Characterization of non-extractable ¹⁴C- and ¹³C-sulfadiazine residues in soil including simultaneous amendment of pig manure

Recently, we reported on soil fate of SDZ residues amended with pig manure treated with 1?C-labeled sulfadiazine 1?C-SDZ). The first objective of the present study was to determine whether this strategy can be substituted by application of 1?C-SDZ to soil. The second objective was to characterize non-extractable SDZ residues by fractionation, size exclusion chromatography (SEC) and solid state 13C-NMR. The fate of 1?C-SDZ was examined for 28 d, using two soils with and without amendment of pig manure. Mineralization of 1?C-SDZ was low; extractable residues decreased to 7-30%. Compared to the previous study, results were similar. 1?C-SDZ derived bound radioactivity was found in HCl-washings, fulvic, humic acids and humin. According to SEC, one bound 1?C portion (70%) co-eluted with fulvic acids (above 910 g mol?1); the other consisted of adsorbed/entrapped 1?C-SDZ. The 13C-SDZ study was performed for 30 d; humic acids were examined by 13C-NMR. A signal (100-150 ppm) was referred to 13C-SDZ. SEC and 13C-NMR demonstrated rapid integration of SDZ into humics.     

Impacts of climate change on land-use and wetland productivity in the Prairie Pothole Region of North America

Wetland productivity in the Prairie Pothole Region (PPR) of North America is closely linked to climate. A warmer and drier climate, as predicted, will negatively affect the productivity of PPR wetlands and the services they provide. The effect of climate change on wetland productivity, however, will not only depend on natural processes (e.g., evapotranspiration), but also on human responses. Agricultural land use, the predominant use in the PPR, is unlikely to remain static as climate change affects crop yields and prices. Land use in uplands surrounding wetlands will further affect wetland water budgets and hence wetland productivity. The net impact of climate change on wetland productivity will therefore depend on both the direct effects of climate change on wetlands and the indirect effects on upland land use. We examine the effect of climate change and land-use response on semipermanent wetland productivity by combining an economic model of agricultural land-use change with an ecological model of wetland dynamics. Our results suggest that the climate change scenarios evaluated are likely to have profound effects on land use in the North and South Dakota PPR, with wheat displacing other crops and pasture. The combined pressure of land-use and climate change significantly reduces wetland productivity. In a climate scenario with a +4 °C increase in temperature, our model predicts that almost the entire region may lack the wetland productivity necessary to support wetland-dependent species.     

Direct GLC Coulometric Analysis of Kraft Mill Gases

A new bromine, microcoulometric titration cell has been used with a commercially-available microcoulometer for the detection and analysis of sulfur-containing gases in various kraft mill emissions. Separation of the constituents of the gaseous mixtures emitted from mill sources including the recovery furnace, digestors, evaporators, lime kiln, and dissolvers was accomplished on an 8-ft, 3/16 in. stainless steel column packed with 10% Triton X-305 on 60–80 mesh Chromosorb G, DMCS-treated. The column was isothermally operated at 30°C for 4–6 mins and then rapidly raised to 70°C The exact program was varied with the type of sample analyzed. Each source gas was initially screened by direct injection of 0.01–0.1 ml of gas to determine whether or not disproportionately large concentrations of one or more components were present. Appropriate sample volumes were then selected to provide “on-scale” recorder peaks for the major constituents. Elution times for the major constituents were observed so that these compounds could be vented at the proper time following injection of large sample volumes (up to 10 ml) for detection and analysis of minor constituents. Venting of the high concentration compounds was necessary when analyzing large volume samples to maintain near equilibrium titration conditions in the microtitration cell.     

Sulfur Gas Emissions from Flue Gas Desulfurization Sludge Ponds

This paper presents initial measurement data on the emission of volatile, reduced sulfur-containing gases from flue gas desulfurization (FGD) storage ponds. Several different types of FGD stored sludges were studied including lime, limestone, and mixtures of fly ash and lime or limestone residues, some of which had been chemically stabilized. The volatile sulfur gas emissions were cryogenically concentrated and determined by wall-coated, open-tubular capillary column gas chromatography using a flame photometric detector. Hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, carbon disulfide, and an unusual, unidentified sulfur-containing compound were found in the gaseous pond flux. Benzene, toluene, and α-pinene were also identified by gas chromatography-single ion monitoring mass spectrometry. The total reduced sulfur gas emission from a 100 acre pond approximated 2.0 kg day^?1 (as sulfur).     

Careers in Air Pollution Control Monitoring-Surveillance

ABSTRACT

The temporal and longitudinal characteristics of volatile organic compound (VOC) emissions from the aeration units of a publicly owned treatment works (POTWs) have been investigated by systematic monitoring and mathematical modeling. Field tests have been conducted at a 120-mgd wastewater treatment plant to investigate the hourly, weekly, and seasonal changes of VOC emissions. Variations of VOC emissions along the length of the aeration units have been tested and modeled. Most VOCs have decreasing concentration profiles. Henry's law coefficients and biodegradation constants for the detected compounds have been validated with the improved models and the field test data. More than one-half of the emissions were found to have been generated from the first one-third of the aeration unit length.     

Using Farmers’ Actions to Measure Crop Loss Due to Air Pollution

The effects of ozone on the profitability of Illinois cash grain farms is investigated by utilizing a profit function framework. This approach uses individual farms as the observational unit so the data are generated under field conditions. Hence, experimental plot data are not used although results from past biological experiments are utilized to frame initial hypotheses and for evaluation of the estimated model. This study demonstrates the benefits of combining economic data and biological science results to estimate the economic reactions of producers in terms of input and output (production) response to an ambient environmental characteristic.

