Showing papers in "Water Air and Soil Pollution in 1990"

Defluoridation of water by adsorption on fly ash

Abstract: The ability of fly ash to remove fluoride from water and wastewaters has been studied at different concentrations, times, temperatures and pH of the solution. The rate constants of adsorption, intraparticle transport, mass transfer coefficients and thermodynamic parameters have been calculated at 30, 40, and 50 °C. The empirical model has been tested at various concentration for the present system. The removal of fluoride is favorable at low concentration, high temperature and acidic pH.

Regional estimates of acid mine drainage impact on streams in the mid-atlantic and Southeastern United States

Abstract: The U.S. Environmental Protection Agency conducted the National Stream Survey (NSS) to provide unbiased estimates of the numbers and distribution of acidic and low acid neutralizing capacity streams in the Mid-Atlantic and Southeastern United States. The NSS employed a probability sample of 500 stream reaches to represent a target population of 64,300 stream reaches in the study area. All NSS samples were screened for acid mine drainage (AMD) influences, and population estimates of the regional extent of AMD impacts were made. Almost 10% of the stream reaches in the Northern Appalachians subregion were acidic during spring baseflow due to AMD. In the entire NSS, an estimated 4590 km (± 1670) of streams (2% of the total NSS length) were acidic due to AMD and another 5780 km (± 2090) of streams were strongly impacted, but not acidic. In subregions of the NSS with observed mine drainage effects, roughly the same number of streams were acidic during spring baseflow due to AMD as due to acidic deposition. The population estimates of mine drainage impact made in the NSS were similar to estimates made in previous surveys that attempted to census all of the streams in coal producing areas. These results demonstrate that a statistically based stream survey is a useful tool for evaluating regional water quality.

On the use of mosses (Hylocomium splendens and Pleurozium schreberi) for estimating atmospheric trace metal deposition

Abstract: Concentrations of trace metals in mosses Hylocomium splendens (Hs) and Pleurozium schreberi (Ps) are compared along with wet deposition at 8 sites in Sweden. Cd, Mn, Zn and Cr concentrations were similar in both mosses, while Cu, Fe, Pb, Ni and V levels were 14 to 24% higher in Hs than in Ps. The comparison to wet deposition estimates indicates that concentrations in mosses are also influenced by other factors than the adsorption of precipitation. No correlation was observed between the wet deposition of Mn, Cr and Ni and moss concentrations.

Use of sequential extraction to evaluate the heavy metals in mining wastes

Abstract: Lead-zinc mine tailings from the ‘old lead-belt’ in Missouri were chemically characterized using total chemical analysis and sequential extraction. These tailings have been considered as an inert and safe material for years. However, the levels of heavy metals in these tailings were found elevated with Pb values as high as 5000 ppm. The sequential extraction results indicated that the Pb was primarily found in the residual fraction and probably is in the PbS form. Some Pb was found in the oxide fraction. Cu, Zn, and Cd were found in several different fractions, but primarily in the residual fraction. Some Cu was found in the organic fraction. The Zn showed a wide variation between samples with high levels in the carbonate, oxide and residual fractions. Very little Pb, Cd, Cu, and Zn was leached by water. The heavy metals in these tailings do appear to be in the more inert forms and should not be readily available to the environment unless there is an interaction of the tailings with acids, microorganisms or chelating materials. The breathing and ingestion of this material may provide such an environment for such interactions and these materials should still be considered dangerous and managed properly.

Specific sorption of antimony (III) by the hydrous oxides of Mn, Fe, and Al

Abstract: The hydrous oxides of Mn, Fe, and Al avidly sorbed Sb from μM Sb(OH), solutions, with uptake levelling off as initial Sb concentration increased. Capacity values decreased along the sequence MnOOH > Al(OH)3 > FeOOH. The amount sorbed by each substrate decreased gradually at pH values > 6. Addition of 0.4M CH3COONa to the aqueous phase (to minimise retention of weakly bound Sb) had little effect on MnOOH uptake capacity (∼160 mmol, kg−1 at pH < 7) but retention dropped rapidly at higher pH. With the other two substrates (pH 6–7) the calculated capacity values for specific Sb sorption were ∼ 45 mmol kg−1 FeOOH and ∼ 33 mmol kg− Al(OH)3; about a third of the total capacity values. On these substrates specific Sb sorption tended to peak in the pH 7 to 8 region. The pH response pattern was modified using Sb tartrate sorbate solutions. Factors influencing Sb sorption included substrate surface charge, chemical form of Sb and surface interactions. Formation of a sparingly soluble metal coating was indicated by the uptake plateaus observed when increasing amounts of solid were added to Sb solutions containing acetate.

