Role of pH in partitioning and cation exchange of aromatic amines on water-saturated soils

Predicting the reversible interactions between aromatic amines and soil is essential for assessing the mobility, bioavailability and exposure from contaminated sites. Reversible sorption mechanisms of aniline and alpha-naphthylamine were investigated by using single and binary solute sorption to five soils at several pH values, and by applying a distributed parameter (DP) model. The DP model assumes linear partitioning of the neutral species into soil organic matter domains and organic cation binding on negative-charged sites with the exchange coefficients represented by a Gaussian probability distribution. Sorption nonlinearity was attributed to cation exchange with varying site affinities, which was adequately simulated using the DP model. Greater uptake by hydrophobic partitioning and selectivity for cation exchange sites was observed for alpha-naphthylamine compared to aniline. Sorption of alpha-naphthylamine was not impacted quantitatively by aniline under those conditions examined; however, aniline sorption was reduced by alpha-naphthylamine with the largest reduction occurring in the soil with the lowest pH. DP model simulations showed that although hydrophobic partitioning increases with soil-solution pH, cation exchange still contributes significantly to the total sorption even at soil-solution pH values greater than pKa + 2.     

Assessment of the effects of herbicide spray drift on a range of plant species of conservation interest

With increasing use of herbicides there has been growing concern that spray drift from treated land will affect vegetation on adjacent nature reserves and other areas of high conservation interest. A preliminary attempt was made to assess this risk by placing a range of native plant species at different distances downwind from standardised drift events and assessing lethal effects and sublethal damage. Five herbicides were tested: asulam, 'Finesse' (chlorsulfuron + metsulfuron-methyl), glyphosate, MCPA and mecoprop. Applications were made at the appropriate time of years for each herbicide (autumn, spring and summer), and at both low and high wind speeds. The maximum safe distance at which no lethal effects were found was 6 m from the sprayer, but for most herbicides the distance was 2 m or less. Generally, damage symptoms were found at greater distances than lethal effects, but in most cases there was rapid recovery by the end of the growing season. These observations are consistent with drift-deposition models, in which the fallout of herbicide droplets has been measured. It is suggested that buffer zones surrounding nature reserves should be in the order of 5-10 m for ground sprayers to minimise the risk of herbicide impacts on these habitats.     

Studies on Barriers for Promotion of Clean Technology in SMEs of China

1 INTRODUCTIONAccording to the definition of SMEs in the TemporaryRegulation of Small and Medium Enterprise in China(2003): SMEs are those enterprises that have either less than2000 employees or 300 million RMB/year sales revenue, or400 million RMB fixed assets. SMEs generally account for99.88% of the total number of manufacturingestablishments in China in 2002, and they contributesignificantly to the social, economic and industrialdevelopment (Su, 2003).However, the majority of t…     

Evaluation of the Trend of Air Quality in Taipei, Taiwan from 1994 to 2003

The data collected from the five air quality monitoring stations established by the Taiwan Environmental Protection Administration (TEPA) in Taipei City were analyzed to assess the changes in air quality. The analyses reveal that the air quality in Taipei City improved over the last decade from 1994 to 2003, as evidenced by the significant downward trends of the various primary air pollutant concentrations, such as CO, NO_X, SO₂, and PM₁₀. An air pollution fee was collected by TEPA in 1995, and several air pollution control measures were likewise taken to improve the air quality in Taiwan. However, although the extreme daily maximum O₃ concentrations occurred more frequently in earlier years and showed a downward trend, its moderately high concentrations increased annually in recent years. It implied that after the reduction of various primary pollutant concentrations, the effective reduction of O₃ pollution still remains an important issue.     

Endocrine disrupting chemicals accumulate in earthworms exposed to sewage effluent

Endocrine disrupting chemicals (EDCs) can alter endocrine function in exposed animals. Such critical effects, combined with the ubiquity of EDCs in sewage effluent and potentially in tapwater, have led to concerns that they could be major physiological disruptors for wildlife and more controversially for humans. Although sewage effluent is known to be a rich source of EDCs, there is as yet no evidence for EDC uptake by invertebrates that live within the sewage treatment system. Here, we describe the use of an extraction method and GC-MS for the first time to determine levels of EDCs (e.g., dibutylphthalate, dioctylphthalate, bisphenol-A and 17beta-estradiol) in tissue samples from earthworms (Eisenia fetida) living in sewage percolating filter beds and garden soil. To the best of our knowledge, this is the first such use of these techniques to determine EDCs in tissue samples in any organism. We found significantly higher concentrations of these chemicals in the animals from sewage percolating filter beds. Our data suggest that earthworms can be used as bioindicators for EDCs in these substrates and that the animals accumulate these compounds to levels well above those reported for waste water. The potential transfer into the terrestrial food chain and effects on wildlife are discussed.     

Inventory methods for trees in nonforest areas in the great plains states

The US Forest Service’s Forest Inventory and Analysis (FIA) program collects information on trees in areas that meet its definition of forest. However, the inventory excludes trees in areas that do not meet this definition, such as those found in urban areas, in isolated patches, in areas with sparse or predominantly herbaceous vegetation, in narrow strips (e.g., shelterbelts), or in riparian areas. In the Great Plains States, little is known about the tree resource in these noninventoried, nonforest areas, and there is a great deal of concern about the potential impact of invasive pests, such as the emerald ash borer. To address this knowledge gap, FIA’s National Inventory and Monitoring Applications Center has partnered with state cooperators and others in a project called the Great Plains Initiative to design and implement an inventory of trees in nonforest areas. The goal of the inventory is to characterize the nonforest tree resource using methods compatible with those of FIA so a holistic understanding of the resource can be obtained by integrating the two surveys. The goal of this paper is to describe the process of designing and implementing the survey, including plot and sample design, and to present some example results from a reporting tool we developed.     

