Determination of VOCs in yellow eel from various inland water bodies in Flanders (Belgium)

Twenty freshwater eels caught in Flanders (Belgium) were analysed by GC-MS for a total of 52 VOCs. The most prominent VOCs are the BTEX and a number of chlorinated compounds such as chloroform and tetrachloroethene. The observed concentrations which, typically, were in the low ng/g wet weight range, could be linked to the major emission sources and the present study gives new evidence that combustion of fossil fuels is a major source of BTEX in the environment. The concentration levels in eels seem to be a reflection of the actual concentrations in their environment. For eels from the same location similar patterns and concentrations were observed, and the concentrations agree with what can be expected from those of the water column. Generally speaking, the observed concentrations do not seem to pose a threat for organisms. More definite statements will, however, require a larger dataset. The study suggests that the yellow eel can possibly be used as a biomonitor or sentinel organism for VOCs.     

Assessment of temporal variations of water quality in inland water bodies using atmospheric corrected satellite remotely sensed image data

The spatial distribution of silicate, ammonium, nitrate, nitrite, phosphate, chlorophyll a and dissolved oxygen in Obidos lagoon was obtained by surveying five sites in eight campaigns, between October 2004 and October 2006. A confined inner branch of the lagoon showed higher availability of ammonium (1.2-81 micromol l(-1)), phosphate (1.9-17 micromol l(-1)), silicate (0.85-86 micromol l(-1)) and chlorophyll a (0.30-18 microg l(-1)) than other sites (0.47-25 micromol l(-1), 0.10-3.9 micromol l(-1), 0.47-25 micromol l(-1), 0.25-11 microg l(-1), respectively). According to several trophic classification tools, that branch is considered eutrophic to polytrophic, emphasising its deteriorated conditions, while the rest of the lagoon is of better quality. In autumn/winter nutrients were inversely correlated to salinity (r > 0.93) reflecting the freshwater inputs enriched in nitrogen and phosphorous compounds to the inner branch. In warmer periods, dissolved oxygen concentrations dropped during the night, and sediments of the branch become an important source of ammonium and phosphate. The low DIN:P ratio (median = 10) obtained in the branch, which suggests an excess of phosphate, that increased in warmer periods and changed the limiting nutrient in the entire lagoon. These results emphasize the spatial heterogeneity of water quality in Obidos lagoon, its seasonal variability, and the importance of recognising these distributions before defining homogenous water body on the scope of Water Framework Directive.     

Screening and identification of early warning algal species for metal contamination in fresh water bodies polluted from point and non-point sources

The water bodies of Lucknow, Unnao and Kanpur (U.P.), India polluted through various point and non point sources were found to be either eutrophic or oligotrophic in nature. These water bodies supported a great number of algal diversity, which varied seasonally depending upon the physico-chemical properties of water. Further, the water bodies polluted through non point sources supports diverse algal species, while the water bodies polluted through point sources supports growth of tolerant blue green algae. High biomass producing algal species growing in these water bodies have accumulated significant amount of metals in their tissues. Maximum amount of Fe was found accumulated by species of Oedogonium sp. II (20,523.00 mug g(-1) dw) and Spirogyra sp. I (4,520.00 mug g(-1) dw), while maximum Chromium (Cr) was found accumulated in Phormedium bohneri (2,109.00 mug g(-1) dw) followed by Oscillatoria nigra (1,957.88 mug g(-1) dw) and Oedogonium sp. I (156.00 mug g(-1) dw) and Ni in Ulothrix sp. (495.00 mug g(-1) dw). Results showed that some of these forms growing in polluted environment and accumulating high amounts of toxic metals may be used as bioindicator species, however, their performance in metal contaminated water under different ecological niche is to be ascertained.     

Applying value analysis and fuzzy logic to select areas for installing waste fills

This article discusses a methodology for assessing and rankinga predefined universe of objects to assist in the selectionof suitable areas for the construction of sanitary landfills.The methodology is, in principle, for universal application. Its development was initially based on the `Value Analysis' methodology and then on the `Fuzzy Eigenvector Method', or `Fuzzy Logic' as it is sometimes referred to. The focus of thestudy herein is on the comparative appraisal of a group ofelements which are part of the guidelines to be adopted whendetermining the choice of the most suitable site for a sanitarylandfill. This set of guidelines includes technical, economical,environmental, social and political aspects. As an example of themethodology proposed, four different areas were chosen. They werestudied to determine which is the most appropriate site for thedevelopment of a new solid waste fill site. The results for thesefour areas, together with the functions chosen and functionweights, are presented here.     

