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811.
Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed1
Leslie L. Orzetti R. Christian Jones Robert F. Murphy 《Journal of the American Water Resources Association》2010,46(3):473-485
Orzetti, Leslie L., R. Christian Jones, and Robert F. Murphy, 2010. Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed. Journal of the American Water Resources Association (JAWRA) 46(3):473-485. DOI: 10.1111/j.1752-1688.2009.00414.x Abstract: This study tested the efficacy of restored forest riparian buffers along streams in the Chesapeake Bay watershed by examining habitat, selected water quality variables, and benthic macroinvertebrate community metrics in 30 streams with buffers ranging from zero to greater than 50 years of age. To assess water quality we measured in situ parameters (temperature, dissolved oxygen, and conductivity) and laboratory-analyzed grab samples (soluble reactive phosphorus, total phosphorus, nitrate, ammonium, and total suspended solids). Habitat conditions were scored using the Environmental Protection Agency Rapid Bioassessment Protocols for high gradient streams. Benthic macroinvertebrates were quantified using pooled riffle/run kick samples. Results showed that habitat, water quality, and benthic macroinvertebrate metrics generally improved with age of restored buffer. Habitat scores appeared to stabilize between 10 and 15 years of age and were driven mostly by epifaunal substrate availability, sinuosity, embeddedness, and velocity depth regime. Benthic invertebrate taxa richness, percent Ephemeroptera, Plecoptera, Trichoptera minus hydropsychids (%EPT minus H), % Ephemeroptera, and the Family Biotic Index were among the metrics which improved with age of buffer zone. Results are consistent with the hypothesis that forest riparian buffers enhance instream habitat, water quality, and resulting benthic macroinvertebrate communities with noticeable improvements occurring within 5-10 years postrestoration, leading to conditions approaching those of long established buffers within 10-15 years of restoration. 相似文献
812.
Christian Vogel Camille Rivard Verena Wilken Andreas Muskolus Christian Adam 《Ambio》2018,47(1):62-72
A pot experiment was carried out with maize to determine the phosphorus (P) plant-availability of different secondary P-fertilizers derived from wastewater. We analyzed the respective soils by P K-edge X-ray absorption near-edge structure (XANES) spectroscopy to determine the P chemical forms that were present and determine the transformation processes. Macro- and micro-XANES spectroscopy were used to determine the chemical state of the overall soil P and identify P compounds in P-rich spots. Mainly organic P and/or P adsorbed on organic matter or other substrates were detected in unfertilized and fertilized soils. In addition, there were indications for the formation of ammonium phosphates in some fertilized soils. However, this effect was not seen in the maize yield of all P-fertilizers. The observed reactions between phosphate from secondary P-fertilizers and co-fertilized nitrogen compounds should be further investigated. Formation of highly plant-available compounds such as ammonium phosphates could make secondary P-fertilizers more competitive to commercial phosphate rock-based fertilizers with positive effects on resources conservation. 相似文献
813.
Christian P. Andersen Wilma Ritter Rainer Matyssek 《Environmental pollution (Barking, Essex : 1987)》2010,158(8):2604-2609
Canopies of adult European beech (Fagus sylvatica) and Norway spruce (Picea abies) were labeled with CO2 depleted in 13C to evaluate carbon allocation belowground. One-half the trees were exposed to elevated O3 for 6 yrs prior to and during the experiment. Soil-gas sampling wells were placed at 8 and 15 cm and soil CO2 was sampled during labeling in mid-late August, 2006. In beech, δ13CO2 at both depths decreased approximately 50 h after labeling, reflecting rapid translocation of fixed C to roots and release through respiration. In spruce, label was detected in fine-root tissue, but there was no evidence of label in δ13CO2. The results show that C fixed in the canopy rapidly reaches respiratory pools in beech roots, and suggest that spruce may allocate very little of recently-fixed carbon into root respiration during late summer. A change in carbon allocation belowground due to long-term O3 exposure was not observed. 相似文献
814.
Bryan N. Duncan Yasuko Yoshida Jennifer R. Olson Sanford Sillman Randall V. Martin Lok Lamsal Yongtao Hu Kenneth E. Pickering Christian Retscher Dale J. Allen James H. Crawford 《Atmospheric environment (Oxford, England : 1994)》2010,44(18):2213-2223
We investigated variations in the relative sensitivity of surface ozone formation in summer to precursor species concentrations of volatile organic compounds (VOCs) and nitrogen oxides (NOx) as inferred from the ratio of the tropospheric columns of formaldehyde to nitrogen dioxide (the “Ratio”) from the Aura Ozone Monitoring Instrument (OMI). Our modeling study suggests that ozone formation decreases with reductions in VOCs at Ratios <1 and NOx at Ratios >2; both NOx and VOC reductions may decrease ozone formation for Ratios between 1 and 2. Using this criteria, the OMI data indicate that ozone formation became: 1. more sensitive to NOx over most of the United States from 2005 to 2007 because of the substantial decrease in NOx emissions, primarily from stationary sources, and the concomitant decrease in the tropospheric column of NO2, and 2. more sensitive to NOx with increasing temperature, in part because emissions of highly reactive, biogenic isoprene increase with temperature, thus increasing the total VOC reactivity. In cities with relatively low isoprene emissions (e.g., Chicago), the data clearly indicate that ozone formation became more sensitive to NOx from 2005 to 2007. In cities with relatively high isoprene emissions (e.g., Atlanta), we found that the increase in the Ratio due to decreasing NOx emissions was not obvious as this signal was convolved with variations in the Ratio associated with the temperature dependence of isoprene emissions and, consequently, the formaldehyde concentration. 相似文献
815.