The PAH and organic content of sediment particle size fractions

Abstract: The relationship of nine Polycyclic Aromatic hydrocarbons (PAH) with organic matter present in various river sediment size fractions, from 63 μm to 1.0 to 2.0 mm, has been investigated. It is suggested that the PAH and organic matter content have bimodal distributions through the sediment size fractions which may be explained by the presence of two types of organic material in the sediment. Maxima in both factors are found in the two largest and the smallest size fractions. A positive linear relationship beween PAH concentration and organic matter has been demonstrated and the slope of this relationship has been used to identify sites where PAH pollution is generally high. The relative proportions of each PAH compound in the sediment remains relatively constant regardless of temporal and spatial differences in total PAH concentration and organic matter content and certain PAH compounds may be grouped together depending on their association with organic matter. Differing PAH compound availabilities, competition for adsorption sites and the reactivity of PAH compounds may all result in the unchanging sediment PAH profile seen in each size fraction. The organic material present in the sediment may have a similar affinity for all PAH's in a particular group.

Sources of petroleum hydrocarbons in urban runoff

Abstract: In an effort to provide a better understanding of the sources of petroleum hydrocarbons in urban runoff, petroleum products as well as probable source materials were analyzed for hydrocarbons and trace metals and then compared to urban runoff samples from four different land use areas. The petroleum products considered were No. 2 and No. 6 fuel oils, used and virgin crankcase oils, and gasoline. Source materials included street dust, roadside soil, roadside vegetation, and atmospheric fallout; and the land use categories were commercial, residential, interstate highway, and industrial areas. The samples were compared on the basis of hydrocarbon (saturated and aromatic) and trace metal (Cd, Pb, Mn, Cu, Fe, Zn) loadings and distributions. Results indicated that the hydrocarbon content in runoff at all four land use sites originated primarily from used crankcase oil, with a small amount of No. 2 fuel oil detected at the industrial site. Only a small portion of the crankcase oil component came from the sources surveyed, and the majority of this oil probably came from: (1) oil drops within the driving lanes on the road surfaces or deposits in parking areas, and/or (2) direct dumping of waste crankcase oil down storm drains.

Buffer capacity and lead retention in some clay materials.

Abstract: The link between buffer capacity and the ability of clays to retain Pb in interactions between Pb contaminant leachate and the clays, has been studied, using a natural clay from Quebec and laboratory-prepared clays (kaolinite, illite, and smectite). The retention of Pb in the clay suspensions as they received increasing amounts of acid was investigated, and the results examined in terms of the buffer capacity of the clays. As the clays receive increasing amounts of acid (e.g. akin to addition of acid leachate), high amounts of Pb can be retained if the buffer capacity prevents the pH from dropping to values where precipitation mechanisms are not operative. The high carbonate content in the illite gave it a higher buffer capacity than the smectite and natural clay, and permitted it to retain high amounts of Ph. High Pb uptake by the clays can affect the buffer capacity and the Pb retention capacity.

Effect of solid-phase speciation on metal mobility and phytoavailability in sludge-amended soil

Abstract: Sequential extraction was utilized for partitioning Cd, Cr, Ni, and Zn, in soil and sludge samples into five operationally-defined fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. The highest amounts of Cd, Ni, and Zn, expressed as per cent of the total, were found in the Fe-Mn oxide fraction of the sewage sludge. Chromium was significantly associated with the organic fraction of the sludge. The residue was the most abundant fraction for all metals studied in the untreated soil, and for Cd and Ni in the sludge-treated soil. The concentration of exchangeable Cd and Cr was relatively low in the untreated soil and did not change much after sludge application, whereas the concentrations of exchangeable Zn increased about 50 times and the concentrations of exchangeable Ni doubled in the sludge-treated soil. The lysimetric experiment revealed an increase in Zn and Ni uptake by ryegrass and in the percentage of metals leached from the soil profile after massive sludge application. In contrast only negligible changes were observed for Cd and Cr. The assumption that mobility and biological availability are related to metal speciation was confirmed by the agreement between the distribution pattern of Cd, Cr, Ni and Zn in the soils, the uptake of the metals by plants and their capacity for leaching out from the soils.