A fuzzy multi-stakeholder multi-criteria methodology for water allocation and reuse in metropolitan areas

In this paper, a fuzzy decision making methodology is proposed to find a socially optimal scenario for allocating effluent of wastewater treatment plants and urban and suburban runoffs to agricultural regions and recharging aquifers. The presented methodology named modified fuzzy social choice (MFSC) considers multi-stakeholder multi-criteria problems under uncertainties inherent in a decision making process utilizing a fuzzy ranking method and the fuzzy social choice (FSC) theory. A set of water and wastewater allocation scenarios are proposed for water quantity and quality management of the study area, while six main stakeholders with conflicting utilities and different negotiation powers are involved. The proposed methodology is applied to Tehran metropolitan area, the capital city of Iran with the population of about 8 million people, to examine its applicability and effectiveness. The results shows that using fuzzy multi-stakeholder multi-criteria decision making method considering equal and different negotiation powers can lead to different outcomes. Based on the results, the MFSC method, which considers a number of decision makers having different negotiation powers, degrees of importance of decision making criteria, and some important uncertainties, performs more promising in real water resources management problems.     

Comparison of different semi-empirical algorithms to estimate chlorophyll-a concentration in inland lake water

Based on in situ water sampling and field spectral measurement from June to September 2004 in Lake Chagan, a comparison of several existing semi-empirical algorithms to determine chlorophyll-a (Chl-a) content was made by applying them to the field spectra and in situ chlorophyll measurements. Results indicated that the first derivative of reflectance was well correlated with Chl-a. The highest correlation between the first derivative and Chl-a was at 680 nm. The two-band model, NIR/red ratio of R_710/670, was also an effective predictor of Chl-a concentration. Since the two-band ratios model is a special case of the three-band model developed recently, three-band model in Lake Chagan showed a higher resolution. The new algorithm named reverse continuum removal relies on the reflectance peak at 700 nm whose shape and position depend strongly upon chlorophyll concentration: The depth and area of the peak above a baseline showed a linear relationship to Chl-a concentration. All of the algorithms mentioned proved to be of value and can be used to predict Chl-a concentration. Best results were obtained by using the algorithms of the first derivative, which yielded R ² around 0.74 and RMSE around 6.39 μg/l. The two-band and three-band algorithms were further applied to MERIS when filed spectral were resampled with regard to their center wavelengths. Both algorithms showed an adequate precision, and the differences on the outcome were small with R ² = 0.70 and 0.71.     

Short-term in vitro and in vivo genotoxicity testing systems for some water bodies of Northern India

The genotoxicity of certain water bodies was evaluated employing the DNA repair defective mutants of Escherichia coli, induction of prophage lamda in the lysogen and the plasmid nicking assay. All the test DNA repair defective mutants invariably exhibited more sensitivity than their isogenic wild-type strains but distinctive patterns against the three water samples viz. industrial waste water and the groundwater samples obtained from industrial estate of Aligarh as well as river water of Yamuna at Agra. A significant level of phage induction was also recorded in the test system exhibiting maximum induction in case of industrial waste water followed by that in river and groundwater samples, respectively. The single- and double-strand breaks were also observed in the plasmid DNA treated with industrial waste water and the river water samples. These findings are suggestive of the DNA damage induced by the test samples with the probable role of SOS repair in E. coli.     

Capillary microextraction for simultaneous analysis of multi-residual semivolatile organic compounds in water

Capillary microextractor (CME) in combination with a gas chromatograph-mass spectrometer (GC-MS) was employed for the determination of trace priority hazardous substances in water. Three groups of semivolatile organic compounds (SVOCs), i.e., chlorinated hydrocarbons, pesticides and polycyclic aromatic hydrocarbons (PAHs), were simultaneously determined. SVOCs were extracted from 7 mL of water samples on a 100 cm commercial gas chromatographic column (0.32 mm id x film thickness 0.25 microm, HP-5 capillary column) and eluted with only 3 microL of acetonitrile. The extractant was analyzed by GC-MS in the selected ion monitoring mode. The method showed good linearity over the concentration range 10 ng L(-1) to 3.0 mg L(-1) with correlation coefficients (r) greater than 0.99 and low limits of detection ranged from 10 ng L(-1) to 1.0 mg L(-1). High recovery (more than 80%) was obtained with relative standard deviation less than 10%. The method was successfully applied for trace level analyses of SVOCs in water samples.     

