Personal Research Database

Full Text: 1996\Wat Air Soi Pol89, 159.pdf

Abstract: The presence of Salmonella spp in estuarine waters was investigated along the Patras harbor where pipes containing urban sewage terminate. Salmonellae detection was performed by a conventional culture and a DNA probe technique (Gene-Trak Salmonella assay-Gene Trak Systems, Framingham). The Gene Trak colorimetric Salmonella assay uses the ribosomal hybridization format followed by a colorimetric detection system. Salmonellae were detected in 3 out of 102 water samples (2.9%) when the culture tehnique was used and in 7 out of 102 samples (6.8%) when the DNA probe technique was used. All DNA probe positive samples were confirmed by culture of the pre-enrichment Gram-negative broth and biochemical tests according to the manufacturers instructions. Culture positive samples were confirmed by serological tests in the National Salmonella-Shigella Center (National Institute of Public Health). The data demonstrate that the colorimetric hybridization method and the conventional culture method are equivalent in their ability to detect Salmonellae in estuarine waters (chi (2) = 0.33 < 2.43). Both methods have the disadvantage of giving false negative results. However, the Gene Trak assay saves time by lessening the response time in the case of a contamination problem.

Sadiq, M. (1997), Arsenic chemistry in soils: An overview of thermodynamic predictions and field observations. Water Air and Soil Pollution, 93 (1-4), 117-136.

Full Text: W\Wat Air Soi Pol93, 117.pdf

Abstract: Published information, both theoretical and experimental, on As chemical behavior in soils is reviewed. Because of many emission sources, As is ubiquitous. Thermodynamic calculations revealed that As(V) species (HAsO₄^2-> H₂AsO₄^-at pH 7) are more abundant in soil solutions that are oxidized more than pe+pH>9. Arsenic is expected to be in As(III) form (HAsO₂ = H₃AsO₃>AsO₂^-= H₂AsO₃^-at pH 7) in relatively anoxic soil solutions with pe+pH<7.

Adsorption on soil colloids is an important As scavenging mechanism. The adsorption capacity and behavior of these colloids (clay, oxides or hydroxides surfaces of Al, Fe and Mn, calcium carbonates, and/or organic matter) are dependent on ever-changing factors, such as hydration, soil pH, specific adsorption, changes in cation coordination, isomorphous replacement, crystallinity, etc. Because of the altering tendencies of soil colloids properties, adsorption of As has become a complex, empirical, ambiguous, and often a self contradicting process in soils. In general, Fe oxides/hydroxides are the most commonly involved in the adsorption of As in both acidic and alkaline soils. The surfaces of Al oxides/hydroxides and clay may play a role in As adsorption, but only in acidic soils. The carbonate minerals are expected to adsorb As in calcareous soils. The role of Mn oxides and biogenic particles in the As adsorption in soils appears to be limited to acidic soils. Kinetically, As adsorption may reach over 90% completion in terms of hours.

Precipitation of a solid phase is another mechanism of As removal from soil solutions. Thermodynamic calculations showed that in the acidic oxic and suboxic soils, Fe-arsenate (Fe₃(AsO₄)₂) may control As solubility, whereas in the anoxic soils, sulfides of As(III) may control the concentrations of the dissolved As in soil solutions. In alkaline acidic oxic and suboxic soils, precipitation of both Fe-and Ca-arsenate may limit As concentrations in soil solutions.

Field observations suggest that direct precipitation of discrete As solid phases may not occur, except in contaminated soils. Chemisorption of As oxyanions on soil colloid surfaces, especially those of Fe oxide/hydroxides and carbonates, is believed to a common mechanisms for As solid phase formation in soils. It is suggested that As oxyanions gradually concentrate on colloid surfaces to a level high enough to precipitate a discrete or mixed As solid phase.

Arsenic volatilization is another As scavenging mechanism operating in soils. Many soil organisms are capable of converting arsenate and arsenite to several reduced forms, largely methylated arsines which are volatile. These organisms may generate different or similar biochemical products. Methylation and volatilization of As can be affected by several biotic (such as type of organisms, ability of organism for methylation, etc.) and abiotic factors (soil pH, temperature, redox conditions, methyl donor, presence of other ions, etc.) factors. Information on the rate of As biotransformations in soils is limited. In comparison to the biologically assisted volatilization, the chemical volatilization of As in soils is negligible.

