Showing papers in "Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering in 1989"

Solidification of hazardous substances‐a TGA and FTIR study of Portland cement containing metal nitrates

Abstract: Type I Portland cement samples containing the soluble nitrates of the priority pollutant metals chromium, lead, barium, mercury, cadmium and zinc have been investigated using thermogravimetric and fourier—transform infrared techniques (including diffuse reflectance). The major vibrational bands and thermal stability of the carbonate, sulfate, silicate, water and nitrate species are tabulated and discussed in comparison to uncontaminated Portland cement. The solubility and volatility of mercury in cement and the effect of metal nitrate concentration on the silicate condensation process is discussed. Although results suggest that retardation of cement setting by Zn and Pb salts occurs by limiting hydration, the chemistry of the two processes is distinctly different.

Uptake of mercury from aqueous solution by duckweed: The effects of pH, copper and humic acid

Abstract: Studies indicated that duckweed absorbed mercury in water (e.g. lakes) strongly and that after three days it contained up to 2000 ppm of mercury by weight of duckweed. The uptake of mercury was little affected by acidity at pH 4.0 and pH 5.0. The presence of copper ion suppressed the mercury uptake significantly. The presence of 1.0 mM EDTA in solution also suppressed the mercury uptake significantly. Further 10 mg of humic acid in 400 mL solution suppressed the mercury uptake to some degree, probably by complexing the mercury.

Effect of high salt concentrations on ozone decomposition in water

Abstract: Ozone decomposition in water in the presence of different salts has been studied. The stability of ozone varies depending on the salt nature and the pH. At low pH, molecular phosphoric acid has a positive influence upon ozone conversion. At neutral and basic pH, ozone decomposes through a radical mechanism, whose termination step depends on the type of ionic species present. So, at pH 6 in the absence of salts or in the presence of chloride ions it is proposed a second order termination step. In addition, the direct reaction between ozone and chloride ion has to be considered. When there are sulphate, phosphate or carbonate ions present in the water, the termination step changes to first order due to the hydroxyl radical scavenging effect of these ions. Hence, these ions estabilize molecular ozone in water.

Fly-ash for the treatment of water enriched in lead(II)

Abstract: The removal of Pb(II) is dependent of contact time, concentration, pH and temperature, of the solution. The various rate parameters of adsorption, have been determined at different concentrations and temperatures for the present system. An empirical model has been tested to understand the kinetics of Pb(II) removal at different concentrations. The pore diffusion is mainly rate controlling step. The Langmuir isotherm has been applied to find out the adsorption parameters involved in the present adsorption process. The isosteric heat of adsorption has been determined at different surface coverages of the adsorbent. The negative value of enthalpy change (? H= ‐7.269 Kcal mol‐1) suggests the exothermic nature of the adsorption process. The activation energy has been determined and found to be ‐8.533 Kjoules. The various thermodynamic parameters have been calculated to understand the clear mechanism involved in the adsorption process.

Nitrate leaching under irrigation in the United States—a review

Abstract: The literature was reviewed for nitrate leaching under irrigation The mass of nitrate leached is directly related to the percolation volume Both water management and nitrogen management are important in controlling nitrate leaching Applying only enough nitrogen fertilizer to meet yield goals, timing of nitrogen application and the use of slow release fertilizers are nitrogen management practices that will reduce nitrate leaching There have been a number of nitrogen simulation models that have been developed, but there is a lack of field data to validate the models

Studies on copper removal by lignin solution/suspension

Abstract: The increasing awareness of the potential environmental impacts of heavy metal pollution and the techno‐economic limitations of conventional metal removal techniques have led to the study alternate, inexpensive methods. Lignin, an easily available polymer from pulp and paper industry waste, appears to he an attractive material for heavy metal removal. Copper removal by lignin is affected by both copper and lignin solution pH as well as the lignin dose. Copper removal is also markedly influenced by the extent of lignin in suspension and the final pH of the filtrate. Maximum (95%) Cu removal was obtained with both lignin and copper solution pH at 5.5 and a 1ignin dose of about 1 g/l. The optimum final pH corresponding to maximum Cu removal was between 4.4 and 5.0. Inhibition by hydrogen ions at low pH and dissolution of the lignin‐metal complex at higher pH result in poor copper removals.

