• Energy Research
• 6. Clean water close
• Energy Procedia close
• European Marine Science close

AbstractThis paper assesses how parameter uncertainties in the model for rise velocity of CO2 droplets in the ocean cause uncertainties in their rise and dissolution in marine waters. The parameter uncertainties in the rise velocity for both hydrate coated and hydrate free droplets are estimated from experiment data. Thereafter the rise velocity is coupled with a mass transfer model to simulate the fate of dissolution of a single droplet.The assessment shows that parameter uncertainties are highest for large droplets. However, it is also shown that in some circumstances varying the temperature gives significant change in rise distance of droplets.

AbstractMicroorganisms play an important role in the transformation of material within the earth’s crust. The storage of CO2 could affect the composition of inorganic and organic components in the reservoir, consequently influencing microbial activities. To study the microbial induced processes together with geochemical, petrophysical and mineralogical changes, occurring during CO2 storage, long-term laboratory experiments under simulated reservoir P-T conditions were carried out. Clean inner core sections, obtained from the reservoir region at the CO2 storage site in Ketzin (Germany) from a depth of about 650 m, were incubated in high pressure vessels together with sterile synthetic formation brine under in situ P-T conditions of 5.5 MPa and 40 °C. A 16S rDNA based fingerprinting method was used to identify the dominant species in DNA extracts of pristine sandstone samples. Members of the α- and β-subdivisions of Proteobacteria and the Actinobacteria were identified. So far sequences belonging to facultative anaerobic, chemoheterotrophic bacteria (Burkholderia fungorum, Agrobacterium tumefaciens) gaining their energy from the oxidation of organic molecules and a genus also capable of chemolithoautotrophic growth (Hydrogenophaga) was identified.During CO2 incubation minor changes in the microbial community composition were observed. The majority of microbes were able to adapt to the changed conditions. During CO2 exposure increased concentrations of Ca2+, K+, Mg2+ and SO42− were observed. Partially, concentration rises are (i) due to equilibration between rock pore water and synthetic brine, and (ii) between rock and brine, and are thus independent on CO2 exposure. However, observed concentrations of Ca2+, K+, Mg2+ are even higher than in the original reservoir fluid and therefore indicate mineral dissolution due to CO2 exposure.

AbstractHigh and medium molecular weight of synthetic cationic polymers (3150 and 8265) and natural cationic polymer (chitosan) were selected to study the effect of cationic polymers on microbial granulation in anaerobic digestion. The optimal dose of each type of cationic polymer for the initial microbial agglomeration was determined in laboratory-scale jar test. The suitable dose of 3150, 8265 and chitosan was 2.0, 2.0 and 13.0mg/g VSS, respectively. The bench reactors were operated for a period of 120 days at organic loading rate (OLR) of 0.5-2.0kg COD/m3.d. As the results, these cationic polymers enhanced anaerobic granulation in term of granule properties which consists of physical, chemical and biological properties. Size distribution of all reactors increased specially addition of polymer 3150 which provided the granule percentage from 2.74% to 16.40%. Chitosan contributed on increased of extracellular polymeric substances (EPS) production from 20.2 to 50.0mg/g VSS, and also specific methanogenic activity (SMA) reached to 0.18g COD/g VSS.d. The experimental results showed that addition polymer 3150 and chitosan gave well productive in term of granule properties. Granule scanning electron microscope (SEM) and fluorescent in situ hybridization (FISH) with confocal laser scanning microscope (CLSM) photographs indicated the accomplishment of granulation by progressively increasing the OLR.

AbstractFish and seafood may represent risks for human health since they are often contaminated by toxic elementts from aquatic environment, the magnitudes of which are magnified through the food chain. The purpose of this study was to analyze and evaluate the levels of toxic and trace metals in five species of fresh water fish and five species of marine fish bought from commercial markets in Bangkok, Thailand. The edible part of fish samples were analyzed by instrumental neutron activation analysis using the comparator techniques at Thai Research Reactor (TRR-1/M1) at the Thailand Institute of Nuclear Technology. The contents of As, Cd, Co, Cr, Fe, Hg, Rb, Sb, Sc, Se and Zn found in fish samples were 0.19-11.65, <13, 0.10-0.14, 5.34-11.29, <14.00-31.95, <0.55-1.37, <2.00-44.41, <0.30, <0.01, <0.50-2.07 and 18.18-36.92ppm, respectively. As contents in all fresh water fish species did not exceed the standard limit of 2ppm recommended by the Ministry of Public Health of Thailand, but the limit was exceeded in four marine fish species (3.11-11.65ppm). The standard limit recommended for Hg is 0.50ppm, and the amount of Hg in two fresh water fish species and three marine fish species exceeded this limit (0.75-1.37ppm). Cd contents of all fish samples were below the detection limit of 13ppm. While other trace elements are non-toxic.

AbstractAlgae represent a favourable and potentially sustainable source of biomass for bioenergy-based industrial pathways in the future. The study, performed on a real pilot plant implemented in Augusta (Italy) within the frame of the BioWALK4Biofuels project, aims to figure out whether seaweed (macroalgae) cultivated in near-shore open ponds could be considered a beneficial aspect as a source of biomass for biogas production within the co-digestion with local agricultural biological waste. The LCA results confirm that the analysed A and B scenarios (namely the algae-based co-digestion scenario and agricultural mix feedstock scenario) present an environmental performance more favourable than that achieved with conventional non-renewable-based technologies (specifically natural gas - Scenario C). Results show that the use of seaweed (Scenario A) represent a feasible solution in order to replace classical biomass used for biofuel production from a land-based feedstock. The improvement of the environmental performances is quantifiable on 10% respect to Scenario B, and 38 times higher than Scenario C.

AbstractCO2 leakage from subsurface storage sites is one of the main concerns connected with the CCS technology. As CO2 leakages into near surface formations appear to be very unlikely within pilot CCS projects, the aim of this work is to emulate a leakage by injecting CO2 into a near surface aquifer. The two main questions pursued by the injection test are (1) to investigate the impact of CO2 on the hydrogeochemistry of the groundwater as a base for groundwater risk assessment and (2) to develop and apply monitoring methods and monitoring concepts for detecting CO2 leakages in shallow aquifers.The presented injection test is planned within the second half of 2010, as a joint project of the University of Kiel (Germany), the Helmholtz-Centre for Environmental Research (Leipzig, Germany) and the Engineering Company GICON (Dresden, Germany). The test site has been investigated in detail using geophysical methods as well as direct-push soundings, groundwater well installation and soil and groundwater analyses. The present paper presents briefly the geological and hydrogeological conditions at the test site as well as the planned injection test design and monitoring concept.