Analysis of the genotoxicity of municipal solid waste incinerator ash.

Combined bottom and fly ash obtained from a Chicago, IL, municipal solid waste incinerator (MSWI) was extracted with organic solvents, water or acidified water. The mean amounts of organic material isolated from each extraction procedure were 688.2, 91.8 and 167.7 micrograms/g MSWI ash. These extracts were evaluated for toxicity and mutagenicity in Salmonella typhimurium strains TA98 and TA100. We developed and calibrated a micropreincubation assay to evaluate small concentrations of the organic extracts. No direct-acting mutagens were found, however the acid-treated aqueous extracts were toxic. Materials isolated with methylene chloride methanol were mutagenic after hepatic microsomal activation (S9). The mutagenic potencies of the organic extract normalized to a per gram ash basis was the induction of 103.46 revertants in TA98 and 247.5 revertants in TA100. The aqueous extracts were neither toxic nor mutagenic. However, the acid-treated aqueous extract was mutagenic to TA100. The organic material isolated from the acidic extract had an induced mutagenic potency of 44.2 revertants/mg extract. Normalizing these data indicate a mutagenic potency of 7.4 revertants/g MSWI ash leached.     

Screening of organic matter in leachates from sanitary landfills using gas chromatography combined with mass spectrometry

Sanitary landfills are potential groundwater pollution sources, normally producing leachate with very high content of organic matter. Leachates from five Danish sanitary landfills were sampled in order to investigate the composition of the organic matter. The samples were extracted using dichloromethane followed by sodium hydroxide solution, in this way dividing the sample into one phase containing the basic and neutral compounds and one containing the acidic compounds. One of the leachates was extracted using pentane, for analysis of volatile compounds. The three extracts were analysed using gas chromatography combined with mass spectrometry. Several compounds were identified, including chlorinated pesticides (2 of the 5 leachates), aromatic carboxylic acids and alkylbenzenes. Benzene, toluene and trichloroethylene were found in the leachate analysed for volatile compounds. Some of the compounds identified in this work have been reported in the literature to give rise to severe groundwater problems.     

Carcinogenic and genotoxic activity of extracts from contaminated sediments in western Lake Ontario

In order to investigate the putative association between chemical contamination in western Lake Ontario and high prevalences of fish tumors, sediments from Hamilton Harbour and Oakville Creek in Lake Ontario and reference sites in non-polluted areas of Ontario, Canada were collected and extracted for organic contaminants. Sediment extracts from Hamilton Harbour had the highest concentrations of polychlorinated biphenyls and organochlorine insecticides (ppb) and contained very high concentrations of polynuclear aromatic hydrocarbons (ppm); although the levels of these compounds varied widely with sampling location in the harbor. A sediment extract from Hamilton Harbour was mutagenic in the Ames bacterial assay, both with and without microsomal activation. High levels of aromatic DNA adducts were induced in cultured mouse C3H1OT1/2 cells after in vitro exposure to Hamilton Harbour sediment extract. In two separate carcinogenicity experiments involving a sac fry microinjection assay with rainbow trout (Oncorhynchus mykiss), Hamilton Harbour sediment extract induced hepatocellular carcinomas in fish. No hepatic neoplasms were observed in fish that had been treated with sediment extract from Oakville Creek, or with extract from a reference sediment. The significance of these results is discussed in relation to the distribution of neoplasms in feral fish within western Lake Ontario.     

Identification of organic compounds in leachate from a waste tip

Two different types of leachate from a municipal waste tip have been analyzed. The first type of leachate was collected from a waste tip in the acidification stage. The organic load of this leachate was high and consisted mainly of free volatile acids (over 95% of the TOC). Volatile amines and ethanol were also present (0.8 and 0.7% of the TOC respectively). The leachate was extracted with hexane and the extract was analyzed with infrared and nuclear magnetic resonance spectroscopy and a gas chromatograph-mass spectrometer combination. In the extract alcohols, hydrocarbons, esters, terpenes and phthalates have been identified. High molecular weight compounds were present only in a low concentration.The second type of leachate was collected from a waste tip in the methane fermentation stage. The organic load was relatively low. An important part of the organics was identified as high molecular weight compounds. About 32% of the organic carbon consisted of compounds with a molecular weight over 1000. Acids, amines and alcohols could not be detected. This means that the organic compounds present were end products of degradation processes.Furthermore there was a remarkable difference in heavy metal content between the two types of leachate.     

