A rapid routine method for quantitative determination of benzo(a)pyrene in water by low-temperature spectrofluorimetry

Some limitations of the analytical method for the determination of polynuclear aromatic hydrocarbons (PAH) in water have led the authors to study the quantitative application of low-temperature spectrofluorimetry as a rapid routine method for the screening of benzo(a)pyrene (BaP) in the aquatic environment. Experiments on the technique of recovery of BaP from distilled water samples utilizing liquid-liquid extraction have given good results; trials concerned with evaluation of any quenching effects on BaP by other PAH and with the applicability to real water samples (river, rain and drinking waters) have shown the promise of this method for screening analysis of environmental waters. The reproducibility of the method is adequate and the required time of total analysis is very short, especially for drinking water samples.     

The effect of photochemical treatment of water on algal growth

A new method for the destruction of algae in surface waters by dye-sensitized photooxidation is described. The algae (Peridinium, Pediastrum and Cosmarium) used as test organisms were inoculated in an artificial culture medium, containing a dye-sensitizer, with subsequent incubation in a controlled environment (20 ± 2°C, 14 h light, 10 h darkness). Water samples from Peridinium bloom in Lake Kinneret underwent similar treatment. The algicidal effect of various sensitizer concentrations and of different sunlight exposure times was investigated. Complete destruction of algae was obtained in about 2 weeks of incubation after exposure to solar radiation for 30–60 min in the presence of 0.25, 0.15 and 0.75 mg 1⁻¹ methylene blue or 0.5, 0.8 and 0.8 mg 1⁻¹ rose bengal in Peridinium, Pediastrum and Cosmarium cultures, respectively.     

Algae as a chemical speciation monitor—I A comparison of algal growth and computer calculated speciation

An alga, Selenastrum capricornutum, was used to monitor the relationship between metal speciation and toxicity. The principal effect of copper on the algae was a decrease in growth rate constant as the total concentration of copper increased. A 24-h growth experiment was used to monitor the effect of metal on the algae. Chlorophyll measurements at 17 and 23 h were used to estimate the growth rate constant. A plot of growth rate constant versus the speciation variable (total copper, pCu, pCuL, etc.) was used to determine the toxic species and the algicidal concentrations. Solutions containing EDTA, TRIEN, NTA, HIMDA and bicine became algicidal at pCu of 8.0 whereas solutions containing ethylenediamine and citric acid became algicidal at pCu 8.65 and 9.5, respectively. A comparison of growth and calculated speciation suggests that Cu en⁺² and Cu CIT OH⁻² were toxic species.     

Sediment oxygen demand techniques: A review and comparison of laboratory and in situ systems

Sediment oxygen demand (SOD) measurement techniques are reviewed and suggestions offered for improving their performance, including an experimental approach toward standardizing the SOD methodology. Five principal analytical systems are used to evaluate SOD. These are conveniently classified as: (1) batch (laboratory and in situ); (2) continuous flow; (3) manometric; (4) electrolytic and (5) dehydrogenase activity. Comparison of SOD methods requires establishing certain criteria which should be met for a given method to be considered acceptable. These criteria are: (1) consistency; (2) reproducibility and (3) efficiency. Laboratory techniques can meet the acceptability criteria more easily than in situ techniques. A SOD reaction chamber used in our laboratory provided reproducible data for replicate analyses of stream and lakes sediments and met our acceptability criteria.     

Removal of bacteriophage Escherica coli T1 by sand columns using Ca2+ as a filter aid

Calcium was shown to enhance the removal of T₁ coliphage by model sand columns. The concentration of calcium necessary to cause effective removal of the virus was shown to be stoichiometric with the virus titer.The effectiveness of the 2.54 cm (1 in.) i.d., 10.16 cm (4 in.) deep model filters to remove T₁ coliphage in the presence of calcium was shown to decrease as the sand grain size increased. Ca²⁺ enhanced removal most effectively at slightly acid pH's. That is, more Ca²⁺ is required to produce effective removal of the virus as the pH is raised.     