Fluorescent screening of phytoplankton and organic compounds in sea water

The flow-through spectrofluorometers, FLUO-IMAGER, were developed to measure the abundance of phytoplankton, including the analysis of pigment composition and concentration of organic pollution and dissolved organic matter (DOM), in continuous mode. The measurements can be carried out without the time-consuming pretreatment of water samples. The analytical concept uses the technique of spectral fluorescent signatures (SFS), based on the systematized spectral library comprising the SFS of major phytoplankton species and chemical pollution. The SFS technique has been applied for several years in qualitative and quantitative screening of organic compounds and phytoplankton in the Baltic, North and Norwegian Seas. The results of the analysis of phytoplankton pigments, the dynamic processes of bloom development, DOM and oil pollution are presented.     

Optimization models for siting water quality monitoring stations in a catchment

A water quality monitoring network (WQMN) must be designed so as to adequately protect the water quality in a catchment. Although a simulated annealing (SA) method was previously applied to design a WQMN, the SA method cannot ensure the solution it obtained is the global optimum. Therefore, two new linear optimization models are proposed in this study to minimize the deviation of the cost values expected to identify the possible pollution sources based on uniform cost (UC) and coverage elimination uniform cost (CEUC) schemes. The UC model determines the expected cost values by considering each sub-catchment being covered by which station, while the CEUC model determines the coverage of each station by eliminating the area covered by any upstream station. The proposed models are applied to the Derchi reservoir catchment in Taiwan. Results show that the global optimal WQMN can be effectively determined by using the UC or CEUC model, for which both results are better than those from the SA method, especially when the number of stations becomes large.     

Investigation and assessment of volatile organic compounds in water sources in China

456 water samples collected from 152 water sources in 2006 were analyzed for 21 volatile organic compounds (VOCs). Concentrations of 21 VOCs ranged from below method detection limits of the laboratory to 7.65 ??g/L (toluene), but seldom exceeded the concentration limits set in the National Drinking Water Quality Standards (GB5749-2006) or the National Environmental Quality Standards for Surface Water (GB3838-2002) of China. Of the 21 individual VOCs analyzed, 11 VOCs were detected in at least one sample at or above 1.0 ??g/L; 6.6% of the water samples had a detection of at least one VOC at or above 1.0 ??g/L, and 2.6% had a detection of at least two VOCs at or above 1.0 ??g/L. Based on the statistical data of detection frequencies above the method detection limits, 75% of the samples detected at least one VOC, and 65% of the samples detected at least two VOCs. Chloroform, toluene, and 1,2-dichloroethene were the three most frequently detected VOCs, with detection frequencies of 76.97%, 68.42%, and 44.08%, respectively. Volatile halogenated hydrocarbons and gasoline components were the two most frequently detected VOC groups.     

Study of odor compounds in gaseous effluents generated during production of poultry feather and viscera meal using headspace solid phase microextraction

This work reports the screening and characterization of odor compounds in gaseous effluents generated during the production of poultry feather and viscera meal, the by-products of the poultry meat industry. Chemical analysis was carried out by solid phase microextraction in the headspace (HS-SPME) mode. Exhaust air of thermal processing of poultry feather and viscera were sampled online from a bench-scale digester, condensed, and collected in sampling flasks. Both volatile and semivolatile organic compounds present in the condensed gases were extracted under agitation at constant temperature. The extracts were analyzed with a gas chromatograph coupled to a mass spectrometric detector (GC/MSD). The identification of compounds was carried out by comparing the mass spectra obtained with those from the Wiley library and quantification was accomplished through authentic analytical standards. For the determination of the best extraction conditions and analysis, extraction fibers of different coatings and polarities were tested: divinylbenzene/carboxen/polydimethyilsiloxane (DVB/CAR/PDMS), carbowax/divinylbenzene (CW/DVB), and polydimethylsiloxane (PDMS) and chromatography columns of different polarities: DB-WAX (polar) and DB-5 (nonpolar). The best extraction conditions and analysis of the compounds of interest were obtained by the use of the SPME fiber with DVB/CAR/PDMS coating and analysis by GC/MSD with polar capillary column. Several carboxylic acids were identified, as well as mercaptans, amines, and aldehydes of great environmental importance.     

