Comparison of end-of-life vehicle material flows for reuse,material recycling,and energy recovery between Japan and the European Union

Journal of Material Cycles and Waste Management - Japan and the European Union (EU) both have well-established End-of-Life Vehicle (ELV) policies and management systems. However, due to the...     

Recycling of biodiesel fuel wastewater for use as a liquid fertilizer for hydroponics

Wastewater is discharged during washing processes in the production of biodiesel fuel (BDF) using alkaline catalysts. It can be recycled as a liquid fertilizer for hydroponics by adding essential components for plant growth. The effects of the liquid fertilizer on plant growth were investigated. Liquid fertilizer containing a smaller amount of the BDF wastewater had a similar effect on plant growth as the standard nutrient solutions. This result reveals that BDF wastewater can be recycled for use as a liquid fertilizer for hydroponics. However, fertilizer with a larger amount of the BDF wastewater showed poor and varied plant growth due to the growth of microorganisms in the contaminated wastewater. Hence, when BDF wastewater becomes contaminated during storage, sterilization is necessary to recycle it as a liquid fertilizer. Moreover, contamination during storage should be avoided for successful recycling.     

Selection and Substantiation of an Organic Solvent Removal Apparatus at a Print Shop by Comparative Experiments Using the Activated Carbon Adsorption and Catalytic Oxidation Methods

ABSTRACT

The investigation of an appropriate organic solvent removal apparatus for installation in a newly reconstructed print shop as a countermeasure for preventing the exhaust of organic solvents was conducted.

The selection of an organic solvent removal apparatus was made after bench-scale tests of the activated carbon adsorption method and the catalytic oxidation method, both of which are effective for the removal of organic solvents, were performed on the actual exhaust gas at the print shop. The results showed that both methods were efficient enough to be applied to the removal of organic solvents, but the activated carbon adsorption method had many drawbacks, such as the need for frequent replacement of activated carbon and complex maintenance. For the catalytic oxidation method, running costs are high, but there are many merits, such as that the catalysts do not have to be replaced as often and maintenance is simple. After considering these factors, a catalytic oxidation removal apparatus was installed at the new print shop. In the results of the substantiation test on the actual apparatus using mixed catalysts of platinum and manganese plus copper, the removal efficiency was 97.998.7% and the concentration of the outlet exhaust gas was about 10 ppm (the average concentration of the inlet exhaust gas was 528 ppm) at a space velocity of 30,000 hr^-1 and a reaction temperature of 200 °C. The results of this study were substantiated.     

Municipal solid waste composition and food loss reduction in Kyoto City

For 35 years, Kyoto City has conducted detailed household waste composition surveys under the guidance of Kyoto University by dividing household waste into approximately 400 categories. In addition, the city has conducted detailed composition surveys of commercial waste generated by businesses. These surveys show that food loss accounts for approximately 40% of total waste, of which leftovers and untouched food account for about 40% in both households and business facilities. Consequently, the annual generation of household and commercial food loss is estimated at about 30,000 tons. Various efforts have been made to reduce waste, including food loss, but further reduction in environmental burden is needed. Thus, Kyoto City revised the ordinance for waste reduction, and in March 2015, formulated a new municipal waste management plan. The plan not only includes the 2Rs (reduce, reuse), but also, for the first time in Japan, sets quantitative targets for reducing food loss. Kyoto City must ensure that the necessary waste reduction measures are clearly explained to the residents and business operators. To ensure that this plan is successful, it is important to clarify concrete actions that residents and business operators should implement, along with their effects.     

Simplified Fabrication of Optically Transparent Composites Reinforced with Nanostructured Chitin

Optically transparent films reinforced with micro to nano scale chitin particles were successfully developed in this study. Chitin composites based on micro scale particles which are larger than the optical wavelength do not cause light scattering provided that chitin particles are composed of nano structure networks which allow monomer impregnation and polymerization. This could lead a simplified process for fabricating transparent composites. The composites reinforced by the chitin micro particles not only retained the transparency of the plastic but also helped the effectiveness of its co-efficient of thermal expansion as similar to chitin nanofibers. Furthermore, chitin nanofibers transparent films are thermally stable against temperature as high as 200 °C for a long period of time. This could lead to number of important commercial applications, and is a significant move towards the sustainable utilization of marine bio-resources.     

Greenhouse gas emissions from biogenic waste treatment: options and uncertainty

A simplified life cycle assessment was conducted to estimate greenhouse gas (GHG) emissions and energy production from each component of biogenic waste treated in an open dumping site, and by composting, anaerobic digestion, and incineration employed with additional options. The impact of uncertainties and sensitivities of the parameters in the treatment methods were investigated. We conducted a sensitivity analysis to identify the most sensitive parameters, and we discussed the relationship between uncertainty and sensitivity. Our results revealed that the moisture content of food waste and the biomass-derived carbon and methane concentration of the landfill gas of biogenic waste subjected to open dumping are the most sensitive parameters across all the treatment methods. The net GHG emissions from food waste treated in an open dumping site ranged over ten times (0.30 ? 3.67 Gg CO₂ eq/Gg). In addition, by employing additional options for the open dumping site, including soil cover, a landfill gas collection system, shifting to a semi-aerobic condition, and energy conservation by using a gas engine, we found that the net GHG emissions could be reduced by 10, 27.9, 37.4 %, and up to 56.7 %, respectively. Shifting to a semi-aerobic system is the most effective method for reducing GHG emissions, followed by landfill gas collection.     