Some considerations on the sorption and desorption phenomena of iodide and iodate on soil

Abstract: Radiotracer experiments on the sorption of I− (iodide) and IO inf 3 p− (iodate) from water by soils such as field soil, rice paddy soil and sandy soil, as well as by some soil components, have been carried out with special reference to the effects of heating and gamma-irradiating the soil. Desorption phenomena of I from soil to various solutions were also studied. The sorption of I− by soil was markedly reduced through treatments of air-drying and heating the soil prior to its equilibration with water. The results indicated that I− sorption was by the soil fraction which was unstable at about 150 °C, while IO inf 3 p− sorption was by the soil fraction which was relatively stable to heating. Gamma-irradiation at 27 kGy affected the sorption to a smaller extent than heating at 150 °C. A very high sorption (or soil-water distribution coefficient, Kd) was found in untreated field soil (andosol) with a low organic C (humus) content, while the sorption by sandy soil was considerably smaller than the other soils. Neither I− or IO inf 3 p− were well sorbed by clay minerals, Al2O3 and quartz sand, while the sorption by Fe2O3 was IO inf 3 p− were desorbed by 1N NaOH solution. By acidifying this solution, only a part of the desorbed I was re-precipitated with humic acid. The desorption by solutions containing K2SO3 or KI was also high, while that by solutions containing HCI, CH3COONH4 or chemical fertilizer was considerably lower. These findings suggested the possibility that I was not directly associated with humic acid itself.

Filamentous fungi as metal biosorbents: A review

Abstract: Common filamentous fungi (e.g. Penicillium spp, Rhizopus spp) serve as sources of highly effective heavy metal biosorbents. Derivatives of fungal biomass range from purified cell wall fractions to whole, heat killed mycelium otherwise unmodified. Limited trials suggest a moderate degree of regenerability. When compared with commercial ion-exchange resins, carbons and metal oxides, fungal derivatives generally perform well. Fungal systems offer considerable versatility with respect to metals taken up and bound including the cations Fe, Ni, Cu, Zn, Ag, Cd, La, Pb, Th, and U as well as Cr and Mo anions. Versatility also extends to physico-chemical conditions such as pH and heat tolerance. A deterrent to the application of these materials to waste water management has been a lack of standardized conditions along with the inability to make interspecies comparisons. However, potentials for use of filamentous fungi as biosorbents and their tailoring by genetic techniques to meet specific needs, recommend them for further research and development.

Use of wollastonite in the removal of Ni(II) from aqueous solutions

Abstract: The ability of wollastonite to adsorb Ni (II) from water has been carried out. A removal of 92% of Ni (II) with 20 g L−1 of adsorbent was observed at 50 mg L−1 adsorbate concentration, 6.5 pH and 30 °C. The process follows a first order rate kinetics with diffusion controlled nature and the data fits the Langmuir adsorption isotherm. Removal of Ni increases from 10 to 92% with the rise of pH from 3.0 to 8.0 and thereafter it remains almost unchanged. This change has been explained on the basis of aqueous-complex formation and the subsequent acid base dissociation at the solid-solution interface.

Lead, zinc, cadmium and fluoride in small mammals from contaminated grassland established on fluorspar tailings

Abstract: The total body concentrations of Pb, Cd, and fluoride were higher at the contaminated grassland site established on fluorspar tailings compared to an uncontaminated control site for all three species of small mammal, Apodemus sylvaticus, Microtus agrestis and Sorex araneus. Zn was also higher in M. agrestis and S. araneus but in A. sylvaticus it significantly decreased and, overall, there was good evidence of homeostatic control of Zn in all three species even at the high dietary intakes at the tailings dam. Accumulation in kidney, liver and bone(femur) showed the expected pattern with Pb and fluoride highest in bone and Cd in the kidney for both the control and the contaminated sites. The only exception was S. araneus at the contaminated site were Cd was highest in the liver rather than the kidney. The accumulation of Pb, Cd and fluoride at the contaminated site was in the decreasing species order S. araneus > M. agrestis > A. sylvaticus in terms of total body concentration or target organ concentration. This order probably reflected the decreasing dietary intake rates of the three species although physiological interspecific differences may be of significance. For example, S. araneus showed considerable capability for bioconcentrating Cd to much higher total body than dietary concentrations at the high dietary intake rates at the contaminated site.

