Occurrence and assessment of polycyclic aromatic hydrocarbons in soils from vegetable fields of the Pearl River Delta, South China

Surface soil (0-20 cm) samples from nine representative vegetable fields located in Guangzhou, Shenzhen, Zengcheng and Huadu within the Pearl River Delta, South China were collected and analyzed for 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) using gas chromatography coupled to mass spectrometry (GC-MS). Total concentrations of 16 PAHs (Sigma(PAHs)) ranged from 160 to 3700 microg kg(-1). Large variations were observed also between concentrations of individual PAHs from different vegetable fields and within the site as well. Acenapthylene, benzo[b]fluoranthene, fluoranthene, benzo[a]pyrene and benzo[k]fluoranthene were consistently the most prevalent individual PAHs. The values of PAH isomer ratios [anthracene/(anthracene+phenanthrene) and fluoranthene/(fluoranthene+pyrene)] indicate that combustion processes are the major sources of PAHs. Concentrations of PAHs were poorly correlated with organic carbon concentrations of soils, suggesting different sources and also indicating that the PAH pollution of this area is recent. The same outcome is confirmed by the predominance of PAHs with fewer rings (相似文献   

Use of EO-1 Advanced Land Imager (ALI) multispectral image data and real-time field sampling for water quality mapping in the Hirfanlı Dam Lake, Turkey

This paper focuses on the evaluation of water quality variations in Hirfanl? Water Reservoir, which is one of the most important water resources in Turkey, through EO-1 (Earth Observing-1) Advanced Land Imager (ALI) multispectral data and real-time field sampling. The study was materialized in 20 different sampling points during the overpass of the EO-1 ALI sensor over the study area. A multi-linear regression technique was used to explore the relationships between radiometrically corrected EO-1 ALI image data and water quality parameters: chlorophyll a, turbidity, and suspended solids. The retrieved and verified results show that the measured and estimated values of water quality parameters are in good agreement (R ²?>?0.93). The resulting thematic maps derived from EO-1 multispectral data for chlorophyll a, turbidity, and suspended solids show the spatial distribution of the water quality parameters. The results indicate that the reservoir has average nutrient values. Furthermore, chlorophyll a, turbidity, and suspended solids values increased at the upstream reservoir and shallow coast of the Hirfanl? Water Reservoir.     

Production of zeolitic materials in pilot scale based on coal ash for phosphate and potassium adsorption in order to obtain fertilizer

Environmental Science and Pollution Research - The use of different types of zeolites (X, Na-P1, and 4A) synthesized by different methods and scales were tested in this work to adsorb nutrients...     

Status and trends of terrestrial arthropod abundance and diversity in the North Atlantic region of the Arctic

Ambio - The Circumpolar Biodiversity Monitoring Programme (CBMP) provides an opportunity to improve our knowledge of Arctic arthropod diversity, but initial baseline studies are required to...     

Effects of a soil organic amendment on metal allocation of trees for the phytomanagement of mining-impacted soils

Environmental Geochemistry and Health - The suitable application of phytomanagement by phytostabilisation using plant tree species in metal-polluted soils requires an assessment of the fate of...     

Brazil’s Amazonian protected areas as a bulwark against regional climate change

Regional Environmental Change - Brazil’s Amazonian protected areas play an important role in maintaining the environmental services of the region, including Amazonia’s role in regional...     

Comparison of modeling with empirical calculation of diffuse and fugitive methane emissions in a Spanish landfill

One of the most significant environmental problems arising from landfills is the emission of methane into the atmosphere. In this study, methane emissions from a currently in-use Spanish landfill were modeled as well as being experimentally measured using a two-step method. The first step involved a qualitative walkover survey to detect where gases were being emitted on the surface of the landfill. The second stage comprised a quantitative analysis of these surface methane emissions at a selected number of points on the landfill surface using a specially designed flux chamber. The statistical analysis of the data obtained was based on the Sichel function and resulted in an average emission rate of 74.9 g·m^?2·day^?1, with 27.8 and 202.1 g·m^?2·day^?1 as the lower and upper limits of the 95% confidence interval, respectively. The total emission for the landfill, with an emitting surface of 335,000 m², is 9.16 × 10³ ton/yr. These values have been compared with those from three different models, with the model results being above the calculated mean emissions measured at the landfill, but below the upper confidence limit at 95%.

Implications: One of the main environmental problems arising from the presence of landfills is the emission of biogas (which mainly contains methane and carbon dioxide) into the atmosphere. Several experimental methods as well as models have been developed to quantify these emissions. In this work, the authors have compared the results obtained using experimental measurements with those provided by some local and international models using the default parameters proposed. The results obtained from the experimental method are in accordance with those provided by the models, although the models could be slightly overestimating these emissions.     

Assessment of alternatives to environmental toxic formalin for DNA conservation in biological specimens

Environmental Science and Pollution Research - One essential step of museum and clinical specimen preservation is immersion in a fixative fluid to prevent degradation. Formalin is the most largely...     

Effect of salt solution treatment on impurity removal: A case study on phosphogypsum

This study gives a brief demonstration of impurity removal efficiency upon salt solution treatment of phosphogypsum (PG). The experimental set up has been designed according to a multi-variable Box–Behnken Design (BBD) with stirring time, solid: liquid (PG:salt solution) ratio and temperature as the conducted in various salt solutions. PG sample has been treated with sea water, 5% NaCl and 10% NaCl solutions according to the BBD matrix. Fluoride (F), copper (Cu), manganese (Mn), and nickel (Ni) amounts in the PG sample have been measured upon pre- and post-treatment with salt solutions. Among other operating conditions, temperature has been the dominant factor on fluoride removal efficiency, and responses for the factors determined in the experiment runs indicated that a significant correlation could be established between temperature and fluoride removal, sea water being the most efficient salt solution. Higher copper, manganese, and nickel removal efficiencies have been observed in single salt NaCl solution systems however no significant correlation could be established between factors. Results indicate that pre-treatment of PG located near coastal regions with sea water can be a cost-effective approach and applicable on industrial scale when fluoride removal is of importance.