An international comparative study of end-of-life vehicle (ELV) recycling systems

End-of-life vehicles (ELV) have become a global concern as automobiles have become popular worldwide. An international workshop was held to gather data and to discuss 3R policies and ELV recycling systems, their background and present situation, outcomes of related policies and programs, the framework of recycling and waste management, and case studies on related topics in several countries and regions, as well as the essential points of the comparison. Legislative ELV recycling systems are established in the EU, Japan, Korea, and China, while in the US, ELV recycling is managed under existing laws on environmental protection. Since automobile shredding residue (ASR) has a high calorific value and ash content, and includes heavy metals as well as a mass of unclassified fine particles, recycling ASR is considered highly difficult. Countries with a legislative ELV system commonly set a target for recovery rates, with many aiming for more than 95 % recovery. In order to reach this target, higher efficiency in ASR recovery is needed, in addition to material recycling of collectable components and metals. Environmentally friendly design was considered necessary at the planning and manufacturing stages, and the development of recycling systems and techniques in line with these changes are required for sound ELV management.     

Transfer of brominated flame retardants from components into dust inside television cabinets

Television (TV) set components are highly flame resistant, with their added brominated compounds such as polybrominated diphenyl ethers (PBDEs). These compounds might be released indoors via dust, which presents a potential exposure pathway for humans in the home environment. In this study, we collected dust from inside TV sets and TV set component samples (parts of housing front cabinets, rear cabinets and circuit boards) of five sets used in Japan. We measured BFRs (i.e., PBDEs, tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs)) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/DFs). Analytical results of the TV components showed that the concentrations of PBDEs, TBBPA and PBDFs (48,000mug/g, 19,000mug/g and 9600ng/g as mean values, respectively) were all highest in the rear cabinets. The SigmaPBDD concentrations (460ng/g as a mean value) detected were highest in the circuit board samples. The respective SigmaPBDE and SigmaPBDF concentrations in the dust samples were 67-500mug/g (mean 300mug/g) and 180-650ng/g (mean 410ng/g). Such concentrations were 2-3 orders of magnitude higher than those previously reported for house dust samples, which suggests that the brominated compounds are transferred from TV components into dust. Comparison of congener patterns of the brominated compounds in the dust identified the components as the source of these BFRs.     

A Geographic Information System (GIS)-based approach to adaptation to regional climate change: a case study of Okutama-machi,Tokyo, Japan

Recently, local governments have an increasing need to take extensive and effective local measures to adapt to regional climate change, but have difficulty knowing how and when to adapt to such change. This study aims: 1) to characterize an efficient and cost-effective database management tool (DMT) for developing a Geographic Information System (GIS) based approach to using observed and projected data, for decision-making by non-expert government authorities, and 2) to document how DMT can be used to provide specialized yet understandable climate change information to assist local decision-makers in clarifying regional priorities within a wide array of adaptation options. The DMT combines climate change mapping, statistical GIS, and a vulnerability assessment. Okutama-machi, a 225.63 km² sparsely populated mountainous region (2012 population 5,856) northwest of Tokyo, Japan, was chosen for this pilot study. In this paper, the most recent regional climate projections (5 km resolution) are transcribed into an understandable form for use by non-expert citizens who use the GIS-based DMT. Results illustrate qualitative agreement in projection of summer daily mean temperatures; the mean temperature increase at Okutama-machi is the greatest of any area in Tokyo. In comparing near future and future conditions, August monthly mean temperature will increase more than 0.7–0.9 °C and 2.8–2.9 °C, and monthly precipitation by 50 % and 25–41 %, respectively. However, the root mean square (RMS) errors and bias of percentage change for monthly precipitation in summertime are 26.8 % and 4.3 %, respectively. These data provide an early warning and have implications for local climate policy response.     

Synthesis and characterizations of Zr(IV)-loaded orange waste for effective sequestration of Mo(VI) and W(VI) from water

Journal of Material Cycles and Waste Management - An efficient and environmentally benign biosorbent for Mo(VI) and W(VI) sequestration was developed by loading Zr(IV) ions onto Saponified Orange...     

