Personal Research Database

Full Text: 1995\J Env Sci Hea Par A-ESETHSC30, 831.pdf

Abstract: The effect of root-treatment of cauliflower, spinach and parsley plants with lead and cadmium were studied. Both metal ions showed obvious growth inhibition of treated plants with cadmium having higher toxicity on growth than lead. Cadmium was more concentrated in the edible parts of the three treated plants whereas lead was more concentrated in the edible parts of cauliflower and spinach plants only. Metal ion concentrations and total metal ion content of treated plants increased with the increase of concentration of cadmium or lead ions in solutions used for treatment. The uptake of metal ion per unit concentration decreased in treated plants with the increase of concentration of cadmium or lead ions in solutions used for treatment. Metal ion concentration and metal uptake were higher in the plants treated with cadmium than those treated with lead.

Keywords: Cauliflower, Spinach, Parsley, Irrigation, Lead, Cadmium, Growth, Uptake, Uptake Distribution, Sewage Water, Radish Plants, Heavy-Metals, Soil Type, Copper, Zinc, OAT

Albanis, T., Danis, Th., Voutsa, D. and Kouimtzis, Th. (1995), Evaluation of chemical parameters in Aliakmon river northern Greece. Part III. Pesticides. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 30 (9) 1945-1956.

Full Text: 1995\J Env Sci Hea Par A-ESETHSC30, 1945.pdf

Abstract: A two-year survey on the water quality characteristics of Aliakmon river in northern Greece is described. Pesticides were determined and their concentration levels were related to the flow characteristics of the river and the influence from agricultural activities. Eight herbicides, alachlor, atrazine, 2,4-d, EPTC, MCPA, metolachlor, simazine and trifluralin were identified in river waters at eight sampling stations. Four insecticides, diazinon, fenthion, lindane and methyl parathion were also detected in the same places. Peak concentrations of some pesticides were observed corresponding to their application in the fields. Episodic peaks in concentrations occur during the period from May to August. Highest concentrations were determined for the pesticides: alachlor (0.21 µg/L), atrazine (2.16 µg/L), MCPA (1.56 µg/L), methyl parathion (0.21 µgL), metolachlor (0.34 µg/L), simazine (0.34 µg/L) and trifluralin (0.55 µg/L).

Keywords: Pesticides, River Water, Degradation Products, Heavy-Metals, Herbicides, Samples, Waters

Salim, R., Al-Subu, M.M. and Isa, M. (1995), Effect of root-treatment of cauliflower, parsley and spinach plants with copper and zinc on the plant-growth. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 30 (10), 2123-2132.

Full Text: 1995\J Env Sci Hea Par A-ESETHSC30, 2123.pdf

Abstract: The effect of copper and zinc ions as growth-inhibitors of plants was studied by the root-treatment of cauliflower, parsley and spinach plants. Both copper and zinc showed an obvious growth-inhibition effect on the growth of the studied plants as well as on their various parts. The sensitivities of cauliflower, parsley and spinach plants towards treatment with copper and zinc solutions were compared between each other as well as between their various parts. The toxicity effects of zinc and copper on the growth of plants were compared. Copper showed higher toxic effect on the growth of treated cauliflower, spinach and parsley plants as well as on the growth of the various parts of treated plants.

Keywords: Root-Treatment, Copper, Zinc, Growth-Inhibition, Cauliflower, Parsley, Spinach, Radish Plants, Cadmium, Lead, Metals, Soil

Panayotova, M. (1996), The motor vehicles: A significant cause for air pollution in big towns of Bulgaria. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (1), 157-165.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 157.pdf

Abstract: Taking as an example the Bulgarian capital (Sofia town) an attempt has been made to emphasize on the “contribution” of motor transport to the air pollution. By comparing the data from air monitiring stations situated in different areas of the town (city centre, industrial regions and residental quarters) it has been estimated that motor vehicles are the major source of CO, hydrocarbons (CnHm), PAH’s and Pb-aerosols and a significant source of NO_x, SO_x, CO₂ and vapours of dangerous organic compounds.

Keywords: Air Pollution, Exhaust Gases

Juang, R.S., Tseng, R.L., Wu, F.C. and Lin, S.J. (1996), Use of chitin and chitosan in lobster shell wastes for color removal from aqueous solutions. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (2), 325-338.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 325.pdf

Abstract: Chitin and chitosan prepared from lobster shell wastes were used as adsorbents for the removal of various dyes from aqueous solutions. It was shown that high adsorption capacities were observed for reactive dyes, The adsorption equilibrium data could be well described by Langmuir equation under the concentration range investigated (50 similar to 500 mg/L), On the basis of Langmuir adsorption capacity, chitosan obtained in this work was found to be more effective compared to chitin and a commercial chitosan.

Keywords: Chitin, Chitosan, Adsorption, Equilibria, Dyes, Textile Effluents, Activated Carbon, Adsorption, Dyestuffs, Equilibrium, Cost, Dyes, Adsorbents

Cajuste, L.J., Carrillogonzalez, R., Laird, R.J. and Cajuste, L. (1996) Adsorption of lead and cadmium by some volcanic ash soils. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (2), 339-354.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 339.pdf

Abstract: The adsorption of cadmium (Cd) and lead (Pb) by three volcanic ash soils with varying chemical properties was studied. Soil samples were equilibrated with increasing amounts of both CdSO₄-8H₂O and Pb (NO₃)₂ in 1: 5-1: 20 soil: solution ratios at several time intervals, in the presence of various surfactant concentrations (0.05-1.0%). Concentrations of Cd and Pb remaining in solution after equilibrium time were determined by atomic absorption. The study showed that there was a decrease in percentage of adsorbed Cd with an increase in soil: solution ratio and an apparent adsorption plateau with shaking time. Adsorption of Cd varied according to soil types, being in the order of 80-96% at low surfactant and Cd concentrations in the soil with the highest organic matter content. At low surfactant concentration (up to 0.5%) most of the Pb was retained by the soils after a 15 minute shaking time, regardless of soils: solution ratio. Substantial amounts of Pb, however, remained in solution in most soils at higher surfactant concentrations, presumably due to the ability of the surfactant accompanying cation to compete with Pb for adsorbing sites. Cadmium and Pb adsorption maxima and their relationship with some soil properties with regard to their implications in waste-treatment processes also were discussed.

