Preliminary evidence of a decline in perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations in American Red Cross blood donors

The purpose of this pilot study was to determine whether perfluorooctanesulfonate (PFOS,C(8)F(17)SO(3)(-)) and perfluorooctanoate (PFOA,C(7)F(15)CO(2)(-)) concentrations in American Red Cross blood donors from Minneapolis-St. Paul, Minnesota have declined after the 2000-2002 phase-out of perfluorooctanesulfonyl-fluoride (POSF, C(8)F(17)SO(2)F)-based materials by the primary global manufacturer, 3M Company. Forty donor plasma samples, categorized by age and sex, were collected in 2005, and PFOS and PFOA concentrations were compared to 100 (non-paired) donor serum samples collected in 2000 from the same general population that were analyzed at the time using ion-pair extraction methods with tetrahydroperfluorooctanesulfonate as an internal standard. Eleven of the 100 samples originally collected were reanalyzed with present study methods that involved (13)C- labeled PFOA spiked into the donor samples, original samples, control human plasma, and the calibration curve prior to extraction, and was used as a surrogate to monitor extraction efficiency. Quantification was performed by high performance liquid chromatography tandem mass spectrometry methods. Among the 100 serum samples analyzed for PFOS, the geometric mean was 33.1 ng ml(-1) (95% CI 29.8-36.7) in 2000 compared to 15.1 ng ml(-1) (95% CI 13.3-17.1) in 2005 (p<0.0001) for the 40 donor plasma samples. The geometric mean concentration for PFOA was 4.5 ng ml(-1) (95% CI 4.1-5.0) in 2000 compared to 2.2 ng ml(-1) (95% CI 1.9-2.6) in 2005 (p<0.0001). The decrease was consistent across donors' age and sex. To confirm these preliminary findings, additional sub-sets of year 2000 samples will be analyzed, and a much larger biomonitoring study of other locations is planned.     

Electrochemical degradation applied to the metabolites of Acid Orange 7 anaerobic biotreatment

The electrochemical oxidation of the biotic degradation products of the textile dye C.I. Acid Orange 7 (AO7) was achieved using a boron doped diamond electrode (BDD). Tests were performed with model solutions of the biotic degradation products, sulphanilic acid (SA) and 1-amino-2-naphthol (AN), and also with real effluents obtained in experiments carried out in an up-flow anaerobic sludge blanket (UASB) reactor, fed with a simulated textile effluent containing AO7, working in mesophilic or thermophilic conditions. Bulk electrolysis was studied using two different supporting electrolytes - NaCl and Na(2)SO(4). The influence of initial metabolite concentration and current density on the electrodegradation rates of the biotic products was investigated. For the UASB effluents, oxidation tests were carried out for different electrolytes and at different current densities. Samples were collected at pre-selected intervals and absorbance measurements, chemical oxygen demand (COD) and total organic carbon (TOC) tests and high performance liquid chromatography (HPLC) analysis were performed. Results have shown an almost complete elimination of the persistent pollutants and a COD removal higher than 70% for both AN and SA. For the UASB effluents, COD removals between 45% and 90% and TOC removals varying from 19% to 41% were obtained.     

The historical record of PCB and PCDD/F deposition at Greifensee, a lake of the Swiss plateau, between 1848 and 1999

Dated sediment cores provide an excellent way to investigate the historical input of persistent organic pollutants into the environment and to identify possible sources of pollution. The vertical distribution of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCB) was investigated in a sediment core from Greifensee to elucidate the historical trends of PCDD/F and PCB inputs between 1848 and 1999. Concentrations of PCB and PCDD/F increased by more than one order of magnitude between 1930 and 1960. PCB and PCDD/F concentrations were 5700 ng/kg dry weight (dw) and 160 ng/kg dw, respectively, in sediments originating from the late 1930s and reached a maximum of 130,000 ng/kg dw and 2400 ng/kg dw, respectively, in the early 1960s. From 1960 on, concentrations decreased to the 1930s level by the mid 1980s. A remarkable shift in the PCDD/F pattern was observed after the early 1940s. Before 1940, the PCDD/F pattern was PCDF dominated (ratio of PCDD to PCDF=0.41+/-0.11), while the PCDD started to be the major species after the early 1940s (ratio of PCDD to PCDF=1.46+/-0.38). The temporal trends of PCB and PCDD/F correlate surprisingly well with each other. This might be due to the coincidence of two factors. The introduction of PCB on the market in the 1930s resulted in emissions due to the widespread use of these industrial chemicals. In the same time period, waste incineration became an increasingly popular way to get rid of garbage, boosting the PCDD/F emissions significantly. The rapid decline of PCDD/F and PCB concentrations in the sediment starting in the early 1960s reflects the result of better emission control techniques in thermal processes and the improvement of waste water treatment in the catchment of Greifensee.     