Variation in some element contents of water hyacinth due to cadmium or nickel treatment with or without anionic surface active agents

Abstract: The changes in some metal components of water hyacinth by exposure to cadmium, nickel with or without surface‐active agents are determined. Metal contents of Cd, Ni, Al, Ca, Si, Mn in tops and roots were changed in relatively short time by treatment with Cd or Ni. The values of concentration factors are reduced in both tops and roots under the presence of the anionic surface‐active agents.

Penetration of pentachlorophenol and tetrachlorophenol through human skin

Abstract: Penetration of Chlorophenols through Human Skin Penta and tetrachlorophenol are widely used wood preservatives which have received increasing regulatory attention form EPA and OSHA. While primary concerns have focused on dioxin contaminant levels there has been considerable controversy over the risks associated with perdermal penetration: both in the workplace and the environment. Based on very limited acute dose rate experiments, the EPA has estimated dermal penetration of 50% for pentachlorophenol inorganic solutions (typically diesel oil) and 1% for aqueous sodium pentachlorophenate solutions. No estimates are available for tetrachlorophenol. Utilizing human cadaver skin and a validated skin permeation test protocol, departmental investigators have investigated skin penetration of commercial preparations of penta and tetrachlorophenol. The results show penetration of diesel oil preparations to be 62% for pentachlorophenol and 63% for tetrachlorophenol. In the case of an aqueous based commercia...

Modeling and simulation of compressive gravity thickening of activated sludge

Abstract: A mathematical model of compressive thickening is developed which is based on Kos’ model yet can be calibrated from measurements of concentration, concentration gradient, and bulk underflow velocity in continuous thickening experiments. The need for sensitivity and difficult measurements such as interparticle pressure or volumetric solids concentration is eliminated. Numerical programs to simulate the model are described. The model was calibrated and tested using steady state continuous thickening experiments. Unsteady state continuous thickening was studied by use of computer simulation of the model. Programs are described for nonlinear regression of the models to continuous thickening column data, and for steady state and unsteady state simulation.

Identification of heavy residual oils by GC and GC‐MS

Abstract: Seven unweathered heavy residual oils, analyzed and compared for source identification purposes, demonstrate that the comparison of heavy residual oils must be performed with great care using a variety of analytical techniques and comparison methods. Furthermore, these methods are best applied to known common‐source pairs and to known non‐common‐source pairs in addition to the unknown pairs. Physical and chemical tests showed that, for the most part, these properties for the seven oils were within the error range of the test. Visual comparison of the chromatograms also showed that they were very similar. Normalized normal paraffin and isoprenoid peak height profiles, when subjected to measurement‐error and statistical comparisons, provided quantitative evaluations of the relative likelihood that the members of the various oil pairs were from a common source.

Algal assays to interpret toxicity guidelines for natural waters

Abstract: Algal assays were used to establish toxicity guidelines for natural waters. ‘Cu equivalent’ rather than the conventional EC 50 value was used as the toxicity unit. By correlating Cu dosages with % of control growth, Cu reference curves were constructed for our test species, Chlorella and Scenedesmus. These Cu curves, which compensated for species sensitivity differences, were then used to translate algal growth response to toxicity of the test waters. Expressed in Cu equivalent, our test waters displayed a toxicity range from 25 to 300 ug Cu.l‐1 . After further tests with Cu on organisms such as algae, Daphnia and rainbow trout, ‘sensitive’ water where delicate plankton species could not survive, was found at Cu eq. concentrations between 90 and 120 ug.l‐1.

Determination of phenolic pollutants in water using permeation sampling

Abstract: A passive sampling technique for the determination of time‐weighted‐average concentrations of phenolic priority pollutants in water is described. Phenols permeate a silicone polycarbonate membrane and are collected on a polymeric adsorbent. For high concentration ranges, phenols are adsorbed on the XAD‐7 resin and then desorbed with acetonitrile. Low ppb concentrations of phenols are analyzed by collection on Tenax‐TA followed by thermal desorption. Separation and quantification is achieved by capillary column gas chromatography using a flame ionization detector. A linear relationship between the amount of phenols collected and the products of the exposure time and phenolic concentrations over the range of 5 ppb ‐ 20 ppm have been determined. Temperature and solution pH affect permeation rates of the phenols. The sampling method is simple, inexpensive and suitable for multilocation monitoring.

