Effects of introducing energy recovery processes to the municipal solid waste management system in Ulaanbaatar,Mongolia

Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production,incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently,3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery.However, safety control and marketability of RDF will be required at that moment.     

Effects of introducing energy recovery processes to the municipal solid waste management system in Ulaanbaatar,Mongolia

Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production, incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently, 3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery. However, safety control and marketability of RDF will be required at that moment.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in blood and breast milk collected from 60 mothers in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs), and mono-ortho polychlorinated biphenyls (mono-ortho PCBs) in paired samples of blood and breast milk collected from 60 mothers in Sapporo City, Hokkaido Prefecture, Japan. The present study is one of the few studies in which PCDDs, PCDFs, and dioxin-like PCBs have been measured in blood and breast milk collected from 60 same mothers. Of these 60 mothers, 30 were primipara (mean: 30.1 years, median: 28.0 years) and 30 were multipara (mean: 32.2 years, median: 32.5 years). The arithmetic mean TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the primiparous mothers were 9.0, 3.3, 5.7, and 0.4 pg TEQ g(-1) lipid, respectively, and 5.2, 2.2, 4.5, and 0.4 pg TEQ g(-1) lipid, respectively, with the total TEQ concentrations of these dioxin-like compounds being 9.3-42.9 (mean: 18.4, median: 17.3) and 7.0-41.1 (mean: 12.3, median: 11.4) pg TEQ g(-1) lipid, respectively. In the case of multiparous mothers, the arithmetic mean TEQ concentrations of these dioxin-like compounds in blood and breast milk were 7.1, 2.7, 5.3, and 0.4 pg TEQ g(-1) lipid, respectively, and 3.9, 1.7, 3.8, and 0.4 pg TEQ g(-1) lipid, respectively, with the total TEQ concentrations being 3.4-28.1 (mean: 15.5, median: 13.9) and 2.7-20.0 (mean: 9.8, median: 9.2)pg TEQ g(-1) lipid, respectively. The total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of primiparous mothers in Sapporo City appeared to be generally lower than those recently surveyed throughout the greater area of Japan. Significant correlations were observed between age and the total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in the blood of primiparae and multiparae, and significant correlations were also observed between age and the total TEQ concentrations of these dioxin-like compounds in the breast milk of primiparae and multiparae. The total TEQ concentrations of PCDDs, PCDFs, and dioxin-like PCBs in the blood of primiparous mothers showed a close correlation to those in their breast milk and also showed good correlations between the total TEQ concentrations of these dioxin-like compounds in the blood of multiparous mothers and those in their breast milk. The result of a comparison of the arithmetic mean concentrations of each congener of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk indicated that the transfer of octachlorodibenzo-p-dioxin (OCDD) from the blood to the breast milk was lower than those of other congeners. In contrast, among mono-ortho PCBs congeners, the arithmetic mean concentrations of 2,3',4,4',5-pentachlorobiphenyl (PentaCB) (#118) and 2,3,3',4,4'-PentaCB (#105) in the breast milk were slightly higher than those in the blood, which suggested that breast-fed infants may be at higher risk from mono-ortho PCBs.     

Congener-specific analysis of non-dioxin-like polychlorinated biphenyls in blood collected from 195 pregnant women in Sapporo City, Japan

We conducted a congener-specific analysis of non-dioxin-like polychlorinated biphenyls (non-dioxin-like PCBs) in blood collected between July 2002 and July 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which full congener concentrations of non-dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years, median: 28.0 years) and 94 were multipara (mean: 32.3 years, median: 33.0 years). Among the 197 non-dioxin-like PCB congeners, 58 congeners were identified in the blood of pregnant women. The arithmetic mean total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers in Sapporo City were 42.2-329.3 (mean: 114.5, median: 98.6) and 31.5-258.0 (mean: 100.3, median: 91.4)ngg(-1)lipid, respectively. The results show that the contamination of non-dioxin-like PCBs in the blood of women has decreased compared to past levels in other domestic areas, in which the subject age was similar to that in this study. The results of the present study indicate that current levels of non-dioxin-like PCBs in the blood of Japanese women and can be used as baseline data for future temporal trends. The sums of the ratios of the concentrations of hexaCBs and heptaCBs to the total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers were 78.5% and 77.7%, respectively. The hexaCBs ratios in the blood of primiparous and multiparous mothers were 45.4% and 44.7%, respectively. HexaCB-153 among hexaCBs congeners, the most abundant congener in the blood of primiparous and multiparous mothers, contributed approximately 22.0% and 21.8% to the total concentrations of 58 non-dioxin-like PCBs congeners that were measured in the blood, respectively. Among the non-dioxin-like PCB congeners measured in the present study, hexaCB-138, heptaCB-170, heptaCB-180, and heptaCB-182/heptaCB-187 also showed high ratios to total concentrations of 58 non-dioxin-like PCB congeners detected in the blood of primiparous and multiparous mothers. With regard to the relationship between the total concentrations of 58 non-dioxin-like PCB congeners in maternal blood and the number of deliveries or the age of primiparous and multifarious mothers, the total levels of these PCB congeners tended to decreases with increases in the number of deliveries and significantly increased with increasing maternal age in both groups. Furthermore, significant correlations were observed between the total concentrations of these PCB congeners in blood and the age of primiparae and multiparae. The concentrations of hexaCB-153 in the blood of primiparous and multiparous mothers showed a close correlation to the total concentrations of these PCBs, suggesting that hexaCB-153 could be an indicator of total concentrations of non-dioxin-like PCB congeners in the blood of pregnant women.     