Keywords: Heavy Metals, Surfactants, Allophanic Soils, Calcareous Soils, Sorption, Copper, Acid

Low, K.S., Lee, C.K. and Wong, A.M. (1996), Carbonized spent bleaching earth as a sorbent for some organic dyes. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (3), 673-685.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 673.pdf

Abstract: The potential of carbonized spent bleaching earth (CSBE) to remove/reduce acid and basic dyes in aqueous solution was investigated. Results show that CSBE was more effective in removing basic dyes. Parameters like pH initial concentration, agitation rate, contact time and temperature which affect the sorption process were studied As determined from Langmuir isotherms the maximum sorption capacities of CSBE for Basic Blue 3 and Methylene Blue were 102.6 and 94.5 mg/g respectively Hence CSBE could be a useful sorbent in the treatment of baisc dyes in wastewater.

Keywords: Carbonized Spent Bleaching Earth, Sorption, Basic Dyes, Natural Adsorbents, Aqueous-Solutions, Activated Carbon, Acid Dye, Removal, Cost, Equilibrium, Dyestuffs

Tsai, W.T., Chang, C.Y. and Lee, H.C. (1996), Adsorption of organic vapors containing N, N-dimethylformamide on activated carbon and hydrophobic zeolite. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (5), 995-1008.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 995.pdf

Abstract: The adsorption of N, N-dimethylformamide (DMF), listed as one of the hazardous air pollutants or air toxics, on the two commercial granular adsorbents, i.e., activated carbon PCB (coconut shell) and hydrophobic zeolite DAY, was studied. The laboratory investigation was conducted at various temperatures of 293, 303 and 313 K. The physical properties and characterization of the two adsorbents were also measured and compared with each other, The experimental results indicate that the adsorption capacity of activated carbon PCB is significantly higher than that of zeolite DAY. It was found thar the measured adsorption data can be reasonably well fitted by the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm equations. The values of the parameters of the adsorption equations were thus obtained for the two adsorbents. The adsorption capacity of DMF vapor on the two adsorbents examined in this study appears to be mainly determined by the physical properties of adsorbents (e.g. BET surface area and micropore volume), which are consistent with the isotherm parameters obtained from the experimental results.

Keywords: Adsorption Isotherm, N, N-Nimethylformamide, Activated Carbon, Hydrophobic Zeolite, Occupational Dimethylformamide Exposure

Arayici, S., Apak, R. and Apak, V. (1996), Equilibrium modeling of pH in environmental treatment processes. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (5), 1127-1134.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 1127.pdf

Abstract: This work describes a novel approach to the theoretical prediction of optimal pH values of critical importance to the efficiency of a number of wastewater treatment processes such as precipitation, coprecipitation, coagulation, flocculation, adsorption, oxidation and reduction. The developed equlibrium pH modelling approach is comprised of selecting the appropriate representative equlibrium data among other complex equlibria which is key to the prediction of the optimal pH under investigation, and subsequently solving the algebraic or differential hydrogen ion-dependent equation resulting from this evaluation. This approach has been applied to environmental problems such as minimum solubility of boehmite, phosphate precipitation by ferric and aluminium salt flocculants. lime-sulfide treatment of zinc ion containing wastewater. silver ion precipitation from photographic effluents, and isoelectric pH of hydrous ferric oxide in the absence and presence of chromate.

Keywords: Wastewater Treatment, pH, Equilibrium Modelling, Hydrous Oxides, Isoelectric Point, Minimum Solubility, Precipitation, Adsorption, Adsorption, Chromate

Lin, S.H. and Chen, Y.W. (1996), Adsorption and desorption characteristics of 1,1-dichloro-1-fluoroethane by granular activated carbon and activated carbon-fiber. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (6), 1279-1292.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 1279.pdf

Abstract: Experiments have been conducted to examine the adsorption/desorption characteristics of 1,1-dichloro-1-fluoroethane (HCFC-141b) by granular activated carbon (GAG) and two grades of activated carbon fiber (ACF-1300 and ACF-1500). The HCFC-141b is currently deemed as an excellent replacement for CFC-11, a blowing agent widely used in the rigid polyurethane foam industries. Experimental results of adsorption and desorption were analyzed in terms of the equilibrium adsorption capacity, time to reach equilibrium and desorption efficiency of adsorbent and with an aim to assess the viability of the use of both adsorbents for possible HCFC-141b recovery. The results have clearly revealed Beat potentials of both adsorbents for this purpose. In terms of the overall adsorption and desorption performances, ACF-1500 is the best, followed by ACF-1300 and GAC.

Keywords: Hydrochlorofluorocarbon, Adsorption, GAC, Activated Carbon Fiber, Decomposition, Dichlorodifluoromethane, Chlorofluorocarbons, Destruction, CFC-113

Low, K.S. and Lee, C.K. (1996), Removal of trivalent chromium using hexane-extracted spent bleaching earth. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (6), 1317-1330.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 1317.pdf

Abstract: The removal of trivalent chromium from synthetic solution by hexane-extracted spent bleaching earth was investigated on a laboratory scale under various conditions. Data obtained followed the Langmuir isotherm for the Cr(III)-hexane extracted spent bleaching earth. Maximum sorption was calculated to be 9.48 mg/g at room temperature.

