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PubMed2006

Effect of modified Fenton's reaction on microbial activity and removal of PAHs in creosote oil contaminated soil.

This study describes the removal of polycyclic aromatic hydrocarbons (PAHs) from creosote oil contaminated soil by modified Fenton's reaction in laboratory-scale column experiments and subsequent aerobic biodegradation of PAHs by indigenous bacteria during incubation of the soil. The effect of hydrogen peroxide addition for 4 and 10 days and saturation of soil with H(2)O(2) on was studied. In both experiments the H(2)O(2) dosage was 0.4 g H(2)O(2)/g soil. In completely H(2)O(2)-saturated soil the removal of PAHs (44% within 4 days) by modified Fenton reaction was uniform over the entire soil column. In non-uniformly saturated soil, PAH removal was higher in completely saturated soil (52% in 10 days) compared to partially saturated soil, with only 25% in 10 days. The effect of the modified Fenton's reaction on the microbial activity in the soil was assessed based on toxicity tests towards Vibrio fischeri, enumeration of viable and dead cells, microbial extracellular enzyme activity, and oxygen consumption and carbon dioxide production during soil incubation. During the laboratory-scale column experiments, the toxicity of column leachate towards Vibrio fischeri increased as a result of the modified Fenton's reaction. The activities of the microbial extracellular enzymes acetate- and acidic phosphomono-esterase were lower in the incubated modified Fenton's treated soil compared to extracellular enzyme activities in untreated soil. Abundance of viable cells was lower in incubated modified Fenton treated soil than in untreated soil. Incubation of soil in serum bottles at 20 degrees C resulted in consumption of oxygen and formation of carbon dioxide, indicating aerobic biodegradation of organic compounds. In untreated soil 20-30% of the PAHs were biodegraded during 2 months of incubation. Incubation of chemically treated soil slightly increased PAH-removal compared to PAH-removal in untreated soil.

Aliivibrio fischeri↗
PubMed2005

Source apportionment of groundwater pollution around landfill site in Nagpur, India.

The present work attempts statistical analysis of groundwater quality near a Landfill site in Nagpur, India. The objective of the present work is to figure out the impact of different factors on the quality of groundwater in the study area. Statistical analysis of the data has been attempted by applying Factor Analysis concept. The analysis brings out the effect of five different factors governing the groundwater quality in the study area. Based on the contribution of the different parameters present in the extracted factors, the latter are linked to the geological setting, the leaching from the host rock, leachate of heavy metals from the landfill as well as the bacterial contamination from landfill site and other anthropogenic activities. The analysis brings out the vulnerability of the unconfined aquifer to contamination.

Enterobacteriaceae↗
PubMed2007

Pentacyclic triterpenes with selective bioactivity from Sebastiania adenophora leaves, Euphorbiaceae.

Six known pentacyclic triterpenes possessing oleanane, lupane, or taraxerane-type skeletons were isolated from the leaves of Sebastiania adenophora (Euphorbiaceae) and are reported for the first time in this species. These compounds include 3-epi-beta-amyrin, beta-amyrinone, 3-epi-lupeol, lupenone, taraxerol, and taraxerone. Structures were elucidated by comparison with literature data. The bioactivities of these compounds were tested on the root growth of Amaranthus hypochondriacus, amaranth (Amaranthaceae), Lycopersicon esculentum, tomato (Solanaceae), and Echinochloa crus-galli, barnyard grass (Poaceae). All six triterpenes were selectively bioactive. An important stimulatory effect was observed on amaranth root growth (23% to 56%) for almost all tested triterpenes (250 microg/ml). These triterpenes significantly inhibited the root growth of barnyard grass (28% to 78%) and tomato (23% to 49%). Aqueous leachate and organic extracts of S. adenophora leaves significantly inhibited the root growth of all test species. The possible ecological role of the allelochemicals isolated is discussed.

Euphorbiaceae↗
PubMed1987

The determination of trace metals in sweat by anodic stripping voltammetry.

Sweating was induced on the forearm of subjects by pilocarpine iontophoresis, and the sweat collected on a small membrane filter. Zinc, cadmium, lead and copper were then determined in the filter by anodic stripping voltammetry (ASV) using one of two alternative techniques: leaching the filter with a supporting electrolyte (0.1 M NaNO3/0.002 M HNO3), followed by ASV of the leachate; or, direct ASV analysis of the trace metals in the membrane filter using a novel thin-layer cell. Average values found for zinc, cadmium, lead and copper in sweat from males were (micrograms 1-1): 720, less than 3, 15 and 80, respectively. Copper in sweat from females was lower (23 micrograms l-1) than for males, although use of oral contraceptives appeared to increase copper concentration.

