Evaporation of trichloroethylene (TCE) is a viable option in the remediation of TCE contaminated water. In this study, laboratory batch experiments were conducted to understand the evaporation kinetics of TCE in surface water, with further extension of this knowledge to field application. Experiments were set up for 15, 30, 60, and 90 min time intervals in open glass containers with initial concentration of 10 mgl-¹ TCE in 100 ml water. The containers were either exposed to wind or were placed on an orbital shaker to produce constant water motion. A reference study carried out in absence of wind and water-motion showed much slower rate of TCE evaporation, compared to other studies done with wind or orbital shaker. Experiments with water turbulence at 150 rpm yielded a higher volatilization coefficient, Kv = 4.36 h-¹ for TCE. The wind at a flow rate of 0.7 m/s also gave rise to 2.24 h-¹ coefficient for TCE evaporation. The volatilization coefficient for the reference study yielded a smaller value of 0.23 h-¹, with corresponding half-life of 3 h, indicating the importance of wind and water motion in TCE evaporation. Experiments conducted at 150rpm and 0.7 m/s wind velocity showed consistent evaporation trend, and were in better agreement with the extrapolated rate of evaporation obtained through the first order rate equation.

Multi-block (heavy metals, pesticides, physico-chemical parameters) data set pertaining to the soils of alluvium region in Indo-Gangetic plains was analyzed using principal component analysis (PCA) and multiple factor analysis (MFA) methods to delineate the contaminated sites and to identify the possible contamination sources in the study region. In normal PCA, the first three factors were dominated mainly by heavy metals, pesticides and physico-chemical variables, respectively, thus identifying samples/sites contaminated with these. The MFA results, due to its unique weighting scheme of variables of different blocks extracted, to more realistic information about the spatial distribution of samples and relationships among the variables. MFA minimized the influence of variables of one single block on the first few components, allowing variables of all blocks equally to share the common MFA space. This resulted in delineating the sites/regions contaminated with variables (Al, Co, Cu, Mn, Ni, Pb, V, Na, SO₄, aldrin, lindane, HCB, HCH, DDT, and endosulfan) of all the blocks, rather than by particular block variables as in case of normal PCA, where, the variables of single block dominate the first factors, suppressing other block variables. MFA which can be considered as a method for standardization of the multi-block variables was successfully applied to the three block data set of soils.

We attempted to elucidate seasonal variations in fossil-fuel-derived carbon (FC) and biomass-derived carbon (BC) in urban atmospheric aerosols. We undertook continuous measurements of the composition of fine particle (PM₂.₁) in central Tokyo, including the ¹⁴C/¹²C ratio. The percent modern carbon (pMC) contained in all samples averaged 43, and the highest was 54 in late December and the lowest was 31 in early August. From the observed carbonaceous component concentrations and the pMC we could calculate the content ratio of FC and BC in PM₂.₁ and investigate their seasonal variations. Although there was almost no seasonal variation in the ratio of FC, the ratio of BC was observed to rise in early winter. This indicates that FC is influenced by the emission sources without seasonal variations (such as automobiles driven in urban areas). Furthermore, there is significant correlation between BC and organic carbon (OC), and even for urban areas, it is considered that the contribution of biomass carbon to OC in PM₂.₁ is high.

In order to restore the forest ecosystem in the vicinity of an industrial park, Ulsan, southeastern Korea, which has been heavily acidified by air pollution, a preliminary experiment by applying tolerant plants selected through several procedures, and dolomite and sewage sludge as soil ameliorators was carried out. Furthermore, a restoration based on the results was executed and the effects were evaluated based on the creation of safe sites, where new species can establish: regeneration of the forest with species similar in composition to the natural vegetation of native forests that are distant from the industrial park; increase in species diversity. In a preliminary study, the necessity of soil amelioration was diagnosed. Quercus serrata, Alnus firma and Ligustrum japonicum, which represent for tree, subtree, and shrub layers of vegetation in this region, were used as sample plants. Dolomite, sludge, and a mixture of both materials were applied as soil ameliorators. Bare ground (BG), and two grasslands dominated by forbs (GF) and grass (GG), respectively were designated as experimental plots based on a vegetation map of the corresponding area. BG and GF plots, which have lower organic matter contents, increased the growth of sample plants in response to soil amelioration, whereas that with higher contents, GG plot, did not show this response. The result suggests that necessity of soil amelioration depends on site quality. The effects of soil amelioration depended also on the sample plants. This difference is due to an ecological property of A. firma, which can fix atmospheric nitrogen through a symbiotic relationship with actinomycetic fungi. This result implies that this alder could be used as a substitute for soil ameliorators in restoration plan of this area. The height and standing crop of undergrowth, which forms dense grass mat and thereby impedes establishment of new plants, decreased in the restored stands. Such a decrease in the height and biomass of undergrowth could be recognized as providing safe sites, in which the other plants can invade, by removing the dense carpet formed by Miscanthus sinensis. The results of stand ordination showed a progression of the former bare grounds to either M. sinensis (GG) or Pueraria thunbergiana (GF) stands, suggesting a natural recovery through succession toward the stands dominated by both plants. But the change was not progressed beyond the grassland stage. Active restoration practice, which was carried out by applying tolerant plants, however, led to a change toward species composition similar to the natural vegetation before devastation. Furthermore, restored stands reflected the restoration effect by showing higher diversity than the stands in the degraded state. These results showed that the restorative treatment carried out by introducing tolerant plants functioned toward increasing both biological integrity and ecological stability and thereby could meet the restoration goal.