Keywords: Hexane-Extracted Spent Bleaching Earth, Trivalent Chromium, Sorption

Majid, A., Toll, F., Boyko, V.J. and Sparks, B.D. (1996), Fixation of lead in contaminated soils by co-agglomeration with metal binding agents. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (6), 1469-1485.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 1469.pdf

Abstract: Adsorption of lead from an aqueous solution by both agricultural peat moss and soil has been measured. The results may be described by a Langmuir isotherm model. Adsorption isotherms fitted the “H” type described in the Giles classification. Saturation adsorption was reached at equilibrium lead concentrations > 3000 mg/L for peat, compared with similar to 250 mg/L for soil. Calculation of the isotherm parameters showed the maximum lead adsorption to be 150 mglead/g of peat. This compared with only 12.64 mg/g of lead for soil alone. Several tests were carried out to evaluate the lead binding capacity of peat in a spiked soil sample. Results from leaching tests (Environmental Protection Agency, EPA, Toxicity Characteristic Leaching Procedure, TCLP, at pH 2.9) on soil-peat mixtures confirmed the excellent metal binding capacity of peat in the samples tested. The amount of lead leached from a soil sample, spiked with 1840 mg/kg of water-soluble lead, decreased with increasing amounts of peat loading. Total fixation was achieved at a peat loading of 20%.

Keywords: Spent Bleaching Earth, Extractability, Adsorption, Adsorbent, Cadmium, Copper, Zinc

Rizzuti, A.M., Cohen, A.D. and Stack, E.M. (1996), Effects of irradiating peats on their ability to extract BTEX and cadmium from contaminated water. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (8), 1917-1949.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 1917.pdf

Abstract: This paper reports on research designed to investigate the effects of increasing amounts of gamma radiation on the abilities of peats with different chemical, physical, and microbiological properties to extract gasoline-derived contaminants (BTEX’s) and cadmium from water. Unaltered and irradiated peats were slurried under controlled conditions in aqueous solutions of gasoline and of cadmium. All pear types were also examined by various analytical methods for physical, chemical, or microbiological changes that might have occurred due to the radiation.

Radiation was found to increase BTEX sorption capacity by 10-65%, depending on the peat type. A maximum BTEX sorption capacity was reached somewhere between 4.5 and 6.5 megarads of radiation. The more fibric pears tended to reach their BTEX sorption maximum more quickly than the more sapric peats.

In contrast to the hydrocarbons, cadmium sorption capacity tended to be decreased by radiation, for the more fibric peats (by as much as 80%); while, the more sapric peat’s sorption capacity became sporadic (i.e. tended to fluctuate with time but showed a slight increase in adsorption by the end of the test).

Microbial enumeration analyses showed that the number of microorganisms living within the peats was greatly reduced as the dosage of radiation was increased. Additionally, pyrolysis GC/MS results showed evidence of significant chemical changes in the peats due to radiation; although, these increases and decreases in pyrolysis products were not consistent from one peat type to another.

Keywords: Pear, Radiation, Sterilization, Sorption, Btex, Hydrocarbons, Cadmium, Gamma-Irradiation, Removal

Viraraghavan, T., Subramanian, K.S. and Rao, B.V. (1996), Drinking water at the tap: Impact of plumbing materials on water quality. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (8), 2005-2016.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2005.pdf

Abstract: Copper and galvanized steel plumbing systems in houses contribute to trace metal concentrations in drinking water. Levels of lead, zinc, copper, iron and manganese in tap water at various locations in Regina, Canada were monitored and the effect of various factors such as building height, type of building, plumbing age and type of plumbing and water chemistry on trace metal levels was examined. It was found that there was no significant effect of plumbing age or type on the extent of metal leaching in South Regina. In North Regina, plumbing type had a marked effect on the lead and iron levels in drinking water. Lead levels in some individual residences were high; these were probably local effects. It was found that corrosion of solders did not contribute significantly to metal levels. Metal leaching into standing water was found to be mostly from kitchen faucets.

Keywords: Drinking Water Quality, Plumbing Materials, Trace Metals

Atun, G. and Sismanoglu, T. (1996), Adsorption of 4,4’-iso propylidene diphenol and diphenylolpropane 4,4’dioxyaceticacid from aqueous solution on kaolinite. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (8), 2055-2069.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2055.pdf

Abstract: The adsorption of 4,4’-iso propylidene diphenol (Bis-phenol A) and diphenylolpropane 4, 4’dioxyaceticacid (Bis acid A2) on kaolinite type clay have been studied as the function of their solution concentration and temperature. The adsorption rates at low concentrations of Bis-phenol A was found to fit the first-order equation with two kinetic steps. In all cases, the first step of adsorption was more rapid than the second one. The results indicated that the adsorption rate is controlled by either a film diffusion or a intra-particle diffusion. It can be concluded that the adsorption reaction begins with the film diffusion. Since the film-diffusion rate is much higher than the rate of intra-particle diffusion, the reaction is governed by intra-particle diffusion in the second step. In the case of Bis acid A2 only one kinetic step was observed corresponding to the film diffusion mechanism. Using the Arrhenius equation, the activation energies for both systems were evaluated. The corresponding values of thermodynamic parameters were calculated using Eyring’s equation of absolute reaction rate. The adsorption data of Bis-phenol A and Bis acid A2 were fitted to Freundlich and B.E.T isotherms, respectively. The results could be interpreted in terms of a parallel orientation of Bis acid A2 molecules on the adsorbent surface.

