Physico-chemical characterization of atmospheric trace metal emissions from a primary zinc-lead smelter

Emissions from the stacks of a major primary zinc--lead smelter were characterised using X-ray powder diffraction spectrometry (XRD). The following chemical phases were identified: PbSO4, PbO X PbSO4, PbO, PbS, PbO, ZnO, alpha-ZnS, CdO. A complementary environmental investigation revealed that, within the works boundary, the airborne metals might be associated mainly with the fugitive blowage of coarse particles containing primary ore minerals. However, such fugitive emissions were found to be of low significance in the local environment outside the works perimeter, where fine particle emissions from the stacks of the smelter were the predominant source of airborne cadmium, lead and zinc.     

An assessment of the contribution from paint flakes to the lead content of some street and household dusts

A method has been developed for estimating crudely the quantity of lead in dusts derived from paint flakes. This involves an assessment of the paint mass in the dust: gravimetrically in the coarse fractions, and by microscopic measurement in the fine fractions. Some street and house dust samples were examined. The street dusts contained up to 20% of lead from paint, and the house dusts up to 15%. However, it was the least lead-polluted dusts that contained the highest proportions of lead from paint. In the samples examined the paint flakes contained only low to moderate amounts of lead (0.07-4.21% w/w) and in the case of high lead paints the contribution from this source could be considerably greater.     

Rapid flameless atomic absorption analysis of the metallic content of sewage sludges II. Chromium,nickel and zinc

The development of a new rapid flameless atomic absorption procedure for the analysis of chromium, nickel and zinc in sewage sludges is described. The technique has previously been found suitable for the analysis of lead, cadmium and copper. Sample preparation has been minimised and multi-elemental analysis of a single sample is possible.     

Rapid flameless atomic absorption analysis of the metallic content of sewage sludges I. Lead,cadmium and copper

The application of flameless atomic absorption analysis to the determination of cadmium, copper and lead in sewage sludges is described. The technique is sensitive and very rapid, since the normal lengthy sample pre-treatment has been virtually eliminated. The method can be potentially extended to a large range of metals in all types of sludges.     

Characterization of trace metal species and measurement of trace metal stability constants by electrochemical techniques

Differential pulse polarography and differential pulse anodic stripping voltammetry were used to determine copper, lead, cadmium and zinc complexes of relevance to environmental conditions. The dependency of peak current on pH and alkalinity was interpreted in terms of the variation in the metal species present. Stability constants of copper and lead complexes with carbonate were determined from the magnitude of the shift of peak potential using the method of Lingane. Inclusion of the transfer coefficient, calculated from the peak half-width for electrochemically irreversible systems, was used to determine the stability constant. By using both electroanalytical techniques, the investigator validates the correctness of his results without needing to rely on prior determinations of the stability constant for verification.     

Comparative studies on trace metal levels in marine biota I. Mercury in marine organisms from western Italian coast,the strait of Gibraltar and the North Sea

The mercury level has been determined in the edible part of 36 marine species (867 specimens) caught from 1975 to 1976 mainly close to the Western Italian coast, the Strait of Gibraltar and in some selected regions of the North Sea. Sample pretreatment was performed after careful preparation by nitric acid pressure decomposition of frozen stored subsamples using up to 2.5 g fresh weight (FW). The analytical method was automated cold vapour atomic absorption spectrophotometry after preconcentration on silver wool. Accuracy and precision of the method was checked by interlaboratory intercomparisons and intralaboratory test measurements of repeatability and also the use of Standard Reference Materials. The total mercury (HgT) values obtained ranged from 20 μg/kg FW to ?2,000 μg/kg Fresh weight for the Mediterranean Sea and for some pelagic species showed significantly elevated mercury values compared with organisms from the Atlantic and North Sea. For benthic organisms, however, probably due to dominating local influences, a similar behaviour has not been observed. Evaluation of body weight/mercury concentration ratios showed significant correlations for several species differing between distinct locations.     

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.     