Comparative seed germination tests using ten plant species for toxicity assessment of a metal engraving effluent sample

Abstract: An effluent sample was collected from the acid bath of a metal engraving plant where the sample had been pretreated with lime to pH 10.6. The sample was adjusted to pH 7.37 (and in a second test to 7.25) and diluted to a series of solutions using hard, standard water. The seed germination thod was employed to test the phytotoxicity of the sample to ten plant species. The experimental results of this study compared to previous studies indicated that cabbage, carrot, Japanese millet, oat, and wheat lost some viability during storage. The germination rates of these species fell below 85% in this study, although the rates of cabbage, Japanese millet, and wheat were above 85% in the previous studies. Of the remaining species with adequate germination rates, cucumber and white proso millet were relatively insensitive to the effluent toxicity. The promising candidates for toxicity testing were rice, lettuce, and tomato, based on long shelf life, high germination rate and sensitivity to toxicity.

Seasonal variability in the Mercury speciation of Onondaga Lake (New York)

Abstract: Dissolved and particulate Hg speciation was determined on four occasions in the Spring to Fall interval of 1989, at three depths of the water column of Onondaga Lake, New York; an urban system in which the sediments and fish flesh are contaminated with Hg. Species determined included total Hg (Hgt), reactive (‘ionic’) Hg (Hgi), monomethylmercury (CH3HgX), elemental Hg (Hg°) and dimethylmercury (CH3)2Hg). Onondaga Lake was found to contain very high levels of Hgt (2 to 25 ng L−1 Hg), Hgj (0.5 to 10 ng L−1 Hg), and CH3HgX (0.3 to 7 ng L−1 Hg), which generally increased with depth in the lake. These concentrations represent a significant level of contamination, based upon comparisons with other polluted and pristine sites. Elemental Hg levels were typically about 0.05 ng L−1 and (CH3)2Hg was near the limits of detection (−0.001 ng) L−1 in most samples. The greatest CH3HgX concentrations in the hypolimnion, as well as the largest gradients of both CH3HgX and (Hgt), were observed upon the first onset of stratification, in early summer. These concentrations did not become more pronounced, however, as stratification and H2S levels in the hypolimnion increased throughout the summer. The very low concentrations of (CH3)2Hg in these MeHg and sulfide-rich waters calls into question the belief that CH3HgX and H2S will react to yield volatile dimethyl-mercury, which can then escape to the atmosphere by diffusion. Mercury speciation was highly dynamic, indicating active cycling within the lake, and an apparent sensitivity to changes in attendant Iimnological conditions that track the stratification cycle.

Effects of liming on carbon and nitrogen mineralization in coniferous forests

Abstract: A temporary decline in tree growth has often been observed after liming in coniferous forests poor in N but seldom in forests rich in N. To test the hypothesis that the decline was caused by decreases in N supply, C and N mineralization were estimated in incubated soil: (1) after liming in the laboratory, and (2) after earlier liming in the field. Liming increased the C mineralization rate in needle litter, mor humus and 0 to 5 cm mineral soil for a period of 40 to 100 days at 15°C. After that period, liming had no effect on the CO2 evolution rate in materials poor in N (C:N ratios 30 to 62) but increased the CO2 evolution rate in materials rich in N (C:N ratios 24 to 28). When liming induced nitrification, the evolution rate was reduced. Liming resulted in lower net N mineralization rate in needle litter and mor humus. The reduction was more pronounced when NH4 + was the only inorganic form than when NO3 ‒ was the predominant form. The reason is probably that chemical fixation of NH3 and amino compounds increases with increasing pH. Because of the fixation, the incubation technique most likely underestimated the mineralized N available to the roots. Taking this underestimation into consideration, liming initially reduced the N release in the litter layer. In the other soil layers, liming increased the N release in soils rich in N and had only small effects in soils poor in N. For the total N supply to the roots in the litter, humus and 0 to 5 cm mineral soil layers, liming caused a slight reduction in soils poor in N and a slight increase in soils rich in N. Data on tree growth corresponded with these results. The hypotheses that tree growth depressions can be caused by reduced N supply after liming and that tree growth increases can be caused by increased N supply after liming thus seem reasonable.

