On-road motor vehicle emissions and fuel consumption in urban driving conditions

This paper reports on the analysis of on-road vehicle speed, emission, and fuel consumption data collected by four instrumented vehicles. Time-, distance-, and fuel-based average fuel consumption, as well as CO, HC, NOx, and soot emission factors, were derived. The influences of instantaneous vehicle speed on emissions and fuel consumption were studied. It was found that the fuel-based emission factors varied much less than the time- and distance-based emission factors as instantaneous speed changed. The trends are similar to the results obtained from laboratory tests. The low driving speed contributed to a significant portion of the total emissions over a trip. Furthermore, the on-road data were analyzed using the modal approach. The four standard driving modes are acceleration, cruising, deceleration, and idling. It was found that the transient driving modes (i.e., acceleration and deceleration) were more polluting than the steady-speed driving modes (i.e., cruising and idling) in terms of g/km and g/sec. These results indicated that the on-road emission measurement is feasible in deriving vehicle emissions and fuel consumption factors in urban driving conditions.     

The effects of perennial ryegrass and alfalfa on microbial abundance and diversity in petroleum contaminated soil

Enhanced rhizosphere degradation uses plants to stimulate the rhizosphere microbial community to degrade organic contaminants. We measured changes in microbial communities caused by the addition of two species of plants in a soil contaminated with 31,000 ppm of total petroleum hydrocarbons. Perennial ryegrass and/or alfalfa increased the number of rhizosphere bacteria in the hydrocarbon-contaminated soil. These plants also increased the number of bacteria capable of petroleum degradation as estimated by the most probable number (MPN) method. Eco-Biolog plates did not detect changes in metabolic diversity between bulk and rhizosphere samples but denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified partial 16S rDNA sequences indicated a shift in the bacterial community in the rhizosphere samples. Dice coefficient matrices derived from DGGE profiles showed similarities between the rhizospheres of alfalfa and perennial ryegrass/alfalfa mixture in the contaminated soil at week seven. Perennial ryegrass and perennial ryegrass/alfalfa mixture caused the greatest change in the rhizosphere bacterial community as determined by DGGE analysis. We concluded that plants altered the microbial population; these changes were plant-specific and could contribute to degradation of petroleum hydrocarbons in contaminated soil.     

Sorption of biodegradation end products of nonylphenol polyethoxylates onto activated sludge

IntroductionRecently ,nonylphenolpolyethoxylates (NPnEO (n :numberofethoxyunits(EOs) )havebecomeaproblematicissueforthereasonthatthesecompounds,animportantgroupofnonionicsurfactants ,havebeenusedwidelyinvariousindustriesasflocculants,dispersants,emulsifie…     

Arsenic species in the well water and sediments of the blackfoot disease area in Taiwan

The blackfoot disease (BFD) observed in southwestern Taiwan is due to drinking high arsenic concentrations in well water. This paper presents some results concerning the distributions of arsenic species in water and sediments collected in the BFD (well, river and coastal) area and the background (lake and ocean) area for comparison. The results show that the concentrations of arsenate (870 ± 26 ug/L) and arsenite (70.2 ± 2.6 ug/ L) in well waters, and the contents of arsenic (1640 ug/g) with high percentage of easily reducible (Fe and Mn oxides, 91.7%) and exchangeable and carbonate (4.6%) phases in well sediments were much higher than those in river, lake and coastal samples. Low arsenic (3.46–31.8 ug/g) with high percentages (73.8–97.3%) of detritus and minerals phase with low percentages (0.4–9.8%) of total carbonate and exchangeable phases were found in the river and coastal samples in the BFD area as well as the lake and ocean samples in background area. It might suggest that the higher concentrations of toxic As(III) in well water and arsenic with higher values of easily reducible, carbonate and exchangeable phases in the well sediments, combined with the higher values of dissolved organic carbon, humic and fulvic acids and aromatic carbon as well as the higher fluorescence indensity in the well water are the key factors to cause the BFD in Taiwan.     

Dynamic changes in radial oxygen loss and iron plaque formation and their effects on Cd and As accumulation in rice (Oryza sativa L.)

Temporal variations and correlations between radial oxygen loss (ROL), iron (Fe) plaque formation, cadmium (Cd) and arsenic (As) accumulation were investigated in two rice cultivars at four different growth stages based upon soil pot and deoxygenated solution experiments. The results showed that there were significant differences in ROL (1.1–16 μmol O₂ plant^?1 h^?1), Fe plaque formation (4,097–36,056 mg kg^?1), Cd and As in root tissues (Cd 77–162 mg kg^?1; As 49–199 mg kg^?1) and Fe plaque (Cd 0.4–24 mg kg^?1; As 185–1,396 mg kg^?1) between these growth stages. ROL and Fe plaque increased dramatically from tillering to ear emergence stages and then were much reduced at the grain-filling stage. Furthermore, significantly positive correlations were detected between ROL and concentrations of Fe, Cd and As in Fe plaque. Our study indicates that increased Fe plaque forms on rice roots at the ear emergence stage due to the increased ROL. This stage could therefore be an important period to limit the transfer and distribution of Cd and As in rice plants when growing in soils contaminated with these toxic elements.     