Keywords: Adsorption Rate, Film Diffusion, Intra-Particle Diffusion, Freundlich Type Isotherm, Bet Type Isotherm, Bisphenol A, Bis Acid A2, Activated Carbon, Water

? García-Delgado, R.A., García-Herruzo, F., Rodríguez-Maroto, J.M. and Vereda, C. (1996), Influence of soil carbonates in lead fixation. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (9), 2099-2109.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2099.pdf

Abstract: Despite the progressive decrease in emissions coming from a variety of sources, lead continues to be one of the toxic metals more often found as environmental pollutants. Of particular concern is lead migration through the soil which may result in contamination of water supplies through;he leaching caused by water infiltration. Carbonate minerals are frequently found in soils and those of heavy metals are usually insoluble so carbonates in the soil could act as a sink for heavy metals for as long as the environmental conditions guarantee their stability. The influence of soil composition on the fixation of lead from aqueous solutions of this metal has been studied. Two clayey soils with different carbonate content have been used in the tests. The kinetics and equilibrium of retention of lead in the soils under different conditions of pH and salinity have been determined using batch and fixed-bed column experiments. Carbonate precipitation and ion exchange were the main processes responsible for the Pb uptake by the soils and concentrations of up to 50% were achieved. The results obtained show that carbonates confer the soil a high immobilization capacity for lead, impeding the advance of the contamination under natural conditions.

Keywords: Cadmium, Carbonates, Clay, Contamination, Environmental, Fixed Bed, Heavy Metals, Heavy-Metals, Ion Exchange, Leaching, Lead, Lead Fixation, Metals, Soil Pollution, Trace-Metals

Wilkins, E. and Yang, Q. (1996), Comparison of the heavy metal removal efficiency of biosorbents and granular activated carbons. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (9), 2111-2128.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2111.pdf

Abstract: The adsorption efficiencies of granular activated carbon (GAG) and biosorbents: Saccaromyces cerevisiae yeast (caustic treated and active) immobilized in GAG; Yeast (caustic treated) immobilized in alginate acid and alginate itself were compared for the removal of Cu²⁺, Cd²⁺, Zn²⁺ from simulated waste waters. Yeast biomass has a high capacity for uptake of heavy metal ions and can be adsorbed on activated carbon. The alginate used in this study was used as an entrapment material to immobilize yeast. It was observed that the pH of the solution was a critical parameter for the adsorption process; the value chosen in the experiments was 4.5. Two different experimental modes were used, a batch mode and a flow mode were used. In batch mode operation, using biosorbents yeast immobilized on GAC and on alginate, the percentage removal of heavy metal can exceed 90%. When only GAC was used as an adsorbent, acceptable results were obtained. Comparing the two different experimental modes, no difference was observed in the percentage removal of metal ions, although a longer time was needed for the now system to reach adsorption equilibrium compared to batch mode.

Keywords: Dissolved Copper, Aqueous-Solution, Biosorption, Recovery, Cadmium, Adsorption, Biomass, Yeast

McGeehan, S.L. (1996), Arsenic sorption and redox reactions: Relevance to transport and remediation. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (9), 2319-2336.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2319.pdf

Abstract: Sorption and redox reactions strongly influence the toxicity, bioavailability, and potential mobility of arsenic (As) in soils. The objective of this paper is to describe the impact of soil flooding on the sorption and oxidation state of As. Soils were flooded in a batch system, and aqueous-phase measurements including Eh, pH, and dissolved Fe, Mn, and As were recorded at the end of each flooding period. In addition, aqueous-and solid-phase arsenite and arsenate were determined by ion chromatography and x-ray absorption spectroscopy. Soil suspension Eh decreased rapidly during the initial two days of flooding, thereby establishing anaerobic conditions for the remainder of the flooding period. Dissolved Fe and Mn levels increased, suggesting reductive dissolution of Fe and Mn (hydr)oxides occurred. Dissolved As decreased rapidly during the initial 24 h of the experiment, most likely the result of sorption. Oxidation state measurements showed dissolved arsenate disappeared with a concurrent increase in dissolved arsenite. Furthermore, solid-phase arsenate declined with a concurrent increase in arsenite. These aqueous and solid-phase observations indicate that arsenate is reduced to arsenite in flooded soils although it is not clear whether this reduction occurs in solution or on the soil particles.

Keywords: Evaporation Pond Water, Soils, Adsorption, Selenium, Lead, Spectroscopy, Speciation, Sediments, Salinity, Removal

Resce, J.L., Ragsdale, R.G. and Overcamp, T.J. (1996), Vitrification of an incinerator blowdown waste containing both chloride salts and carbon. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (9), 2381-2393.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2381.pdf

Abstract: A low-level, mixed-waste simulant, derived from incinerator blowdown residue, has been vitrified in a series of crucible tests. Major components of this waste simulant included carbon, sodium chloride, silica, and alumina. Hazardous and surrogate radioactive metal complexes were also included. Two different formulations of additives were combined with the waste to facilitate glass formation. These glass formulations included NaNO₃ to serve as a flux and to assist in the oxidation of the carbon. During vitrification, a chloride salt layer was observed on the melt surface which volatilized during the course of heating. Furthermore, significant concentrations of As, Cd, Cs, Ni, Pb, Sb, Se, Tl, and Zn had volatilized during vitrification. It is postulated that this was due, in part, to the formation of volatile metal chlorides. Upon quenching, small metal nuggets, containing Pb, Sb, Ag, and Ni separated from the glasses. This reduction of the metal oxides was caused by the presence of carbon in the simulant. The chemical durability was evaluated by both the Toxicity Characteristic Leaching Procedure (TCLP) and the Product Consistency Test (PCT). The TCLP results were below the limits for the toxicity characteristic for a hazardous waste and also met the Universal Treatment Standards for listed wastes such as F006. The PCT elemental release rates were considerably below the waste acceptance criteria for high level waste glass, which is also indicative of highly leach resistant glasses. Even though the glass products themselves were chemically durable, the formation of secondary waste streams, due to the presence of the chloride and carbon, may pose difficult challenges for the vitrification of incinerator wastes.