The effect of phosphate and temperature on growth of activated sludge and on biodegradation of surfactants

Occasional inconsistent and low removals of readily biodegradable surfactants and poor growths of sludge have been traced to sub-optimal concentrations of phosphate in the synthetic sewage used in the EEC method of assessment. The variable concentration of phosphate in this sewage was probably the result of variable amounts present in the organic components, peptone and meat extract. Reduced removal of alkylphenol ethoxylate surfactants at low temperature has been shown not to be related to a phosphate deficiency.     

The occurrence of organic micropollutants in the river Rhine and the river Maas in 1974

For several years KIWA has investigated the pollution of the river Rhine and river Maas for specific organic groups. A quantity of 20 l. of water was extracted weekly with hexane and the extract divided into several groups. The extracts were analysed by gas chromatography and mass-spectrometry. The results of these investigations during 1974 have been summarized in this article and show that the river Rhine is heavily polluted by oil, a number of aromatics and aromatic bases and a number of oxygenated substances. The river Maas however, is much less polluted by these substances with the exception of oil.     

Complexity of ultrafiltration membrane fouling caused by macromolecular dissolved organic compounds in secondary effluents

Recent investigations indicate the relevance of extracellular polymeric substances (EPS) in terms of fouling of low-pressure membranes in advanced wastewater treatment. In this study, the high impact of the macromolecular fraction of effluent organic matter on fouling was confirmed in cross-flow ultrafiltration experiments using secondary effluent with and without autochthonous biopolymers. A method for the extraction of a natural mixture of EPS derived from the bacterium Sinorhizobium sp. is presented. Ultrafiltration of solutions of this bacterial EPS extract revealed a correlation between the concentration of EPS and the loss of permeate flux. However, in ultrafiltration tests using extracted bacterial EPS in a model solution as well as in secondary effluent without autochthonous biopolymers, the extent of membrane fouling was not identical with the fouling provoked by secondary effluent organic matter, although the biopolymer concentrations were comparable. The differences in the fouling behaviour of the extracted bacterial EPS and effluent organic matter are considered to be due to different compositions of the biopolymer fraction in terms of proteins, polysaccharides, and other organic colloids, indicating a particular impact of proteins on ultrafiltration membrane fouling.     

Characterization of soil phosphorus in a fire-affected forest Cambisol by chemical extractions and P-NMR spectroscopy analysis

This study was conducted to investigate the long-term effects of fire on soil phosphorus (P) and to determine the efficiency of different procedures in extracting soil P forms. Different P forms were determined: labile forms (Olsen-P, Bray-P, and P extracted by anion exchange membranes: AEM-P); moderately labile inorganic and organic P, obtained by NaOH-EDTA extraction after removing the AEM-P fraction; and total organic and inorganic soil P. ³¹P-NMR spectroscopy was used to characterize the structure of alkali-soluble P forms (orthophosphate, monoester, pyrophosphate, and DNA). The studied area was a Pinus pinaster forest located at Arenas de San Pedro (southern Avila, Spain). The soils were Dystric Cambisols over granites. Soil samples were collected at 0-2 cm, 2-5 cm, and 10-15 cm depths, two years after a fire in the burned area and in an adjacent unburned forest area. Fire increased the total N, organic C, total P, and organic and inorganic P content in the surface soil layer. In burned soil, the P extracted by the sequential procedure (AEM and NaOH + EDTA) was about 95% of the total P. Bray extraction revealed a fire-induced increase in the sorption surfaces. Analysis by chemical methods overestimated the organic P fraction in the EDTA-NaOH extract in comparison with the determination by ignition procedure. This overestimation was more important in the burned than unburned soil samples, probably due to humification promoted by burning, which increased P sorption by soil particles. The fire-induced changes on the structure of alkali-soluble P were an increase in orthophosphate-P and a decrease in monoester-P and DNA-P.     

