Chromium uptake by rice and accumulation in soil amended with municipal solid waste compost

Effect of addition of municipal solid waste compost (MSWC) on chromium (Cr) content of submerged rice paddies was studied. Experiments were conducted during the three consecutive wet seasons from 1997 to 1999 on rice grown under submergence, at the Experimental Farm of Calcutta University, India. A sequential extraction method was used to determine the various chromium fractions in MSWC and cow dung manure (CDM). Chromium was significantly bound to the organic matter and Fe and Mn oxides in MSWC and CDM. Chromium content in rice straw was higher than in rice grain. Chromium bound with organic matter in MSWC best correlated with straw Cr (r=0.99**) followed by Fe and Mn oxides (r=0.97*) and water soluble as well as exchangeable fractions (r=0.96*). The water soluble and the exchangeable fractions in MSWC best correlated with grain Cr (r=0.98*). The Cr content of rice grain had the highest correlation with water soluble and exchangeable Cr (r=0.99**) while the straw Cr best correlated with the Fe and Mn oxides (r=0.98*). Both the carbonate bound and residual fractions in MSWC and CDM did not significantly correlate with rice straw and grain Cr. MSWC would be a valuable resource for agriculture if it can be used safely, but long-term use may require the cessation of the dumping by the leather tanneries and other major contributors of pollutants.     

Trace gases and particulate matter emissions from wildfires and agricultural burning in Northeastern Mexico during the 2000 fire season

An inventory of air pollutants emitted from forest and agricultural fires in Northeastern Mexico for the period of January to August of 2000 is presented. The emissions estimates were calculated using an emissions factor methodology. The inventory accounts for the emission of carbon monoxide (CO), methane, nonmethane hydrocarbons, ammonia, nitrogen oxides, and particulate matter (PM). Particulate matter emissions include estimates for fine PM and coarse PM. A total of 2479 wildfires were identified in the domain for the period of interest, which represented approximately 810,000 acres burned and 621,130 short tons emitted (81% being CO). The main source of information used to locate and estimate the extent of the fires came from satellite imagery. A geographic information system was used to determine the type of vegetation burned by each fire. More than 54% of the total area burned during the period of study was land on the State of Tamaulipas. However, >58% of the estimated emissions came from the State of Coahuila. This was because of the mix of vegetation types burned in each state. With respect to the temporal distribution, 76.9% of the fires occurred during the months of April and May consuming almost 78% of the total area burned during the period of study. Analysis of wind forward trajectories of air masses passing through the burned areas and 850-mb wind reanalyses indicate possible transboundary transport of the emissions from Mexico to the United States during the occurrence of the major wildfires identified.     

Decolorization of synthetic dyes using a copper complex with glucaric acid

Selected azo, acridine, triphenyl methane, anthraquinone and thiazine-based dyes were decolorized using a catalytic system consisting of Cu(II)/glucaric acid/H(2)O(2). More than 90% decolorization was obtained with 100 ppm Acridine Orange, Azure B, Chicago Sky Blue, Crystal Violet, Methyl Orange, Poly B-411, Reactive Black 5, Reactive Blue 2, and Remazol Brilliant Blue R within 24 h. Seventy to eighty percent decolorization was achieved within the first 6 h. The decolorizaton was not affected by pH. The involvement of hydroxyl radicals produced in the system in the decolorization of the dye molecules was confirmed by electron spin resonance study.     

Application of rough sets analysis to identify polluted aquatic sites based on a battery of biomarkers: a comparison with classical methods

The evaluation of toxicological effects at the cellular and molecular levels in organisms are often used to determine sites subjected to contamination problems that pose a threat to the long-term survival of organisms. However, the integration of multiple measurements on the health status of organisms into a model for site discrimination is challenging. This study compares two discrimination methods which are based on rule inference: rough sets (RS) analysis and classification trees (CT) with classical multivariate discriminant analysis (DA). Site classification was attempted with six biomarkers of effects: metallothionein levels, lipid peroxidation, DNA damage, levels of lipophosphoproteins (i.e., vitellins), phagocytosis activity and haemocyte cell viability on clam (Mya arenaria) populations from the Saguenay River fjord (Quebec, Canada). Rule based methods have the advantage of complete independence from data distribution constraints in contrast to the classification methods from multivariate analysis that are more commonly used in ecotoxicology. Results show that RS and CT gave better classifications than DA because they do not require strong distributional assumptions. Moreover, RS provided classification rules that could identify the most important biomarker(s) for site discrimination. RS and CT were shown to be simple and efficient methods for classifying multivariable ecotoxicological data. This methodology would be especially useful when freedom from distributional assumptions is required.     

