排序方式: 共有30条查询结果,搜索用时 15 毫秒
1.
Somerset VS Klink MJ Baker PG Iwuoha EI 《Journal of environmental science and health. Part. B》2007,42(3):297-304
The behavior of an amperometric organic-phase biosensor consisting of a gold electrode modified first with a mercaptobenzothiazole self-assembled monolayer, followed by electropolymerization of polyaniline in which acetylcholinesterase as enzyme was immobilized, has been developed and evaluated for organophosphorous pesticide detection. The voltammetric results have shown that the formal potential shifts anodically as the Au/MBT/PANI/AChE/PVAc thick-film biosensor responded to acetylthiocholine substrate addition under anaerobic conditions in selected organic solvent media containing 2% v/v 0.05 M phosphate buffer, 0.1 M KCl (pH 7.2) solution. Detection limits in the order of 0.147 ppb for diazinon and 0.172 ppb for fenthion in acetone-saline phosphate buffer solution, and 0.180 ppb for diazinon and 0.194 ppb for fenthion in ethanol-saline phosphate buffer solution has been achieved. 相似文献
2.
3.
Priscilla W. Baillie 《Environmental management》1995,19(1):115-126
Treated wastewater from a food-processing plant, together with intermittent outflow from a hypereutrophic pond, were discharged
over a 20-year period to a cattail-dominated wetland and hence to a small stream. Organics and nutriet levels in the effluent
were comparable to levels in domestic wastewater. Fifteen variables were monitored upstream and downstream from the plant
over 18 months. Means for most variables were slightly higher downstream, but differences between stations were not statistically
significant. Wetland processing of nitrogen was markedly affected by a change from drought to flood conditions. After accounting
for dilution, the overall effect of the wetland on the effluent was to reduce biological oxygen demand 43.7%, ammonia N 46.3%,
nitrate/nitrite N 17.4%, and conductivity 15.6%. However, total suspended solids were increased 41.4%, total organic nitrogen
28.8%, and total phosphorus 24.7%. It was concluded that the wetland effectively renovated the effluent but the removal efficiency
would be improved if the effluent were pretreated to reduce phosphorus and dispersed to increase residence time in the wetland. 相似文献
4.
Assessing Risks to Biodiversity from Future Landscape Change 总被引:11,自引:0,他引:11
Denis White Priscilla G. Minotti Mary J. Barczak Jean C. Sifneos Kathryn E. Freemark Mary V. Santelmann Carl F. Steinitz A. Ross Kiester & Eric M. Preston 《Conservation biology》1997,11(2):349-360
We examined the impacts of possible future land development patterns on the biodiversity of a landscape. Our landscape data included a remote sensing derived map of the current habitat of the study area and six maps of future habitat distributions resulting from different land development scenarios. Our species data included lists of all bird, mammal, reptile, and amphibian species in the study area, their habitat associations, and area requirements for each. We estimated the area requirements using home ranges, sampled population densities, or genetic area requirements that incorporate dispersal distances. Our measures of biodiversity were species richness and habitat abundance. We calculated habitat abundance in two ways. First, we computed the total habitat area for each species in each landscape. Second, we calculated the number of habitat units for each species in each landscape by dividing the size of each habitat patch in the landscape by the area requirement and summing over all patches. Species richness was based on presence of habitat. Species became extinct in the landscape if they had no habitat area or no habitat units, respectively. We then computed ratios of habitat abundance in each future landscape to habitat abundance in the present for each species. We also computed the ratio of future to present species richness. We then calculated summary statistics across all species. Species richness changed little from present to future. There were distinctly greater risks to habitat abundance in landscapes that extrapolated from present trends or zoning patterns, however, as opposed to landscapes in which land development activities followed more constrained patterns. These results were stable when tested using Monte Carlo simulations and sensitivity tests on the area requirements. We conclude that this methodology can begin to discriminate the effects of potential changes in land development on vertebrate biodiversity. 相似文献
5.