Survival and distribution of aeromonas hydrophila in near-shore coastal waters of Puerto Rico receiving rum distillery effluent

For a period of 1 year, monthly water samples were taken for estimates of Aeromonas hydrophila density at 6 sites in Ensenada de Boca Vieja near San Juan, Puerto Rico. Five sites were associated with the effluent plume of the world's largest rum distillery, the sixth site was 177 m upcurrent. Fifteen water quality parameters were monitored concurrently with A. hydrophila estimates. The toxic and stimulatory nature of the effluent made correlations with any physicochemical parameter difficult. However, a significant multiple regression was obtained against density of A. hydrophila using temperature, total phosphorus, total organic carbon and orthophosphates. Densities of A. hydrophila were always higher in the effluent plume and usually highest at the site closest to effluent outfall. Suspensions of A. hydrophila placed in diffusion chambers at the effluent point source not only survived, but gradually increased in density, while 500 m upcurrent densities of A. hydrophila in diffusion chambers rapidly declined. Significant differences in A. hydrophila density between the two sites could be detected after only 18 h. The diffusion chamber studies confirm natural correlations with water quality that indicate A. hydrophila densities in marine habitats can become elevated under the appropriate conditions. Higher densities of other potential pathogens e.g. Klebsiella pneumoniae, Vibrio cholerae, were also observed in the rum distillery effluent plume.     

Nitrosamines in tap water after concentration by a carbonaceous adsorbent

Ambersorb XE-340 carbonaceous adsorbent removed trace levels of volatile nitrosamines (NAs) that were added to the influent water. Recovery of seven added NAs was between 58–99% as determined by a gas-liquid chromatograph interfaced with a Thermal Energy Analyzer (GLC-TEA). When municipal (tap) water (10–42 l.) was passed through the Ambersorb XE-340 column. N-nitrosodimethylamine (NDMA; 0.003–0.006 μg 1⁻¹) and -morpholine (NMOR; 0.006–0.018 μg 1⁻¹) were the principal NAs found. All of the NDMA and 18 of 20 NMOR samples were confirmed by high resolution mass spectrometry. Secondary amines added to tap water at levels of 1 mg 1⁻¹ and 10 μg 1⁻¹ formed apparent NAs, suggesting a possible component(s) in the water that caused NA formation. Low levels of volatile NAs were detected by GLC-TEA in commercial, pure, adsorbents (activated carbon). NAs were confirmed by high resolution mass spectrometry except where concentrations were too low. In the latter case, the apparent NAs were found to be photolabile when subjected to u.v. light (365 nm) and were reanalyzed by GLC-TEA thus providing additional evidence that the TEA responsive compounds were NAs.     

Factors affecting the extraction and analysis of polynuclear aromatic hydrocarbons in water

Factors expected to affect the efficiency of extraction of Polynuclear Aromatic Hydrocarbons (P.A.H.) from environmental water samples have been systematically investigated. Such factors include the initial concentration of P.A.H., the presence of suspended solids and prolonged storage of the sample prior to analysis. Extraction efficiencies between 30 and 85% have been found and these data make possible more accurate measurements of levels of P.A.H. in water. Analyses of environmental water samples have been performed using both Thin layer chromatography (TLC) and Gas-liquid chromatography (GLC). Accuracy of analysis was assessed by addition of P.A.H. to environmental water samples before extraction. Thin layer chromatography was found to be the better procedure for the compounds analysed, and avoided the need for purification of the solvent extract prior to analysis.     

Direct influence of wastewater pollutants on flocculation and sedimentation behaviour in biological wastewater treatment—I model system E. coli B

The influence of different chemicals on flocculation and sedimentation in wastewater was investigated in a model system of washed E. Coli B harvested at the end of the logarithmic phase. It was found that the amount of extracellular polymeric material present in the system affected the coagulation by neutral salts and also the degree of influence of the model pollutants investigated. Considerable effects on sedimentation could be found for several of the pollutants when the cells were in the state of slow coagulation close to the critical coagulation concentration (ccc). These effects were attributed to interactions between the extracellular polymers and pollutants influencing the bridging between cells.     

A model study of ozone-sparged vessels for the removal of organics from water

Ozone-sparged vessels for the oxidation of a model organic compound, methanol, was studied. The parameters under study included superficial gas velocity, the gas phase ozone concentration, the rate of ozonation of methanol and its oxidative products, the residence time, etc. The scale-up method based on the mathematical model developed in this study accurately predicts the superficial gas velocity and the gas phase ozone concentration required for two larger geometrically similar vessels to achieve the same level of total organic carbon removal obtained in a small vessel.     