Estimation of selected physicochemical properties for methylated naphthalene compounds

Liquid aqueous solubility (S(w,L)), octanol/water partition coefficients (K(ow)), liquid vapor pressure (P(v,L)), and Henry's law constants (H(c)) were estimated for 20 methylated naphthalenes ranging from monomethyl to tetramethylnaphthalenes. Chromatographic methods were used for the estimation. Chromatographic retention measurements were conducted for 11 reference compounds and regressions were fit between the retention indices and the physicochemical properties. HPLC octadecylsilyl column with acetonitrile/water eluent was used for the estimation of S(w,L) and K(ow). Two GC columns, HP5-MS and a more hydrophobic HP-1, were tested for the estimation of P(v,L). Measured retention indices for the methylated naphthalenes were entered to the regression equations to calculate the physicochemical properties for these compounds. Literature values, where available, were used to validate the calculated values. The method accurately estimated the physicochemical properties. Estimated S(w,L) and P(v,L) decreased with the number of methyl groups. K(ow) increased with the number of methyl groups. There was no obvious relation between H(c) and the number of methyl groups. Log S(w,L) ranged from 0.885 for 1,2,5,6-tetramethylnaphthalene to 2.269 for 1-methylnaphthalene (mmol/m(3)). Log K(ow) varied from 3.89 for 1-methylnaphthalene to 4.95 for 1,2,5,6-tetramethylnaphthalene. Log P(v,L) ranged from -0.983 for 1,2,5,6-tetramethylnaphthalene to 0.789 for 2-methylnaphthalene (Pa). Log H(c) varied from 1.03 for 1,4,5-trimethylnaphthalene to 1.73 for 2,6-dimethylnaphthalene (Pa m(3)/mol). There were no apparent effects of GC column hydrophobicity on the accuracy of the results. Estimation of S(w,L) and K(ow) based on GC retention indices was not as accurate as with HPLC. Comparison of the estimated values with values predicted by EPIWIN indicated that EPIWIN is useful in giving order-of-magnitude prediction of physicochemical properties.     

Evaluation of caged freshwater mussels as an alternative method for environmental effects monitoring (EEM) studies

On three occasions between 1998 and 2000, freshwater mussels were collected by divers in Lake Memphremagog during the spring and transplanted to various locations in the St-Fran?ois River (Quebec, Canada). Mussel growth was monitored by comparing total weight and length at the beginning and end of the exposure period. In 1998, mussels were caged for 60 days at 10 stations, including locations receiving treated effluents from three pulp and paper mills. Overall, there was an apparent trend of increased mussel growth from upstream to downstream along the river. However, mussels caged downstream from the effluent discharge of a bleached kraft pulp and paper mill grew more slowly than those caged immediately upstream in the river. In 1999 and 2000, we further investigated the situation in the vicinity of this bleached kraft mill. The measurements again indicated that growth of mussels in the effluent plume from this mill was reduced in comparison to sites upstream. Overall, in terms of growth, the caged mussels responded both positively and negatively to different environmental conditions. Compared with other monitoring approaches used at these sites during the same period, the caged mussel experiment results were consistent with the trends observed with the benthic invertebrate survey but not with the trends observed for fish.     

