Association of organic matter, iron and inorganic phosphorus in lake waters

Gel permeation chromatography was used to fractionate ³²PO₄³⁻ labelled components by molecular size in filtered, destabilized lake foam, concentrated lake water, and lake sediment extracts. Evidence is presented for the abiotic formation of organic matter iron inorganic P complexes in lake foam, water and sediments. ³²PO₄^staggered was found to excahnge with low molecular weight, dissolved P fraction, probably an organic matter -Fe- inorganic P complex, but not with a high molecular weight, non-inorganic dissolved reactive P pool, hypothesized to be similar to the dimer. Our experiments suggest that inorganic P binding by high molecular weight organic matter may play a significant role in the P cycle. If the bound P is unavailable to algae and bacteria, the complexes could explain Rigler's (1968) hypothesis that the molybdenum blue technique may overestimate the free orthophosphate concentration by 10–100 times.     

Introduction to and experimental conditions during the first year of the GMR chronic inhalation studies of diesel exhaust

A chronic exposure study was initiated to determine the effects of diesel exhaust on the health of experimental animals. For this purpose, test atmospheres of clean air (control) or freshly diluted diesel exhaust at concentrations of 250, 750, and 1500 μg/m³ were supplied to four 12.6 m³ inhalation chambers which housed rats and guinea pigs. Diesel aerosol size and concentration, as well as chamber temperature and relative humidity, were continually monitored and controlled to maintain the exposure dose levels and an environment of 22±2°C and 50%±20% relative humidity. The concentrations of CO and NO_x were found to be 5.8±1.0 mg/m³ and 7.9±1.0 mg/m³ above ambient in the chamber containing 1500 μg/m³ of particulate. Animals were supplied from the chambers, on a random basis, for both intramural and extramural studies throughout the exposure period. The experiment ran uninterrupted for over twelve months with mean diesel particle mass concentrations within 2% of the target values.     

The use of ultra filtration in trace metal speciation studies in sea water

During this work, size fractionation technique "ultra filtration" is used in speciation studies of trace elements in the coastal sea water. Filtration is the most commonly used method to fractionate trace metal species, but often only "dissolved" and "particulate" fraction. The purpose of the present study is to determine colloidal and suspended particulate concentrations of Fe, Zn, Cu, Ni, and Mn in sea water. Suspended particulate matter were separated in three different size groups namely (>2.7 microm, <2.7->0.45 microm and <0.45->0.22 microm) by suction filtration using cellulose acetate and nitrate filter membranes. Thereafter to concentrate the solution with colloidal particle <0.22 microm-1.1 nm (0.5 k Nominal Molecular Weight cut-off Limit {NMWL}), the solution obtained from filtration through <0.22 microm, is sequentially passed through the ultra-filtration membranes having pore diameters of 14 nm (300 k NMWL), 3.1 nm (50 k NMWL), 2.2 nm (30 k NMWL), 1.6 nm (10 k NMWL) and 1.1 nm (0.5 k NMWL) by using Stirred Ultra-filtration Cells, operating in concentration mode. The concentration of Fe, Zn, Cu, Ni, and Mn were measured in suspended and dissolved fraction by ion chromatography, ICP-AES and Atomic Absorption Spectrometer. The salinity of the solution in various dissolved fractions of sequential filtration varies between 30.89-34.22 parts per thousand. The maximum concentrations of colloidal Zn, Cu, Ni and Mn in dissolved fraction were in <2.2->1.6 nm fraction. In case of Fe, colloidal fractions <2.2->1.6 nm and <1.6-<1.1 nm shows higher concentration. The concentration of Zn, Cu, Ni and Mn increase with decrease in size in suspended particulate matter, while the reverse is observed in case of Fe. This size separation data that specifies the partitioning of metals between dissolved and suspended solid phases is necessary for developing physically based models of metal transport in aquatic system.     