Organic indicators of groundwater pollution by a sanitary landfill

The organic composition of leachate from the Barcelona sanitary landfill is described. According to the low degree of stabilization of the disposed garbage the acid fraction accounts for 80–90% of the total organic extract. More than 50 individual organic components have been identified, indicating catabolic degradation of lipids (e.g. C₄–C₁₁ carboxylic acids), proteins (e.g. indole derivatives) and lignins (e.g. p-hydroxyphenyl derivatives) or simply compounds originally present in the refuse that have been washed out by percolating waters (nicotine, caffeine, phthalates).To obtain a monitoring system for the groundwater pollution originated by this landfill leachate, an analytical method is proposed based on the GC-ECD fingerprinting of groundwater acidic extracts after derivatization with PFB bromide. The chromatogram contains carboxylic and phenolic components and the profiles exhibited by waters from several test wells in the downstream edge of the landfill were indicative of the suspected leachate pollution.     

Characterizing algogenic organic matter (AOM) and evaluating associated NF membrane fouling

Occasional algal blooms, comprised of blue-green algae and/or green algae, cause significant challenges in drinking water treatment due to the release of algogenic organic matter (AOM) into water extracellularly and, upon cell lysis, intracellularly. AOM has been extracted from blue-green algae (cyanobacteria) by various means and analyzed by UV absorbance scanning, HPSEC-UV-fluorescence-DOC, UV absorbance ratio index (URI), FTIR, and fluorescence excitation emission matrix (EEM). AOM extracted in water as a solvent exhibited a high hydrophilic fraction (57.3%) with a low SUVA (1.0 L/m-mg). The molecular weight (MW) distribution showed a significant heterogeneity (high value of polydispersivity) and high protein content (as indicated by specific fluorescence). Significant amounts of proteinaceous components such as mycosporine-like amino acids (MAAs, UV-screening components) and phycobilins (light-harvesting pigment) were detected by UV/visible absorption. The presence of proteins was confirmed by FTIR (at 1661 and 1552 cm(-1)), EEM spectra (EX:278-282 nm and EM:304-353 nm), and high URI values (3.1-6.0). A bench-scale cross-flow unit, employing a flat-sheet membrane specimen, was used to examine nanofiltration (NF) membrane fouling and removal of natural organic matter (NOM) derived from different blends of Suwannee River humic acid (SRHA) and AOM: SRHA 10 mgC/L, AOM 3mg C/L + SRHA 7 mgC/L, AOM 7 mgC/L + SRHA 3 mgC/L, and AOM 10 mgC/L. The study focused mainly on the effects of two different sources of organic matter on NF (NF 200) membrane fouling under otherwise similar conditions. Flux decline and organic matter rejection as a function of delivered DOC (cumulative mass of feed DOC per unit area) showed significantly different results depending on the organic matter composition of samples even though the test conditions were the same (organic matter concentration, pH, temperature, inorganic salt composition and concentration, and recovery). A higher flux decline was observed with increasing proportions of AOM. Organic matter rejections also decreased with higher AOM contributions to the samples, indicating that lower molecular weight (MW) AOM components were not well rejected by the NF 200 membrane having a 360 Da MWCO. However, SRHA that exhibited a relatively high MW (1000-5000 Da range) and high SUVA (7.4 L/m-mg) was preferentially rejected through electrostatic repulsion/size exclusion by the NF 200 membrane, having a high negative charge, low MWCO, and relatively low hydrophobicity. Even though the DOC concentration of feed water is a decisive factor for membrane fouling along with membrane properties and operating conditions, the characteristics of organic matter are more influential in fouling potential. Protein-like and polysaccharide-like substances were found as major foulants by FTIR.     