The effect of pH and hardness metal ions on the competitive interaction between trace metal ions and inorganic and organic complexing agents found in natural waters

The effect of pH and hardness metal ions on the interactions between trace metals and both inorganic and organic complexing agents has been studied under conditions simulating natural aquatic conditions, by employing anodic stripping voltammetric titration techniques. The complexation of Bi(III), Cd(II), Cu(II), Pb(II), and Tl(I) with the hydroxo- and carbonato-ligands found in a carbonate medium has been observed to generally increase with increasing pH. Both labile and nonlabile interactions have been observed. Nonlabile interactions are predominant at low pH and labile interactions generally increase with increasing pH. Neither calcium nor magnesium affects these interactions. The complexation of humic acids with trace metals in a carbonate medium was found to be more intense than metal ion-inorganic complexation. Both labile and nonlabile complexation was found; however, no generalizations can be made concerning the type and extent of complexation because of the individual nature of the interactions of each trace metal. Calcium was found to be more effective than magnesium in inhibiting trace metal-organic complexation. The effect of calcium is to inhibit labile complexation and is most pronounced with the cadmium-humic acid system.     

The use of physical separation techniques in trace metal speciation studies

Size fractionation techniques used in speciation studies of trace metals in natural waters have been reviewed. Centrifugation, filtration, ultrafiltration (UF), dialysis and gel filtration chromatography (GFC) have been considered with respect to trace metal contamination, adsorption effects and size selectivity. Size differentiation during centrifugation is impeded due to density effects on particle settling rates. Filtration is the most commonly used method to fractionate trace metal species, but often only “issolved” and “particulate” fractions are identified. Filters may be decontaminated with dilute nitric acid and adsorption effects may be minimised by preconditioning with a dilute calcium nitrate solution. Several studies concerning the size selectivity of filters indicate that at present only Nuclepore polycarbonate filters are suitable for size spectrum investigations. Those difficulties outlined above are also experienced with UF methods but generally have not been so well resolved. particularly with respect to adsorption. Adsorption during UF causes an overestimation of the molecular size of metal complexes. Dialysis techniques have been utilized with some success in order to isolate trace metal species in true solution but have seen only limited applications in comprehensive speciation schemes. GFC offers considerable potential in physicochemical speciation studies. The major advantage lies with the ability to determine metal concentrations over a continuous size spectrum rather than at discrete size ranges. In contrast to other methods, adsorption during GFC will cause the molecular weight of organometallic complexes to be underestimated. Several examples of the environmental application of each technique have been considered, thereby illustrating the value of examining the size distribution of metal species in natural waters.     

Air pollution, hygiene and health of Danish schoolchildren.

A comprehensive investigation forming part of a joint European study under the auspices of "WHO Long-Term Air Pollution Programme" uses 7-13 year old schoolchildren as the target group. The study has included social, housing, hygienic and epidemic factors as well as family smoking habits. The results indicate that, at exposure to low levels of air pollution, these factors dominate as causes for the impairment of health especially that of respiratory health.     

Mercury in feathers of wild birds from the mercury - polluted area along the shore of the Shiranui Sea, Japan

Total mercury content in the feathers of 95 stuffed, wild birds collected all over the shore of the Shiranui Sea (where Minamata disease occurred in many towns and villages in the 1960's) was measured. They were collected over 25 years, from 1955 to 1980. They showed relatively high mercury levels till the late 1970's, although drainage of waste water containing methylmercury from the Chisso Corporation's Minamata Factory was stopped in 1968. In addition, a strong correlation between feeding habits and mercury content was observed; thus the five groups in order of diminishing mercury content were: fish-eating sea birds (mean ± SD = 7.1 ± 3.7 ppm, N = 14), omnivorous water fowl (5.5 ± 5.6 ppm, N = 17), predatory birds (3.6 ± 2.9 ppm, N = 16), omnivorous terrestrial birds (1.5 ± 1.2 ppm, N = 31), and herbivorous water fowl (0.9 ± 0.4 ppm, N = 17). Mercury content of the feathers of omnivorous terrestrial birds in the Shiranui Sea was exceedingly high compared with those in China and Korea. The findings in the present study suggest that stuffed, wild birds may be a good index of past environmental pollution.     

Activity of benzo[a]pyrene monooxygenase in fish from the Sava River, Yugoslavia: correlation with pollution

Benzo[a]pyrene monooxygenase (B[a]PMO) activity in non-migratory fish from a given river segment is highly correlated to the recent pollutional history of that part of the river. The enzyme activity level can serve as a relevant measure for the harmful pollutant potential in aquatic ecosystems. Caged experimental fish exposed for about 10 days in river segments show BaPMO activity changes with the same predictive validity as that of the natural population.     