Keywords: As Chemical Forms, As Solid Phase, As Solubility, Biotransformation of As, As Adsorption, Chemisorption, Surface-Chemistry, Solubility Relationships, Iron Hydroxide, Adsorption, Sorption, pH, Trimethylarsine, Ferrihydrite, Environment, Oxidation

Gao, S.A., Walker, W.J., Dahlgren, R.A. and Bold, J. (1997), Simultaneous sorption of Cd, Cu, Ni, Zn, Pb, and Cr on soils treated with sewage sludge supernatant. Water Air and Soil Pollution, 93 (1-4), 331-345.

Full Text: W\Wat Air Soi Pol93, 331.pdf

Abstract: Disposal of sewage sludge creates the potential for heavy metal accumulation in the environment. This study assessed nine soils currently used as Dedicated Land Disposal units (DLDs) for treatment and disposal of municipal sewage sludge in the vicinity of Sacramento, California. Adsorption characteristics of these soils for Cd, Cu, Ni, Zn, Pb, and Cr were studied by simultaneously mixing these elements in the range of 0-50 mol L^-1 with sludge supernatant and reacting with the soil using a soil: supernatant ratio of 1: 30, pH = 4.5 or 6.5, and constant ionic strength (0.01 M Na-acetate). The concentration of metals in the supernatant was determined after a 24 hr equilibration period. Adsorption isotherms showed that metal sorption was linearly related to its concentration in the supernatant solution. The distribution coefficient K_d (K_d = concentration on solid phase/concentration in solution phase) was computed as the slope of the sorption isotherm. The distribution coefficients were significantly correlated to soil organic matter content for Ni, Cu, Cd, and Pb at pH 4.5 and for Ni, Cu, Zn, and Cd at pH 6.5. There was also a correlation between K_d and soil specific surface area but no relationship to other soil properties such as CEC, clay content, and noncrystalline Fe and Al materials. Therefore, soil organic carbon and surface area appear to be the most important soil properties influencing metal adsorption through formation of organo-metal complexes. The K-d values for all elements were higher at pH 6.5 than at 4.5. Selectivity between metals resulted in the following metal affinities based on their Kd values: Pb>Cu>Zn>Ni>Cd approximate to Cr at pH 4.5 and Pb>Cu approximate to Zn>Cd>Ni>Cr at pH 6.5.

Keywords: Metal Sorption, Sewage Sludge, Sorption Isotherms, Competitive Sorption, Organo-Metal Complexes, Organic-Ligands, Zinc, Complexation, Adsorption, Cadmium, Copper, Acid, Reduction, Behavior, Chromium.

Marsh, A.S. and Siccama, T.G. (1997), Use of formerly plowed land in New England to Monitor the vertical distribution of lead, zinc and copper in mineral soil. Water Air and Soil Pollution, 95 (1-4), 75-85.

Full Text: W\Wat Air Soi Pol95, 75.pdf

Abstract: In this study, we used once-plowed lands that have returned to forest for over 50 years to study the vertical distribution of meteorologically-deposited lead. These mineral soils were an essentially homogeneous 20 cm-thick layer when last plowed. As such, they were effectively a ‘clean slate’ upon which pollutants deposited since the last plowing can be measured without the confounding aspects of well-developed natural soil horizons and the spatial heterogeneity of native forest soils. The concentration and amount of lead as well as copper and zinc, biologically active metals, were measured at five sites in New England. In the mineral soil, copper content ranged from 25 mgcm depth^-1m^-2 at 0-2 cm depth to 37 mgcm depth^-1m^-2 at 6-8 cm depth, but showed no consistent pattern with depth at all sites. Zinc concentrations and amounts increased with depth in the mineral soil to 14 µgg^-1 and 167 mgcm depth^-1m^-2, respectively. In contrast, lead showed a decrease with depth from 350 mgcm depth^-1m^-2 at 0-2 cm depth to 102-108 mgcm depth^-1m^-2 between 10 and 20 cm depth. At all five sites, decreases in lead concentration with depth were correlated with decreases in the amount of organic mater. Amounts of total lead deposited since the abandonment from plowing have been estimated at 1.4 gm^-2 in rural sites. Thirty-five percent of this presumably anthropogenically-derived lead was in the forest floor; the remaining 65 % was in the upper mineral soil.

Beverland, I.J., Crowther, J.M. and Srinivas, M.S.N. (1997), Episodic nature of wet deposition of acidic material at a site in south-east England. Water Air and Soil Pollution, 96 (1-4), 73-91.