A time series of cross sectional data on cash grain farms in Illinois is used to estimate two profit functions. Ozone data are measured on a growing season basis by county. The estimated model shows ozone has a negative effect on profits. Increases in ozone levels tend to depress output levels and lessen the demand for variable inputs. Additionally, a production function is derived from one of the profit functions. The impact of ozone is found to be in general agreement with dose-response data obtained in Illinois by plant scientists.     

Wetfall Deposition and Precipitation Chemistry for a Central Appalachian Forest

Abstract

Although extensive research on acidic deposition has been directed toward spruce-fir forests, less research has been done on the impacts of air pollution on eastern montane hardwood forests. The purpose of this study was to describe precipitation chemistry for several Appalachian hardwood forest sites at or near the Fernow Experimental Forest (FEF) to assess the potential for problems associated with acidic deposition. Emphasis was placed on seasonal patterns of ionic concentrations (H+, Ca++, NH4+; NO3-, and SO4=) and spatial variability of ionic concentrations and deposition among sites. Seasonal patterns of most ions showed highest concentrations during the summer months and deposition of H+ was especially pronounced during this time. Deposition of all ions was generally greater (related to greater precipitation) at three montane forested sample sites compared to a nonforested riverbottom site. Precipitation chemistry at FEF was similar to other sites throughout the eastern United States and contrasted sharply with mid-western and western sites. Eastern sites, including means for FEF sites, were uniformly 3-4 times higher in H+ and SO4= concentration than the mid-western and western sites. Precipitation at FEF was chronically acidic, more so during the growing season, and highest at higher elevations where environmental stresses can be most severe. Furthermore, there were occasional large discrepancies between the low-elevation site and the higher-elevation forested sites for precipitation chemistry and acidic deposition. These results suggest that synoptic-scale (network) data may greatly underestimate the pollutant conditions to which highelevation forest trees are exposed, since network data rarely take elevation into account and typically are based on annual ionic concentration and deposition means that may be considerably lower than those of the growing season.     

The Role of Periphyton in Mediating the Effects of Pollution in a Stream Ecosystem

The effects of pollutants on primary producers ramify through ecosystems because primary producers provide food and structure for higher trophic levels and they mediate the biogeochemical cycling of nutrients and contaminants. Periphyton (attached algae) were studied as part of a long-term biological monitoring program designed to guide remediation efforts by the Department of Energy’s Y-12 National Security Complex on East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee. High concentrations of nutrients entering EFPC were responsible for elevated periphyton production and placed the stream in a state of eutrophy. High rates of primary production at upstream locations in EFPC were associated with alterations in both invertebrate and fish communities. Grazers represented >50% of the biomass of invertebrates and fish near the Y-12 Complex but <10% at downstream and reference sites. An index of epilithic periphyton production accounted for 95% of the site-to-site variation in biomass of grazing fish. Analyses of heavy metals in EFPC periphyton showed that concentrations of zinc, cadmium, copper and nickel in periphyton decreased exponentially with distance downstream from Y-12. Zinc uptake by periphyton was estimated to reduce the concentration of this metal in stream water ~60% over a 5-km reach of EFPC. Management options for mitigating eutrophy in EFPC include additional reductions in nutrient inputs and/or allowing streamside trees to grow and shade the stream. However, reducing periphyton growth may lead to greater downstream transport of contaminants while simultaneously causing higher concentrations of mercury and PCBs in fish at upstream sites.     

Removal of estrogenic activity of natural and synthetic hormones from a municipal wastewater: efficiency of horseradish peroxidase and laccase from Trametes versicolor

Some researches studied the removal of steroid estrogens by enzymatic treatment, however none verified the residual estrogenicity after the enzymatic treatment at environmental conditions. In this study, the residual estrogenic activities of the key natural and synthetic steroid estrogens were investigated following enzymatic treatment with horseradish peroxidase (HRP) and laccase from Trametes versicolor. Synthetic water and municipal wastewater containing environmental concentrations of estrone, 17beta-estradiol, estriol, and 17alpha-ethinylestradiol were treated. Liquid chromatography-mass spectrometry analysis demonstrated that the studied steroid estrogens were completely oxidized in the wastewater reaction mixture after a 1-h treatment with either HRP (8-10 U ml(-1)) or laccase (20 U ml(-1)). Using the recombinant yeast assay, it was also confirmed that both enzymatic treatments were very efficient in removing the estrogenic activity of the studied steroid estrogens. The laccase-catalyzed process seemed to present great advantages over the HRP-catalyzed system for up-scale applications for the treatment of municipal wastewater.     

A survey of DNA methylation across social insect species, life stages, and castes reveals abundant and caste-associated methylation in a primitively social wasp

DNA methylation plays an important role in the epigenetic control of developmental and behavioral plasticity, with connections to the generation of striking phenotypic differences between castes (larger, reproductive queens and smaller, non-reproductive workers) in honeybees and ants. Here, we provide the first comparative investigation of caste- and life stage-associated DNA methylation in several species of bees and vespid wasps displaying different levels of social organization. Our results reveal moderate levels of DNA methylation in most bees and wasps, with no clear relationship to the level of sociality. Strikingly, primitively social Polistes dominula paper wasps show unusually high overall DNA methylation and caste-related differences in site-specific methylation. These results suggest DNA methylation may play a role in the regulation of behavioral and physiological differences in primitively social species with more flexible caste differences.