Effect of moisture content on emanation at different grain size fractions - A pilot study on granitic esker sand sample

It is known that in soils and sediments moisture adsorbed on particle surfaces and in the pore system significantly affects the behaviour of recoiling radon (²²²Rn) atoms after decay of parent ²²⁶Ra, leading to increased ²²²Rn emanation. As a first step in an effort to characterize the ²²²Rn source term in mineralised sediments in the present study, complementing previous studies in the area, granitic esker sand samples were collected in order to test how moisture content affects ²²²Rn emanation at different grain size fractions. Emanation fractions measured for natural samples were compared with theoretical calculations. Six different grain size fractions were studied at 0%, 5% and 10% moisture contents relative to the mass of solids. In a further study necessary complementary information on the chemical and structural distribution of ²²⁶Ra was gained by selective leaching experiments. The results showed that ²²⁶Ra concentration increases from 50 Bq/kg at grain size 1-2 mm to 200 Bq/kg at grain size <0.063 mm. Respectively, the emanation factor increased from 0.12 to 0.30 at 5% moisture content. Both emanation factor and radium concentration increased significantly when grain size was below 0.125-0.250 mm. Above this fraction, the emanation fraction was approximately constant, 0.13 at 5% moisture content. In most of the grain size fractions, emanation reaches its maximum at 5% moisture content, being twice as high as in a dry sample. For the small particles (<0.063 mm) the ²²⁶Ra distribution is rather complex and depends on the mineral composition compared to larger particles wherein emanation from the internal pore system and the adjacent matrix is dominating over the contribution from external surface.     

Aerosol filtration by a cocurrent moving granular bed: Penetration mechanisms

An experimental apparatus has been constructed to investigate aerosol filtration by a cocurrent moving granular bed filter (CMGBF). In a CMGBF, aerosol passes downward through a descending bed of dirty granules while clean granules are added continously at the bed top. The effect of an intergranular dust deposit on penetration in a CMGBF was investigated in a 2⁴ factorial experiment in which the control variables were superficial gas velocity (100 and 250 mm/s), bed depth (130 and 230 mm), granule size (2.1 and 2.7 mm), and the intergranular dust deposit expressed as percent by weight of collected dust in the bed (1% and 5%). All tests were conducted at ambient temperature and pressure using resuspended utility boiler fly ash as the test aerosol.Mass penetration data identified two major penetration mechanisms: (1) straight through penetration and (2) reentrainment due to granular motion. A static, intergranular dust deposit produced high filtration efficiency (>99%) at the low superficial velocity. When the bed was moving, reentrainment of collected dust was significant and accounted for about three-quarters of the penetrating dust. Particle size analyses reveal that the two penetration mechanisms are size dependent. Most particles larger than about one micrometer in diameter that penetrate the CMGBF do so by reentrainment after being collected initially. Virtually no particles smaller than about 0.3 μm in diameter penetrate by reentrainment; when these small particles penetrate, they pass straight through without being collected.     

Two-year follow-up study of nonregulatory recommendations for better air quality in indoor ice arenas

A standardized questionnaire was used in a two-year follow-up study to test the effectiveness of non-regulatory recommendations to improve indoor air quality of 103 ice arenas in Finland. In addition, the performance of a state-of-the-art emission control technology (ECT) on propane-fueled resurfacers was evaluated by measuring the one-week average nitrogen dioxide (NO₂) concentration in a small sample of arenas. The number of retrofitted ECT on propane-fueled resurfacers increased from 6 to 37 (8% to 37% of ice arenas) and the number of electric resurfacers from 7 to 9 (both 9% of arenas) in 1994–1996. At the same time, the prevalence of inadequate ventilation increased among the most susceptible small arenas (volume <30 000 m³) from 11 (31%) to 19 (38%). Combustion-powered resurfacers (88%) and inadequate ventilation (24%) were prevalent also among the 17 new arenas built in 1994–1996. ECT resurfacers significantly decreased the mean indoor NO₂ concentration of eleven arenas from 650 μg/m³ to 147 μg/m³. Thus, retrofitting resurfacers with ECT seems to be a feasible mitigation option to improve indoor air quality in ice arenas, but the ultimate solution is an electric ice resurfacer. Non-regulatory recommendations seem to be partially effective in abatement against the air quality problems, but additional regulatory measures are needed for full compliance in all arenas.     