The sorption of hydrophobic organic pollutants on soils or sediments has been widely studied. However, more attention in the previous studies has been paid to sorption mechanism and effects of relevant environmental factors, few studies were reported on effects of heavy metals on the sorption of hydrophobic organic pollutants. In this paper, sorption of phthalate esters (diethyl phthalate, DEP, and di-n-butyl phthalate, DnBP) and copper on the Yellow River sediment was investigated with particular attention to the effects of copper on the phthalate sorption. The experimental results show that the sorption isotherms of phthalates could be reasonably described by the Freundlich equation. Higher sorption equilibrium constant was obtained for DnBP due to its greater hydrophobicity. The existence of copper would enhance the sorption of DnBP. Moreover, strong sorption of copper to sediment were found and attributed to abundant carbonates in the Yellow River sediment. After carbonates were removed, notable effects of copper on the phthalate sorption were observed due to the decrease of copper sorption and the increase of aqueous copper concentration. With 153 mg l-¹ copper added, the partition coefficient decreases by 52% for DEP and increases by 79% for DnBP. Primary factors that may influence interaction between the sorption of copper and DEP and DnBP were also investigated, such as complexation between copper and phthalate, and phthalate hydrophobicity. The complexation between phthalate esters and copper was substantiated by polarogram and fluorescence spectrograph, and the calculated mol ratio of complexation (copper : phthalate) was found to be 2:1.

Ground-level concentrations of three atmospheric mercury species were measured using manual sampling and analysis to provide data for estimates of mercury dry deposition. Three monitoring stations were operated simultaneously during winter, spring, and summer 2004, adjacent to three mercury wet-deposition monitoring stations in northern, central, and southern Indiana. The monitoring locations differed in land-use setting and annual mercury-emissions level from nearby sources. A timer-controlled air-sampling system that contained a three-part sampling train was used to isolate reactive gaseous mercury, particulate-bound mercury, and elemental mercury. The sampling trains were exchanged every 6 days, and the mercury species were quantified in a laboratory. A quality-assurance study indicated the sampling trains could be held at least 120 h without a significant change in reactive gaseous or particulate-bound mercury concentrations. The manual sampling method was able to provide valid mercury concentrations in 90 to 95% of samples. Statistical differences in mercury concentrations were observed during the project. Concentrations of reactive gaseous and elemental mercury were higher in the daytime samples than in the nighttime samples. Concentrations of reactive gaseous mercury were higher in winter than in summer and were highest at the urban monitoring location. The results of this case study indicated manual sampling and analysis could be a reliable method for measurement of atmospheric mercury species and has the capability for supplying representative concentrations in an effective manner from a long-term deposition-monitoring network.