On-road emission factors from light-duty vehicles measured in Hsuehshan Tunnel (12.9 km), the longest tunnel in Asia

This study is based on 82 days of continuous air-quality monitoring using two mobile monitoring vans provided by the Taiwan Environmental Protection Administration (TEPA). The purpose of the study is to reveal variations of air quality without forced ventilation from on-road emissions of light-duty vehicles (LDV) inside the Hsuehshan Tunnel. Since it was opened to traffic in June 2006, only LDV have been allowed to pass the Hsuehshan Tunnel, the longest tunnel in Taiwan and in Asia. The hourly concentrations of air pollutants at four monitoring sites inside the tunnel (pollutant: downslope entrance, downslope exit, upslope entrance, upslope exit) are as follows: (CO: 6.9 +/- 5.4, 13.6 +/- 8.7, 4.6 +/- 3.2, 14.6 +/- 8.0 ppm), (NO(X): 534 +/- 311, 1198 +/- 640, 460 +/- 242, 1704 +/- 692 ppb), (SO2: 7 +/- 5, 18 +/- 10, 9 +/- 4, 26 +/- 10 ppb), (NMHC: 1.9 +/- 2.5, 3.5 +/- 3.0, 0.8 +/- 0.9, 2.7 +/- 1.9 ppm), (PM10: 50 +/- 28, 62 +/- 29, 59 +/- 25, 85 +/- 30 microg m(-3)), and (PM(2.5): 31 +/- 18, 45 +/- 22, 35 +/- 18, 62 +/- 23 microg m(-3)). The emission factors (EFs) from LDV in this study (pollutant: downslope EF, upslope EF in mg veh(-1) km(-1)) is estimated respectively as follows: (CO: 909 +/- 469, 1468 +/- 631), (NO(X): 145 +/- 67, 331 +/- 166), (SO2: 3 +/- 2, 6 +/- 3), (NMHC: 96 +/- 65, 121 +/- 63), (PM10: 2 +/- 2, 5 +/- 4), and (PM(2.5): 2 +/- 2, 4 +/- 3). It shows that the upslope pollutant EFs are twice as big as those of the downslope. However, among these EFs, the NMHC EF is less affected by the road gradient. Likewise, its upslope EF is only 1.3 times as big as that of the downslope. In summary, the results are useful for examining the emissions from the local fleet of vehicles under the driving conditions present during the study and for observing the changes in fleet emission rates upon future replication of the study.     

Use of space-filling curves to select sample locations in natural resource monitoring studies

The establishment of several large area monitoring networks over the past few decades has led to increased research into ways to spatially balance sample locations across the landscape. Many of these methods are well documented and have been used in the past with great success. In this paper, we present a method using geographic information systems (GIS) and fractals to create a sampling frame, superimpose a tessellation and draw a sample. We present a case study that illustrates the technique and compares results to those from other methods using data from Voyageurs National Park in Minnesota. Our method compares favorably with results from a popular plot selection method, Generalized Random Tessellation Stratified Design, and offers several additional advantages, including ease of implementation, intuitive appeal, and the ability to maintain spatial balance by adding new plots in the event of an inaccessible plot encountered in the field.     

Mercury capture into biogenic amorphous selenium nanospheres produced by mercury resistant Shewanella putrefaciens 200

Shewanella putrefaciens 200, resistant to high concentration of Hg(II), was selected for co-removal of mercury and selenium from aqueous medium. Biogenic Hg(0) reduced from Hg(II) by S. putrefaciens 200 was captured into extracellular amorphous selenium nanospheres, resulting in the formation of stable HgSe nanoparticles. This bacterial reduction could be a new strategy for mercury removal from aquatic environments without secondary pollution of mercury methylation or Hg(0) volatilization.     

Stabilization of residues obtained from the treatment of laboratory waste: Part 2--transformation of plasma vitrified slag into composites

The Sustainable Environment Research Center of National Cheng Kung University in Taiwan has set up a treatment plant to dispose of laboratory waste. In the treatment process, the residue from the incineration system and the physical and chemical system is vitrified by a plasma melting system. Part 1 of this study described the treatment path of metals during vitrification. In Part 2, plasma vitrified slag is reused by using a molding technology. Unsaturated polyester resin and glass fiber were used as the molding material and additive, respectively, in the molding process. With an appropriate mixing ratio of unsaturated polyester resin, glass fiber, and slag, the physical properties of composites improved, and the ultimate tensile strength reached 17.6 MPa. However, an excess amount of slag reduced the strength and even retarded the production of composites. Differential thermal analysis and the water bathing test results show that the composite decomposed at 80 degrees C and that it vaporized at 187 degrees C. Although the unsaturated polyester resin decomposed, the metal encapsulated in the slag did not leach out. The results show that the reuse of slag using molding technology should be taken into consideration.