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.

Former gold mining at Rodalquilar in southeastern Spain exploited a high sulphidation epithermal silicified ore deposit that contained significant enrichments in several metals/metalloids such as As, Sb, Bi, and Te. Treatment of this ore took place adjacent to the village and involved physical crushing then chemical extraction of gold using cyanide and zinc. The waste materials from this processing system, contaminated with a range of trace elements, were deposited immediately below the mine, and have been left exposed to erosion. Over the last 40 years these oxidised ferruginous tailings have not only polluted the local drainage system but also provided a point source for contaminated aeolian dust under the prevailing dry, windy climate. Chemical analyses of particulate matter mechanically resuspended from the tailings materials show enrichments in metals and metalloids due to the preferential incorporation of these elements into the inhalable size fraction (PM₁₀). Of particular concern is the fact that these PM₁₀ can contain >1,500 ppm As and >40 ppm Sb. Given that both As and Sb are clastogenic metalloids with proven negative health effects, and that their oxidised forms are especially toxic, such contamination levels in windblown dusts around old mine sites are highly undesirable.

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.

In intensively cultivated areas, agriculture is a significant source of pesticides associated with storm runoff. When these pollutants enter aquatic receiving waters, they have potential to damage nearby aquatic ecosystems. Constructed wetlands are a best management practice (BMP) designed to help alleviate this potential problem. A constructed wetland system (180 x 30 m) comprised of a sediment retention basin and two treatment cells was used to determine fate and transport of a simulated storm runoff event containing the insecticide diazinon and suspended sediment. Wetland water, sediment, and plant samples were collected spatially and temporally over 55 d. Results indicated that 43% of the study's measured diazinon mass was associated with plant material, while 23 and 34% were measured in sediment and water, respectively. Mean diazinon concentrations in water, sediment, and plants for the 55-d study were 18.1 ± 4.5 μg/l, 26.0 ± 8.0 μg/kg, and 97.8 ± 10.7 μg/kg, respectively. Aqueous concentrations fluctuated in the wetlands between 51-86 μg/l for the first 4 h of the experiment; however, by 9 h, aqueous concentrations were approximately 16 μg/l. During the 55 d experiment, 0.3 m of rainfall contributed to fluctuations in diazinon concentrations. Results of this experiment can be used to model future design specifications for mitigation of diazinon and other pesticides.

A powerful 7.3 magnitude earthquake struck Taiwan on September 21, 1999. The stream water chemistry (pH, total alkalinity, conductivity, sodium, potassium, calcium, magnesium, ammonium, fluoride, chloride, sulfate, and nitrate) has been monitored since 1995 at the Guandaushi forestry riparian zone in central Taiwan. Collected data was used as a basis for comparing pre- and post-earthquake impacts. The pH, conductivity, and concentrations of Na, Ca, Mg, SO₄, and HCO₃ in stream water were lowest during the summer season, when stream water discharge was highest. On the other hand, the lowest concentrations of Cl, NH₄, and NO₃ in stream water occurred during the winter season, when stream water discharge was lowest. Also, K and F showed very little seasonal fluctuation in concentration. Downward trends in K and Ca were found 14 months prior to the earthquake; although, an upward trend occurred in NH₄ at the same time.

Ammonia fluxes from application of anaerobically-digested slurry (ADS) and chemical fertilizer (CF) to flooded forage rice (Oryza sativa L.) in Japan were measured using a dynamic flow-through chamber method in lysimeters. The CF was applied at a rate of 300 N ha-¹ (three times) as ammoniacal-N fertilizer, and the ADS was applied to the lysimeters at total rates equivalent to 75, 100 and 150 kg N ha-¹, by broadcasting uniformly into the floodwater at three or six times (equal splits) between 17th June and 17th November, 2005. The emission fluxes for the first 2 days after application were very high from ADS, the highest values being 679 compared with a maximum of 156 mg N m-² d-¹ from CF. Most (61-93%) of the ammonia loss occurred during the first 5 days after each application of fertilizer. The total N loss as ammonia from ADS (29.6-51.7%) was much higher than from CF (12.2%). The highest fluxes were observed in August (2005) when air temperature was highest. More ammonia was lost from the ADS applied at the early stages (i.e. root taking, tiller stages) than at later stages (i.e. elongation, fruiting stages) of rice growth.