Heavy metals in water, sediments, plants and fish of Kali Nadi U.P. (India)

The distribution of heavy metals viz., Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in the water, sediments, plants and fish samples collected from the Kali Nadi (India) have been determined. The studies have shown that there was considerable variation in the concentration of heavy metals from one sampling station to the other which may be due to the variation in the quality of industrial and sewage wastes being added to the river at different places. The orders of the concentration of heavy metals in water, sediments, plants (Eicchornia crassipes) and fish (Heteropnuestes fossilis) were Fe > Zn > Cu > Mn > Cr > Ni > Pb > Co > Cd; Fe > Zn > Mn > Ni > Cr > Co > Cu > Pb > Cd; Fe > Mn > Zn > Cu > Ni > Co > Pb > Cr > Cd and Fe > Zn > Mn > Ni > Pb > Co > Cr > Cu > Cd, respectively.     

Odor-annoyance estimates from roadtraffic combustion exhausts: Calibration with master scaling using pyridine as a reference

The present field study addressed the need for a procedure that provides a defined unit of measurement of perceived annoyance from environmental odors, calibrating the estimates for individual scaling behavior and context effects. In including 25 subjects, the purpose was to demonstrate the applicability of the master-scale procedure with magnitude estimation to perform such a calibration of odor-annoyance estimates for target stimuli such as road-traffic combustion exhausts (13 000 vehicles/d; averaging 47 μg/m³ over the day/night with peaks exceeding 100 μg/m³ of nitrogen dioxide; NO₂). For comparison, calibrated estimates were also obtained for a backyard expected to be considerably less polluted (comparable with 18 μg/m³ of NO₂) and for blank stimuli presented indoors. The data transformation for the calibration procedure with which annoyance is expressed in either master-scale units or pyridine equivalents requires estimates of a reference stimulus for which seven concentrations of pyridine were used. The results provide an illustration of master scaling of odor annoyance, and imply that use of a modulus (standard stimulus with a predefined annoyance magnitude), in contrast to master scaling, is not sufficient for calibration for individual scaling behavior and context effects.     

Concentrations and determinants of outdoor, indoor and personal nitrogen dioxide in pregnant women from two Spanish birth cohorts

Determinants of outdoor, indoor and personal concentrations of nitrogen dioxide (NO₂) were assessed in a subset of pregnant women of the Spanish INMA (Environment and Childhood) Study. Home indoor and outdoor NO₂ concentrations were measured during 48 h with passive samplers for 50 and 58 women from the INMA cohorts of Valencia and Sabadell, respectively. Women from Sabadell also carried personal NO₂ samplers during the same period. Data on time–activity patterns, socio-economic characteristics, and environmental exposures were obtained through questionnaires. Multiple linear regression models were developed to predict NO₂ levels.In Valencia, median outdoor NO₂ levels (42 µg/m³) were higher than median indoor levels (36 µg/m³). In Sabadell, personal NO₂ showed the highest median levels (40 µg/m³), followed by indoor (32 µg/m³) and outdoor (29 µg/m³) levels. Personal exposure to NO₂ correlated best with the indoor NO₂ levels. Temporal and traffic-related variables were significant predictors for outdoor NO₂ levels. Thirty-two percent of the indoor NO₂ variability in the two cohorts was explained by outdoor NO₂ levels and the use of the gas appliances. The model for personal exposure accounted for 59% of the variance in NO₂ levels in Sabadell with four predictor variables (outdoor and indoor NO₂ levels, time spent in outdoor environments and time exposed to a gas cooker). No significant association was found between personal or indoor NO₂ levels and exposure to environmental tobacco smoke (ETS) at home.Personal NO₂ levels were found to be strongly influenced by indoor NO₂ concentrations. The study supports the use of time–activity patterns along with indoor measurements to predict personal exposure to traffic-related air pollution.     