Evaluation of Henry's constant for H2S in water and sewage effluents

Abstract: An experimental set‐up was used to evaluate Henry's constant (H) of H2S in distilled water and one of the sewage treatment plants in Kuwait. Calculated values of (H) for H2S in distilled water were found to agree with published works. For sewage, (H) was found to have a mean value of 601 atm/mole fraction for a temperature range of 20°C to 40°C. Factors affected the value of (H) in sewage were: initial concentration, flow rate of stripping fluid, pH, and pK. Effect of each factor was investigated and results were correlated.

Carbon dioxide concentration as indicator of indoor air quality

Abstract: The concentration of carbon dioxide in office building was used to monitor indoor air quality. A total of one hundred and one (111) measurements was carried out in five buildings during the last th...

Aerobic treatment of molasses distillery waste hater and biomass production

Abstract: Molasses stillage 1s a pyproduct of the sugar cane Industry in Egypt. Candida utilis and Paecilomyces variotii were used separately and in a mixed culture for treatment of this still age and biomass production. A two‐steps aerobic batch process has been adopted. The distillery waste water was treated with C. utilis 1n the first step and with P.. variotii 1n the second step, which was carried out on the supernatant from the first step. The total reduction of the chemical oxygen was found to be 90%, using the mixed culture. On the other hand, the produced biomass was 22 gL‐1, using the mixed culture with a productivity of about 0.5 gL‐1h‐1. On using C. utilis, the biomass produced was 18 gL‐1 and the reduction of the COD of 45% was obtained. Meanwhile, the biomass produced was 5 gL‐1 and the reduction 1n COD of 70% was achieved, using J variotii. The chemical composition and amino content as well as the biological value of the produced biomass have been given. The amino acid profiles are very simil...

Biodegradation of trichloroethylene by bacteria indigenous to a contaminated site

Abstract: Bacteria indigenous to a trichloroethylene (TCE) contaminated site were exposed to 0.56 and 6.7 mg L‐1 TCE. Under the aerobic, oligotrophic conditions of the microcosms, the populations were able to degrade TCE and to increase their numbers by two orders of magnitude within one week. No other substrate was added. The average TCE disappearances were 47 percent and 33 percent for initial TCE concentrations of 0.56 and 6.7 mg L‐1, respectively. No TCE disappearance was observed in controls. Results of individual microcosms suggest that bacteria degraded TCE to levels as low as 1–2 percent of the initial concentration. Lag times of 14 and 18 days were observed for the 0.56 and 6.7 mg L‐1 concentration microcosms, respectively. Bacterial population shifts were noted throughout the experiment. None of the isomers of a dehalogenation reaction were found.

Kinetic study of anaerobic digestion of glucose and sucrose

Abstract: This paper reports the behaviour of an anaerobic digester fed with pure, easily biodegradable substances (glucose and sucrose); for this a kinetic model was used based on the kinetic equation of growth in microorganisms defined by Contois. The model predicts with great exactitude the yields of the digester. Similarly a heavy dependency is observed on the maximum growth rate of the microorganisms of the type of substrate and the concentration of the influent.

Growth and metal accumulation of forage grasses at various clipping dates on acid mine spoils

Abstract: Dry matter yield, heavy metals and Al accumulation by seven forage grasses, bermudagrass (Cynodon dactylon). Kentuckty 31‐tall fescue (Festuca arundinacea), oat (Avena sativa), orchardgrass (Dactylis glomerata), perennial ryegrass (Lolium perenne), triticale (× Triticosecale Wittmack) and winter wheat (Triticum aestivum) were investigated on three different Alabama acid mine spoils. The objective was to study the growth response (dry matter basis) and metal accumulation at different clipping dates to determine which grasses may be effectively used to lower metal levels in the acid spoils during reclamation. The grasses were clipped at 47, 58, 68 and 83 days after planting and dry matter yield and tissue levels of metals determined. Bermudagrass grew best on all spoils and clipping intervals did not generally influence dry matter yield and metal accumulation. The other grasses had late (oat only) or early restricted growth and were not considered effective for use in reclamation of spoils studied ...