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.

The use of solid-state fermentation (SFF) of low cost substrates by fungal species to generate organic acid solutions for washing of lead from a contaminated soil was evaluated in this study. SFF filtrates were generated by fermentation of four substrates (corn cobs, apple pomace, rice and hay) with three fungal species (Aspergillus niger NRRL 2001 (A. niger 1), Aspergillus niger ATCC 64065 (A. niger 2), Aspergillus foetidus NRRL 337) at three fermentation times. The concentration and speciation of organic acids of the filtrates was found to be a function of the substrate type, the fungal species and the fermentation time. Fermentation of rice resulted in the highest concentrations of citric acid while fermentation of corn cobs, apple pomace and hay tended to generate oxalic acid with an increasing fraction of this acid as the fermentation progressed. Batch extraction tests that employed the SSF filtrates revealed that soluble lead concentrations as high as 35 mg/l could be achieved. Filtrates containing elevated concentrations of citric acid resulted in the greatest lead extraction while oxalic acid inhibited solubilization. Due to the buffering of pH that was provided by the soil in the batch tests this factor did not appear to influence lead extraction. Lead extraction was observed over an extended period of time in a column test. Lead extraction was strongly influenced by the pH of the soil column and less strongly influenced by the organic acid content of the SSF filtrate. The speciation of organic acids was substantially modified from primarily citric acid in the SSF filtrate to gluconic acid in the soil column discharge.

A biomonitoring study using the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was conducted in the city of Valencia (eastern Spain) and surrounding areas in 2002. Plants were exposed to ambient air at seven sites, including four traffic-exposed urban sites, a large urban garden and a suburban and a rural station, for six consecutive 2-week periods using highly standardised methods. Foliar injury was registered at all stations in at least one of the exposure periods. The urban stations submitted to intense traffic showed lower ozone injury than the less traffic-exposed stations. Strong changes in the intensity of ozone injury were observed for the different exposure periods. Leaf injury was significantly related to both mean ozone values (24 and 12 h means) and cumulative exposure indices (AOT20, AOT40). However, correlation strength was moderate (r s = 0.39 to 0.58), suggesting that the plant response to ozone was modified by environmental factors. The use of sensitive bioindicators like tobacco Bel-W3 in cities provides complementary information to that of continuously operating air quality monitors, as the impact of ambient ozone levels is directly measured.

The potential for colloid-facilitated migration in contaminated sites is well known, and remediation techniques such as ultrafiltration are often considered for contaminant removal. Although this approach could be successful, the stability of the contaminant species in groundwater and the removal efficiency need to be investigated to ensure proper decontamination of moving aquifers. In our study, we have sampled contaminated groundwater near a former radioactive liquid disposal area at Chalk River, Ontario, Canada. Samples were taken in 2002 and 2004 to determine the behaviour of radiocontaminants by size fractionation using ultrafiltration, with emphasis on ⁶⁰Co and ¹³⁷Cs. The contaminant concentrations varied significantly for both contaminants in the two samples (34.5 and 25.5 Bq/l for ⁶⁰Co, 25.5 and 97.2 Bq/l for ¹³⁷Cs). On the other hand, the size fractionation (5,000 Daa nominal cut-off) remained consistent between the 2002 and 2004 samples, as most of the ⁶⁰Co (72%-83%) remained in the filtrate, while almost all of the ¹³⁷Cs (>98%) was retained along with the colloidal-sized material. Release of ⁶⁰Co and ¹³⁷Cs from the colloidal material yielded desorption coefficients (K D₋des) of 7.8 x 10⁵ and 1.7 x 10⁸ ml/g for ⁶⁰Co and ¹³⁷Cs, respectively.