Effect of sewage sludge amendment on soil microbial activity and nutrient mineralization

An incubation experiment was performed to study the effect of sewage sludge on microbial respiration and nutrient mineralization in a sandy soil as an indication of its effects on soil biological properties and nutrient transformation. Sewage sludge was amended with a sandy soil at 0, 25, 50, 150 and 350 g kg⁻¹ fresh weight. An increase in the sludge amendment rate caused an increase in both pH and electrical conductivity (EC). However, pH decreased while EC increased and then decreased along the incubation time. Nevertheless salinity and heavy metal contents of the soil sludge mixture were all within the safety guidelines. Soluble NH₄⁺, NO₃²⁻ and PO₃²⁻ increased after amending the soil with sewage sludge, but increasing the application rate to 350 g kg⁻¹ of sludge decreased the N and P mineralization efficiency and created an adverse effect on nitrification. The daily CO₂ evolution pattern was the same in all treatments that CO₂ evolution increased initially and then decreased till the end of the incubation period. All the treatments had peak CO₂ evolution at day 7, except for the soil amended with 350 g kg⁻¹ of sludge which had peak CO₂ evolution at day 2. Similarly, the percentage of C-mineralization decreased with an increase in sludge amendment rate. The present experiment indicated that an application rate of 50–150 g kg⁻¹ sludge for sandy soil would have the optimal beneficial effect on the soil in terms of microbial activity and nutrient transformation.     

Variability of the sorption of Cs, Zn, Sr, Co, Cd, Ce, Ru, Tc and I at trace concentrations by a forest soil along a transect

The variability of the sorption properties (characterized by the distribution coefficient K_d) of a forest soil for Cs, Zn, Sr, Co, Cd, Ce, Ru, Tc, and I were determined along a transect of 150 m in regular intervals of 3 m. Radioactive tracers were used to ensure trace concentrations of these elements. For comparison, for each soil sample the loss on ignition, as a measure of the soil organic matter content, and the pH were also determined. On average, the K_d values increase in the sequence Tc < I < Ru ≈ Co ≈ Zn ≈ Sr < Cd < Ce < Cs; the spatial variability in the sequence I < Zn ≈ Sr ≈ Co ≈ Cd ≈ Ru ≈ Tc < Cs, and I ≈ Ce < Tc. Correlation analysis revealed that, when moving along the transect, the K_d values for some elements changed in a similar, and for others in a dissimilar pattern. In a few cases a correlation between the pH or the loss on ignition and the K_d values was also present. The spatial structure of the data was examined by semivariograms. For the elements Co, Cd, Zn, and Sr, the K_d values showed an almost periodic behaviour along the transect, which is probably due to periodic changes of some soil properties in a forest with regularly spaced trees.     

Characteristics of PM10, PM2.5, CO2 and CO monitored in interiors and platforms of subway train in Seoul, Korea