Effects of nitrogen-containing fertilizers on solubility and plant uptake of cadmium

Abstract: In a pot experiment, three N-fertilizers, differing in NO−3 and NH+4; content, were compared in terms of their effects on the extractability of soil Cd in 1M ammonium acetate at pH 7 and on the uptake of native and added Cd by winter rape (Brassica napus L. var. oleifera Metzger). In another similar experiment the Cd-availability in soils receiving NPK-fertilizer applied in a concentrated, granulated form was compared to that in soils receiving a uniform application of dissolved NPK-fertilizer. Both loamy sand and clay soils were used. With the N-fertilizers levels of extractable soil Cd and plant Cd-contents were lowest in the nitrate of lime treatment, highest in the ammonium sulphate treatment and intermediate in the nitro-chalk treatment. The addition of 1 mg kg−1 DW Cd to the soil increased Cd-levels but did not change the response pattern. There was a strong association between the effects of the various fertilizers on Cd availability and their effects on soil pH: the stronger the acidifying effect the higher the Cd availability. When applied at a low dose, granular NPK was more effective than dissolved NPK at enhancing plant uptake of Cd from both soils, but this was not the case when applied at a higher dose to the sand. The two forms of NPK differed little in their effect on extractable soil Cd. Plant uptake of Cd was greater from soils receiving granular NPK with a high Cd-content than from those receiving granular NPK low in Cd. In both experiments extractable Cd was taken up to a greater extent from the sand than from the clay. An increase in fertilizer dose generally resulted in an increase in levels of soil-Cd and in Cd concentrations in the plants.

Interrelationships between mercury levels in yearling yellow perch, fish condition and water quality

Abstract: Yearling yellow perch were collected from sixteen Muskoka-Haliburton lakes to determine interrelationships between water quality, Hg residues in fish and fish condition. The lakes studied were Precambrian shield lakes with a pH range of 5.6 to 7.3 and total inflection point alkalinities of 0.4 to 16.0 mg L−1. Mercury residues in yellow perch ranged from 31 to 233 ng g−1 and were inversely correlated (p < 0.001; r = 0.84) with lakewater pH. Stepwise linear regression analyses selected lakewater pH as the only significant parameter associated with Hg accumulations. Alkalinities, sulphate, Ca and dissolved organic carbon (DOC) were not selected as significant. Likewise, lakewater pH and Hg residues in yellow perch were inversely (p < 0.001) correlated with fish condition. Lakewater pH, accounted for 74% and Hg in fish a further 11% of the variability in fish condition. Terrestrial drainage size/lake volume ratios were also correlated (p < 0.05; r = 0.78) with Hg accumulations in perch from a subset of nine headwater lakes. No temporal trends in Hg residues were evident in yellow perch over a 9 yr interval (1978–1987).

Effects of Ammonia, Ammonium Sulphate and Sulphur Dioxide on the Frost Sensitivity of Scots Pine ( Pinus Sylvestris L.)

Abstract: The deterioration of forest vitality has been at least partly attributed to air pollution. Especially NH3, originating from intensive livestock farming and locally deposited in high concentrations, may contribute to forest decline in The Netherlands. Therefore, the effect of NH3 and SO2 fumigations on cold stress and water stress of Pinus svlvestris were examined. P. sylvestris trees (3 yr old) were exposed to ambient air supplemented with several NH3 concentrations, with SO2 or a combination of NH3 and SO2.Tops of branches were then exposed to various subzero temperatures and the effect of air pollution on frost damage was examined. Neither ambient air, NH3 or SO2 significantly influenced from sensitivity at −4 or −7°C. Following freezing treatments of −10°C, the influence of NH3 and SO2 became apparent. The effect of the combination of these pollutants is synergistic. Exposure to NH3 alone followed by freezing temperatures lower than −10°C resulted in more severe frost damage in early autumn and spring than in the winter. It also increased the susceptibility of P. sylvestris to water stress. A greater loss of water was observed in NH3-fumigated needles following drought stress, suggesting increased cuticular transpiration. Bud burst and subsequent shoot growth was also strongly reduced by NH3 fumigations.