Full Text: W\Wat Air Soi Pol96, 73.pdf

Abstract: The causal factors for episodic deposition of acidic material in rainfall cannot be fully understood from conventional daily network data. A brief review of the meteorological conditions leading to episodes is given. A definition of ‘episodicity’ was considered and applied to a 6 month data set collected at high temporal resolution using a microprocessor based acid rain monitor at a site in south-east England. The deposition was highly episodic for all of the measured variables when data from individual rain events were considered. Combining the data into daily averages resulted in changes of episodicity classification for several chemical species. A large percentage of the total deposition recorded during the field experiment occurred in a 5 day period when there was an independent report of ecological damage at other locations in England. Nitrate deposition showed the highest degree of episodicity with 51% of the 6 month total occurring during the 5 day episode. Meteorological details of the transport and wet deposition processes during this period were examined. Back trajectory analysis indicated that the episode was the result of pollutant loading in eastern and central Europe of the air masses reaching the site together with an absence of upwind precipitation scavenging.

Lacerda, L.D. (1997), Global mercury emissions from gold and silver mining. Water Air and Soil Pollution, 97 (3-4), 209-221.

Full Text: W\Wat Air Soi Pol97, 209.pdf

Abstract: Mercury has been used in gold and silver mining since Roman times. With the invention of the ‘patio’ process in Spanish colonial America, silver and gold were produced in large scale, mostly in the Americas hut also in Australia, Southeast Asia and even in England. Mercury released to the biosphere due to this activity may have reached over 260,000 t from 1550 to 1930, when silver reserves in Spanish colonial America were nearly exhausted and Hg-amalgamation was replaced by the mon efficient cyanidation process. Exceptional increases in gold prices and the worsening of social-economic conditions in the third world in the 1970’s resulted in a new gold rush in the southern hemisphere, involving over 10 million people in all continents. Presently, Hg amalgamation is used as a major technique for gold production in the South America especially the Amazon, China, Southeast Asia and in some African countries. Mercury inputs to the environment from this activity may reach up to 460 t.yr^-1. Compared with other anthropogenic Hg sources, gold mining is presently responsible for approximately 10% of the global anthropogenic Hg emissions, but has never been included in global models of Hg cycling in the biosphere. Further; most of the Hg released to the biosphere through gold and silver mining during the last 500 years, roughly 300,000 t, may still participate in the global Hg cycle through remobilization from abandoned tailings and other contaminated areas.

Chen, X.B., Wright, J.V., Conca, J.L. and Peurrung, L.M. (1997), Evaluation of heavy metal remediation using mineral apatite. Water Air and Soil Pollution, 98 (1-2), 57-78.

Full Text: W\Wat Air Soi Pol98, 57.pdf

Abstract: The current study investigated the sorption and desorption of dissolved lead (Pb), cadmium (Cd) and zinc (Zn) from aqueous solutions and a contaminated soil by North Carolina mineral apatite. Aqueous solutions of Pb, Cd, and Zn were reacted with the apatite, followed by desorption experiments under a wide variety of pH conditions ranging from 3 to 12, including the extraction fluids used in the Toxicity Characteristic Leaching Procedure (TCLP) of the United States Environmental Protection Agency (US EPA). The sorption results showed that the apatite was very effective in retaining Pb and was moderately effective in attenuating Cd and Zn at pH 4-5. Approximately 100% of the Pb applied was removed from solutions, representing a capacity of 151 mg of Pb/g of apatite, while 49% of Cd and 29% of Zn added were attenuated, with removal capacities of 73 and 41 mgg^-1, respectively. The desorption experiments showed that the sorbed Pb stayed intact where only 14-23% and 7-14% of the sorbed Cd and Zn, respectively, were mobilized by the TCLP solutions. The apatite was also effective in removing dissolved Pb, Cd, and Zn leached from the contaminated soil using pH 3-12 solutions by 62.3-99.9, 20-97.9, and 28.6-98.7%, respectively In particular, the apatite was able to reduce the metal concentrations in the TCLP-extracted soil leachates to below US EPA maximum allowable levels, suggesting that apatite could be used as a cost-effective option to remediating metal-contaminated soils, wastes, and/or water. The sorption mechanisms are variable in the reactions between the apatite and dissolved Pb, Cd, and Zn. The Pb removals primarily resulted from the dissolution of the apatite followed by the precipitation of hydroxyl fluoropyromorphite. Minor otavite precipitation was observed in the interaction of the apatite with aqueous Cd, but other sorption mechanisms, such as surface complexation, ion exchange, and the formation of amorphous solids, are primarily responsible for the removal of Zn and Cd.