Atmospheric weathering caused by dry deposition of acidic compounds

Abstract: The study was conducted to investigate the effects of deposition on galvanized steel and painted panels using mobile covering/deionized spray devices at exposure sites located at Steubenville, OH and Research Triangle Park (RTP), NC. Ambient rain and deionized spray runoff samples from the panels were collected on an event basis for seven months and underwent detailed chemical analysis. The analysis indicated that the dry deposition of acid gases at the sites increased the dissolution rate of galvanized steel corrosion products. Although the average SO2 level in Steubenville was ten times the RTP value, the rate of Zn dissolution was only 1.9. This result in conjunction with the presence of large amounts of Ca in the Steubenville runoff samples suggest that neutralization of acidic gases by dry deposited basic particulates may be important at the Steubenville site. At the RTP site low levels of anions were found in the runoff from the painted panel with H(1+) as the most abundant cation. This result is consistent with the lack of reactivity towards acidic gases due to the absence of alkaline paint components.

Heavy metals in marine organisms of geras gulf, lesvos, Greece

Abstract: The concentration of copper, iron, chromium and nickel in fish and shellfish of Geras gulf, Lesvos island, Greece are determined. Method used is that of Atomic Absorption Spectrometry. Correlation of metal concentration to species and season of the year is tried. Data are compared to the dally allowable values for human beings.

Major, minor and trace element determinations from a Nigerian aquatic sediment

Abstract: Major, minor and trace quantities of ten stable elements have been determined from the aquatic sediments of the Kubanni River Dam (KRD), at Zaria, Nigeria. Instrumental Neutron Activation Analysis (INAA) was used in determining Na, Al, K, Ti, V, Mn, Ba, Sm, Dy and U in the sediment. Four of these elements (Al, Ti, V, Mn) were identified in all the cores with a strong correlation of Al with Ti. Levels of Al, Ti, V, Mn, are intimate indicators that the weathered depositions in the sediments have granitic provenance. Our data for these stable elments will serve as reference levels for assessing further depositions in the aquatic environment as well as baseline information for the proposed continuous monitoring of the area by the research Centre.

Variation in growth and fatty acid contents of trichoderma viride induced by herbicides

Abstract: Summary Effect of paraquat and trifluralin on the growth of a Kuwaiti soil isolate, Trichoderma viride has been studied. The former herbicide inhibited the growth of the microorganism while the latter had little effect on its growth pattern. An analysis of the fatty acid pattern after interaction of the microorganism with paraquat revealed a consistent decrease in the saturated fatty acids content while a consistent increase in polyunsaturated fatty acids was observed. A possible explanation for the changes in fatty acids of the organism is offered.

Interaction of zinc, copper and nickel in soil on yield and metal content in rice

Abstract: Pot culture experiment was conducted under flooded condition using alluvial soil (Haplaquept) with rice cultivar Ratna as the test crop. The treatment consisted of 33 factorial combination of Zn (200, 400 and 800 mg kg‐1 soil) Cu (50, 100 and 200 mg kg‐1 soil) and Ni (25, 50 and 100 mg kg‐1 soil). Significant metal interaction effects for Zn‐Cu, Cu‐Ni and Zn‐Cu‐Ni were observed both for grain and straw yield. The step‐wise multiple regression analyses indicated that the prediction values for grain yield increased significantly when DTPA extractable metals were taken into consideration rather than the metal addition rate. The relative metal contents both the grain and straw were in the order Zn>Cu>Ni. Significant interaction effect of Zn‐Cu was observed for all the three metals both in grain and straw. The mean values of DTPA extractable metals in the post‐harvest soil were 23, 22 and 16 per cent of the added levels for Zn, Cu and Ni, respectively. The metal interaction effects in soil particularl...

Automated permeation sampler for phenolic pollutants

Abstract: A method for the determination of phenolic pollutants in water using an automated permeation sampler is described. Phenols permeating through a membrane are purged into a sampling tube containing Tenax‐TA adsorbent. Samples collected are thermally desorbed onto a capillary column gas chro‐matograph. Phenolic concentrations as low as 10 ppb for several phenols can be achieved by this method. The automated permeation sampler provides an alternative way to monitor concentration of phenolic pollutants. This method has several advantages over the conventional method, such as eliminating time‐consuming preconcentration steps, avoiding use of solvents and providing a high degree of automation.