Electrochemistry↗
PubMed1988

Environmental implications of incineration of municipal solid waste and ash disposal.

Owing to unsightliness and the threat of groundwater pollution, landfilling of municipal solid waste (MSW) is giving way to incineration in many communities. Environmental contamination from particulate and gaseous emissions containing heavy metals, polychlorinated dibenzodioxins (PCDD) and polychlorinated dibenzofurans (PCDF), polycyclic aromatics (PCA), acids and other compounds from such incinerators, as well as safe ash disposal, are of great concern. Concentration ranges of elements and organic toxicants in incinerator ashes, emissions and cooling waters are given. The literature is reviewed concerning the effects of incinerator operating parameters on emissions. Incinerators equipped with modern pollution control devices (electrostatic precipitators, fabric filters, dry scrubbers, spray towers) and operated at optimum temperature with sufficient oxygen, turbulence (mixing) and residence time for complete combustion appear to minimize ash, elemental, gaseous and organic emissions. Environmental aspects of MSW incineration are considered and reviewed. The presence of metals and organics in incinerator quench water and in leachates from ash disposed in landfills are reviewed, as well as their toxicity to fish. The behavior and effects of atmospheric emissions in soils and plants are discussed. Research on the effect of ash-derived PCDD and PCDF on hepatic microsomal mixed function oxidase activity and the immune system in laboratory animals is cited. The presence of metals, organics and mutagens in the incinerator workplace air and the possible effects of air-borne contaminants on inhabitants nearby is reviewed. Several studies dealing with human risk assessment of MSW incineration are cited.

Animals↗
PubMed1988

Determination of heavy metals in samples of urban solid wastes by means of the ICP atomic spectrometry technique.

The concentration of elements of environmental significance in the leachate from landfills of urban solid wastes was determined by means of Inductively-Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The suitability of extraction tests which simulate the leaching process were undertaken. Both highly toxic elements (As, Cd, Co, Cr, Pb and V) and elements present at major concentrations (Al, B, Cu, Fe, Mn, Ni and Zn) were quantified at different levels within and under the landfill. Results showed that the extraction test recommended by EPA is acceptable in order to simulate natural leaching compared with the amounts of the elements which are brought into solution after digestion with nitric acid. Furthermore, significant correlations were found in the landfill composition at different levels for element pairs such as Al-Mn, Co-Cr, Co-Cu, Co-Fe, Co-Mn, Co-Zn, Cr-Fe, Cr-Mn, Cu-Fe, Cu-Zn, Fe-Mn, Fe-Zn, Mn-Zn and Pb-Zn.

Humans↗
PubMed1989

Mutagenicity and disposition of chromium.

Hexavalent chromium was administered to rats at doses of 20-240 mumol kg-1 for several periods of time, from 2 to 14 days. Lung, liver and blood contained the highest amounts of chromium, as detected by atomic absorption or by ICP, 24 h after cessation of treatment. A maximum of 40% of the dose was recoverable in organs along with feces and urine at this same time period, and chromium in soil (5.6% Cr) was absorbed better than equimolar amounts of the hexavalent chromates of calcium or sodium. The contaminated chromium-containing soil was found to have 30-35% of the chromium in the hexavalent state. The mutagenicity of chromium as tested in the bacterial strain of Salmonella typhimurium (strain TA 104) was decreased when tested without metabolic activation with the addition of leachate (of inexact analysis) from a waste site. When studied by alkaline elution, chromium (5-20 microM) caused single strand breaks as well as DNA-protein crosslinks in A549 lung cells, while with L1210 mouse leukemia cells, only DNA-protein crosslinks were found. Chromium(III) compounds caused no damage to DNA.

Animals↗
PubMed1992

Occurrence of butyltin species in sewage and sludge in Canada.

Samples of sewage treatment influent, effluent and sludges collected monthly from five Canadian cities over the period from July 1990 to January 1991 were analysed for butyltin and octyltin species. Monobutyltin was found in all influent samples, but dibutyltin and tributyltin were found only infrequently, and octyltin species were not found at all. In the case of monobutyltin, there was significant reduction in its concentration by degradation and adsorption to sludge during passage through the sewage treatment plant. The average reduction was 40%. The monobutyltin found in the effluent likely came from its use as a poly (vinyl chloride) stabilizer, and from the degradation of tributyltin, which is used as a slimicide. No butyltin or octyltin species was found in five landfill leachate samples in southern Ontario during the same period.

Canada↗
PubMed1994

Toxicity of nickel ores to marine organisms.