Keywords: Inorganic Cation-Exchangers, Synthetic Hydroxyapatites, Lead Orthophosphates, Immobilization, Soils, Ions, Solubility, Adsorption, Sorption, Surface, Acid Mine Drainage, Desorption, Phosphate Rock, Pollution Control, Remediation Technology, Soil and Groundwater Contamination, Sorption, TLCP, Toxic Metals, Waste Management

Tanjore, S. and Viraraghavan, T. (1997), Effect of oxygen on the adsorption of pentachlorophenol by peat from water. Water Air and Soil Pollution, 100 (1-2), 151-162.

Full Text: W\Wat Air Soi Pol100, 151.pdf

Abstract: Pentachlorophenol (PCP), a versatile biocide has been extensively used in industry and agriculture. PCP has been designated as a priority organic pollutant by the United States Environmental Protection Agency (USEPA) and its use in consumer products has been banned since 1984. Extensive use of PCP as a wood preservative has led to soil, surface water and groundwater pollution. Batch adsorption studies using peat at various dissolved oxygen (DO) levels in water showed that higher PCP removals can be attained at elevated DO levels. This effect can be quantified by a comparison of the adsorption capacities of pear from linearized Freundlich isotherms developed for different oxygen levels. An increase of approximately 300% in adsorption was observed for an increase in the DO level from 2 to 26 mg L^-1. Thus, molecular oxygen was found to significantly impact the removals of PCP by pear. The increase in adsorptive capacity of peat was not very significant for an increase in DO level from 2 mg L^-1 to 10 mg L^-1. However a rapid increase in adsorptive capacity was observed for an increase in DO level from 10 to 26 mg L^-1.

Keywords: Pentachlorophenol, Peat, Molecular Oxygen, Adsorption Isotherm, Dissolved-Oxygen, Molecular-Oxygen, GAC Adsorbers, Capacity

Wilkins, B.J., Brummel, N. and Loch, J.P.G. (1998), Influence of pH and zinc concentration on cadmium sorption in acid, sandy soils. Water Air and Soil Pollution, 101 (1-4), 349-362.

Full Text: W\Wat Air Soi Pol101, 349.pdf

Abstract: Batch adsorption experiments were carried out with samples from an A-, Bh- and C-horizon of contaminated sandy soil of podzolic character from the Kempen region at the Dutch-Belgian border. Cadmium sorption was studied on 3 soil samples at 3 different pH-levels (3.6, 4.3 and soil buffered pH) and 3 different additions of zinc (0-40 mg l^-1).

Adsorption of cadmium by acid sandy soils can be fitted by a Freundlich adsorption isotherm. Although zinc competes with cadmium for the sorption sites, we observe a two to three times stronger competition effect of the proton cation, which is explained by the chemical properties of both ions. The cadmium adsorption coefficient KF decreases considerably by an increase of the proton activity used in the sorption experiments. Organic matter content explains for a large part the variation of KF of re three soil samples. Desorption data do not fit the proposed regression model for adsorption. Not all the cadmium, intitially present in the polluted soil, will fylly desorb reversibly. Thus, part of the cadmium may be irreversible bound.

Keywords: Heavy-Metals, Adsorption, Cd, Mobility, Time, Zn

Galvez-Cloutier, R. and Dubé, J.S. (1998), An evaluation of fresh water sediments contamination: The Lachine Canal sediments case, Montréal, Canada. Part II: Heavy metal particulate speciation study. Water Air and Soil Pollution, 102 (3-4), 281-302.

Full Text: W\Wat Air Soi Pol102, 281.pdf

Abstract: Over the last century, discharge of industrial effluents and municipal wastewater have contaminated the Lachine Canal sediments. This study investigated the associations between heavy metals and natural sediment constituents. X-ray Diffraction, Transmission Electron Microscopy and geochemical analysis revealed that the sediments consisted mainly of silt and clay size fractions composed of: feldspar, illite, kaolinite, chlorite, calcite and dolomite as well as minor amounts of Fe minerals. Organic matter and amorphous metal oxides were also identified. Each of these constituents bound heavy metals at varying degrees as assessed by a sequential chemical extraction (SCE) protocol. The associations with each geochemical phase were (in order of decreasing significance): 1) residual phase, 2) oxide phase, 3) carbonate phase, 4) organic phase and 5) exchangeable phase. According to the cation exchange capacity (CEC), carbonate and oxide content measurements, the heavy metals occupied a minor fraction of the total capacity of the sediments to retain metals by these mechanisms. The SCE results revealed that the partition patterns varied with pH. The phases associated to the carbonate and the exchangeable phases were the most sensitive to a change in pH with the residual phase being almost unchanged. The Zn and Cd were sensitive to release when the conditions drifted to acidic conditions. The partition patterns for various grain size fractions (<53 µm, 53-75 µm, 75-175 µm and > 175 µm) revealed that no particular fraction accumulated a certain heavy metal. Finally, from protocols, techniques and results interpretation in this study, various engineering applications such as the technical choice of clean-up scenarios, screening of remediation techniques and the development of remediation quality criteria were proposed within the framework of the management of contaminated sediments.

