An Integrated Assessment by Models for Energy Systems Analysis and Life-Cycle Assessment with a Case Study of Advanced Fossil-Fired Power Plants in China

We developed an integrated assessment (IA) using models for energy systems analysis and life-cycle assessment (LCA). Based on this assessment framework, we developed cost-benefit analysis (CBA) case studies for a hypothetical project designed to introduce advanced fossil-fired power generation technologies in China. Our MARKAL model for Japan confirmed that radical reductions (i.e., 80 % by 2050) of carbon dioxide (CO₂) could be attained from energy systems alone and that credit for emission allowances was required. We evaluated life-cycle costs and emissions of carbon dioxide, sulfur oxide, and nitrogen oxide gases for the energy technologies using an LCA model. Further, we applied a power generation planning model for six Chinese grids to provide a power mix structure, potentially producing credit by installing fossil-fired power generation technology and by using baseline grid emission factors with an average cost of electricity. Finally, by using dynamic emission reductions and additional costs from the two models, we conducted case studies of CBA for a hypothetical project to install the technologies in China. This was accomplished by evaluating emission reductions in monetary terms and by applying a life-cycle impact assessment model. A unique feature of our IA is its dynamic (time-varying) assessment of costs and benefits.     

Survey on readability of online information for upgrading understandability of biomass energy technology

Waste management contributes to renewable energy such as biodiesel production from processes of various types of biomass including vegetable oils, animal fats, and waste of edible oil. Successful waste management effort is influenced by people concern about benefit of waste management including for renewable energy from biomass. It involves their understanding initiated by literacy on biomass energy. To help increase literacy on waste recycle and biomass energy technology, we study readability of online information regarding biomass energy in Indonesian language (Bahasa Indonesia). Indonesia is considered as one of biomass-rich country with a little utilization for energy. The readability is studied by combining two approaches: measurement by readability standard and survey on readability confirming measurement by the standard. This study focuses on the confirmation survey readability standard measured on biomass online information in Indonesian language. In the survey, 19 online text materials were read by respondents and they were asked to give their impression whether the texts are easy or difficult to understand. From this study, what factors influence understandability of text information are shown. The results could be a guidance for preparing text information to raise people concern on waste recycle and renewable energy in general.     

Our future in the Anthropocene biosphere

The COVID-19 pandemic has exposed an interconnected and tightly coupled globalized world in rapid change. This article sets the scientific stage for understanding and responding to such change for global sustainability and resilient societies. We provide a systemic overview of the current situation where people and nature are dynamically intertwined and embedded in the biosphere, placing shocks and extreme events as part of this dynamic; humanity has become the major force in shaping the future of the Earth system as a whole; and the scale and pace of the human dimension have caused climate change, rapid loss of biodiversity, growing inequalities, and loss of resilience to deal with uncertainty and surprise. Taken together, human actions are challenging the biosphere foundation for a prosperous development of civilizations. The Anthropocene reality—of rising system-wide turbulence—calls for transformative change towards sustainable futures. Emerging technologies, social innovations, broader shifts in cultural repertoires, as well as a diverse portfolio of active stewardship of human actions in support of a resilient biosphere are highlighted as essential parts of such transformations.     

Degradation activity of Clostridium species DC-1 in the cis-1,2-dichloroethylene contaminated site in the presence of indigenous microorganisms and Escherichia coli

We showed the cis-1,2-dichloroethylene (cis-1,2-DCE) dechlorination ability of Clostridium species DC-1 in association with other bacteria. Result of denaturing gradient gel electrophoresis showed the dominant band pattern of DC-1 during the degradation time of cis-1,2-DCE and dominance of some other Clostridium species. Experiment with addition of Escherichia coli (E. coli) showed that dechlorinating activity of DC-1 was not inhibited by the presence of E. coli. Pour plate experiment with DC-1 and E. coli revealed that the dominance of Clostridium species caused the decrease of E. coli growth in a bioremediation state. This result suggested the possibility of Clostridium species DC-1 as a degrader of cis-1,2-DCE, in a cis-1,2-DCE contaminated site where an indigenous microbial community is present. Experiment conducting with E. coli suggested that the strain in the contaminated site did not inhibit the degradation of cis-1,2-DCE and during the degradation period, rather some other Clostridium species became dominant and the growth of E. coli would be decreased. This finding could be a very positive approach for implementing the dechlorinating bacteria at aliphatic chlorinated component contaminated sites.     

Finite element analysis of knee injury risks in car-to-pedestrian impacts

In vehicle-pedestrian collisions, lower extremities of pedestrians are frequently injured by vehicle front structures. In this study, a finite element (FE) model of THUMS (total human model for safety) was modified in order to assess injuries to a pedestrian lower extremity. Dynamic impact responses of the knee joint of the FE model were validated on the basis of data from the literature. Since in real-world accidents, the vehicle bumper can impact the lower extremities in various situations, the relations between lower extremity injury risk and impact conditions, such as between impact location, angle, and impactor stiffness, were analyzed. The FE simulation demonstrated that the motion of the lower extremity may be classified into a contact effect of the impactor and an inertia effect from a thigh or leg. In the contact phase, the stress of the bone is high in the area contacted by the impactor, which can cause fracture. Thus, in this phase the impactor stiffness affects the fracture risk of bone. In the inertia phase, the behavior of the lower extremity depends on the impact locations and angles, and the knee ligament forces become high according to the lower extremity behavior. The force of the collateral ligament is high compared with other knee ligaments, due to knee valgus motions in vehicle-pedestrian collisions.     