Queensland Nickel proposes to import New Caledonian (Ballande) and Indonesian (Gebe) nickel ores, one option being ship-to-barge transfer in Halifax Bay, North Queensland. Because small amounts of ore may be split during the unloading and transfer operations, it was important to investigate the potential impact of the spilt ore on the ecological health of the Bay. Long-term leaching of the ores with seawater showed that only nickel and chromium (VI) were released from the ores in sufficient concentrations to cause toxicity to a range of marine organisms. The soluble fractions of nickel and chromium (VI) were released from the ores within a few days. Nickel, chromium (VI) and the ore leachates showed similar toxicity to the juvenile banana prawn Penaeus merguiensis, the amphipod Allorchestes compressa and both temperature (22 degrees C) and tropical (27 degrees C) strains of the unicellular marine alga Nitzschia closterium. In a series of 30-day sub-chronic microcosm experiments, juvenile leader prawns Penaeus monodon, polychaete worms Galeolaria caespitosa and the tropical gastropod Nerita chamaeleon were all very resistant to the nickel ores, with mortality unaffected by 700 g ore per 50 l seawater. The growth rate of the leader prawns was, however, lower than that of the controls. From these data, a conservative maximum safe concentration of the nickel ores in seawater is 0.1 g l-1. The nickel ore was not highly toxic and if spilt in the quantities predicted, would not have a significant impact on the ecological health of the Bay.

Animals↗
PubMed1996

Burning radionuclide question: what happens to iodine, cesium and chlorine in biomass fires?

Fires can mobilize radionuclides from contaminated biomass through suspension of gases and particles in the atmosphere or solubilization and enrichment of the ash. Field and laboratory burns were conducted to determine the fate of I, Cs and Cl in biomass fires. Straw, wood, peat, dulse (seaweed) and radish plants were combusted with temperatures varying from 160 to 1000 degrees C, representing the normal range of field fire temperatures. Loss to the atmosphere increased with fire temperature and during a typical field fire, 80-90% of the I and Cl, and 40-70% of the Cs was lost to the atmosphere. The remainder was left behind in the ash and was soluble. Typically, the ash was enriched in I by a factor of two to three, with higher enrichments of Cs and lower enrichments of Cl, when compared to the initial fuel concentration during field burns. Most of the I was lost to the atmosphere as a gas. If the elements were radioactive isotopes, such as 129I, 137Cs and 36Cl, fires could cause an increased radiological dose to people through inhalation, exposure to ash, or ingestion of plants because of increased uptake of ash leachate.

Air Pollutants, Radioactive↗
PubMed1983

Waste-related cadmium cycle in Switzerland.

The anthropogenic contribution to the global cadmium flux exceeds natural sources by a factor of three. The most important pathway is the atmosphere; therefore, high cadmium concentrations can be found even in remote areas. On a local level, the increase in cadmium consumption can be observed in increasing concentrations in the soil, plants, and food. The question arises as to what extent the soil-plant-man-waste-soil cycle can be loaded with cadmium in order to function without negative impact on the environment. In Switzerland, 120 tons (t) of cadmium are consumed per year. Of this amount, 25 t end up in municipal solid waste, 3 t in wastewater, and 19 t in precipitation and dry fallout. As a consequence of today's waste management practice (75% incineration, 20% sanitary landfill, 5% composting; 75% of all sewage is purified), the annual input to the soil is 40 t: 18 t concentrated in landfills, 19 t dissipated via the atmosphere, and 3 t directly spread via sewage sludge, compost, and fertilizer on agricultural land. If even distribution were possible, the cadmium content of the soil would theoretically double in 150 years. The accumulation in the soil will increase the cadmium content of plants grown on such a soil. According to a simple model, the level of 3 ppm cadmium in soils should not be surpassed. At such concentrations, plants are likely to contain greater than 0.4 mg Cd/kg, a concentration which can cause toxic effects in long-term experiments. The safe level in food might be even lower. In reality, cadmium is not evenly distributed over Switzerland. According to today's practice, it must be assumed that in only 14 years the use of compost will have enriched soils to such an extent that its cadmium content will prohibit the production of food for human consumption. For sewage sludge, this timespan is 130 years. If heavy metal limits in food are to be observed, the input of such metals to the soil has to be limited. In a steady state, the cadmium input to the soil should be equal to its output via plants, leachate, and erosion. This implies that today's dissipative use of cadmium must be stopped.

Air Pollutants↗
PubMed1987

Unavailability of polynuclear aromatic hydrocarbons from coal particles to the eastern oyster.