Keywords: Sequential Extraction, Sewage-Sludge, Trace-Metals, Adsorption, Soils, Fractionation, Lead, Cd, Cu, Zn, Heavy Metals, Particulate Speciation, Sequential Chemical Extractions

Gombert, S. and Asta, J. (1998), The effect of refuse incinerator fumes on the lead and cadmium content of experimentally exposed corticolous lichens. Water Air and Soil Pollution, 104 (1-2), 29-40.

Full Text: W\Wat Air Soi Pol104, 29.pdf

Abstract: Nine corticolous lichens have been used to detect the lead (Pb) and cadmium (Cd) given off by a municipal solid waste incinerator. This bioindication study involved lichens gathered from unpolluted sites around Grenoble (Isere, France) to three conditions: the first batch was set up down wind of the waste incinerator fumes, the second one was set up in the ambient atmosphere of the plant, and the third was kept in a non polluted place. After one month of exposure, the batches were compared. The lichens from the first and second batches did not show any appreciable thallus change. Pb and Cd concentrations have shown that lichens accumulate heavy metals in variable ways according to the species and to the conditions of pollution.

Keywords: Bioaccumulation, Cadmium, Incineration, Lead, Lichens, Epiphytic Lichens, Heavy-Metals, Waste Incinerator, Genus Peltigera, Air-Pollution, Vicinity, Foliage

Karadağ, E., Saraydin, D., Güven, O. (1998), Removal of some cationic dyes from aqueous solutions by acrylamide/itaconic acid hydrogels. Water Air and Soil Pollution, 106 (3-4), 369-378.

Full Text: W\Wat Air Soi Pol106, 369.pdf

Abstract: Acrylamide/itaconic acid (AAm/IA) hydrogels prepared by irradiating with gamma radiating were used in experiments on the uptake of some cationic dyes such as basic red 5 (BR-5), basic violet 3 (BV-3) and brilliant cresyl blue (BCB). The removal of the cationic dyes to AAm/IA hyrogels is studied by batch adsorption technique. In the experiments of the adsorption, L3 type (Langmiur) adsorption in Giles classification system was found. Adsorption studies indicated that monolayer coverages of AAm/IA hydrogel by these dyes were increased with following order; BCB > BR-5 > BV-3.

Keywords: Adsorption, Cationic Dyes, Hydrogel, Poly(Acrylamide/Itaconic Acid), Swelling, Bovine Serum-Albumin, Adsorption, Biocompatibility, Behaviors

Ramachandran, V. and D’Souza, T.J. (1999), Adsorption of cadmium by Indian soils. Water Air and Soil Pollution, 111 (1-4), 225-234.

Full Text: W\Wat Air Soi Pol111, 225.pdf

Abstract: Adsorption behaviour of cadmium (Cd) in soils is an important process which exerts a major influence on its uptake by plant roots. Thirteen soils from various parts of India (tropical region), their pH ranging from 4.2 to 8.4, were subjected to Cd treatment at various concentrations (1 to 100 g ml^-1) and equilibrated at room temperature (25±1°C). The Cd adsorbed by each soil was calculated as the difference between the amount of Cd present in the solution initially and that remaining after equilibration. Results indicated that the adsorption capacity of the soils for Cd increased with an increase in the pH or alkalinity of the soils. The rate of adsorption was, however, found to decrease with increased pH. All the 13 soils used in this study followed linear and Freundlich adsorption isotherms with highly significant positive correlations (r). The neutral and alkaline soils also followed the Langmuir adsorption isotherm, the adsorption maxima being lowest for the neutral soil and highest for the alkaline soil. The adsorption data, in general, indicated that Cd was in a fixed form at higher pH levels. The results are generally similar to those of the temperate regions; however, Cd adsorption capacity of tropical vertisols was comparatively higher than those of temperate vertisols.

Keywords: Adsorption, Cadmium, Freundlich, Isotherm, Langmuir, Linear, Indian Soils, Sorption, Solubility, Copper, Metals, pH

Robles, E., Ramírez, P., González, E., Sáinz, D.G., Martínez, B., Durán, A. and Martínez, E. (1999), Bottled-water quality in metropolitan Mexico City. Water Air and Soil Pollution,