Sayrafi, O., Salim, R. and Sayrafi, S.A. (1996), Removal of cadmium from polluted water using decaying leaves: Effects of type of leaves. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (10), 2503-2513.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2503.pdf

Abstract: The removal of cadmium from aqueous solutions by reed leaves, cypress leaves oak leaves, pine leaves and reed roots has been studied. Reed leaves have been found efficient for removing cadmium from aqueous solutions. Almost all of the cadmium present in solutions having concentrations ranging between 1 mg/L and 6 mg/L was removed by reed leaves within few days. Pine leaves and reed roots showed only little capability for removing cadmium from aqueous solutions. The results obtained on reed leaves were found to follow the Freundlich adsorption isotherm.

Keywords: Removal, Cadmium, Leaves, Cypress, Oak, Pine, Reed, Concentration, Adsorption Isotherm, Aluminum, Lead

Szefer, P., Szefer, K., Hallera, G.J., Glasby, G.P., Pempkowiak, J. and Kaliszan, R. (1996), Heavy-metal pollution in surficial sediments from the southern Baltic sea off Poland. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 31 (10), 2723-2754.

Full Text: 1996\J Env Sci Hea Par A-ESETHSC31, 2723.pdf

Abstract: The Gulf of Gdansk is one of the pollution “hot spots” of the Baltic Sea. In order to investigate heavy-metal pollution there, 31 bulk (<2 mm), surficial sediments from the Gulf of Gdansk and the southern Baltic Sea were analyzed for 20 elements. Cobalt, Ni, Cs, Rb, Fe, Mg, Li and K covary with Al and display an enrichment factor EF (Al) (M) of about one, indicating that these elements occur in the sediments dominantly in the clay mineral fraction. Zinc, Cd, Pb and Ag display an enrichment factor much greater than one and are thought to be dominantly anthropogenic in origin. Grain size plays a significant role in determining element concentrations within the sediments. Systematic trends in the distribution of the heavy metals away from the mouth of the Vistula River were therefore not observed in bulk sediments. However, R-mode factor analysis discriminated between sediments taken from near the mouths of the Vistula and Reda Rivers and the other sediments and indicated that sediments from near the mouths of those rivers are the most polluted with heavy metals. Present evidence suggests that the heavy metals are introduced into marine sediments in part from atmospheric sources.

Sadiq, M., Zaidi, T.H., Al Muhanna, H. and Mian, A.A. (1997), Effect of distribution network pipe material on drinking water quality. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (2), 445-454.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 445.pdf

Abstract: The effect of distribution network material on water quality was evaluated by collecting and analyzing water samples from 40 location in a community in Dhahran. Concentrations of dissolved salts, calcium, magnesium, sodium, chloride, and sulfate in the groundwater were higher than the health guidelines. Desalination process brought these parameters within the recommended guidelines. Concentrations of trace metals, except for lead in three samples, were below the permissible limits. Fluoride concentrations in many drinking water samples were lower than the recommended range.

Water concentrations of copper increased in the distribution network with copper pipes. The PVC pipes in the network contained about 1% of lead and water passing through these pipes contained relatively higher lead concentrations. Leaching of lead from the PVC appears to be responsible for lead elevation in these water samples. Iron concentrations in the water samples from the galvanized pipes were higher than those collected from non-galvanized pipes. The results of this study show that distribution network material can modify water quality during transportation to the consumers.

Keywords: Trace Metals, Corrosion, Lead, Copper, PVC Leaching, Saudi-Arabia

? Melgar, M.J., Miguez, B., Perez, M., Garcia, M.A., Fernandez, M.I. and Vidal, M. (1997), Heavy metals (Cd, Pb, Fe, Mn, Zn, Cu) in drinking water as toxicological indicators. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (3), 687-697.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 687.pdf

Abstract: Heavy metals (Cu, Zn, Pbl Cd, Fe, Mn) have been studied in spring waters in order to assess any toxicological problem. The analysis were realized by Atomic Absorption Spectroscopy. The results showed that the water was not dangerous for human health, so the metals considerated as toxics (Cd, Pb) did not present problems of contamination. The other metals had values below the maximum admisible concentration, except Mn, which presented concentrations above the maximum admisible concentration in six spring waters.

Keywords: Contamination, Heavy Metals, Spring Water, Natural-Waters, Cadmium, Copper, Accumulation

Chang, N.B., Chen, Y.L. and Chen, H.W. (1997), A fuzzy regression analysis for the construction cost estimation of wastewater treatment plants. 1: Theoretical development. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (4), 885-899.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 885.pdf

Abstract: To achieve the water pollution control policy at both the national and local levels, engineering projects regarding the construction of sewer system and wastewater treatment plants have been launched in many regions. But the fuzzy structure of construction cost, where human estimation is influential, may result in an impediment of economic feasibility in decision making. Therefore, an understanding of the track of previous development of wastewater treatment in Taiwan and of the related construction and operating cost structures of these facilities, becomes helpful in creating a valuable management strategy. This paper developes a new cost estimation approach: the modified fuzzy goal regression model. It specifically demonstrates how the fuzzy regression analyses can be established through the use of fuzzy goal programming techniques in a flexible manner.

Gloaguen, V. and Morvan, H. (1997), Removal of heavy metal ions from aqueous solution by modified barks. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (4), 901-912.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 901.pdf

Abstract: Bark, a common waste product in forestry, can be used to selectively remove cations, especially toxic heavy metals from mono or multi saline solutions. Picea, Pinus, Pseudotsuga, Larix, Tectona and Afzelia barks have been used in glass columns, after grinding and treatment with formaldehyde in acid media, to study their ability in binding toxic heavy metal ions such as Pb²⁺, Zn²⁺, Cr²⁺, Fe²⁺ and Cu²⁺. The metals are exchanged against protons on the bark substrates that presumably contain carboxyl groups in both pectin and tannin compounds.