Composition of particulate and dissolved organic matter in a disturbed watershed of southeast Brazil (Piracicaba River basin)

The elemental and isotopic composition of particulate and dissolved organic matter was investigated in the Piracicaba River basin, S?o Paulo State, Brazil. Comparison of riverine organic matter from the Piracicaba River basin, a region where rivers and streams receive urban sewage and industrial effluents, with data reported for the pristine Amazon system revealed significant differences associated with anthropogenic impacts. One important difference was N enrichment in the particulate organic material of the Piracicaba basin rivers, due to (a) urban and industrial effluents, and (b) enhanced phytoplankton growth, which results from the combination of nutrient enrichment and damming of sections of the rivers. Radiocarbon concentrations were overall more depleted (older 14C age) in the Piracicaba basin rivers than in the Amazon, which may reflect the importance of soil erosion in the former. Analyses of stable and radioactive carbon isotopes and lignin-derived compounds indicated that coarse particulate organic material is composed of a mixture of soil particles and degraded organic matter from C3 and C4 vascular plants. Fine particulate organic material was composed mainly of soil particles and phytoplankton cell remains, the latter especially during low water. Ultrafiltered dissolved organic matter was the most degraded fraction according to its lignin oxidation products, and showed the greatest influence of C4 plant sources.     

Mutagenicity of three agricultural soils

A chemical and biological testing protocol was employed to evaluate the mutagenic potential of the organic compounds extracted from three agricultural soils. The analytical procedures used included bioassays with Salmonella typhimurium and Aspergillus nidulans for the detection of point mutations and a gas chromatography/mass spectrometry/computer system to identify major organic constituents. The extracts of all three soils exhibited mutagenic response in the bioassays. At a dose level of 1000 micrograms per plate, the organic extract of the Bastrop clay induced 434 net revertants; while at the same dose level the Norwood sandy clay and the Sassafrass sandy loam induced 35 and 178 net revertants, respectively, in the Salmonella assay with metabolic activation. In the Aspergillus assay, the extract of the Norwood and Bastrop soils induced a positive response without metabolic activation; this effect was reduced or eliminated in the presence of metabolic activation. Chemical analysis identified a variety of initiators, promotors, inhibitors, and cocarcinogens; however, there were no mutagenic compounds identified in any of the soil extracts. The results of this combined testing protocol indicate that the agricultural soils tested had an inherent level of mutagenic activity, which was not detected by GC/MS analysis alone, and this activity may be related to the past history of agricultural practices, including biocide applications, fertilization, and cultivation.     

Tracking natural organic matter (NOM) in a drinking water treatment plant using fluorescence excitation-emission matrices and PARAFAC

Natural organic matter (NOM) in water samples from a drinking water treatment train was characterized using fluorescence excitation emission matrices (F-EEMs) and parallel factor analysis (PARAFAC). A seven component PARAFAC model was developed and validated using 147 F-EEMs of water samples from two full-scale water treatment plants. It was found that the fluorescent components have spectral features similar to those previously extracted from F-EEMs of dissolved organic matter (DOM) from diverse aquatic environments. Five of these components are humic-like with a terrestrial, anthropogenic or marine origin, while two are protein-like with fluorescence spectra similar to those of tryptophan-like and tyrosine-like fluorophores. A correlation analysis was carried out for samples of one treatment plant between the maximum fluorescence intensities (F_max) of the seven PARAFAC components and NOM fractions (humics, building blocks, neutrals, biopolymers and low molecular weight acids) of the same sample obtained using liquid chromatography with organic carbon detection (LC-OCD). There were significant correlations (p < 0.01) between sample DOC concentration, UVA₂₅₄, and F_max for the seven PARAFAC components and DOC concentrations of the LC-OCD fractions. Three of the humic-like components showed slightly better predictions of DOC and humic fraction concentrations than UVA_254. Tryptophan-like and tyrosine-like components correlated positively with the biopolymer fraction. These results demonstrate that fluorescent components extracted from F-EEMs using PARAFAC could be related to previously defined NOM fractions and that they could provide an alternative tool for evaluating the removal of NOM fractions of interest during water treatment.     