This study was performed to investigate the concentration of PM₁₀ and PM_2.5 inside trains and platforms on subway lines 1, 2, 4 and 5 in Seoul, KOREA. PM₁₀, PM_2.5, carbon dioxide (CO₂) and carbon monoxide (CO) were monitored using real-time monitoring instruments in the afternoons (between 13:00 and 16:00). The concentrations of PM₁₀ and PM_2.5 inside trains were significantly higher than those measured on platforms and in ambient air reported by the Korea Ministry of Environment (Korea MOE). This study found that PM₁₀ levels inside subway lines 1, 2 and 4 exceeded the Korea indoor air quality (Korea IAQ) standard of 150 μg/m³. The average percentage that exceeded the PM₁₀ standard was 83.3% on line 1, 37.9% on line 2 and 63.1% on line 4, respectively. PM_2.5 concentration ranged from 77.7 μg/m³ to 158.2 μg/m³, which were found to be much higher than the ambient air PM_2.5 standard promulgated by United States Environmental Protection Agency (US-EPA) (24 h arithmetic mean: 65 μg/m³). The reason for interior PM₁₀ and PM_2.5 being higher than those on platforms is due to subway trains in Korea not having mechanical ventilation systems to supply fresh air inside the train. This assumption was supported by the CO₂ concentration results monitored in tube of subway that ranged from 1153 ppm to 3377 ppm. The percentage of PM_2.5 in PM₁₀ was 86.2% on platforms, 81.7% inside trains, 80.2% underground and 90.2% at ground track. These results indicated that fine particles (PM_2.5) accounted for most of PM₁₀ and polluted subway air. GLM statistical analysis indicated that two factors related to monitoring locations (underground and ground or inside trains and on platforms) significantly influence PM₁₀ (p < 0.001, R² = 0.230) and PM_2.5 concentrations (p < 0.001, R² = 0.172). Correlation analysis indicated that PM₁₀, PM_2.5, CO₂ and CO were significantly correlated at p < 0.01 although correlation coefficients were different. The highest coefficient was 0.884 for the relationship between PM₁₀ and PM_2.5.     

Investigation of equilibria involving carbon dioxide, carbonates and water

Several laboratory techniques are reviewed in this paper, which yield reliable data on carbonate equilibria. In particular, it is emphasized that pco₂ variation is necessary in order to potentiometrically distinguish between hydrogen carbonato and caronato complexes. The essential features of reliable solubility measurements of carbonate phases are summarized. A neglected autoclave technque is described which has been successfully applied for the synthesis of pure, crystalline, MnCO₃, FeCO₃ and CoCO₃. Details of a continuously operating solubility cell for experiments at 5–95°C are also given.Solubilty constants for different ionic media are related by the respective equilibrium vapor pressure of H₂O and the standard potentials of the respective metal electrodes. It is shown that a thermodynamic cycle can be exploited for an indirect determination of the Fe²⁺/Fe standard potential. The application of solubility data is discussed using the pco₂ control in the recent geologic past an an example.     

Using sequential extraction techniques to assess the partitioning of plutonium and neptunium-237 from multiple sources in sediments from the Ob River (Siberia)

Sequential extraction techniques have been developed to assess partitioning of anthropogenic radionuclides (²⁴⁰Pu, ²³⁹Pu, and ²³⁷Np), originating from a variety of sources, as identified by using bulk sediment isotopic composition. Sediments were leached sequentially with a series of six chemical treatments designed to approximate different environmental processes that may occur or to selectively extract trace metals contained in different solid phases of the sediments (i.e., exchangeable, reducible, carbonate, organic, acid leachable, and refractory). Results indicate the majority of Pu and Np is similarly distributed within many of the extracted fractions, with the largest percentage (66–97%) of both elements being observed in sediments treated with buffered citrate dithionite (CDB), which targets easily reduced constituents such as Mn and Fe hydrous oxides. While these results do indicate an association of Pu and Np with redox sensitive elements, the environmental implications are unclear given that the CDB treatment is more extreme than naturally occurring conditions. Minor amounts of Np partition differently from Pu in sediments. The NH₄-acetate treatment, which is designed to liberate trace metals that are loosely adsorbed onto the surfaces of sedimentary materials such as hydrated iron oxides and humic substances, or present at exchangeable sites in clay minerals, mobilized ∼12% of the total Np while Pu levels were below detection. The H₂O₂ treatment, which is designed to liberate trace metals bound to organic matter, mobilized ∼8 and ∼1% of Np and Pu, respectively. These results indicate that a minor portion of the total Np may be affected by environmental conditions that have little or no effect on Pu. Between 7 and 24% of the Pu was observed in treatments designed to liberate Pu and Np that are tightly bound to lithogenic phases or refractory silicates. The ²⁴⁰Pu/²³⁹Pu observed in accessible and refractory fractions ranged between 0.11 and 0.18. With the exception of one sample, the ²⁴⁰Pu/²³⁹Pu isotope ratios measured in the refractory fractions are essentially identical having a mean ratio value of 0.123 ± 0.001 (1σ). The ²⁴⁰Pu/²³⁹Pu ratios provide isotopic evidence that suggests a portion of non-fallout contamination has a refractory nature. The presence of similarly low ²⁴⁰Pu/²³⁹Pu ratios in refractory fractions of sediments from the Ob and Irtysh Rivers suggests the existence of a source of refractory Pu which is consistent with refractory “hot particles” derived from surface tests at the Semipalitinsk test site.     