Removal of these ions depends upon the nature of the bark used, the grain size and the predominant heavy metal ions present in the solutions. The metal ions could be stripped by addition of 0.1 N HCl, making the substrate regeneration and its reutilization possible.

Keywords: Acid, Bark, Cation Sorption, Heavy Metal, Heavy Metal Ions, Heavy Metals, Heavy-Metal, Mercury, Metal, Metal Ions, Metals, Modified Barks, Regeneration, Waste, Water Treatment

Fayad, N.M., Sheikheldin, S.Y., Al-Malack, M.H., El-Mubarak, A.H. and Khaja, N. (1997), Migration of vinyl chloride monomer (VCM) and additives into PVC bottled drinking water. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (4), 1065-1083.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 1065.pdf

Abstract: The migration of vinyl chloride monomer (VCM) and plasticizers, especially adipate and phthalate esters, from polyvinyl chloride (PVC) packaging materials into bottled drinking water was investigated. The study has shown that the concentrations of VCM in various brands of bottled-water were below 0.6 ppb, which is far below the 2 ppb maximum contamination limit set by the United States Environmental Protection Agency for VCM in drinking water. Exposure of the bottled-water to sunlight did not result in a measurable increase in the VCM concentration levels. However, several volatile and semi-volatile organic compounds were tentatively identified by CC-MS in the bottled-water after exposure to sunlight. 2,3-Dichloro-1-propanol and dichloroacetic acid were the volatile compounds repeatedly identified, moreover, the presence of benzene was confirmed in some bottled-water samples. Di-n-octyl adipate and bis(2-ethylhexyl) phthalate were the major semi-volatile organic compounds identified. Migration of these compounds were found to depend on storage time, temperature and exposure to sunlight Di-n-octyl adipate and bis(2-ethylhexyl) phthalate are widely used as plasticizers in PVC packaging materials.

The results of this study suggested that all measures used to store other foodstuffs should be applied to bottled-water to preserve its quality.

Keywords: PVC, Vinyl Chloride, Migration, Bottled-Water, Chromatography-Mass-Spectrometry

Abdo, M.S.E., Nosier, S.A., El-Tawil, Y.A., Fadl, S.M. and El-Khaiary, M.I. (1997), Removal of phenol from aqueous solutions by mixed adsorbents: Maghara coal and activated carbon. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (4), 1159-1169.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 1159.pdf

Abstract: The removal of phenol from a simulated wastewater effluent by adsorption on a homogeneous mixture of Maghara Coal and Activated Carbon in different proportions has been carried out in a fixed bed reactor. It was noted that the adsorption capacity of activated carbon is 12.05 fold that of Maghara Coal. Variables studied were initial phenol concentration, bed height, and type of adsorbent, namely GMC, GAG, (50%GMC+50%GAC), and (25%GMC+75%GAC). The volumetric flow rate of phenol solution and the temperature were kept at 27.5 ml/min and 27°C respectively. Also the adsorption isotherm for both PMC and PAC were studied. The equilibrium data fit well in the Freundlich model of adsorption.

? Yu, H.Q., Wilson, F., Tay, J.H. and Gu, G.W. (1997), Effects of addition of ferric hydroxide or powered activated carbon on sequencing batch reactors treating coke-plant wastewater. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (5), 1605-1619.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 1605.pdf

Abstract: The performance of three sequencing batch reactors (SBRs) treating the effluent from a conventional coke-plant wastewater biological treatment system was evaluated in this study. The addition of powered activated carbon (PAC) to an SBR had a significant effect on chemical oxygen demand (GOD) removal from the coke-plant wastewater, but the addition of ferric hydroxide appeared to have little influence on COD reduction. The conventional SBR, PAC-SEP and bioferric-SER performed similarly in terms of nitrification and sludge settling property. The PAC did not seem to enhance the biodegradation capacity of the activated sludge in the SBR and probably mainly acted as an adsorbent in the PAC-SEP.

Keywords: Activated Carbon, Activated Sludge, Biodegradation, Coke Plant Wastewater, Coke-Plant Waste, Coke-Plant Wastewater, Ferric Hydroxide, Nitrification, Phenolic Waste, Removal, Sequencing Batch Reactor, Wastewater, Water

Chang, M.B., Lin, N.H., Lee, H.M. and Lo, Y.C. (1997), Rainwater contamination and sources in Taoyuan county, Taiwan. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (6), 1641-1653.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 1641.pdf

Abstract: In this study, an acid precipitation monitoring network was set up to investigate the characteristics of contamination and sources in rainwater in Taoyuan County, Taiwan. Wet-only precipitation samples were collected from February 1994 to January 1995. Mean pH ranging from 3.21 to 4.49 is observed in Taoyuan County and reveals that rainwater acidification is indeed severe in this region. Sulfate is the dominant chemical component (153.5 µeql^-1) and follow by Cl^-(133.4), Na⁺ (96.0) and NH₄⁺ (80.9). Source apportionment of soluble ions with marine and crustal origins is calculated from the analysis of neutralization capacity factor and enrichment factor. The implications of results are discussed.

Keywords: Rainwater, Seasalt Contribution, Crustal Contribution, Neutralization Capacity Factor, Enrichment Factor, Taoyuan County, Taiwan, Deposition, China, Precipitation

Low, K.S., Lee, C.K. and Ng, A.Y. (1997), Chromium(VI) sorption on quaternized rice hulls. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (6), 1849-1860.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 1849.pdf

Abstract: The sorption of Cr(VI) from synthetic solution and electroplating waste by quaternized rice hulls was investigated under laboratory conditions to assess its potential in removing Cr(VI). The results show that quaternized rice hulls provided higher sorption capacity and a more workable pH range as compared to the untreated rice hulls. From the Langmuir isotherm the maximum sorption capacity of Cr(VI) was 32.3 mg/g at pH 4.82 at 25°C. Column studies showed that Cr(VI) and Cu(ll) from electroplating waste could be successfully removed or reduced using a combination of untreated and quaternized rice hulls. The effect of different anions on the sorption capacity of quarternized rice hulls was discussed.