Surfactant-enhanced flushing enhances colloid transport and alters macroporosity in diesel-contaminated soil

Soil contamination by diesel has been often reported as a result of accidental spillage,leakage and inappropriate use. Surfactant-enhanced soil flushing is a common remediation technique for soils contaminated by hydrophobic organic chemicals. In this study, soil flushing with linear alkylbenzene sulfonates(LAS, an anionic surfactant) was conducted for intact columns(15 cm in diameter and 12 cm in length) of diesel-contaminated farmland purple soil aged for one year in the field. Dynamics of colloid concentration in column outflow during flushing, diesel removal rate and resulting soil macroporosity change by flushing were analyzed. Removal rate of n-alkanes(representing the diesel) varied with the depth of the topsoil in the range of 14%–96% while the n-alkanes present at low concentrations in the subsoil were completely removed by LAS-enhanced flushing. Much higher colloid concentrations and larger colloid sizes were observed during LAS flushing in column outflow compared to water flushing. The X-ray micro-computed tomography analysis of flushed and unflushed soil cores showed that the proportion of fine macropores(30–250 μm in diameter)was reduced significantly by LAS flushing treatment. This phenomenon can be attributed to enhanced clogging of fine macropores by colloids which exhibited higher concentration due to better dispersion by LAS. It can be inferred from this study that the application of LAS-enhanced flushing technique in the purple soil region should be cautious regarding the possibility of rapid colloid-associated contaminant transport via preferential pathways in the subsurface and the clogging of water-conducting soil pores.     

Phosphorus recovery from secondary effluent and side-stream liquid in a sewage treatment plant using zirconium-loaded saponified orange waste

Zirconium was loaded onto orange waste, a cheap and available agricultural waste in Japan, to investigate the feasibility of its utilization for phosphorus recovery from secondary effluent and side-stream liquid, which contain 5.9 and 68.2 mg/dm³ phosphorus, respectively. The phosphorus removal from side-stream liquid by using zirconium-loaded saponified orange waste (Zr-SOW) gel increased with an increasing solid/liquid ratio, and it was found that Zr-SOW gel showed better performance than zirconium ferrite. The prepared adsorbent was effective for phosphorus removal and exhibited a reasonably high adsorption capacity, twice than that of zirconium ferrite. The secondary effluent was treated in a column packed with Zr-SOW gel, and an dynamic adsorption capacity of 1.3 mol-P/kg was attained. The adsorbed phosphorus from the column was successfully eluted as a concentrated form by using a small amount of 0.2 M NaOH. Throughout the elution process, zirconium was not leaked from the adsorption gel.     

Leaching of heavy metals by citric acid from fly ash generated in municipal waste incineration plants

The leaching behavior of heavy metals from municipal waste incineration (MWI) fly ash was investigated in this study. The leaching process includes two steps, i.e., fly ash was firstly washed with water, and then subjected to citric acid leaching. The main parameters of the washing process such as liquid/solid ratio, washing time, and number of washing were tested. The optimum conditions for water washing were found as follows: washing time 5–10 min, liquid/solid ratio 10:1 (ml:g), and number of washing was twice; under these conditions, 86% Na, 70% K, 12% Ca, 1.2% Al, and 0.5% Pb were removed from the fly ash in the prewashing. From the results of screening tests of leaching lixiviants, citric acid was found to be the most effective leaching agent, taking account of its environmentally benign characteristics. Optimum metal extraction can be achieved with citric acid under the following conditions: pH 3.0, liquid/solid ratio 40 (ml:g), citric acid concentration 0.10 mol/dm³, contact time 20 min at room temperature.     