Binding affinity of proanthocyanidin from waste Pinus radiata bark onto proline-rich bovine achilles tendon collagen type I

Binding affinity of proanthocyanidin (PA) purified from Pinus radiata bark waste onto bovine Achilles tendon collagen (type I) was studied. Adsorption of PA onto the collagen was optimized by examining pH, contact time and temperature. The adsorption was pH-dependent. The maximum adsorption capacity (Q(0)) of PA on collagen was found to be 211 mg g(-1) using the Langmuir isotherm. Comparison between two adsorbents also showed that collagen had higher adsorptivity of approximately 20% more than PVPP (polyvinyl polypyrrolidone). The high affinity between PA and collagen was further confirmed in solvent solubility experiments. The observed solvent resistance was thought to be mainly due to a hydrophobic stacking mechanism reinforced by hydrogen bonding. FT-IR spectra clearly indicated the presence of PA adsorbed on collagen. The results have interesting implications that PA can be a good protective agent for collagen against collagenase and other enzymes.     

Acid-base properties of humic substances from composted and thermally-dried sewage sludges and amended soils as determined by potentiometric titration and the NICA-Donnan model

The acid-base properties of humic acids (HAs) and fulvic acids (FAs) isolated from composted sewage sludge (CS), thermally-dried sewage sludge (TS), soils amended with either CS or TS at a rate of 80 t ha(-1)y(-1) for 3y and the corresponding unamended soil were investigated by use of potentiometric titrations. The non-ideal competitive adsorption (NICA)-Donnan model for a bimodal distribution of proton binding sites was fitted to titration data by use of a least-squares minimization method. The main fitting parameters of the NICA-Donnan model obtained for each HA and FA sample included site densities, median affinity constants and widths of affinity distributions for proton binding to low and high affinity sites, which were assumed to be, respectively, carboxylic- and phenolic-type groups. With respect to unamended soil HA and FA, the HAs and FAs from CS, and especially TS, were characterized by smaller acidic functional group contents, larger proton binding affinities of both carboxylic- and phenolic-type groups, and smaller heterogeneity of carboxylic and phenolic-type groups. Amendment with CS or TS led to a decrease of acidic functional group contents and a slight increase of proton binding affinities of carboxylic- and phenolic-type groups of soil HAs and FAs. These effects were more evident in the HA and FA fractions from CS-amended soil than in those from TS-amended soil.     

Combination of ozonation with conventional aerobic oxidation for distillery wastewater treatment

Laboratory-scale experiments were conducted in order to investigate the effect of ozone as pre-aerobic treatment and post-aerobic treatment for the treatment of the distillery wastewater. The degradation of the pollutants present in distillery spent wash was carried out by ozonation, aerobic biological degradation processes alone and by using the combinations of these two processes to investigate the synergism between the two modes of wastewater treatment and with the aim of reducing the overall treatment costs. Pollutant removal efficiency was followed by means of global parameters directly related to the concentration of organic compounds in those effluents: chemical oxygen demand (COD) and the color removal efficiency in terms of absorbance of the sample at 254 nm. Ozone was found to be effective in bringing down the COD (up to 27%) during the pretreatment step itself. In the combined process, pretreatment of the effluent led to enhanced rates of subsequent biological oxidation step, almost 2.5 times increase in the initial oxidation rate has been observed. Post-aerobic treatment with ozone led to further removal of COD along with the complete discoloration of the effluent. The integrated process (ozone-aerobic oxidation-ozone) achieved approximately 79% COD reduction along with discoloration of the effluent sample as compared to 34.9% COD reduction for non-ozonated sample, over a similar treatment period.     

Risk of polycyclic aromatic hydrocarbon (PAH) exposure from ingested food: the Azerbaijan case study

Risks due to polycyclic aromatic hydrocarbons (PAHs) exposure from food consumption for the population of Azerbaijan were determined using deterministic and probabilistic methods. The guidelines and methods described and presented in the United States Environmental Protection Agency (U.S. EPA) Risk Assessment Guidance for Superfund (RAGS) Part A was used in performing the risk assessments. The current study utilized concentration data from different sources representing international studies performed over the past decade to determine those food products that contribute the most exposure to PAHs through ingestion for the Azeri population. Due to lack of concentration data from middle-Eastern countries, only European countries were considered and used for this analysis. Using the benzo[a]pyrene (BaP) toxicity equivalency factors (TEFs) to adjust the concentrations of the individual PAH compounds to BaP equivalent concentrations, risk analyses were performed. Deterministic risk estimates fell within probabilistic risk estimates. Child risks were consistently four to seven times higher in magnitude than adult risks. Risk potentials determined for the food exposure pathway were also determined to be up to ten times higher in magnitude than risks determined from exposures due to other pathways such as soil contamination. It was observed that three major factors contributed to the variability in the assessment results, which were child and adult body weights, consumption rates of the different food groups, and the variances of the input data. The most prevalent pathways of PAH exposure from the dietary patterns of the Azerbaijani population were determined to be from bread and bakery products, milk and dairy products, and egg products.     

