Search results for "water pollution"
showing 10 items of 186 documents
Organic chlorine compounds in lake sediments. V. Bottom of Baikal near a pulp mill
1990
Abstract Organically bound chlorine (OCl) together with inorganic chloride (Cl − ) was measured from bottom surface samples of the Lake Baikal near a pulp mill and compared to organic matter contents (OM). Although total contents of OCl, Cl − and OM were much lower than, the ratio of OCl to OM was of the same order of magnitude as in pulp mill recipients of Finland.
Use of biological and sedimentation models for designing Peñíscola WWTP.
2004
This paper presents Peñíscola wastewater treatment plant design. Peñíscola is a tourist city in Castellón (Spain), whose population changes significantly between summer and the rest of the year. The design of the biological and settling treatment units has been confirmed by computer model simulations and provided for biological organic matter, nitrogen and phosphorus removal. Two different treatment schemes have been proposed in order to optimize the plant performance during both seasonal operations. During low-load season, the plant will be operated under extended aeration conditions, so further sludge stabilization will not be needed. During high-load season, the plant will be operated un…
Distribution of volatile organic compounds in Sicilian groundwaters analysed by head space-solid phase micro extraction coupled with gas chromatograp…
2008
This work presents the results of an assessment of the existence and concentration of 13 volatile organic compounds (VOCs) in groundwaters from 14 hydrological basins in Sicily (25,710km (2)). On the basis of hydrological, hydrogeochemical and geological studies, 324 sampling points were selected. All groundwater sampled were collected twice, from October to December 2004 and from February to May 2005, and were analysed to determine the concentration and spatial distribution of the VOCs in the aquifers. The need to analyze a large number of samples in a short space of time so as to obtain quantitative analyses in trace concentration levels spurred us to create a new analytical method, both …
Biogenic volatile organoiodine and organobromine hydrocarbons in the Atlantic Ocean from 42°N to 72°S
1997
During the cruise ANT X/1 and 2 of the research vessel Polarstern from November 1991 to March 1992, 39 surface water samples of the Atlantic Ocean from 42°N to 72.5°S were collected and analysed for their concentration of volatile iodinated and brominated hydrocarbons. The concentration of chlorophyll-a was used as an indicator for phytoplankton, which is one of the main producers of iodinated and brominated compounds in the ocean. For determination of chlorophyll-a, fluorescence spectroscopy was applied, whereas the measurement of halogenated volatile hydrocarbons was carried out by a purge and trap system with subsequent gas chromatographic separation and detection by an electron capture …
Reproductive success of Coregonus species in areas loaded by effluents from paper mills
1992
The annual reproductive success of Coregonus albula and C. lavaretus in some polluted and clean areas of the central parts of L. Paijanne was estimated in 1981–90 on the basis of occurrence of larvae in shore seine and seine net samples after the ice melted. In polluted areas (0-5 km from Kaipola paper mill) larvae of coregonids were found only occasionally. In semipolluted areas (5–15 km from the paper mill) the densities of larvae were usually less than 0.1 ind m-2. In ‘clean’ areas the mean densities of larvae ranged from 0.45 to 5.34 inds m-2. A relatively high reproductive success of vendace was observed in 1984–85, moderate success in 1982–83 and low success in 1986–90. The larvae of …
Integrated geophysical survey for 3D modelling of a coastal aquifer polluted by seawater
2013
Geophysical surveys are carried out in the coastal area of Petrosino (south-western Sicily) to study the time evolution of seawater contamination of the coastal aquifer, probably increased due to human impact. The overexploitation of the aquifer, due to an intensive agricultural use has affected significantly the natural hydro-geochemical state of the basin. The study is based on a processing and integrated analysis of hydrogeological, geochemical and geophysical data. In particular in the last two years seasonal time-lapse electrical resistivity tomographies (ERT), new TDEM soundings and Multi-Analysis Surface Wave soundings (MASW) have been carried out. The interpretation of the total set…
Elevated polycyclic aromatic hydrocarbons in a river floodplain soil due to coal mining activities
2007
Elevated PAH concentrations were found in soil samples collected along the Mosel River. These contaminations were associated with the occurrence of coal particles found in the soil. The majority of the PAH contamination in the soils was linked to coal mining activities in the Saar region. Density and grain size separation showed a similar PAH distribution pattern in all of the fractions, indicating a uniform origin of PAHs. Together with coal petrography a good correlation between TOC and PAHs concentration confirmed the impact of former coal mining activity on the PAHs distribution in study area.
The Influence of Floodplains on Mercury Availability
2009
The floodplains of the German river Elbe affect the mercury distribution in the river system in two different ways: they act both as a medium-term sink and as a long-term source. The large amounts of mercury deposited onto the floodplains during annual floodings are first effectively fixed in the soils, rendering them basically unavailable. Sequential extraction experiments reveal that only a small fraction of the mercury (< 3%) is present in available forms, whereas the vast majority is associated with humic substances or present in sulfidic binding forms. After deposition, a small fraction of the total mercury is gradually remobilized into the aqueous phase bound passively to water-solubl…
A hybrid statistical decision-making optimization approach for groundwater vulnerability considering uncertainty.
2021
Recognizing the vulnerable areas for contamination is a feasible way to protect groundwater resources. The main contribution of the paper is developing a hybrid statistical decision-making model for evaluating the vulnerability of Shiraz aquifer, southern Iran, with modified DRASTIC (depth to the water table, net recharge, aquifer media, soil media, topography, impact of the vadose zone, and hydraulic conductivity) by using the genetic algorithm (GA), the analytical hierarchy process (AHP) method, and factorial analysis (FA). First, considering the variation of the uncertain parameters, 32 scenarios were defined to perform factorial analysis. Then using the AHP method and GA, DRASTIC parame…
Removal of Fe(III) from synthetic wastewater into raw and modified clay: Experiments and models fitting
2017
Water pollution by heavy metal ions has become a serious environmental issue especially due to their toxicity and tendency to bioaccumulation. Natural smectite clay was treated using sulfuric acid ...