Optimization of compost fermentation of glycerol by-product discharged from biodiesel fuel production process

Development of a cheap system for reuse of glycerol by-product discharged from the biodiesel fuel (BDF) production process is needed in parallel with development of a low-cost BDF production system. In this article, optimization of compost fermentation of glycerol by-product was studied. The type and amount of additive nitrogen source was studied, and good utilization of glycerol was observed when 0.5 g of urea was added to a mixture of 625 g dry sawdust, 25 g of microbial seed, and 50 g of glycerol by-product. To achieve efficient compost fermentation, repeated batch fermentation was applied and five batch cultures were repeated. Although the pH level and nitrogen and water contents were maintained at suitable levels for microbial growth, the glycerol consumption rate gradually decreased with accumulation of oily compounds in the compost. Finally, a material cost evaluation of the compost fermentation proposed in this study was performed. The total material cost decreased to ￥0.57 /l of BDF when employing an existing compost system for the fermentation process, although sawdust used for mushroom cultivation was used in this study at the very high cost of ￥123 /kg dry sawdust. However, the cost of disposal of the glycerol byproduct as an industrial waste was ￥5.2 /l of BDF produced; therefore, there might be an economical advantage to compost fermentation of glycerol by-product from BDF production.     

Route of egg yolk protein uptake in the oocytes of kuruma prawn,Penaeus japonicus

The route of egg yolk protein uptake into the oocytes of kuruma prawn, Penaeus japonicus, was studied using immunohistochemical and electron microscopical methods. Although a significant immunofluorescence with anti-vitellin-immunoglobulin was observed in the enlarged follicle cells surrounding oil globule stage oocytes of the early vitellogenic ovary, no fluorescence was detected in shrunken follicle cells surrounding oocytes in the yolk granule stage. Electron microscopically, yolk granule stage oocytes have an irregular surface with numerous well-developed microvilli. In contrast, the surface of follicle cells is relatively smooth. The irregular surface of yolk granule stage oocytes was covered with a layer of electron dense material. Similar dense material was found in the spaces between the neighboring follicle cells on the yolk granule stage oocytes. The outer surface of the follicle cells on yolk granule stage oocytes was covered by dense materials which were similar to those found on the irregular surface of oocytes. Micropinocytotic vesicles containing dense material were found in the ooplasm near the irregular surface with numerous well-developed microvilli. Dense material was concentrated in the peripheral part of the small forming yolk bodies of yolk granule stage oocytes. This suggests that the electron dense material, probably egg yolk protein, transferred to the surface of yolk granule stage oocytes from the spaces between the neighboring follicle cells may be incorporated into the ooplasm by pinocytosis through the microvilli and subsequently aggregate to form yolk bodies.     

Energy recovery and greenhouse gas reduction potential from food waste in Japan

Waste-to-energy is one effective waste management approach for a sustainable society. The purpose of this study was to clarify the potential for energy recovery and greenhouse gas (GHG) reduction that could be achieved by introducing anaerobic digestion (AD) facilities in the process of reconstructing aging incineration facilities in Japan. Using statistical data from 1068 incineration facilities, four future scenarios were considered and compared with the current situation. As results, compared with the current situation the amount of electricity generated could increase by 60 % in 2030, by combining AD facilities for food waste with new, high-efficiency incineration facilities for remaining municipal solid waste (MSW). From a life cycle perspective, net energy recovery in 2030 was approximately three times greater than in 2011, and GHG emission could be reduced by 27 %. The introduction of AD facilities is attractive for small authorities, which currently treat <100 t/day of MSW through incineration facilities without energy recovery. An AD facility is also beneficial for large authorities. On the contrary, in middle-scale authorities that treat 100–299 t/day of MSW, the reconstruction of incineration facilities to include electricity production capabilities requires careful consideration, because it will significantly influence energy recovery and GHG reduction effects.     

Rare earth element recovery potentials from end-of-life hybrid electric vehicle components in 2010–2030

Increasing attention is currently given to the management of end-of-life (EoL) hybrid electric vehicles (HEVs), because approximately two decades have passed since they were first introduced to the market. A HEV would be one of the largest consumers of rare earth elements (REEs), and hence represents the greatest potential for REE recovery in the future. The purpose of this study is to clarify the present and future recovery potential of REEs that are disposed of as EoL HEVs. This study first estimated the numbers of EoL HEVs during fiscal years (FYs) 2010–2030, and then clarified the potential for recovery of REEs from two HEV-specific components—the hybrid transmission and NiMH battery unit. The results suggest that 0.51–0.65 million HEVs will reach the EoL stage in FY2030, compared with only 11,000 HEVs in FY2010. As of FY2030, REE recovery potentials will increase to 220 tons and 2900 tons for EoL hybrid transmission and NiMH battery units, respectively. A total of 49,000 tons of REEs will be contained within HEV-specific components of HEVs still in use. Moreover, the potential for recovery of REEs from EoL hybrid transmissions and NiMH battery units is estimated to equal 35.4 and 92.1 % of respective demand.