Thermal cracking of oils from waste plastics

Thermal cracking of decomposed waste plastic oil produces a good yield of olefins. The solvent extraction of such waste plastic oil seems to be efficient for increasing gas yields and recycling monomers. To assess the potential of monomer recovery from municipal waste plastics, the oils were cracked using a laboratory-scale quartz-tube reactor. The waste plastic oils were provided by two commercial plants of the Sapporo Plastic Recycle Co. and the Dohoh Recycle Center Co. in Japan. A model waste plastic oil made in a laboratory was also examined. Yields of ethene, propene, and other products were measured at different temperatures. Two-step pyrolysis reduces coking compared with the direct thermal degradation of plastics. The raffinates from waste plastic oils extracted by sulfolane were also cracked. The primary products were almost the same as those from nontreated oils. The maximum total gas yield was 78wt%–85wt% at 750°C, an increase of about 20wt% compared with that of nonextracted oil. Solvent extraction removes stable aromatic hydrocarbons such as styrene, which is more coked than cracked.     

Sample storage and extraction efficiencies in determination of polycyclic and nitro musks in sewage sludge

Analytical technology is continuously improving, developing better methods for isolating and concentrating trace compounds in environmental samples. Polycyclic and nitro musks (PNMs) are one group of emerging trace compounds detected in municipal wastewater. Differences in sample storage, preparation, and extraction methods for their measurement have led to variability in results. We analyzed 11 PNMs by GC/MS and compared the results of different storage times and extraction methods (supercritical fluid (SFE) or microwave-assisted (MAE)) for 202 samples of primary sludge, waste activated sludge (WAS), raw sludge, and aerobically/anaerobically digested biosolids collected from Canadian municipal wastewater treatment plants. Sixty-three air-dried samples were extracted by SFE, and 139 air-dried, centrifuged, or filtered samples were extracted by MAE. The mean surrogate recoveries were 89% (standard deviation (SD)=11%) for d(10)-anthracene by SFE and 88% (SD=14%) for d(10)-phenanthrene by MAE. Storage study results showed that PNM concentrations changed by a mean of 7% and 9% for primary sludge and WAS respectively after four weeks and decreased up to 25% after 13.5 months of storage in amber glass containers at -18 degrees C. Air-drying of sludge at room temperature caused losses of about 50% of PNM concentrations compared to centrifugation. The proportions of PNMs present in the liquid phase of sludge samples were less than 5% compared to proportions in the sludge solids. The most complete liquid-solid separation was achieved by filtration of frozen/thawed sludge samples, producing a liquid phase that contained less than 1% of the total musk content of the sample.     

Metals in Feathers of Bonin Petrel, Christmas Shearwater, Wedge-Tailed Shearwater, and Red-Tailed Tropicbird in the Hawaian Islands, Northern Pacific

Levels of environmental pollutants are usually higher in mainland and coastal areas than in offshore or oceanic islands due to higher inputs from agricultural and industrial sources. Levels of heavy metals are usually higher in adult than in young birds, because they have had longer to accumulate metals in their tissues, and/or because they may eat larger, more contaminated, prey. We examined the levels of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the adults and young of Bonin petrel (Pterodroma hypoleuca), Christmas shearwater (Puffinus nativitatis) and red-tailed tropicbird (Phaethon rubricauda) on Midway Atoll, and adult wedge-tailed shearwater (Puffinus pacificus) on Midway Atoll and on Manana Island (off Oahu) in the northern Pacific. All birds were analyzed individually except for Christmas Shearwater chicks where samples were pooled to obtain sufficient quantities for analysis. Significant (p<0.05) age-related differences were found for mercury, selenium, manganese and chromium in Bonin petrels, for selenium and mercury in Christmas shearwaters, and for chromium and mercury in Red-tailed Tropicbirds. Lead approached significance for all three species. Adults had higher levels than young except for chromium and manganese in the petrels and arsenic in all three species. There were significant interspecific differences in concentrations of all metals except arsenic for the adults nesting on Midway. Christmas shearwaters had the highest levels of all metals except mercury and chromium. Bonin petrels, the smallest species examined, had mercury levels that were over three times higher than any of the adults of the other three species. For wedge-tailed shearwaters, levels of chromium and lead were significantly higher, and manganese and selenium were lower on Midway than Manana. Knowledge of the foraging ranges and habits of these far-ranging seabirds is inadequately known, but does not currently explain the observed differences among species. We could not find a consistent pattern of differences between the burrow nesting species (Bonin petrel, Wedge-tailed shearwater) and the surface nesting tropicbirds. There was no consistent pairwise correlation between any metals across all species.