Keywords: Quaternized Rice Hulls, Sorption, Hexavalent Chromium, Electroplating Waste, Sphagnum Moss Peat, Adsorption, Removal

Chang, T.W., Yu, W.S., Liu, Y.H., Wu, C.L. and Lee, P.C. (1997), Decreasing electrical conductivity of irrigation water by dilution. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (6), 1861-1872.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 1861.pdf

Abstract: Although 750 µmho/cm is the limit for the electrical conductivity (EC) in the “Standard of Taiwan Irrigation Water Quality, “ the EC of irrigation water is usually over limit, resulted from the pollution dumped into the rivers, streams and creeks. It will be a damage to agricultural crop using polluted irrigation water. The basic principle of dilution can neutralize high EC of polluted water using pure or low EC water. With the increasing quantity of clean water, the polluted water will drop its EC to a certain extent. Therefore, the purpose of this study is to determine the relationship between dilute water quantity and its. EC. As results shown in this study, pure water or water of low EC mixing with water of high EC can be a basic principle for diluting. The practical principle can be used in the farms and the results meet the irrigation water standard. Moreover, the better quality of dilute water is, the less its quantity is the worse the quality the more the quantity is. Furthermore, the electrolyte effect and the principle of Le Chatelier in aquatic chemistry are resulted in solubility of salt and EC of mixed water solution increase. All the precipitation, coagulation and flocculation will decrease free ions’ content and EC in mixed water solution.

Keywords: Electrical Conductivity, Dilution

Teker, M., Saltabas, Ö. and Imamoglu, M. (1997), Adsorption of cobalt by activated carbon from the rice hulls. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (8), 2077-2086.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 2077.pdf

Abstract: The removal of cobalt(II) ion from aqueous solutions, by adsorption on activated carbon prepared from the rice hulls (ACRH), has been investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time have been determined as 6-7, 1.5 g ACRH/50 mt solution and 40 minutes respectively. Freundlich and Langmuir isotherm constants have been calculated at two different temperatures of 293 K and 313 K. Furthermore the other thermodynamic data for G° and S°, have been also calculated at two temperatures of 293 K and 313 K. The adsorption of Co(II) ion from aqueous solutions has been found to be exothermic (H° =-1.543 KJ/mol).

Keywords: Adsorption, Cobalt, Activated Carbon, Rice Hulls, Fly-Ash, Removal

Yen, S.H., Jeng, F.T. and Tsai, J.H. (1997), Adsorption of methyl-ethyl ketone vapor onto zeolites. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (8), 2087-2100.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 2087.pdf

Abstract: Volatile organic compounds (VOCs) emitted from industries are often removed by carbon or zeolite adsorption. This study presents the adsorption capacity of methyl-ethyl ketone (MEK) vapor (inlet concentration = 100 similar to 1500 ppm) onto six different types of zeolites as a function of their properties including surface area, pore volume and Si/Al ratio. The results indicate that the MEK adsorption capacities depend on the type of zeolite, specifically on Si/Al ratio. The measured adsorption data fit reasonably well with Langmuir and Freundlich equations.

Keywords: Adsorption Capacity, Methyl-Ethyl Ketone, Zeolite, Hydrophobic Zeolite, Activated Carbon, Mixtures

Aslan, R., Şekeroğlu, M.R., Gültekin, F. and Bayiroğlu, F. (1997), Blood lipoperoxidation and antioxidant enzymes in healthy individuals: Relation to age, sex, habits, life style and environment. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (8), 2101-2109.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 2101.pdf

Abstract: We report the concentrations of superoxide dismutase (SOD), glutathione peroxidase (GSN-Px) and malonaldialdehyde (MDA) an end product of lipoperoxidation in human whole blood. Method for measuring was the based on spectrophotometer. Blood MDA level was higher in elderly than in children, adults. Smoking, alcohol taking, acute exercise and air pollution group’s MDA levels were increased than their control groups. GSH-Px activity was significantly lower in acute exercise group, and higher in trained group than those of controls. SOD was decreased in elderly, smoking and acute exercise groups and increase in trained individuals. As a result the mean values we obtained were slightly significant in age groups. The life style, environment has polluted air and habits are thought to be responsible for these significance also.

Keywords: Lipoperoxidation, Antioxidants, Sex, Age, Smoking, Alcohol Consumption, Exercise, Environment, Lipid-Peroxidation, Human-Erythrocytes, Glutathione, Systems

Fang, G.C., Cheng, M.T. and Cgang, C.N. (1997), Monitoring and modeling the mass, heavy metal and ion species dry deposition in central Taiwan. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (8), 2183-2199.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 2183.pdf

Keywords: Dry Deposition, Metal, Ion, Coarse Particle, Fine Particle, Atmospheric Coarse Particles, Surface, Urban

Chang, N.B. and Lin, Y.T. (1997), Optimal siting of transfer station locations in a metropolitan solid waste manaferment system. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (8), 2379-2401.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 2379.pdf

Abstract: System analysis for solid waste management currently receives wide attention from both economic and environmental planners because of their complexity during the coordination of various management strategies. This paper deals with the development and application of an operational solid waste management model through a hierarchical approach, in which the siting problem of transfer stations in a large scale metropolitan region is decomposed into two different levels. This analytical approach encompasses a preliminary screening procedure using the Geographical Information System (GIS) and an optimization analysis by a mixed integer programming model. Four criteria are employed in the screening of initial candidate sites and the optimization of a solid waste collection, recycling, treatment, and disposal system is used to direct waste generation to existing or proposed transfer stations, treatment plants and disposal facilities at minimum cost. A case study in Taiwan shows that the optimal siting strategies of transfer stations can successfully reduce system direct cost and generate relatively reasonable operational programs.