Elemental deposition as a function of distance from an industrial zone

Elemental deposition rapidly decreases as a function of distance from an industrial zone, but never drops to zero level. On a country-wide scale, elemental deposition extends more or less like a uniform blanket locally inflated by the discharges of urban or industrial zones.     

An evaluation of transfer function models for the transient growth response of microbial cultures

Experiments were conducted to evaluate the ability of transfer function models to characterize the transient-state growth response of Pseudomonas putida grown in l-lysine minimal media. The results indicated that, while transfer function models could be used to characterize individual transient responses, the values of the parameters in the models varied with the pre-transient growth conditions (i.e. the steady-state specific growth rate prior to the transient) and the type of transient (shift-up or shift-down). Thus, the models were not very useful for predicting transient responses. It is suggested that this poor predictive power is the result of a complex physiological adaptation which is not adequately accounted for in simple transfer function models.     

The distribution and origin of mutagens in airborne particulates, detected by the salmonella/microsome assay in relation to levels of lead, vanadium and PAH

At three stations in central Copenhagen, Denmark, samples of particulate matter were collected simultaneously with different contributions from automobile exhaust products. Samples were obtained at street level, 22 m above street level and within a hospital zone; 32 samples were analysed for levels of polycyclic aromatic hydrocarbons (PAH) and elements, as well as for mutagenicity towards S. typhimurium TA1538. Two classes of mutagens were quantified: a non-polar extract rich in PAH and, other promutagens, and a polar extract containing direct acting mutagens (not requiring microsomal activation). Covariances between lead and mutagenicity, and the varying distribution of the polar and non-polar mutagens at the stations, indicate that at all stations the mutagenicity of the non-polar extract is dominated by automobile exhaust products. The polar extract is relatively less influenced by primary traffic emissions; a considerable part of the activity of this extract is attributed to secondary emissions, transformed by atmospheric reactions, and primary emissions from stationary sources.     

Dye-sensitized-photo-oxidation—a new approach to the treatment of organic matter in sewage effluents

A new approach to the oxidation of organic matter in municipal wastewaters by photosensitization is described. Samples of aerated sewage effluents containing an added dye-sensitizer were exposed to u.v.-lamp or solar radiation. The photochemical oxidation of the sewage caused decreases in the content of the fecal coliform, of the chemical oxygen demand and of the methylene blue-active substances by 100, 67 and 90% of their initial values, respectively. The effluents obtained after the removal of the dye, by precipitation with bentonite clay, were colorless, non-odorous and with the amount of suspended solids considerably reduced.     

Lead content of small mammals at a roadside site in relation to the pathways of exposure

Concentrations of lead have been determined in three species of small mammal, Sorex araneus, Clethrionomys glareolus and Apodemus sylvaticus at roadside and control sites. The results are considered in relation to the lead content of the diet and the air, and it is concluded that the diet provides far the major pathway for lead exposure, even at the roadside site. Bone lead concentrations are found to be consistent with estimated lead exposure and metabolism.     

Natural and acquired resistance of mice to infection by airborne Klebsiella pneumoniae after subchronic intoxication by cadmium administered orally

Mice daily ingested about 22 mg of cadmium per kg of body weight in drinking water for 30 days. On the 30th day, the liver and kidneys of the mice contained about 18 μg of Cd²⁺ perg of fresh organ. A group of these mice was immunized against Klebsiella pneumoniae using two injections of vaccine, the first on the 7th day and the second on the 14th day of intoxication. On the 28th day, the non-immunized and the immunized mice were infected via a respiratory route by one lethal dose 50% of K. pneumoniae (the LD₅₀ for the immunized mice was 2.4 times higher than the LD₅₀ for the non-immunized mice). Comparison with the non-intoxicated control mice showed that the ingestion of Cd²⁺ did not significantly modify the natural resistance or the acquired resistance of the mice to the infection by airborne K. pneumoniae.     