Erika von Schneidemesser Paul S. Monks Christian Plass-Duelmer 《Atmospheric environment (Oxford, England : 1994)》2010,44(39):5053-5064
Speciated volatile organic compound (VOC) and carbon monoxide (CO) measurements from the Marylebone Road site in central London from 1998 through 2008 are presented. Long-term trends show statistically significant decreases for all the VOCs considered, ranging from ?3% to ?26% per year. Carbon monoxide decreased by ?12% per year over the measurement period. The VOC trends observed at the kerbside site in London showed greater rates of decline relative to trends from monitoring sites in rural England (Harwell) and a remote high-altitude site (Hohenpeissenberg), which showed decreases for individual VOCs from ?2% to ?13% per year. Over the same 1998 through 2008 period VOC to CO ratios for London remained steady, an indication that emissions reduction measures affected the measured compounds equally. Relative trends comparing VOC to CO ratios between Marylebone Road and Hohenpeissenberg showed greater similarities than absolute trends, indicating that emissions reductions measures in urban areas are reflected by regional background locations. A comparison of VOC mixing ratios and VOC to CO ratios was undertaken for London and other global cities. Carbon monoxide and VOCs (alkanes greater than C5, alkenes, and aromatics) were found to be strongly correlated (>0.8) in the Annex I countries, whereas only ethene and ethyne were strongly correlated with CO in the non-Annex I countries. The correlation results indicate significant emissions from traffic-related sources in Annex I countries, and a much larger influence of other sources, such as industry and LPG-related sources in non-Annex I countries. Yearly benzene to ethyne ratios for London from 2000 to 2008 ranged from 0.17 to 0.29 and compared well with previous results from US cities and three global megacities. 相似文献
816.
Christiane Schrenk Christian E. W. Steinberg 《Environmental science and pollution research international》1998,5(2):83-88
The metabolism of phenanthrene was studied both in cell suspension cultures of wheat (Triticum aestivum) and soybean (Glycine max), and in intact plants of the water mossFontinalis antipyretica. Metabolism in cell suspension cultures strongly differed between the monocotyle and the dicotyle plant. Only small amounts
oftrans-phenanthrene-9,10-dihydrodiole and phenanthrene-9,10-dione were detectable in the wheat culture. Soybean cultures, in contrast
demonstrated a strong turnover resulting in a 75% reduction of the initial phenanthrene concentration. Metabolites were phenanthrene-9,10-dione,
not further characterized polar metabolites and bound residues. Intact plants ofFontinalis antipyretica metabolized only small amounts of phenanthrene. Data obtained from cell cultures did not provide information for the metabolic
potential in intact plants. Therefore standardized tests with model systems like suspension cultures lead to inadequate assessment
of the ecological risk of certain xenobiotics. 相似文献
817.
Adeyemi Joseph A. Gallimberti Matheus Olise Christian C. Rocha Bruno Alves Adedire Chrs O. Barbosa Jr Fernando 《Environmental science and pollution research international》2020,27(30):37645-37649
Environmental Science and Pollution Research - Bisphenol A (BPA) is a high production volume chemical that has wide industrial applications, especially as a color developer in thermal papers. The... 相似文献
818.
819.
Evaluation of the critical factors controlling stability of chromium, copper, arsenic and zinc in iron-treated soil 总被引:3,自引:0,他引:3
Various environmental factors are expected to affect the mobility of elements in chemically stabilized soils. The aim of this study was to evaluate the effects of pH, oxidizing-reducing potential (Eh), liquid-to-solid ratio (L/S), presence of organic matter (OM) and microbial activity (MA) on the mobility of chromium, copper, arsenic and zinc in zerovalent iron (Fe(0))-stabilized soil. A 2(5) full factorial design was applied to assess the leaching of the elements from the treated soil. The factor having the most impact on the mobility of Cr, Cu and Zn was pH; low pH (3) led to the release of these elements. Arsenic remobilization was controlled by L/S and MA, whilst Eh, though also significant, had less influence. In the identified worst-case scenarios, more than half of the total Zn and Cu and 14% of As can be expected to remobilize from the treated soil. The leaching procedure concerning sample agitation and type of filtration showed to substantially affect the results of As leaching, especially in OM rich soil. 相似文献
820.
Segura PA García-Ac A Lajeunesse A Ghosh D Gagnon C Sauvé S 《Journal of environmental monitoring : JEM》2007,9(4):307-313
A rugged and specific method based on tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry for the determination of anti-infectives in raw sewage and wastewater plant effluents was developed. Analyte recoveries from spiked effluents ranged from 68 to 104%. Two specific selected reaction monitoring transitions and their peak area ratios were used to avoid false positives and confirm the presence of the targeted substances. Detection limits allowed low nanogram per litre detection (0.3-22 ng L(-1)). The method was successfully applied to real samples from the Montréal wastewater treatment plant. All the studied anti-infectives were found in the wastewater samples in concentrations ranging from 39 to 276 ng L(-1). Mean flows of anti-infectives were estimated from effluent concentrations and it was found that large amounts (>118 g day(-1) up to 830 g day(-1)) are discharged in the receiving waters of the St Lawrence River. 相似文献