Relationships Between Copper Species and Forms,Hydrographic and Biomass Parameters in the Taiwan Erhjin Chi Coastal Area

The first incident of green oysters (Crassostrea gigas) was reported in Taiwan in the Charting coastal area in January, 1986 and mortality was reported three months later. the cause of the greened oysters was identified as copper pollution. the copper content of the green oysters was extremely high - 2100 ppm, 2225 ppm, and 4400 ppm dry weight, in January, 1986, February 1987, and January 1989, respectively. in this paper we summarize the seasonal and regional distributions of copper species (complexed by inorganic and organic ligands, labile and non-labile, polar and non-polar) and forms (dissolved and particulate) and the hydrographic and biomass parameters (mainly particulate organic carbon, chloropyll -α, adenosine triphosphate and primary production) in sea water in the Erhjin Chi coastal area. in general, high concentrations of particulate material (0.24 to 724 ppb) and non-labile organic copper (0.03 to 21.5 ppb) were observed. Low values of polar organic copper (<0.02 to 16.5 ppb) indicated that non-polar organic complexes (0.3 to 20.4 ppb) from man-made organic pollutants were the major complexes in the area studied. On the basis of this data, the cause of greening and mortality in oysters is evaluated in relation to the bioavailable copper (sum of particulate and labile copper) and copper assimilative capacity (detoxicant). Finally, the correlations between the species and forms of copper, hydrographic and biomass parameters are also discussed.     

Anthropogenic influence on surface water quality of the Nhue and Day sub-river systems in Vietnam

In order to investigate the temporal and spatial variations of 14 physical and chemical surface water parameters in the Nhue and Day sub-river systems of Vietnam, surface water samples were taken from 43 sampling sites during the dry and rainy seasons in 2007. The results were statistically examined by Mann–Whitney U-test and hierarchical cluster analysis. The results show that water quality of the Day River was significantly improved during the rainy season while this was not the case of the Nhue River. However, the river water did not meet the Vietnamese surface water quality standards for dissolved oxygen (DO), biological oxygen demand (BOD₅), chemical oxygen demand (COD), nutrients, total coliform, and fecal coliform. This implies that the health of local communities using untreated river water for drinking purposes as well as irrigation of vegetables may be at risk. Forty-three sampling sites were grouped into four main clusters on the basis of water quality characteristics with particular reference to geographic location and land use and revealed the contamination levels from anthropogenic sources.     

Bioavailability evaluation of naphthalene in soil using persulfate oxidation and ultrasonic extraction method

Bioavailability is defined as the fraction of a soil contaminant readily available for microbial degradation and for naphthalene it could be estimated by conventional exhaustive extraction methods. In this study, a novel method that employed persulfate oxidation in combination with ultrasonic extraction (POUSE) was developed. Three parameters, temperature, duration of persulfate oxidation, and the ratio of persulfate to soil organic matter (2S,082 /SOM; g g-1), were investigated to obtain an optimum operating conditions. Under the condition, naphthalene bioavailability estimated by the POUSE method was verified and compared with other three exhaustive methods i.e. sonicator, supercritical fluid extraction (SFE), and soxhlet extraction (SE). When the S2,O(8)2-/SOM ratio was controlled at 11.6 g g-1, the optimum operating conditions of the POUSE method were 70 degreesC and 3 hr, for the temperature and duration. Under these conditions, the residual naphthalene concentrations were correlated well with the residual naphthalene concentrations for both the cases of freshly spiked and aged soils. By contrast, the sonicator, SFE, and the SE overestimated the naphthalene bioavailability since these three methods extracted naphthalene much more than that of biodegradation test. These results demonstrated that the POUSE could estimate more precisely the naphthalene bioavailability.     

Lead contamination in surface soil on roads from used lead–acid battery recycling in Dong Mai,Northern Vietnam

Used lead–acid battery (ULAB) recycling has caused numerous health and environmental issues in developing countries. Surface soil pollution from ULAB recycling activities has been linked with elevated levels of lead in human blood. We measured surface soil lead in and surrounding the ULAB recycling village of Hung Yen in northern Vietnam in 2011, 2013, and 2014. The data were analyzed statistically and discussed with respect to distance from the contamination source, year of measurement, contamination pathway, and countermeasures against the contamination. Transportation routes from the smelter or collection site displayed the greatest concentration of surface soil lead (median 6400–10,000 mg/kg). Surface soil lead decreased significantly with distance along the road from the ULAB recycling site, although such a decrease was not observed for rice fields, agricultural roads, or garden soil. Re-suspension and adherence by traffic were identified as key pollution pathways. Distance from the source, covering of the surface of roads, construction of walls, and position relative to the source were shown to be the most effective factors in the reduction of surface soil lead pollution. Application of a combination of these measures should result in improvement in the health of residents.     

Plastic waste as a valuable resource: strategy to remove heavy metals from wastewater in bench scale application

Environmental Science and Pollution Research - Single-use plastic waste is gradually considered a potential material for circular economy. Ion exchange resin obtained from polystyrene waste by...