Electrochemical speciation of trace metals in sea water

Various approaches, such as bioassays, computer-assisted modelling and direct measurement following physical separation are currently being used to investigate the speciation of trace metals in sea water. The electrochemical techniques used successfully as a necessary prerequisite for the experiments involved include conventional polarography, anodic stripping voltammetry (ASV) and potentiometry. Differential pulse anodic stripping voltammetry (DPASV) using mercury film electrodes enables direct studies in ultratrace levels present in non-contaminated ocean waters.By varying the conditions of the sample chemistry and electroanalysis it is possible to characterize metal-organic interactions. This is demonstrated in the case of natural sea water samples subjected to ASV diagnosis. Differences in the Pb and Cu values yielded for Baltic waters by two methods based on DPASV and AAS are discussed with regard to speciation.An analysis of the existing literature is used to briefly summarize the needs of future research. Important problems requiring a more precise quantitative analysis include the adsorption of organics on electrodes and the kinetics and thermodynamic constants of chelates with special regard to the physico-chemical nature of metal-humic substances. The introduction of new and improved electroanalytical techniques and equipment for speciation studies is strongly recommended.     

Interaction and mobility of cobalt-60 between water and sediments in marine environments possible effects by acid rain

In Japan, all nuclear power stations have been constructed facing sea-shores and the operating radioactive wastes have been either stored at the sites or discharged into marine environments, if permissible. The purpose of this investigation was to understand the behavior of a radioactive cobalt (⁶⁰Co), one of the typical radionuclides produced by operating nuclear reactors, in marine environments, namely cobalt interaction between water and sediments. Great emphasis was focused on demonstrating a quantitative difference in behavior of cobalt between marine and freshwater environments.Under natural conditions, cobalt remained in the water phase in marine environments more than 5 times as much as in freshwater environments. In freshwater, most cobalt (over 95%) is absorbed by and permanently retained within bed sediments under the normal environmental conditions. However, in marine environments cobalt gains mobility. Furthermore, this mobility of cobalt once established did not diminish nor disappear when surrounding conditions were changed.In short, cobalt in marine environments is generally mobile. This considerable mobility was greatly influenced by the environmental factors: (e.g. pH, the redox potential, the ionic strength, the type of sediments and the length of reaction time) but, it was primarily determined by the initial environmental conditions. The result of this experiment suggests that the treatment and the storage of radioactive cobalt waste should be done in freshwater environments rather than in a marine environment if we try to reduce the mobility. Because the mobility depends on pH, acid rain is, therefore, to be expected to strongly influence the mobility of ⁶⁰Co in aquatic environments.     

Multielement analysis of fingernail,scalp hair and water samples from Egypt (a preliminary study)

Scalp hair, fingernail and water samples collected from different parts of Egypt are analysed by atomic absorption spectrophotometry and neutron activation analysis.The results for hair show minimum variation of Zn among different regions; a relatively well-controlled dispersion of values (maximum to minimum <2) for Co, Fe, Mn and Se; an overall inter-regional variation of factors of 7, 10, 6, 4 and 6 for the elements Ag, Cd, Cs, Sc and W, respectively; a steady decline in the concentration of Sc from south (Aswan) to north (Alexandria).The findings for nail show a steady decline in the concentration of Fe and Sc from south (Aswan) to north (Alexandria); elevated levels of Cd in samples from Aswan area; and regional variations extending up to factors of 6.5, 3.6, 4.7, 5.0, 4.4, 4.5 and 1.9 for Co, Cr, Cs, Mn, Mo, W and Zn, respectively.No unified relationship is observed between the elemental compositions of hair and nail. For Cr, Cs, Fe, Sb and Sc mean values for hair are lower than in nails. Among the remaining elements the ratio nail/hair is <1 for Ag in Assiut, El Kharga and Alexandria, for Cd in all of the areas with the exception of Aswan, for Co, Mn and Mo in Cairo, for Zn in Cairo and Alexandria, and for W in Alexandria.The data for water samples reflect highest concentration of all the measured elements in the Mediterranean sea; a steady increase of the concentration of Cu in drinking water from south to north and for Nile water a similar trend for Ca and Mg; and elevated concentrations of Sb and Mn in river water.No distinct trend for the interrelationship between water and tissue elemental concentrations could be established for the regions around Cairo, Aswan and Alexandria.