Co-treatment of hydrogen sulfide and methanol in a single-stage biotrickling filter under acidic conditions

Biofiltration of waste gases is cost-effective and environment-friendly compared to the conventional techniques for treating large flow rates of gas streams with low concentrations of pollutants. Pulp and paper industry off-gases usually contain reduced sulfur compounds, such as hydrogen sulfide and a wide range of volatile organic compounds (VOCs), e.g., methanol. It is desirable to eliminate both of these groups of compounds. Since the co-treatment of inorganic sulfur compounds and VOCs in biotrickling filters is a relatively unexplored area, the simultaneous biotreatment of H2S and methanol as the model VOC was investigated. The results showed that, after adaptation, the elimination capacity of methanol could reach around 236 g m(-3) h(-1) with the simultaneous complete removal (100%) of 12 ppm H2S when the empty bed residence time is 24 s. The pH of the system was around 2. Methanol removal was hardly affected by the presence of hydrogen sulfide, despite the low pH. Conversely, the presence of the VOC in the waste gas reduced the efficiency of H2S biodegradation. The maximal methanol removal decreased somewhat when increasing the gas flow rate. This is the first report on the degradation of methanol at such low pH in a biotrickling filter and on the co-treatment of H2S and VOCs under such conditions.     

Effect of chelating agents and solubility of cadmium complexes on uptake from soil by Brassica juncea

Brassica juncea, or Indian mustard, was grown in soil artificially contaminated with either a soluble salt, CdCl(2), at 186mg Cdkg(-1), or alternately an insoluble, basic salt, CdCO(3), at 90mg Cdkg(-1). These experiments study the range of Cd uptake by Indian mustard from conditions of very high Cd concentration in a soluble form to the other extreme with an insoluble Cd salt. After plants were established, four different chelating agents were applied. Chelating agents increased plant uptake of Cd from the CdCl(2) soil but did not significantly increase plant uptake of Cd from the CdCO(3) contaminated soil. Addition of ethylenediaminetetraacetic acid (EDTA) increased the plant concentration of Cd by almost 10-fold in soils contaminated with CdCl(2), with a concentration of 1283mg Cdkg(-1) in the dried EDTA-treated plants over a concentration of 131mg Cdkg(-1) in plants without added chelate. However, EDTA increased the aqueous solubility of Cd by 36 times over the soil matrix without added chelator, and thereby, increased the possibility of leaching. Other chelators used in both experiments were ethylenebis(oxyethylenenitrilo)tetraacetic acid, trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid, and diethylenetriaminepentaacetic acid (DTPA) increasing Cd in plants to 1240, 962, and 437mg Cdkg(-1), respectively. The other chelating agents increased the solubility of Cd in the leachate but not to the extent of EDTA. Comparing all chelating agents studied, DTPA increased plant uptake in terms of Cd in dried plant concentration most relative to the solubility of complexed Cd in runoff water.     

Treatment of carbofuran-bearing synthetic wastewater using UASB process

In the present study, fate of carbofuran in anaerobic environments and the adverse effects of carbofuran on conventional anaerobic systems were evaluated. Carbofuran degradation studies were carried out in batch reactors with varying carbofuran concentrations of 0 to 270.73 mg/L corresponding to a sludge-loading rate (SLR) of 2.12 x 10(-6) to 3.83 x 10(-3) g of carbofuran/g of volatile suspended solids (VSS)/d. Carbofuran concentration was reduced to undetectable levels at the end of 8 and 13 days in the batch reactors operated with a SLR of 2.12 x 10(-6) and 3.33 x 10(-5) g of carbofuran/g of VSS/d, respectively. Performances of two anaerobic reactors i.e. upflow anaerobic sludge blanket (UASB) and modified UASB (with tube settlers) were evaluated in the presence and absence of carbofuran using synthetic wastewater. In the absence of carbofuran, the soluble chemical oxygen demand (COD) removal efficiency in the conventional UASB reactor at 8 h and 6 h hydraulic retention time (HRT) was nearly 88% and 76%, respectively, whereas in modified UASB reactor it was increased to 90% at 8 h HRT and 78% at 6 h HRT. When 28 mg/L (SLR of 1.19 x 10(-2) g of carbofuran/g of VSS/d) of carbofuran was introduced in the reactors, the COD removal efficiency was reduced to 41% and 44% in conventional and modified UASB reactors respectively. However, the reactor could maintain around 80% COD removal efficiency at a carbofuran concentration of 7.84 mg/L (SLR of 3.64 x 10(-3) g of carbofuran/g of VSS/d). The reactor efficiency was also measured in terms of specific acetoclastic methanogenic activity (SMA). The toxic effect of carbofuran was reversible to a certain extent. Carbofuran removal efficiency in the conventional UASB reactor at carbofuran concentrations of 7, 13 and 28 mg/L were 40 +/- 3%, 27 +/- 3%, and 11 +/- 3%, respectively. In modified UASB reactor, carbofuran removal efficiency was almost uniform at 7 and 13 mg/L but it was reduced nearly by 56% at 28 mg/L. The major metabolite of carbofuran i.e. 3-keto carbofuran was found in all the reactors.