Evaluation of potassium permanganate for inactivation of bacteriophage MS-2 in water systems

Abstract: Potassium permanganate (KMnO4) has been as an oxidant for decades to remove and control iron and manganese in surface water supplies. This oxidant was investigated for its ability to inactivate bacteriophage MS‐2 and thereby reduce the amount of chlorine required for a 99.99% reduction of virus during drinking water treatment as required by the U.S. Environmental Protection Agency's Surface Treatment Rule (U.S. EPA 1989). Experiments were conducted in potassium monophosphate buffer (pH 6.0 and pH 8.0) at 7°C. At time intervals from 0 to 30 min, samples were taken and mixed immediately with a solution of sodium thiosulfate:sodium thioglycolate to neutralize residual KMnO4. At 0.5 and 5.0 mg/L KMnO4, results showed no significant differences (p<:0.05) in the inactivation of MS‐2 between experiments done at pH 6.0 and those at pH 8.0. Ninety‐nine percent of the virus was inactivated after 50, 35, and 5 min of exposure time to 0.5, 1.5, and 5.0 mg/L potassium permanganate at pH 8.0, respectively. It ...

Influence of best management practices on water quality in the appoquinimink watershed

Abstract: Surface and ground‐water quality were monitored in the Appoquinimink Watershed as part of the Appoquinimink Rural Clean Water Project (RCW)). Surface water was monitored for seven years and ground water was monitored for three years. As part of the RCWP plan, conservation tillage, fertilizer management and pesticide management were the most widely used best management practices. Best management practices decreased total phosphorus and total suspended solids concentrations in surface water. The unfiltered ortho phosphorus as a percentage of total phosphorus increased. Nitrogen concentrations did not change over the seven year monitoring period. The BOD concentrations increased because of increased residues left on the surface from conservation tillage. Atrazine was detected in the shallow ground water at concentrations ranging from 1 to 45 μg/L. Aldicarb was only detected in one monitoring well. Nitrate concentrations were above 10 mg/L in some areas of the watershed.

Dissolved oxygen dynamics in the mid‐passaic river: Mathematical model

Abstract: A systematic methodology for mathematically simulating photosynthetically driven DO variations in the mid‐Passaic River system is presented and discussed. A steady‐state model for BOD‐DO dynamics, calibrated and verified to data from two stream surveys conducted during the Summer and Fall of 1983, is first presented. Diurnal DO fluctuations due to algal photosynthetic activity are then simulated by Fourier series. The resultant models display good correlation to the data.

Measurement of blood-lead levels in school children of Jeddah Saudi Arabia and assessment of sub-toxic levels of lead on some sensitive hematological parameters

Abstract: Blood samples from 200 Saudi Arabian school boys, aged 6–8 years, were analyzed for their Pb concentrations by graphite furnace atomic absorption spectrometry, Mean Blood‐Pb concentration was found to be 69 (±34) ug/dl The blood samples were also examined for some hematological parameters : total counts of erythrocytes and leucocytes, hematocrit, mean corpuscular volume, hemoglobin, mean corpuscular hemoglobin concentration, and basophilic stippling, using a Coulter Counter All values obtained were within the ‘normal ranges’ However, the hematological effects of sub‐toxic levels of Pb in blood were assessed by considering the seven cases whose Blood‐Pb values were between 15 ‐ 25 ug/dl The data indicate that sub‐toxic levels of Pb in blood may be related to early stages of microcytic anemia

Blood selenium in select mid‐income Florida employees

Abstract: Blood samples from 19 healthy, mid‐income Floridians (5 females, 14 males) were collected and analyzed for copper, zinc, and selenium using atomic absorption spectroscopy. The mean (± 1 S.D.) values were copper 1.00 ± 0.29 ppm; zinc, 0.86 ± 0.19 ppm; and selenium, 132 ± 29 ppb. The mean selenium level for the females (n = 5) was 125 ± 37 ppb and 132 ± 31 ppb for males (n = 14). No significant difference was observed for the two groups. No correlation was observed between copper and zinc. The correlations between zinc and selenium appeared to fall into two groupings, and the correlation between copper and selenium appeared to be slightly negative. These are among the relatively few data that have been collected for selenium levels in Floridians, and implications are discussed.

Effect of competition on the adsorption of some ions (copper, zinc, zirconium, selenium and strontium) on river ‐ mud

Abstract: The effect of presence of several ions as competing ions during the adsorption process of copper, zinc, zirconium, selenium and strontium on river‐mud has been studied. The effect of concentration of competing ions on their competitive efficiencies has been concluded. The competitive efficiencies of the ions studied here have been compared and arranged.