Mercury in fish in Swedish lakes ? Linkages to domestic and European sources of emission

Abstract: The work deals primarily with data from 894 Swedish lakes. The following parameters are discussed: Hg- and Se-concentrations and Hg-quantity in the mor layer reflecting the atmospheric deposition of Hg and Se-, Hg- and S-emissions deposition from Swedish and continental sources, precipitation, Hg in pike, lake area, lake mean depth, pH, color, alkalinity, hardness, S and chloride in lake water. The results are focused on geographical variations and statistical correlations for the Hg-content in 1-kg pike (=FHg), and on computer simulations to get insights and data on the linkages between various historical Hg-emissions and FHg. Selected results: Increased FHg-values may be attributed to atmospheric emissions of Hg and to acid rain. Southern Sweden is significantly influenced by continental Hg-emissions. East Germany, Great Britain, West Germany and Poland seem to have contributed with the largest foreign Hg-amounts in the Swedish mor layer and, at the end, to increased Hg-concentrations in Swedish fish. We have calculated that there are about 10 300 Swedish lakes with FHg > 1 mg Hg kg−1 (= the Swedish blacklisting limit). What would happen with FHg if atmospheric depositions of Hg and S were significantly reduced? Reductions of S would be beneficial primarily for lakes in S. Sweden. About 50% of the elevated levels of Hg in Swedish pike in the 1980s may be linked to Swedish Hg-emissions during the last 100 yr, about 10 to 15% could be attributed to foreign Hg-emissions and 35 to 40% to acid rain. There is a long lag phase between emission reduction and reduction of FHg. The known, major Swedish emissions of Hg have already been significantly reduced, but new point sources of Hg have appeared. There has been a significant change in the character of the Hg-emissions during the last decades. High FHg-values in fish in Swedish lakes will be a major environmental problem for decades to come.

The effects of forest liming on fertilization on fine-root growth

Abstract: Results are reported from the investigations of fine-root development in Norway spruce and Scots pine stands in South and Central Sweden, subjected to different liming and fertilization regimes. The growth responses of the fine roots to varying mineral nutrient regimes seem to be dependent on the tree species, the age of the tree population and soil conditions. Nitrogen fertilization in some of the investigated stands had negative effects on the development of fine roots, resulting in a reduction in the amount of fine roots to about 50% of that in the control. However, negative effects were not consistent in all stands, positive growth responses were also obtained. In these stands, the amount of fine roots was increased by 2 to 3 times. Liming in combination with fertilization resulted in a strong decrease in the amount of fine roots to about 30% of that in the control in some of the investigated stands. Liming in high doses is expected to produce a persistent increase in pH (H2O) and base saturation in the soil. However, results from the present study suggest that liming may have a negative effect on the development of tree fine roots, particularly in areas with a high N deposition. The application of crushed dolomite had less negative effects on fine root development than crushed calcitric lime and different types of residue products, such as wood and peat ashes.

Heavy metal deposition in polish national parks — Changes during ten years

Abstract: Biomonitoring studies of heavy metals (Cd, Cr, Ni, Pb, Cu, Zn, Fe, Mn) and other elements (Mg, Na, K, Ca) were done in all Polish national parks in 1976 and again in 1986. Two moss species (Pleurozium schreberi and Hylocomium splendens) were used to estimate the concentrations of these elements, mainly derived from atmospheric deposition. Significant differences were found between particular parks in the concentration of heavy metals and nutrients, the lowest concentration being recorded in the mosses from the parks in northern and eastern Poland, the higher ones in the southern parks. Significant differences in the content of elements were also observed between the green and brown parts of mosses, between moss species and between years of sampling.

A field study on factors influencing Cd levels in soils and in grain of oats and winter wheat

Abstract: The influence of selected factors on Cd levels in soils and in grain of oats and winter wheat was investigated. Soil and grain were sampled at sites randomly distributed over Sweden. Organic soils generally had higher Cd contents and lower pH levels than mineral soils, and plants growing in organic soils tended to have higher Cd contents than plants growing in mineral soils. In mineral soils the amount of soil Cd extractable in 2M HNO3 was positively correlated with the pH and the contents of organic matter and clay. The studied variable best correlated with the Cd content of oat grain grown on mineral soils was the pH (negative correlation). Soil contents of organic matter, clay, HNO3-extractable Cd and Zn were also found to be significantly related to the Cd content in a stepwise regression analysis. In winter wheat grain, Cd content was best correlated with the HNO3-extractable Cd (positive correlation). Additional significant factors were pH, grain yield and contents of organic matter, clay and HNO3-extractable Zn. In winter wheat the presence of Zn reduced Cd uptake, and vice versa; no such mutually antagonistic relationship was apparent in oats. In oats, but not in wheat, it was possible to predict most of the differences in grain Cd content, caused by the factors described above, based on the variation in CaCl2-extractable soil Cd. Analysis of samples from field trials indicated that there were differences in Cd content between varieties of both crops. Variation in factors described generally explained most of the differences in soil- and grain Cd levels between regions.