Behavior and analysis of Cesium adsorption on montmorillonite mineral

The adsorption of Cs by montmorillonite and the effects of experimental conditions on adsorption were investigated by using ¹³⁴Cs as a radioactive tracer. Additionally, the Cs-adsorbed and the modified montmorillonite were analyzed by X-ray Diffractometer System (XRD) and Scanning Electron Microscopy (SEM). The results showed that the adsorption of Cs by montmorillonite was efficient in the initial concentration (C₀) of 30 μg/L Cs nitrate solution with 20 g/L montmorillonite at room temperature. In this condition, more than 98% Cs⁺ ions could be adsorbed at pH 8. The adsorption equilibrium was achieved within 5 min and the relationship between the concentration of Cs⁺ in aqueous solutions and adsorption capacities of Cs⁺ can be described by the Langmuir adsorption isotherm. The adsorption rate would decrease when temperature increase from 0 °C to 50 °C or in presence of coexistent K⁺, Na⁺ and Ca²⁺, while modification by (NH₄)₂SO₄, [Ag(NH₃)₂]⁺, [Cu(NH₃)₄]²⁺ or 450 °C could improve the adsorption abilities of montmorillonite for Cs⁺. However, more than 89% of adsorbed Cs⁺ on montmorillonite could be desorbed by 2 mol/L HNO₃ solutions. The XRD and SEM analysis further showed that the structure of the Cs-adsorbed or modified montmorillonite were different from that of the original one.     

Biologically available trace metals in Mytilus edulis from the coast of Northeast England

The concentrations of Fe, Mn, Zn, Cr, Cu, Pb, Ni, Cd, and Ag were determined in soft tissue and shell material of mussel Mytilus edulis collected in the winter season from five coastal sites in the northeast of England. The trace metal levels observed were significantly high, particularly at locations affected by past coal mining activities (Blackhall) and present industrial sources (Middleton). The mussels from the chosen control site (Holy Island), a shellfish-designated area, were particularly enriched in Cu and Ag. The metal pollution index for the Bran Sands site, a heavily industrialised area on the Tees Estuary, was relatively low. At four sites out of five, the levels of Fe and Cu were negatively correlated with mussel size. No significant correlation with size was found for the other metals. With few exceptions, the elements Fe, Zn, and Mn accumulated preferentially in the soft tissue, whereas Pb, Cd, Cr, Ag, and Ni were more abundant in the hard part of the mussels. The Ag values in shell material were remarkably similar (about 6 mg kg⁻¹ – 7 mg kg⁻¹, dry wt) at all sites studied. In general, the data show that the mussels from the coastline studied accumulate metal concentrations comparable to or higher than the most contaminated sites reported in the literature.     

Size dependent cytotoxicity of fly ash particles

Fly ash samples were collected from the electrostatic precipitator of a coal-fired power plant in Hong Kong. The particles of the respirable range (smaller than 10 μm) were divided into 4 groups according to their particle size (mass median aerodynamic diameters). The surface morphology and the metal contents (Fe, Mn, Al and Zn) of fly ash particles were examined by a scanning electron microscope and an inductively coupled plasma spectrophotometer, respectively. The particles were very heterogenous in size and shape as well as the concentration of metals. The cytotoxicity of these four groups of fly ash particles was evaluated using an in vitro rat alveolar macrophages culture assay. The viability of alveolar macrophages was lower when incubated with smaller size particles. This relationship was also reflected by the damage of the surface morphology of the cells and the release of cytoplasmic (lactate dehydrogenase) and lysosomal (acid phosphatase and β-glucuronidase) marker enzymes into the culture media.     