Poly-chlorinated biphenyls,poly-chlorinated naphthalenes and polynuclear aromatic hydrocarbons in severn estuary (U.K.) sediments

Sediments taken from the upper part of the Severn Estuary have been extracted by cyclic steam distillation into hexane. Analysis of the extract revealed a variety of organic pollutants including alkanes and several poly-nuclear aromatic hydrocarbons (PNA's). A PCB residue was detected and quantified using the technique of carbon-skeleton gas chromatography employing a 3% palladium catalyst and 2% RbCl salt column. The level of PCB in the sediments was found to be of the order of 1 ppm. No significant levels of poly-chlorinated napthalene (PCN) or DDT and related species were found.Organic contamination of one sediment (Arlingham) was found to be associated with the coal particles present in the sample. Levels of contamination at Arlingham were thus shown to be a function of sample composition rather than of the geographical location of the site.     

Experiments with haliscomenobacter hydrossis in continuous culture without and with zoogloea ramigera

A study has been made of the sheath-forming bacterium Haliscomenobacter hydrossis, by growing the organism in continuous culture. Glucose together with components from trypticase soy broth/yeast extract were used as the energy source. At low dilution rates glucose was a more important energy source than components from trypticase soy broth/yeast extract. H. hydrossis was unable to produce large amounts of reserve material even in the presence of an excess of glucose. The minimum doubling time was approximately 13 h in the complex medium. The uptake sequence of amino acids derived from the trypticase soy broth yeast extract was found to be as follows: glutamic acid, glycine, methionine, tryptophan, lysine and arginine were easily consumed by the micro-organism, whereas the other amino acids were taken up mainly at low dilution rates.Competition experiments were carried out with H. hydrossis and Z. ramigera at two different dilution rates (0.016 and 0.005 h^-t). At both dilution rates Z. ramigera was dominantly present in the cultures.Finally the glucose respiration and glucose uptake of a washed cell suspension of H. hydrossis was studied. The oxygen uptake rate increased only very slightly upon addition of glucose. The difference between endogenous respiration and oxygen uptake rate in the presence of glucose was increased when the washed cells had been aerated a period of time.     

Total copper content and its distribution in acid vineyards soils developed from granitic rocks

Total and extractable (5 extractants) Cu concentrations were determined in thirteen acid vineyards soils. Mean total copper concentration was 259 mg kg(-1) and most of the soil samples (87%) were above the upper limit allowed by the European Union for this element in soils. The largest Cu fraction was found to be that bound to soil organic matter, which accounted for 49% of the total Cu. None of the Cu fractions showed significant differences with depth. Nevertheless, bioavailable Cu (extracted in Na(2)-EDTA) was found to show a strong correlation with Cu bound to soil organic matter, which may indicate that Na(2)-EDTA is able to extract part of the organically bound Cu, resulting in an overestimation of bioavailable Cu. However, practices associated to soil use change and management affecting the stability of Cu organic complexes could induce an increase in bioavailable Cu levels in these soils.     

The enzymology of sludge solubilisation utilising sulphate-reducing systems: the properties of lipases

The first stage in the degradation and recycling of particulate organic matter is the solubilisation and enhanced hydrolysis of complex polymeric organic carbon structures associated with the sulphidogenic environment. An investigation into the enzymology of these processes has shown that lipase enzyme activities were found predominantly associated with the organic particulate matter of the sewage sludge. Sonication of the sludge gave an increase in enzyme activity as the enzymes were released into the supernatant. pH and temperature optimisation studies showed optima between 6.5 and 8 and 50-60 degrees C, respectively. All the lipase enzymes from the methanogenic bioreactors indicated extensive stability for at least an hour at their respective optimum temperatures and pH; sulphidogenic lipases reflected limited stability at these temperatures and pH during this time period. Though sulphate showed inhibitory properties towards lipases both sulphide and sulphite appeared to enhance the activity of the enzymes. It is argued that these sulphur species, liberated at different times during the sulphate reduction process, disrupt the integrity of the organic particulate floc by neutralising acidic components on the surface. The release of further entrapped enzymes from the organic particulate matter result in a subsequent enhancement of hydrolysis of polymeric material.