Effects of road deicing salt on chloride levels in four adirondack streams

Abstract: A 2 yr study was conducted in 1987 and 1988 to determine the effects of road salt run-off from New York State highway 28N on chloride levels in four tributary streams to Rich Lake, located in the central Adirondack Mountains of New York. All four study streams exhibited significant increases in chloride concentrations at sampling stations located 50 and 100 m downstream from the highway. Chloride concentrations in downstream samples were as much as 31 times higher than comparative upstream samples. Elevated chloride levels continued throughout the 6 mo period following the termination of winter salt applications. A water chemistry profile developed for Rich Lake revealed a slight increase in chloride content at lower depths.

The influences of temperature on aqueous aluminium chemistry

Abstract: Temperature affects the solubility of Al(OH)3(s), the solubility product formed, the hydrolysis and molecular weight distribution of aqueous Al species as well as the pH of the solutions. In the present work, identical solutions of inorganic Al (400, 600, and 800 μg Al L−1) were stored for 1 mo at either 2 or 25 °C. In the solutions stored at 25 °C pH varied from 4.83 to 5.07, while in the corresponding solutions stored at 2 °C pH varied from 5.64 to 5.78. In spite of the relatively low pH at 25 °C, significant amounts of high molecular weight Al species were precipitated from the solution and the solubility product (log*K s ) of (Al(OH)3) (s) was low (9.0). Substantial amounts of high molecular weight Al species were also formed at 2 °C, but the majority was present as colloids in the solution. The solubility product (converted from 2 into 25 °C) was 10.2, reflecting a solubility product of an amorphous (Al(OH)3)(s) phase. The different physico-chemical forms of Al present at 2 and 25 °C should have relevance for water/soil chemistry modeling.

Laboratory mesocosm studies of Fe, Al, Mn, Ca, and Mg dynamics in wetlands exposed to synthetic acid coal mine drainage.

Abstract: To evaluate the potential for constructed wetlands to treat acid coal mine drainage, six model wetland mesocosms (each 2.4 m × 15 cm) were filled with Sphagnum peat (15 cm deep), planted either with cattails (Typha latifolia) and living Sphagnum, living Sphagnum only, or left as bare peat (2 mesocosms per treatment). The model wetlands were exposed to synthetic acid coal mine drainage (pH 3.5, concentrations of Fe2+, Al3+, Mn2*, Ca2+, and Mg2+ of 78.8, 10.0, 5.2, 12.0, and 4.5 mg L−1, respectively) at a rate of 90 mL min−1, 6 hr d−1, 5 d wk−1, over a 16 week period. Chemical analysis of peat at periodic intervals indicated that the model wetlands were net sources of Al3+, Mn2+ Ca2+ and Mg2+, but net sinks for Fe2+. Type of vegetation had no significant effect on Fe2+ retention; of the 204 g of Fe2+ added to the model wetland systems, 162 g were retained. Formation of Fe oxides accounted for 73 to 86% of the Fee' retention, with exchangeable Fe contributing 0.2 to 1.2%, organically bound Fe contributing 4 to 19%, and residual Fe contributing 7 to 15% of total Fee' retention. Fe retention was greatest at the inflow ends of the model wetlands where Fe retention appeared to reach saturation at a final Fe concentration in the peat of 235 mg g−1. At the rate of application of the synthetic acid mine drainage, we estimated that the model wetland systems would have reached complete Fe saturation after 157 days. We suggest that the mesocosm approach could be useful in generating site-specific data that can be applied to the formulation of cost-benefit analyses that can compare a proposed wetland treatment system with alternative conventional chemical methods for treating acid mine drainage.

