour imagery and used to calculate long-term frequency of occurrence of the plumes. The proportional contribution of riverine loads of dissolved inorganic nitrogen, total suspended sediments and Photosystem-II herbicides from each catchment was used to scale the surface exposure maps for each pollutant. A classification procedure was also applied to satellite imagery (only Wet Tropics region) during 11 flood events (2000–2010) through processing of level-2 ocean colour products to discriminate the changing characteristics across three water types: “primary plume water”, characterised by high TSS values; “secondary plume water”, characterised by high phytoplankton production as measured by elevated chlorophyll-a (chl-a), and “tertiary plume water”, characterised by elevated coloured dissolved and detrital matter (CDOM+D). This classification is a first step to characterise flood plumes.
Afficher plus [+] Moins [-]Pigmentation of massive corals as a simple bioindicator for marine water quality
2012
Cooper, Timothy F. | Fabricius, Katharina E.
Photo-acclimatisation by the algal endosymbionts of scleractinian corals to changes in environmental conditions may influence their density and/or the concentration of photosynthetic pigments, and hence coral brightness, on short time-scales. To examine coral pigmentation as a bioindicator of water quality, the brightness of massive corals was quantified using colour charts, concentrations of the pigment chlorophyll a and reflectance spectrometry in the field and with manipulative experiments. Along a water quality gradient, massive Porites became progressively lighter as nutrients decreased and irradiance increased. A laboratory experiment showed that Porites nubbins darkened within 25days following exposure to reduced water quality. The results of a transplantation experiment of Porites nubbins in a manipulation incorporating multiple depths and zones of water quality confirmed colony brightness as a simple tool to monitor changes in marine water quality, provided effects due to other influences on pigmentation, e.g. seawater temperatures, are taken into consideration.
Afficher plus [+] Moins [-]Low altitude remote-sensing method to monitor marine and beach litter of various colors using a balloon equipped with a digital camera
2012
Kako, Shin’ichiro | Isobe, Atsuhiko | Magome, Shinya
This study aims to establish a low-altitude remote sensing system for surveying litter on a beach or the ocean using a remote-controlled digital camera suspended from a balloon filled with helium gas. The resultant images are processed to identify the litter using projective transformation method and color difference in the CIELUV color space. Low-altitude remote sensing experimental observations were conducted on two locations in Japan. Although the sizes of the litter and the areas covered are distorted in the original photographs taken at various angles and heights, the proposed image process system is capable of identifying object positions with a high degree of accuracy (1–3m). Furthermore, the color difference approach in the CIELUV color space used in this study is well capable of extracting pixels of litter objects of various colors allowing us to estimate the number of objects from the photographs.
Afficher plus [+] Moins [-]Long term monitoring of photosystem II herbicides – Correlation with remotely sensed freshwater extent to monitor changes in the quality of water entering the Great Barrier Reef, Australia
2012
Kennedy, Karen | Schroeder, Thomas | Shaw, Melanie | Haynes, David | Lewis, Stephen | Bentley, Christie | Paxman, Chris | Carter, S. (Steve) | Brando, Vittorio E. | Bartkow, Michael | Hearn, Laurence | Mueller, Jochen F.
Photosystem II (PSII) herbicides are used in large quantities on agricultural lands adjoining the Great Barrier Reef (GBR). Routine monitoring at 14 sites in inshore waters of the GBR using passive sampling techniques detected diuron (32–94% of sampling periods) at maximum concentrations of 1.7–430ngL⁻¹ in the relatively pristine Cape York Region to the Mackay Whitsunday Region, respectively. A PSII herbicide equivalent (PSII-HEq) index developed as an indicator for reporting was dominated by diuron (average contribution 89%) and typically increased during the wet season. The maximum PSII-HEq indicates the potential for photosynthetic inhibition of diatoms, seagrass and coral-symbionts. PSII herbicides were significantly positively correlated with remotely sensed coloured dissolved organic matter, a proxy for freshwater extent. Combining these methods provides for the first time the potential to cost-effectively monitor improvements in water quality entering the GBR with respect to exposure to PSII herbicides.