Stagnant surface water bodies (SSWBs) as an alternative water resource for the Chittagong metropolitan area of Bangladesh: physicochemical characterization in terms of water quality indices

The concern over ensuing freshwater scarcity has forced the developing countries to delve for alternative water resources. In this study, we examined the potential of stagnant surface water bodies (SSWBs) as alternative freshwater resources in the densely populated Chittagong metropolitan area (CMPA) of Bangladesh??where there is an acute shortage of urban freshwater supply. Water samples were collected at 1-month intervals for a period of 1 year from 12 stations distributed over the whole metropolis. Samples were analyzed for pH, water temperature (WTemp), turbidity, electrical conductivity (EC), total dissolved solids, total solids, total hardness, dissolved oxygen (DO), chloride, orthophosphates, ammonia, total coliforms (TC), and trace metal (Cd, Cr, Cu, Pb, As, and Fe) concentrations. Based on these parameters, different types of water quality indices (WQIs) were deduced. WQIs showed most of CMPA-SSWBs as good or medium quality water bodies, while none were categorized as bad. Moreover, it was observed that the minimal water quality index (WQI_m), computed using five parameters: WTemp, pH, DO, EC, and turbidity, gave a reliable estimate of water quality. The WQI_m gave similar results in 72% of the cases compared with other WQIs that were based on larger set of parameters. Based on our finding, we suggest the wider use WQI_m in developing countries for assessing health of SSWBs, as it will minimize the analytical cost to overcome the budget constraints involved in this kind of evaluations. It was observed that except turbidity and TC content, all other quality parameters fluctuated within the limit of the World Health Organization suggested standards for drinking water. From our findings, we concluded that if the turbidity and TC content of water from SSWBs in CMPA are taken care of, they will become good candidates as alternative water resources all round the year.     

Use of water quality index and multivariate statistical techniques for the assessment of spatial variations in water quality of a small river

Rapid urban development has led to a critical negative impact on water bodies flowing in and around urban areas. In the present study, 25 physiochemical and biological parameters have been studied on water samples collected from the entire section of a small river originating and ending within an urban area. This study envisaged to assess the water quality status of river body and explore probable sources of pollution in the river. Weighted arithmetic water quality index (WQI) was employed to evaluate the water quality status of the river. Multivariate statistical techniques namely cluster analysis (CA) and principal component analysis (PCA) were applied to differentiate the sources of variation in water quality and to determine the cause of pollution in the river. WQI values indicated high pollution levels in the studied water body, rendering it unsuitable for any practical purpose. Cluster analysis results showed that the river samples can be divided into four groups. Use of PCA identified four important factors describing the types of pollution in the river, namely (1) mineral and nutrient pollution, (2) heavy metal pollution, (3) organic pollution, and (4) fecal contamination. The deteriorating water quality of the river was demonstrated to originate from wide sources of anthropogenic activities, especially municipal sewage discharge from unplanned housing areas, wastewater discharge from small industrial units, livestock activities, and indiscriminate dumping of solid wastes in the river. Thus, the present study effectively demonstrates the use of WQI and multivariate statistical techniques for gaining simpler and meaningful information about the water quality of a lotic water body as well as to identify of the pollution sources.     