Priscilla Bocskor Plumb Susan D. Day Theresa M. Wynn-Thompson John R. Seiler 《Environmental management》2013,52(4):861-876
We studied stormwater detention basins where woody vegetation removal was suspended for 2 years in Virginia, USA to determine if woody vegetation can control Typha populations and how early woody plant succession interacts with Typha, other herbaceous vegetation, and site factors. Distribution and composition of woody vegetation, Typha and non-Typha herbaceous vegetation biomass, and site factors were assessed at 100 plots in four basins ranging in age from 7 to 17 years. A greenhouse study examined the interaction of shade and soil moisture on Typha biomass and persistence. Principal component analysis identified an environmental gradient associated with greater water table depths and decreased elevation that favored Typha but negatively influenced woody vegetation. Elevation was correlated with litter layer distribution, suggesting that initial topography influences subsequent environmental characteristics and thus plant communities. Soil organic matter at 0–10 cm ranged from 5.4 to 12.7 %. Woody plants present were native species with the exception of Ailanthus altissima and Pyrus calleryana. In the greenhouse, shade and reduced soil moisture decreased Typha biomass and rhizome length. The shade effect was strongest in flooded plants and the soil moisture effect was strongest for plants in full sun. Typha in dry soil and heavy shade had 95 % less total biomass and 83 % smaller rhizomes than Typha in flooded soil and full sun, but even moderate soil moisture reductions decreased above- and below-ground biomass by 63 and 56 %, respectively. Suspending maintenance allows restoration of woody vegetation dominated by native species and may suppress Typha invasion. 相似文献
6.
Martins Bruna Alves de Albuquerque Priscilla Barbosa Sales de Souza Marthyna Pessoa 《Journal of Polymers and the Environment》2022,30(10):4023-4039
Journal of Polymers and the Environment - Polymers used as raw materials for synthetic packaging, i.e., those obtained from petroleum-derived sources, are resistant to degradation. Because of this,... 相似文献
7.
Soares Jéssica Maria Alexandre da Silva Júnior Elenildo Dário Oliveira de Veras Bruno Yara Ricardo de Albuquerque Priscilla Barbosa Sales de Souza Marthyna Pessoa 《Journal of Polymers and the Environment》2022,30(1):217-231
Journal of Polymers and the Environment - Bioactive biodegradable films are emerging biomaterials in the food packaging field. This study aims to investigate the effect of different Cenostigma... 相似文献
8.
We show that a higher vertebrate can graze surficial intertidal biofilm, previously only considered a food source for rasping invertebrates and a few specialized fish. Using evidence from video recordings, stomach contents, and stable isotopes, we describe for the first time the grazing behavior of Western Sandpipers (Calidris mauri) and estimate that biofilm accounts for 45-59% of their total diet or 50% of their daily energy budget. Our finding of shorebirds as herbivores extends the trophic range of shorebirds to primary consumers and potential competitors with grazing invertebrates. Also, given individual grazing rates estimated at seven times body mass per day and flock sizes into the tens of thousands, biofilm-feeding shorebirds could have major impacts on sediment dynamics. We stress the importance of the physical and biological processes maintaining biofilm to shorebird and intertidal conservation. 相似文献
9.
Priscilla W. Baillie 《Environmental management》1992,16(4):531-540
Development of a marina in a flooded brownstone quarry will require construction of a canal to the Connecticut River through
an isthmus separating the two systems. An environmental audit over a 16-month period developed quantitative limnological data
required by regulatory agencies. The deep quarry basin, protected by high sandstone walls, became strongly stratified in summer.
Development of littoral vegetation in the quarry was prevented by the steep sides of the basin. Unusual characteristics of
the manmade quarry basin, compared to most natural lakes in Connecticut, included a mean depth of 14 m, an intense thermocline,
and negative heterograde oxygen profiles with metalimnetic minima. Alkalinity, conductivity, and nutrient levels differed
significantly between the quarry and the river. Mean chlorophyll a concentrations in the two systems were similar, but the
distribution of phytoplankton classes were quite different. The environmental audit, by comparing physical, chemical, and
biological characteristics of the quarry to those of the river, allowed prediction of changes in trophic status when the two
systems are joined. 相似文献
10.
Over the past decade the U.S. Environmental Protection Agency (EPA) and the states have partnered in developing a web-based
information sharing initiative that provides state environmental agencies easy access to federal environmental monitoring
data and to the environmental data of other states, and gives the EPA access to data from state sources. The Environmental
Information Exchange Network (EIEN) has established basic data exchange nodes in each of the states. Using multiple regression
analysis we investigate the factors that account for the number and development stage of the data exchanges in which the states
participate as of 2009. Overall, we find that administrative factors, especially the EPA’s grant program, are more important
than political or environmental conditions. Participation in the exchanges is important not only as a way to reduce costs
for data reporting and communication, but also as a precursor to greater eventual interstate environmental collaboration.
Though clear evidence of a transition to collaboration is not yet seen here, there are some indications it may emerge in time. 相似文献