Adsorption studies using gas-liquid chromatography—IV. Adsorption from bisolute systems

Gas-liquid chromatography with a flame ionization detector system using the direct injection of aqueous solutions was used to monitor the adsorption of selected organic compounds dissolved in water onto activated carbon.

The effects of competitive adsorption in bisolute solution systems were investigated. In general, the higher molecular weight compound was more favourably adsorbed because of the higher affinity of the larger molecule to the carbon surface.     

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.     

Assessing unrecorded organic pollution from agricultural, urban, and wooded lands

An investigation was conducted of the organic pollution for seven small New Jersey watersheds representing agricultural, urban, and wooded lands. The 5-day biochemical oxygen demand (BOD) was used as a main index of organic pollution. Data obtained for a 2·5 yr period indicate background BOD concentrations averaging from 0·5 to 2·0 mg l⁻¹ in all streams, except that a value of 9·0 mg l⁻¹ was obtained for a residential-commercial-industrial area. During or after rainstorms, the BOD loadings, in pounds per day per unit area, averagely became more than ten times as the background amount for all streams. No significant correlation was found between BOD concentration and flow rate, but good correlations were obtained between BOD loadings and flows. The seasonal pattern of BOD loading distribution was examined. Also the frequency distribution of BOD concentrations and loadings were obtained.     

Effects of trial disposal of acid-iron effluent from titanium dioxide production on the seafloor and epibenthic macroflora offshore from Koombana Bay, Western Australia

The effects of a trial discharge of acid-iron effluent, resulting from titanium dioxide production, on the seafloor and epibenthic macroflora offshore from Koombana Bay, Western Australia, were assessed. Approximately 88,0001 day⁻¹ of effluent containing 28 g l⁻¹ of iron and 137 g l⁻¹ of H₂SO₄ were discharged through a submarine pipeline from February 1976 to December 1977. This amount of effluent, constituting approx. 5% of total production, was intended to provide a guide as to the environmental effects on the seafloor of discharging the total amount of effluent.Preliminary studies suggested that discernible effects of the discharge were likely to be restricted to the immediate vicinity of the outfall. Consequently, surveys of the effects of the discharge were conducted by divers in December 1976 and April and December 1977 within 400 m of the outfall. The parameters measured were iron concentration in the surface sediment, number of macroscopic plant species (algae and seagrass) and leaf characteristics of the seagrass, Posidonia ostenfeldii. Additional observations on iron staining of the sediment and the condition of the macroscopic plants were also recorded by the divers.By December 1976, the outfall was surrounded by a zone, with a diameter of approx. 200 m, which was totally denuded of macroscopic plants. Extending further from the outfall was a zone in which some effects of the effluent (e.g. sediment stained by iron, reduction in macroscopic plants) were discernible. The total area of seafloor discernibly affected by the effluent in December 1977 when this study finished was 16 ha. At that time, the affected area may have still been increasing in size, and thus the figure of 16 ha must be considered only as the minimum area likely to have been affected by the discharge.     

The effects of pH and suspended solids in the removal of organics from waters and wastewaters by the activated carbon adsorption process

The effects of pH, inorganic suspended solids and organic suspended solids on the adsorption of organics by activated carbon were investigated using sewage effluents and selected organic compounds of varying size, structure, molecular weight and properties in model solutions. It was found that suspended solids, and in particular organic suspended solids, could interfere with the adsorption process, both in terms of adsorption capacity and adsorption rate; the effect of the solids diminished as the size of the adsorbate increased. The effect of pH variation became more significant as the acidity or basicity of the adsorbate in solution increased. Adsorption of organics from biologically treated sewage effluents was somewhat more effective in the acid and alkaline pH regions than in the neutral pH region.     

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.     

Sulfuric acid aerosol.

A brief discussion of the significance of sulfuric acid aerosol is presented together with a review of methods for its sampling, separation and determination.     

Biological technology of the treatment of leachate from sanitary landfills

A laboratory investigation was conducted into low cost treatment of leachate from sanitary landfills. At room temperatures (20–25°C), anaerobic treatment was shown to remove over 95% of the soluble BOD and essentially all the iron, while over 90% of the nitrogen was converted to free ammonia. Two complete schemes of leachate treatment are suggested for pilot plant evaluation. Each has primary steps of anaerobic processing with disposal by spray irrigation or municipal sewer, followed by ammonia stripping and aerobic polishing if discharge to surface waters is required.