Environmental monitoring using surface water, river sediments, and vegetation: A case study in the Famatina Range, La Rioja, NW Argentina

This work discusses trace elements studied beneath the semiarid endorheic region of the Famatina Range (La Rioja, NW Argentina). The results obtained in 27 control sites allow the determination of five distinct geochemical patterns in the Famatina Range. Pattern 1 reflects the composition of underlying Paleozoic and Tertiary bedrock (background level: water pH, 7.5–9; specific conductance, 0.2–0.7 mS cm⁻¹), which is influenced by mineralization. Pattern 2 exhibits water pH, 6; specific conductance, 0.7 mS cm⁻¹; high contents of Cu, Cd, Rb, Zn, Sn, and Be in waters; and high contents of Cu, Cd, Zn, Pb, Cr, Sb, Ag, Be, Co, Ni, Bi, Rare Earth Elements (REE), Li, Ba, Cs, and Sr in sediments. Pattern 3 exhibits water pH, 3–4; specific conductance, 1.0 mS cm⁻¹; high contents of Pb, Co, Be, Au, As, Cr, Hg, Th, Ba, Cs, Rb, Sb, Y, Zr, REE, and Hf in waters; high contents of Cd, Zn, Mo, and As in sediments). Pattern 3 is also modified by the input of elements from a source external to the Famatina Range. Pattern 4 exhibits water pH, 7–8; specific conductance, 1.5–2.3 mS cm⁻¹; high contents of B, Li, Ba, Sr, and Zn in waters; high contents of Li, Cr, Sr, Ni, and Cs in sediments. Finally, Pattern 5 is developed on the red sandstones from De la Cuesta Formation (water pH, 8; specific conductance, 2.5–5.0 mS cm⁻¹; high contents of Sr, Mo, U, B, Li, Rb, and Hf in waters; high contents of B, Ba, Cs, Li, and Rb in sediments). The mobility of above-mentioned elements is mainly related to water pH changes and evaporation processes.     

Carbon isotopes and sulphur contents as indicators of atmospheric pollution from burning fossil fuels

This paper summarized the study carried out in Krakow, Poland in 1975-76 on the estimated local air pollution as measured by carbon isotopes and total sulphur measurement in plants. Good correlation was found between δ¹⁴C value and the total sulphur (measured by radionuclide excited X-ray fluorescence) in beech leaves collected in the late summer, indicating the common source of both pollutants. Sampling and measurement of σ¹³C in atmospheric CO₂ has shown that σ³C can be used as a pollution indicator only in the winter period when no fluctuations exist ddue to plant respiration. A method of CO₂ sampling using molecular sieve proved to be feasible for instantaneous sampling with no isotope fractionation. The highest pollution by fossil CO₂ was measured in winter (12.8% excess. During spring and summer the average contribution of fossil CO₂ was 4.5 to 5.6%.     

Adsorption of thorium from aqueous solutions by perlite

The use of expanded perlite for the adsorption of thorium from aqueous solution by batch technique is presented. The effects of particle size, pH of the solution, initial thorium concentration, shaking time, V/m ratio and temperature were determined. It was found that the adsorption capacity increases by the increase in the pH of the suspensions. The rate of thorium adsorption on expanded perlite was observed to be fast in the first hour of the reaction time. Adsorption isotherms were expressed by Langmuir and Freundlich adsorption models and the adsorption experiments conducted at 30 ± 1 °C showed that the adsorption isotherms correlated well with the Langmuir model. From the adsorption data, thermodynamic parameters such as ΔG^o, ΔH^o and ΔS^o were calculated as a function of temperature.