Keywords: Solid Waste Management, Environmental System Analysis, Inear-Programming Approach, Uncertainty

Fytianos, K., Voudrias, E. and Tsechpenakis, A. (1997), Removal of Cr(VI) from aqueous and wastewater samples by fly ash. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 32 (9-10), 2419-2427.

Full Text: 1997\J Env Sci Hea Par A-ESETHSC32, 2419.pdf

Abstract: Batch sorption experiments were conducted to investigate the removal of hexavalent chromium [Cr(VI)] from aqueous solutions and tannery wastewater samples by fly ash. The results showed that the optimum removal was accomplished at pH 2 with a contact time between fly ash and Cr(VI) solution of 2 hours. The isotherm data followed the Freundlich equation and resulted in comparable sorbed phase concentrations for both the aqueous and the tannery wastewater samples spiked with Cr(VI).

Keywords: Adsorption, Chromium(VI), Water

? Wang, J.L., Zhan, X.M. and Yi, Q. (2000), Removal of Cr(VI) from aqueous solution by macroporous resin adsorption. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 35 (7), 1211-1230.

Full Text: 2000\J Env Sci Hea Par A-ESETHSC35, 1211.pdf

Abstract: The removal of Cr(VI) by macroporous anion exchange resin adsorption was investigated. Batch adsorption studies demonstrate that the resin has a significant capacity for adsorption of Cr(VI) from aqueous solution. The parameters investigated in this study included pH, contact time, initial chromium concentration, resin dosage and temperature. The adsorption process of Cr(VI) can be described by Langmuir isotherm and Freundlich isotherm model. Application of the Langmuir isotherm to the systems yielded maximum adsorption capacity of 53.03 mg/g resin. The specific surface areas of the macroporous resin was calculated to be 47.35 m²/g. The kinetics and thermodynamic parameters were also evaluated. It was found that the separation process is partly diffusion controlled. The mass transfer coefficient was calculated to be 8.62×10^-5 cm/s. The activation energy and change of enthalpy were evaluated and found to be 4.81 kcal/mol and 8.79 kcal/mol at the temperature of 25°C, respectively. The free energy of the process was small but positive, and it decreases with an increase of temperature. The change of entropy was found to be small and remains almost unchanged over the 20 to 35°C temperature range. The desorption studies are also performed and the results show that the Cr(VI) adsorbed by macroporous resin can be eluted by 4 M NaOH. This suggested that the resin saturated with chromium can be regenerated by NaOH solution.

Keywords: Chromium, Adsorption, Macroporous Resin, Kinetics, Thermodynamics, Mass Transfer Coefficient, Adsorption Isotherm, Hexavalent Chromium, Carbon

? Aksu, Z. and Dönmez, G. (2001), Comparison of copper(II) biosorptive properties of live and treated Candida sp. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 36 (3), 367-381.

Full Text: 2001\J Env Sci Hea Par A-ESETHSC36, 367.pdf

Abstract: Biosorption of copper(II) ions from aqueous solutions was studied to compare the binding capacities of untreated (live) or treated (dried, autoclaved, perchloric acid (HClO₄)-washed, ethanol-treated, formaldehyde-treated) Candida sp. Due to the ion exchange nature of metal biosorption, copper(II) uptake was strongly affected by the solution pH and optimum adsorption pH value was determined as 5.0 for all the live and treated Candida sp. At the optimal conditions, metal ion uptake increased with increasing initial copper(Il) concentration up to 300 mg l^-1 for all the biomass types. It is found that all the treatment methods used to kill the yeast (except for formaldehyde treatment) increased the copper(II) biosorption capacity of Candida cells. The results also indicated that copper(II) biosorption by live, autoclaved and formaldehyde-treated yeasts was consisted of an initial, rapid surface binding of copper(II) followed by a second, slower intracellular uptake of copper(II), but copper(II) uptake by the other treated yeasts took place only via surface binding. Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of copper(II) by all the untreated and treated Candida.

Keywords: Biosorption, Copper(II), Candida Sp, Saccharomyces-Cerevisiae, Metal-Cations, Biomass, Ions, Bioaccumulation, Removal

? Saito, M. and Magara, Y. (2003), Removal of organic pollutants and metabolic adaptation of microorganisms by micro-aeration. Journal of Environmental Science and Health Part A-Environmental Science and Engineering & Toxic and Hazardous Substance Control, 38 (6), 991-1005.

Full Text: 2003\J Env Sci Hea Par A-ESETHSC38, 991.pdf

Abstract: Aerobic systems are high rate processes for wastewater treatment, but they consume much power for aeration. Several low-cost anaerobic systems have been developed for mid- and low-income countries. The removal efficiencies of nutrients, particulate matter, and pathogens are not satisfactory for the anaerobic systems. Micro-aeration is a type of low-cost aerobic application which enhances oxygen transfer through water surface. Trickling was found the most efficient method of micro-aeration and batch experiments were performed to evaluate the effectiveness. When soluble organic carbon was removed, ORP7 (redox potential rectified to pH at 7) were around -120 or +260 mV. When soluble organic carbon increased due to organic overload, ORP7 was around +30 mV. At +30 mV, carbon fraction of biomass increased to 0.54 (higher than average value of 0.46). It was presumable that the ORP7 of -120, +260, and +30 mV were anaerobic, aerobic, and internal storage mode, respectively. Maximum reaction rate of aerobic condition was four times as high as that of anaerobic condition. At internal storage mode, the rate was halved from aerobic mode. It is concluded that microorganisms adapt the metabolic systems to conform to the redox environment, which can be evaluated by ORP. Organic overload results metabolic shift to internal storage mode which retards mineralization of organic matter.