Organochlorine compounds in red deer (Cervus elaphus L.) and fallow deer (Dama dama L.) from inland and coastal Croatia

Polychlorinated biphenyl (PCB) and organochlorine pesticide (OCP) levels in fat tissue of red and fallow deer (Cervus elaphus L. and Dama dama L.) from two inland and an Adriatic area were established. Of 17 analysed PCBs, PCB-28, PCB-138, PCB-153, PCB-180 and PCB-118 were found in all samples, whilst PCB-101 and PCB-170 were found in more than 50% of samples. They ranged between 0.03 and 5.98 ng g(-1) fat weight. Of seven analysed OCPs, HCB, γ-HCH and 1,1-dichloro-2,2-di(4-chlorophenyl)ethylene (DDE) were found in all samples, whilst β-HCH was found in more than 50% of samples. They ranged between 0.17 and 22.14 ng g(-1) fat weight. The dominating compounds were DDE, PCB-138, PCB153, PCB-118 and PCB-180. According to the Duncan multistage test, the levels of PCB-138, PCB-153, PCB 170 and PCB-180 were significantly higher in perirenal fat samples of specimens taken from the Adriatic area. DDE was significantly higher in the inland deer samples. Some species differences were determined and were mostly related to higher PCB and β-HCH levels in fallow deer samples and higher DDE levels in red deer samples. No sex difference was established. As for age, significantly higher levels of PCB-118 and PCB-52 were found in fawns.     

Mathematical models for accurate prediction of atmospheric visibility with particular reference to the seasonal and environmental patterns in Hong Kong

Atmospheric visibility impairment has gained increasing concern as it is associated with the existence of a number of aerosols as well as common air pollutants and produces unfavorable conditions for observation, dispersion, and transportation. This study analyzed the atmospheric visibility data measured in urban and suburban Hong Kong (two selected stations) with respect to time-matched mass concentrations of common air pollutants including nitrogen dioxide (NO(2)), nitrogen monoxide (NO), respirable suspended particulates (PM(10)), sulfur dioxide (SO(2)), carbon monoxide (CO), and meteorological parameters including air temperature, relative humidity, and wind speed. No significant difference in atmospheric visibility was reported between the two measurement locations (p > or = 0.6, t test); and good atmospheric visibility was observed more frequently in summer and autumn than in winter and spring (p < 0.01, t test). It was also found that atmospheric visibility increased with temperature but decreased with the concentrations of SO(2), CO, PM(10), NO, and NO(2). The results showed that atmospheric visibility was season dependent and would have significant correlations with temperature, the mass concentrations of PM(10) and NO(2), and the air pollution index API (correlation coefficients mid R: R mid R: > or = 0.7, p < or = 0.0001, t test). Mathematical expressions catering to the seasonal variations of atmospheric visibility were thus proposed. By comparison, the proposed visibility prediction models were more accurate than some existing regional models. In addition to improving visibility prediction accuracy, this study would be useful for understanding the context of low atmospheric visibility, exploring possible remedial measures, and evaluating the impact of air pollution and atmospheric visibility impairment in this region.     

Performance optimization of a membrane assisted passive sampler for monitoring of ionizable organic compounds in water

A thin-walled silicone rubber hollow fibre membrane has been developed as a passive sampler. The inside of the tube is filled with an aqueous solution at an appropriate pH. The tube is sealed at both ends and then immersed in a water sample. In order for the ionizable permeating compounds to be trapped in the aqueous receiving phase, the pH is adjusted such that the compounds are ionized and trapped. The major advantages are its simplicity, low cost and high selectivity, since only ionizable organic compounds are trapped. Additionally, the sampler uses no organic solvent. By adjusting the pH of the acceptor phase, it is possible to control the extraction process and whether the sampler is used in the kinetic or equilibrium regime. Since it is very selective, no further clean-up of the extract is required. The membrane assisted passive sampler has been tested for extraction of chlorophenols under laboratory conditions. The extraction process was found to be linear over a 72 h sampling period. Selectivity of the passive sampler in river water was demonstrated and the extraction process was independent of sample concentration, even at lower concentration levels of analytes. However, the sample matrix in some river water samples led to incomplete trapping, thereby reducing the amount trapped in the acceptor phase. Detection limits (three times signal to noise ratio) were dependant on sample matrix and type of detection system and ranged from 0.05 microg L(-1) to about 1 microg L(-1) with a UV photodiode detector in water samples from one river and 1.0 microg L(-1) to 20 microg L(-1) in another but with an ordinary UV detector. The enrichment factors in river water were 28 for 2-chlorophenol and 44 for 2,4-dichlorophenol over a 72 h sampling period. 4-chlorophenol was poorly extracted and its enrichment factor was 3.