A new fertilization strategy in declining forests

Abstract: In central Europe and to some degree in North America, the so called “new type” forest damages occur over large areas. Various studies indicate the declines are more or less frequently associated with nutritional disturbances that have developed within rather short time periods. The most common disorder is a Mg deficiency that produces specific discoloration symptoms such as tip-yellowing in Norway spruce. But also K deficiencies and other disturbances exist in coniferous as well as in deciduous forests. Good correlations between the site specific substrate chemistry and the actual nutritional status of the trees and stands were found. To explain the sudden and widespread development of the forest declines adverse anthropogenic influences such as increased N and H+ deposition, land use and forestry mismanagement as well as natural stresses are discussed. The hypothesized causal mechanisms are multiple, but include generally soil degradation processes associated with losses of alkaline nutrient ions from the rooted solum. Recent and previous fertilization (and liming) experiments have shown that a fast and sustained revitalization and restabilization of declining forest ecosystems marked by nutrient deficiencies can be achieved. This was demonstrated by chemical and histological foliar analyses and the visible improvement of the trees. Soil analyses also revealed a positive change of the chemical soil status when site and stand specific fertilizer applications were utilized in the appropriate amounts. However, under certain site and stand conditions risks and limitations exist that have to be evaluated when fertilization practices are discussed. To overcome or minimize these influences the treatments must be adapted to the site, and stand specific fertilization needs as indicated by soil and foliar analysis, humus form, hydrologic parameter and atmospheric deposition rates.

Changes in fruitbody production of mycorrhizal and litter decomposing macromycetes in heavy metal polluted coniferous forests in North Sweden

Abstract: Basidiomycete fruitbodies growing in coniferous forests along a complex heavy metal pollution gradient in north Sweden were identified and counted over a 4 yr period. The dominant metals in the humus layer were As, Cd, Cu, Pb, and Zn. Pb occurred at the highest levels in a range of 80 to 8500 μg g−1 dry wt. Both the number of fruitbodies and the number of fruiting species decreased strongly with increasing pollution level. A few species appeared to sustain the metal loads. Many of these were ectomycorrhizal fungi. The relationship between fruitbody frequencies and plant species composition were also studied statistically although no obvious relations were found. Metal content of the fruitbodies of six species were also analyzed and their bioaccumulation calculated. Amanita muscaria accumulated Cd efficiently.

Vanadium: Toxicity and accumulation by beans

Abstract: Hydroponic and rhizotron studies were conducted to determine the effect of V on soybean [Glycine max (L.) Merr.] and bush bean (Phaseolus vulgaris L.) biomass and mineral nutrition. In the hydroponic study, 6 mg V L−1 (as VOSO4) in the nutrient solution drastically altered soybean nutrition, and significantly reduced plant biomass. Vanadium accumulated in the roots but not in the aerial portions of the plants. The data support the hypothesis that tissue V and Ca contents are related with high concentrations of both elements in the roots, and low concentrations in the aerial portions of the plant. Analysis of data with the Diagnostic and Recommendation Integrated System (DRIS) identified Ca as deficient in aerial tissues. The changes in Ca concentrations induced by V treatment may also have antagonized the concentrations of others macronutrients, most notably K and Mg. DRIS also indicated that K, Mg, and Zn levels were relatively high. The rhizotron study, which dealt with bush beans grown in metal-treated soils, further showed that V was primarily concentrated in the roots of the plants, with very little accumulated in the aerial portions.

The effect of nitrate and organic matter upon mobility of selenium in groundwater and in a water treatment process

Abstract: Kesterson Reservoir in Merced County, California was formerly used as a storage and evaporation facility for Se-contaminated agricultural drain water. Very little Se entered the shallow aquifer below the ponds with percolating pond water. With few localized exceptions, most of the Se was removed from the water and retained in the first decimeter of soil, which was rich in decaying organic matter. Where it was present in groundwater, Se was nearly always associated with nitrate. Nitrate induces mildly oxidizing conditions (Eh ≈ 350 mV) and inhibits microbial fixation of Se. In the absence of nitrate, relatively reducing conditions prevail in the groundwater (Eh ≈ -50 mV), and Se is quickly removed. Selenate follows oxygen and nitrate in the order that soil microbes utilize electron acceptors. The process of Se removal from water by soil was reproduced in the laboratory, and the effect of nitrate was confirmed. This natural process might be applied to water treatment for Se removal. The deep water ecosystem at Kesterson Reservoir was highly productive. Vegetation growing in water treatment ponds should supply enough organic matter to maintain anaerobic conditions in the sediment. This process, including algae culture, was operated in an outdoor 79 cm column for 100 days. At percolation rates of 15 and 30 m yr−1 Se removal averaged 94%, with an additional 2% converted to volatile compounds.