The accumulation by oysters of polycyclic aromatic hydrocarbons (PAH) from coal dust entering the estuarine environment has been postulated in the vicinity of coal transfer operations. Oysters Crassostrea virginica were exposed to coal dust plus 15 day leachate at concentrations of 10 mg litre(-1) and 1 mg litre(-1) coal dust for 28 days in a flow-through test system. Potential effects of the exposures were measured by comparing the uptake of PAH and the growth of the exposed animals versus control groups. Oysters sampled at 7, 14 and 28 days did not exhibit an increase in PAH body burden over control animals provided the guts were first purged of particulates. Even at the high test concentrations (10 mg litre(-1)), no effect of the exposure on shell growth was observed.

Journal Article↗
PubMed1989

Effect of pH and inoculum size on phenol degradation by bacteria isolated from landfill waste.

Four aerobic species of mesophilic bacteria which catabolise phenol as the sole carbon source were isolated from landfill waste, and identified as Acinetobacter, Arthrobacter, Micrococcus and Nocardia spp. In vitro studies in defined medium revealed variations in abilities of the isolates to catabolise phenol, and in pH growth optima ranging from 6.8 to 7.6. The pH of culture media decreased with growth, and phenol catabolism was impeded below pH 5.4. Phenol catabolism in landfill leachate occurred after longer lag phases than in defined medium, and relative efficiencies of phenol catabolism did not correspond with the patterns in defined medium. Inoculum size affected phenol removal rates. The results describe factors which may be manipulated to prevent pollution problems in the codisposal of phenolic industrial waste.

Journal Article↗
PubMed1990

Limited compensation of ozone stress by potassium in Norway spruce.

The effects of potassium fertilization and ozone stress were investigated in a clone of Picea abies (L.) Karst, by studies of the uptake of CO(2) by the crowns, the element content, on leaching of the youngest needles, and the longevity of the needles. All plants were exposed to 0.075 microl litre(-1) SO(2) from January to April 1986. The average ozone concentrations applied during the subsequent growing season (May-December) were 0, 0.027, 0.050 and 0.100 microl litre(-1). Half of the trees received liquid fertilizer applications from April to July 1986. CO(2) uptake by the crowns was significantly reduced in non-fertilized plants at ozone doses of 100-200 microl litre(-1) h, whereas similar reductions were recorded in fertilized plants only above an ozone dose of 300 microl litre(-1) h. Independent of the fertilization, however, the concentrations of calcium, magnesium and nitrogen in the needles increased in parallel with the ozone dose, whilst potassium, phosphorus and sulphur showed little response to ozone. In both nutrient regimes, the diffusive loss of elements from chloroform-washed needles was similar and tended to be reduced at the highest ozone concentration, when relating the leachate to the corresponding element content in the needles. Needles formed in the highest ozone treatment were significantly shed during the succeeding year, regardless of the nutrient supply. It appears that increased potassium supply has little compensating effect on ozone stress in spruce.

Journal Article↗
PubMed1992

Studies on leaching from spruce twigs and beech leaves.

Leaching, depending on the acidity of the eluent, was investigated for K, Mg and Mn. The curves for the leachate concentration versus time could be described by a power function. Leaching from old needles exceeded leaching from young needles to a high degree, but the ratios of the leached elements were almost equal. A method for continuous measurements of pH change in solutions contacting plant materials was developed. The results were in agreement with data on acidity changes in water falling through spruce or beech canopies.

Journal Article↗
PubMed1995

Use of freshwater plants for phytotoxicity testing: a review.

Phytotoxicity data for aquatic plants have served a relatively minor role in regulatory decisions concerning the environmental hazard of most potential contaminants. A variety of phytotoxicity tests have been conducted with freshwater green algae, duckweed, blue-green algae, diatoms and rooted macrophytes (whole plants and seeds). Several test methods have been standardized for microalgae which are used primarily with chemicals, effluents, contaminated sediment elutriates and hazardous waste leachates. Current scientific understanding concerning the phytotoxic effects of these contaminants is based mostly on results for a few green algae. The greatest limitation of these results is their uncertain environmental relevance due to the large interspecific variation in response of standard algal test species and the unrealistic experimental test conditions. Results of the few field validation toxicity tests conducted to resolve this uncertainty have been chemical-specific and unpredictable. Aquatic vascular plants have been used less frequently than algae as test species. Duckweeds have been used more often than rooted submersed species but the uncertain nature of their sensitivities relative to animal and other plant species has limited their use. Regulatory interest in wetland protection, contaminated sediment evaluations and sediment quality criteria development will result in increased use of whole rooted plants and their seeds as test species. Overall, regardless of the test species, if phytotoxicity data are to be more available and effective in the hazard assessment process, additional information concerning species sensitivity, and environmental relevance of the results will be needed.