Afficher plus [+] Moins [-]Biosorption of Reactive Dyes: A Review
2012
Asgher, Mahwish
Development of treatment technologies to alleviate water pollution has been a challenging and demanding task for researchers. Furthermore, synthetic dyes fabricated of complex aromatic structures turned out to be a great hazard as they impart color to water reservoirs making them abhorrent for human use. Reactive dyes being water soluble prove difficult to be eliminated by conventional treatment technologies. In recent times, biosorption has gained prominence as a finishing technology to remove pollutants being cost-effective and environment friendly. This paper describes the hazards posed by dyeing effluents, exclusively reactive dyes, on the environment and use of various biosorbents to remove reactive dyes from aqueous solution under optimum physicochemical parameters. Enhancement of biosorption capacity by chemical treatment and immobilization; equilibrium, kinetic and thermodynamic modeling of biosorption process; characterization by FTIR and SEM and regeneration of biosorbents is also plainly and comprehensively discussed.
Afficher plus [+] Moins [-]A Catabolic Activity of Sphingomonas wittichii RW1 in the Biotransformation of Carbazole
2012
Nam, In-Hyun | Kim, Young-Mo | Murugesan, Kumarasamy | Chang, Yoon Seok
The well-known bacterium Sphingomonas wittichii RW1 catabolically degrades dibenzo-p-dioxin and dibenzofuran, as well as their chlorinated derivatives. The catabolic degradation of dioxin is initiated by a ring-hydroxylating dioxygenase. The biotransformation of carbazole by S. wittichii RW1 was determined in the present study. Dioxin dioxygenase from the dibenzofuran induced RW1 strain was thought to be unable to attack carbazole, which includes a heterocyclic aromatic dibenzopyrrole system. However, our results showed that carbazole was transformed to anthranilic acid and catechol. The color of the culture suspension changed upon addition of carbazole due to formation of a nitrogen-containing metabolite. Relevant metabolic intermediates were identified by gas chromatographic mass spectrometry and electrospray ionization time-of-flight mass spectrometry with comparison to the corresponding authentic compounds. The dioxygenase of the dibenzofuran induced RW1 attacked at the angular position adjacent to the nitrogen atom to give a dihydroxylated metabolic intermediate. Contrary to predictions made in previous reports, S. wittichii RW1 displayed positive catabolic activity toward carbazole.
Afficher plus [+] Moins [-]Methylene Blue Degradation by Sphingomonas paucimobilis under Aerobic Conditions
2012
Che Noraini, Che Hasnam | Morad, Norhashimah | Norli, Ismail | Teng, Tjoon Tow | Ogugbue, Chimezie Jason
The presence of synthetic dyes in industrial wastewaters may create serious environmental problems due to their mutagenicity and toxicity to aquatic life and humans. In this study, the decolourization and degradation of methylene blue (MB) by a Sphingomonas paucimobilis strain isolated from industrial wastewater was investigated under aerobic conditions. Decolourization extent of MB in medium was over 85 % when the bacterium was grown on a high concentration of the dye (1,000 mg/L) after a retention time of 5 days, while reduction in COD was 92.99 % suggesting mineralization of dyes as a result of microbial activities. The bacterium retained decolourizing activity over a wide range of pH (2–10), with peak activity obtained at pH 9. Analysis of samples extracted from decolourized culture flasks at pH 9 using UV–visible and Fourier transform infrared (FTIR) spectroscopy confirmed that the mechanism of colour removal was due to biodegradation rather than adsorption of dye on cells. Scanning and transmission electron microscopy revealed the secretion of exopolysaccharides (EPS) by S. paucimobilis cells on exposure to MB—a probable physiological defence mechanism to ensure controlled diffusion of dye molecules into cellular structures. Biokinetic coefficients, namely, growth yield, Y; specific biomass decay, K d; maximum specific substrate rate, k; saturation constant for substrate, K ₛ; and maximum specific biomass growth rate, μ ₘₐₓ, were determined by the Monod type kinetic equation. Results indicate that S. paucimobilis holds a promise as a good candidate for the biological treatment of industrial effluent containing high concentrations of synthetic dyes.
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