Differences in the Spatial Variability Among CO2, CH4, and N2O Gas Fluxes from an Urban Forest Soil in Japan

The spatial variability of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) fluxes from forest soil with high nitrogen (N) deposition was investigated at a rolling hill region in Japan. Gas fluxes were measured on July 25th and December 5th, 2008 at 100 points within a 100 × 100 m grid. Slope direction and position influenced soil characteristics and site-specific emissions were found. The CO₂ flux showed no topological difference in July, but was significantly lower in December for north-slope with coniferous trees. Spatial dependency of CH₄ fluxes was stronger than that of CO₂ or N₂O and showed a significantly higher uptake in hill top, and emissions in the valley indicating strong influence of water status. N₂O fluxes showed no spatial dependency and exhibited high hot spots at different topology in July and December. The high N deposition led to high N₂O fluxes and emphasized the spatial variability.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in blood collected from 195 pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho coplanar polychlorinated biphenyls (non-ortho PCBs), and mono-ortho coplanar polychlorinated biphenyls (mono-ortho PCBs) in blood collected between 2002 and 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which PCDDs, PCDFs, and dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years) and 94 were multipara (mean: 32.4 years). The arithmetic mean total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs of primiparous and multiparous mothers in Sapporo City were 17.4 (median: 15.7) and 14.0 (median: 13.9)pgTEQ/glipid, respectively, and the concentrations were in the range of 6.6-43.4 and 3.4-28.2pgTEQ/glipid, respectively. In regard to the relationship between the total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in maternal blood and the number of deliveries or age of primiparous and multiparius mothers, the levels of these dioxin-like compounds tended to decrease with increases in the number of deliveries and significantly increased with increasing maternal age in both groups. Furthermore, significant correlations were observed between the total TEQ concentrations of these dioxin-like compounds and the age of primiparae and multiparae. The total TEQ concentration of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs measured in 195 pregnant women has decreased compared to past levels in Japan for the last several decades. The results of the present study have indicated that dioxin contamination in the blood of young women in Japan is continuing to decrease.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in blood and breast milk collected from pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), and non-dioxin-like PCBs in paired samples of blood and breast milk collected from 67 secundiparas in Sapporo City, Japan, and combined this data with those of the 30 secundiparas previously measured. The arithmetic mean total toxic equivalents (TEQ-WHO) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the 97 secundiparous subjects were 3.0-23 (mean: 13, median: 14) and 2.7-20 (mean: 8.6, median: 8.5) pg TEQ g⁻¹ lipid, respectively. The sums of the concentrations of 56 non-dioxin-like PCB congeners that were measured in the subjects’ blood and breast milk were 16-326 (mean: 107, median: 100) and 12-252 (mean: 73, median: 67) ng g⁻¹ lipid, respectively. The partitioning ratios of individual congeners of PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin-like PCBs from blood to breast milk in secundiparas were almost the same as those of primiparas that have been recently reported, suggesting that the partitioning ratios of these compounds from maternal blood to breast milk in women is little affected by delivery. Furthermore, the partition of PCB congeners with chlorine at the 2-, 3-, 4′-, and 5-positions or the 2-, 4-, 4′-, and 5-positions of the biphenyl ring from the blood to the breast milk tended to occur at a higher level than that of other congeners. In particular, the levels of tetraCB-74 and hexaCB-146 in the breast milk for both primiparous and secundiparous mothers were slightly higher than those in the blood.     

Enrichment of elements in industrial waste incineration bottom ashes obtained from three different types of incinerators,as studied by ICP-AES and ICP-MS

The elemental composition of the industrial waste incineration bottom ash (IWIBA) samples collected from three different types of incinerator with different kinds of wastes were compared. The major-to-ultratrace elements in the IWIBA samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). As a result, ca. 40 elements in the concentration range from milligrams per gram to submicrograms per gram could be determined with relative standard deviations of less than 5%. The IWIBA sample from petrochemical wastes contained lower concentrations of the elements, because fewer mineral constituents were contained in the input waste materials. On the contrary, the elemental concentrations in the IWIBA sample from industrial solid wastes provided the highest values for most elements, while the elemental compositions of the IWIBA sample from food wastes were similar to those of municipal solid waste incineration bottom ash. In addition, it was found from the analytical results that the levels of various heavy metals such as Cr, Mn, Fe, Ni, Cu, As, Zr, Mo, Sb, Ba, and Pb were higher in the IWIBA samples than in municipal solid waste incineration bottom ash. The enrichment factors of the elements in the IWIBA samples were estimated from the analytical results to compare the elemental distributions in incineration bottom ashes in relation to their mining influence factors, which are the indices for human use of the elements.