Fluvial bed sediments are widely used for characterizing anthropogenic contaminant signals in urban watersheds. This study presents the first preliminary examination of sequentially extracted Pb from grain size fractionated bed sediments using the optimized (standardized) BCR procedure. Baseline sediment samples and samples from the vicinity of three storm-sewer outlets in Nuuanu Stream, Honolulu, Hawaii, were examined. The weighted average Pb liberated from four sequentially extracted phases was 144 ± 26 mg/kg (±SD). These Pb concentrations are high compared to 3 mg/kg leached by a 0.5 M HCl solution, and 13 mg/kg from a 4-acid total digestion of baseline sediments. Over a 1.8 km section of stream channel, land use variations and traffic density differences had little impact on the magnitude of Pb in specific phases for each of the six grain size fractions examined. Regardless of grain size or spatial location, Pb in the reducible phase exceeded that in oxidizable, residual and acid extractable phases. Weighted reducible Pb concentrations for three sewer outlet sites ranged from 69 to 92 mg/kg, and this phase typically accounted for 70-80% of all labile Pb. The <63 μm grain size class did not exhibit the highest Pb concentration, instead this was found in either the 125-250 μm or 500-1,000 μm fractions. Examining bed sediment phase associations of Pb over a smaller length dimension (i.e., 40 m) centered around one sewer outlet, indicated higher concentrations at the outlet (180 mg/kg) compared to upstream (132 mg/kg) or downstream (150 mg/kg). The differences were primarily associated with higher Pb concentrations in the reducible and oxidizable phases of the coarse sand fractions (500-2,000 μm) at the outlet. Overall, all data point to a significant anthropogenic signal for Pb in bed sediments in the urbanized section of Nuuanu Stream.

Recent developments in satellite remote sensing technologies resulted in the ability to observe major pollution events such as dust and smoke around the world on a daily basis. Satellite imagery can sometimes detect long-range transport episodes. In this paper, a high CO episode at remote GAW station, Mt. Waliguan, detected by MOPITT CO dataset during the end of April 2002, is described. CO concentrations above 600 hPa almost doubled on 27 April and CMDL surface sample measurements also observed this significant CO enhancement. Using NCEP data, satellite fire products data and backward trajectory model we suggest that this high CO episode of 27 April is not a local pollution event, but that it is due to long-range transport from active biomass burning and biofuel burning areas located in the border areas of Pakistan and India. The trajectory cluster analysis shows that the origins of 5-day backward trajectories, for air masses reaching Mt. Waliguan station, at all altitudes, mainly overlap with the fire spot locations detected by TRMM data and biofuel burning in India.

To obtain basic information for evaluating critical levels of O₃ under different nitrogen loads for protecting Japanese beech forests, two-year-old seedlings of Fagus crenata Blume were grown in potted andisol supplied with N as NH₄NO₃ solution at 0, 20 or 50 kg ha-¹ year-¹ and exposed to charcoal-filtered air or O₃ at 1.0, 1.5 and 2.0 times the ambient concentration from 16 April to 22 September 2004. The O₃ induced significant reductions in the whole-plant dry mass, net photosynthetic rate at 380 μmol mol-¹ CO₂ (A ₃₈₀), carboxylation efficiency (CE) and concentrations of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and total soluble protein (TSP) in the leaves. The concentrations of Rubisco and TSP were negatively correlated with the concentration of leaf acidic amino acid, suggesting that O₃ enhanced the degradation of protein such as Rubisco. The N supply to the soil did not significantly change the whole-plant dry mass and A ₃₈₀, whereas it significantly increased the CE and concentrations of Rubisco and total amino acid. No significant interactive effects of O₃ and N supply to the soil were detected on the growth, photosynthetic parameters and concentrations of protein and amino acid in the leaves. In conclusion, N supply to the soil at <=50 kg ha-¹ year-¹ does not significantly change the sensitivity to O₃ of growth and net photosynthesis of Fagus crenata seedlings.

The dynamics of macroalgal communities and the impact of sewage on their growth were studied in the tidal zone around Zhanqiao Pier of the Qingdao coastal area, in the northwest of the Yellow Sea, China, from September 2001 to September 2003. The tidal zone of the study area is divided into western and eastern sections by the Zhanqiao Pier. Inorganic nitrogen and phosphorus in seawater showed higher concentrations on the eastern side of Zhanqiao Pier than on the western side, because a sewer drains into the eastern side. The macroalgal communities on each side of the Pier showed an obvious difference due to the effect of this sewage discharge. A total of 47 macroalgal species including 10 greens, 11 browns and 26 reds was identified in this study. The species composition and biomass indicated higher values in the nutrient-rich area on the eastern side of Zhanqiao Pier compared with the nutrient-poor area on the western side of Zhanqiao Pier. Some ephemeral and filamentous species dominated seasonally on the eastern side of Zhanqiao Pier, in contrast to the western side where slow-growing species dominated throughout the year. Nutrient gradients and temperature were considered the main factors affecting the distribution of macroalgae communities in time and space. The results are consistent with the common observation that nutrient-poor areas are dominated by slow-growing rather than ephemeral algal species. Moreover, the species diversity in the whole study area had declined when compared to previous records.