Journal Article↗
PubMed1989

Immunotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the Love Canal.

The organic phase of the leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The immunotoxic potential of OPL was determined in two mouse strains which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was administered in corn oil in a single oral gavage to male BALB/cByJ (Ahb/Ahb) mice (0.5, 0.8, or 1.1 g/kg) and DBA/2J (Ahd/Ahd) mice (0.6, 0.9, or 1.3 g/kg). TCDD was similarly administered at 0.25, 1.0, 4.0, or 16.0 micrograms/kg. Two days later all mice were immunized with sheep erythrocytes (SRBC). The antibody response (PFC) and organ weights were evaluated 4 days later. OPL produced thymic atrophy and hepatomegaly in both strains at all dose levels. The PFC/spleen in BALB/cByJ mice was significantly reduced at the three doses to 34, 13, and 15%, respectively, of the control response. Serum anti-SRBC antibody levels and relative spleen weights were also reduced. The only immune effect in the DBA/2J mice was a decrease of the PFC/spleen to 58% of the control at the highest dose. TCDD decreased the relative thymus and spleen weights only in BALB/cByJ mice. However, TCDD produced hepatomegaly, a decrease in serum antibody, and a decrease in PFC/spleen in both BALB/cByJ and DBA/2J mice to 3 and 15%, respectively, at 16 micrograms/kg. Thus, the TCDD dose required to cause a 50% suppression (ED50) of PFC/spleen for the BALB/cByJ and DBA/2J strains was 1.84 and 3.89 micrograms/kg, respectively. The ED50 for OPL was 0.24 g/kg in BALB/cByJ mice. The TCDD concentration in the OPL was estimated to be 7.6 ppm, which agrees closely with the chemical analysis (3 ppm). The results suggest that the immunosuppression caused by OPL in BALB/cByJ mice was primarily due to TCDD, that the non-TCDD components of OPL diminished the TCDD immunotoxicity in the DBA/2J strain, and that the thymic atrophy and hepatomegaly were caused primarily by the non-TCDD components of the OPL.

Animals↗
PubMed1989

Teratology of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the love canal.

The organic phase of a leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). The teratogenic potential of OPL was determined in two inbred and one hybrid mouse strain which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was orally administered in corn oil on Days 6-15 of gestation to C57BL/6J mice (Ahb/Ahb) at doses of 0, 0.1, 0.3, 0.5, and 0.7 g kg-1 day-1 and to DBA/2J (Ahd/Ahd) females, which were mated with either DBA/2J or C57BL/6J males, at 0, 0.5, 1, and 2.0 g kg-1 day-1. In C57BL/6J mice, which express a high-affinity Ah receptor that avidly binds TCDD, the ED50's of OPL for cleft palate and hydronephrosis were 0.44 and 0.11 g OPL kg-1 day-1, respectively. Maternal mortality was 5% at the highest dose. In DBA/2J fetuses, which express a low-affinity receptor, neither treatment-related cleft palate nor hydronephrosis was induced by dose levels that caused 36% maternal mortality. In hybrid D2B6F1 fetuses, the incidence of cleft palate reached only 8% at 2 g OPL kg-1 day-1 but the ED50 for hydronephrosis was 0.76 g OPL kg-1 day-1. TCDD was similarly administered to pregnant C57BL/6J mice at 0, 0.5, 1, 2, and 4 micrograms kg-1 day-1 and to DBA/2J mice at 0, 0.5, 2, 4, and 8 micrograms kg-1 day-1. In C57BL/6J fetuses, the ED50's for cleft palate and hydronephrosis were 4.6 and 0.73 microgram TCDD kg-1 day-1, respectively. In DBA/2J fetuses the ED50's for cleft palate and hydronephrosis were 15.0 and 6.4 micrograms TCDD kg-1 day-1, respectively. Both the OPL and TCDD caused maternal hepatomegaly and thymic atrophy in all strains, but increased only C57BL/6J fetal weights. OPL decreased the number of fetuses per C57BL/6J dam at the two highest doses but there were no other reproductive effects in any of the groups. It was concluded that the OPL is teratogenic and that hydronephrosis is a sensitive measure of TCDD toxicity in a complex organic mixture. Based on the ED50's of OPL- and TCDD-induced cleft palate and hydronephrosis in the C57BL/6J strain, the OPL had TCDD equivalence of 6.6 and 10.5 ppm, respectively. These values compare closely with the chemical analysis of 3 ppm.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