Nematode community composition in hydrothermal vent and adjacent non-vent fields around Myojin Knoll,a seamount on the Izu-Ogasawara Arc in the western North Pacific Ocean

In contrast to specific large benthic invertebrates in chemosynthetic ecosystems such as hydrothermal vents, meiofaunal communities in such habitats have been reported to have strong taxonomic overlap with meiofauna in the adjacent “normal” environments. However, meiofauna have only recently been included in studies of those environments and detailed information on these communities is still rare. This is especially true in the Northwest Pacific Ocean, even though there are many seamounts with active vents in the calderas of the region. Nematode community composition at the genus level in sediments from a hydrothermal vent field in the caldera of Myojin Knoll (32°06′N, 139°52′E, depth 1,300 m), a seamount on the Izu-Ogasawara Arc, Japan, was investigated for the first time and was compared with adjacent non-vent areas inside and outside the caldera. Multivariate analyses showed that the composition of nematodes in the hydrothermal field was significantly different from that in the non-hydrothermal fields around the caldera. However, the common genera, such as Oxystomina, Pareudesmoscolex, Desmoscolex, and Microlaimus were found in two, or all three vent fields while their rank contributions differed among the three fields. When the data from Myojin Knoll were compared with those from other deep-sea vent environments in different regions (e.g., North Fiji Basin, East Pacific Rise, Mid-Atlantic Ridge), the nematode composition in the vent field of the Myojin caldera was more similar to that of the non-vent fields around the caldera than the composition in vent fields of other regions. These data from the Northwest Pacific Ocean also suggest the absence of long-range transport systems and local adaptations for meiofauna in hydrothermal vent fields.     

Chemical and bioassay monitoring of PCB-contaminated soil remediation using solvent extraction technology

Illegal dumping of polychlorinated biphenyl (PCB) capacitors was discovered in Kobe, Japan, in 2001, leaving about 68 m(3) (92 tons) of soil contaminated with approximately 6.6 kg of PCBs. Solvent extraction technology carried out in 2002-2003 using isopropyl alcohol remedied the affected soil at the site. Forty-seven batch treatments were conducted during full-scale treatment. On average, 8.4 extraction cycles per batch were needed to achieve the clean-up goal for PCBs (i.e., the Japanese environmental quality standard for soil). Analytical results showed that the average PCB concentration (88 microg g(-1)-dry soil) in untreated soil samples of all the batches was decreased to 1.2 microg g(-1)-dry soil in treated soil samples, yielding a removal efficiency of 98.6%. Dioxin responsive-chemical activated luciferase gene expression assay (DR-CALUX) and enzyme-linked immunosorbent assay (ELISA) adopting a monoclonal antibody against 2,3',4,4',5-pentachlorobiphenyl (PCB #118) were used to rapidly screen soil samples before and after solvent extraction. The DR-CALUX and ELISA results were in good agreement with World Health Organization toxicity equivalent values and analytically determined PCB concentrations, respectively. Regular monitoring during the treatment period confirmed that the applied technology met Japanese environmental and control regulations concerning treatment and disposal of contaminated soils and treatment residues. After full-scale treatment, the amount of PCBs recovered from the solvent purification system approximated the estimated amount of PCBs spilled.     

Determination of flame-retardant hexabromocyclododecane diastereomers in textiles

To establish a concise and rapid procedure to analyze hexabromocyclododecane (HBCD) diastereomers in flame-retarded textiles, three different methods of extraction—Soxhlet, ultrasonic, and soaking extractions with toluene and dichloromethane (DCM)—were compared. During Soxhlet extraction using toluene, the percent contribution of α-HBCD to total HBCDs increased slightly and that of γ-HBCD decreased, indicating that γ-HBCD was isomerized to some extent at the boiling point of toluene (110.6 °C). For ultrasonic extraction, the temperature of the water bath can easily increase over time during the procedure, which might lead to undesirable effects. Therefore, we considered soaking extraction with DCM to be the most facile procedure to analyze HBCD diastereomers in textiles. Using the method established in this study, commercially available textiles in Japan (n = 10) were analyzed to understand the actual composition of HBCD contents and its diastereomer profiles. With the exception of one textile sample, HBCDs were detected in all the samples analyzed, with concentrations ranging from 22 000 to 43 000 mg kg⁻¹ (i.e. 2.2–4.3%). We found a higher proportion of the α-diastereomer in most textile products compared with that of commercial HBCD mixtures, indicating that γ-HBCD isomerized to α-diastereomer by heating processes to incorporate the commercial formulation into treated materials or that the α-diastereomer preferentially absorbed onto textile materials during the manufacturing of flame-retarded consumer products.