Recovery from acidification in central Europe--observed and predicted changes of soil and streamwater chemistry in the Lysina catchment,Czech Republic

The geochemical model MAGIC was applied to estimate streamwater and soil chemistry between 1851 and 2030 at the Lysina catchment, an acid-sensitive granitic catchment covered by planted Norway spruce monoculture in the western Czech Republic. The total deposition of sulfur to the catchment was 164 meq m(-2) in 1991, but had declined to 52 meq m(-2) by 2000. Although SO2 emissions in the region declined by 90% compared to the 1980s, acidification recovery was small within the period 1990-2000. Stream pH increased only slightly (from 3.92 to 4.07), although SO4 concentration declined sharply from 568 microeq l(-1) (1990) to 232 microeq l(-1) (2000). Organic acids played an important role in streamwater buffering. According to the MAGIC prediction using deposition measured in 1999-2000, streamwater pH will increase to 4.3 and soil base saturation will increase to 6.2% by 2030 (from 5.7% in 2002). Pre-industrial pH was estimated to be 5.5 and soil base saturation 24.7%. The loss of base cations (Ca, Mg, Na, K) was caused predominantly by atmospheric acidity, but intensive forestry was responsible for approximately one third of the net base cation loss via accumulation in harvested biomass. Severely damaged sites, under continued pressure from forestry, will not return to a good environmental status in the near future (if ever) when the acid deposition input is only partially reduced.     

Distribution and relationships of trace metals in soft tissue,byssus and shells of Mytilus edulis trossulus from the southern Baltic

Concentrations of Hg, Cd, Pb, Ag, Cu, Zn, Cr, Ni, Co, Mn, and Fe in soft tissues, shells and byssus of blue mussel (Mytilus edulis trossulus) from 23 sites along the Polish coast of the Baltic Sea were determined by AAS method. Byssus, as compared with the soft tissue, concentrated more effectively Pb, Cu, Cr, and especially Ag, Ni, Mn and Fe, moderately Hg and Zn and less effectively Cd. Significant inter-regional and inter-size differences in metal concentrations in both soft tissues and byssus were recorded. Highly significant correlations (P<0.01, P<0.05) were observed between tissue and byssal concentrations of Cd, Pb, Ni and Ag. Factor analysis showed clear separation of both the tissue and byssi samples based on their geographic distribution, possibly reflecting a different rate of deposition of clay minerals at the head of the Pomeranian Bay and the Gulf of Gdańsk. The Pomeranian Bay differs from the Gulf of Gdańsk in respect to geological structure of bottom sediments as a substrata for the M. edulis trossulus as well as in relation to various sources of metallic pollutants. From the data obtained in the present study and those reported previously the soft tissue and especially byssus of M. edulis, in contrast to shells, appear to be a significantly better bioindicator for identification of coastal areas exposed to metallic contaminants.     

Adsorption of sugar beet herbicides to Finnish soils

Three sugar beet herbicides, ethofumesate, phenmedipham and metamitron, are currently used on conventional sugar beet cultivation, while new varieties of herbicide resistant (HR) sugar beet, tolerant of glyphosate or glufosinate-ammonium, are under field testing in Finland. Little knowledge has so far been available on the adsorption of these herbicides to Finnish soils. The adsorption of these five herbicides was studied using the batch equilibrium method in 21 soil samples collected from different depths. Soil properties like organic carbon content, texture, pH and partly the phosphorus and oxide content of the soils were tested against the adsorption coefficients of the herbicides. In general, the herbicides studied could be arranged according to their adsorption coefficients as follows: glyphosate>phenmedipham>ethofumesate approximately glufosinate-ammonium>metamitron, metamitron meaning the highest risk of leaching. None of the measured soil parameters could alone explain the adsorption mechanism of these five herbicides. The results can be used in model assessments of risk for leaching to ground water resulting from weed control of sugar beet in Finland.     

Generation of PCDD/F in fly ash from municipal solid waste incinerators

Fly ash from municipal solid waste incinerators (MSWIs) has been characterized in terms of polychlorinated dibenzyl-p-dioxin and polychlorinated dibenzofuran (PCDD/F) content. Increasing values of PCDD/Fs have been found to correlate with decreasing temperatures of sampling points in flue gas treatment lines of the plants, confirming other researchers' findings about temperature as the major controlling parameter for the PCDD/F formation. Measured PCDD/F ratios show that de novo synthesis is the dominant formation mechanism. The increasing trends of particulate-bound PCDD/Fs can be explained not only through the dominant de novo synthesis process but also considering the adsorption of gaseous PCDD/Fs on fly ash deposits, even outside the typical de novo synthesis temperature ranges. The effective role of a post-combustor unit, imposed by Italian law to destroy PCDD/ Fs, also needs to be carefully reconsidered.