bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the Impact of Ocean Disposal of Stabilized/Solidified Municipal Solid Waste Incinerator Ash on Marine Sediments
Authors: Kinner NE , Durling DB , Lyons WB , Gress DL , Collins MR
Published: March 2009

This research explored the feasibility of ocean disposal of stabilized/solidified (S/S) municipal solid waste (MSW) incinerator ash in organic-rich near-shore marine sediments. A mixture of MSW bottom ash (92%) and fly ash (8%) from a starved-air mass burn MSW incinerator was combined with Type II Portland cement in a 4.54:1 ash:cement ratio. After curing, specimens were cut and placed in centrifuge tubes filled with sediment. Controls containing concrete (cement and sand) specimens and containing sediments alone were also prepared. All samples were incubated in a flow-through seawater system. Over the first ten months of the experiment, the sediment controls reflected conditions similar to those in northern New England estuaries with respect to pH (7.8 ± 0.1), alkalinity (8.7 ± 1.0 meq/L), total dissolved iron (16.7 ± 4.0 mg Fe/L) and SO42-/Cl- (mM) ratios (0.034 ± 0.0025). The S/S ash and concrete control samples exhibited a higher pH (8.9 to 9.6) and more reducing conditions (SO42-/Cl- ratio = 0.015 to 0.020; alkalinity = 3.0 to 5.6 meq/L; total dissolved iron = 0.08 to 0.67 mg/L) in their sediments than the sediment controls. No statistically significant [confidence interval (CI) = 90%] amounts of metals (arsenic, copper, lead, cadmium) were detected in the sediments adjacent to the S/S ash specimens as compared to the controls. Either (1) the metals were not being released from the S/S ash into the surrounding sediment, or (2) they were released but at concentrations below our detection capabilities.
Effects of Selected Waste Constituents on Solidified/Stabilized Waste Leachability
Authors: Jones LW , Bricka RM , Cullinane MJ
Published: March 2009

The effects of ten common waste constituents that have the potential to interfere with the strength and contaminant immobilization properties of solidified/stabilized metal finishing wastes were studied. A synthetic, metal finishing waste treatment sludge containing high levels of cadmium, chromium, mercury, and nickel was prepared. Interference materials, which were individually added to the sludge during treatment, included: three heavy metals (copper, lead, and zinc as nitrate salts), sodium hydroxide (NaOH), sodium sulfate (Na2SO4), and five organic substances (grease, oil, trichloroethene, hexachlorobenzene, and phenol). Solidification/ stabilization was accomplished using one of three binder systems: portland cement (CEM), portland cement plus fly ash (CFA), and a lime/fly ash (LFA). Specimens were tested in duplicate using the U.S. Environmental Protection Agency (EPA) extraction procedure.

Leachate concentrations of the three metals in the sludge (cadmium, chromium, and nickel) and the three metal interference materials (copper, lead, and zinc) were primarily related to the final pH of the extraction solution. Of the interference materials tested, the metal nitrates reduced the leachate pH values to the greatest extent and thus had the greatest effect on the metal concentrations in the leachate. The addition of NaOH as an interfering material increased the final pH of the leachate and thus tended to suppress leachate metal concentrations, especially in the less buffered CFA specimens. On the other hand, the addition of Na2SO4 reduced leachate pH only slightly, again mainly in the CFA specimens, and thus tended to slightly increase the metal concentration in the leachates. The addition of up to 8% by weight of the organic interference materials had no significant effect on metal concentrations in the leachates, nor on the leachate pH. Phenol, the most polar of the organic interference materials used in this study, was itself extracted at appreciable levels from all three binder systems. However, phenol addition had little effect on metal leaching. Leachate mercury concentrations were not affected by the addition of the interference materials, except perhaps by phenol. Nearly equal mercury concentrations were found in leachates from the raw sludge and all treated samples.

In general, the effects of the added interference materials on the short-term leachate metal concentrations could be explained by differences in the leachate final pH. None of the interfering materials appeared to act as carriers or to change the solubility of the metal contaminates other than through their effects on the leachate pH. This research confirms the need for waste-binder specific studies before selecting a chemical stabilization/solidification process for the treatment of hazardous waste.
Short-Term Leaching Behavior of Co-60, Sr-85, and Cs-137 from Cemented Ion-Exchange Resin Waste Forms
Authors: Lee J-O , Han K-W , Buckley LP
Published: March 2009

The leaching characteristics of Co-60, Sr-85, and Cs-137 from cemented ion-exchange resin waste forms containing water-extendible polyester resin and Zeolon 900-sodium additives were investigated using three different types of leach tests, that is, the American Nuclear Society (ANS) 16.1, the Battelle Materials Characteristics Centre (MCC) MCC-4S and modified MCC-4S methods. Specimens used in the leach tests were fabricated with cement and ion-exchange bead resins present in the Li+-OH- form. The ion-exchange resins were doped with Co-60, Sr-85, and Cs-137 to simulate the spent resin waste from nuclear power plants.

The presence of Zeolon 900-sodium additive to the waste form formulation provided distinctly improved adsorption for Cs-137 and seemed not to reduce effectively the releases of Co60 and Sr-85. The leaching processes of the three radionuclides from the waste forms were dominated by diffusion. The leaching rates of Co-60 and Sr-85 were both appreciably affected by the leachant flow rate, while Cs-137 was not apparently sensitive. The presence of nonsorbing backfill material was likely to induce the radionuclides to follow longer transport paths than for specimens only in the presence of water. The clinoptilolite selected as a sorbing backfill material did not retard the Co-60 release, but there was strong absorption of Sr-85 and Cs-137 onto the clinoptilolite.
Stabilization and In Situ Management of Radioactive Contaminated Sediments of the Port Hope Harbor
Authors: Dolinar GM , Killey RWD , Philipose KE
Published: March 2009

This paper presents the findings of laboratory and field studies undertaken to assess the feasibility of in situ management of contaminated sediments in Port Hope harbor. The contaminated sediments stem from historic releases from an adjacent radium and uranium refinery, and uranium, arsenic, and radium are the most abundant contaminants. With improved emission controls, currently accumulating sediments have much lower levels of contamination, and the harbor waters currently meet water quality limits for the contaminants of concern. Within a few years, however, the continuing sedimentation will render the harbor unusable. Field tests have confirmed that dredging will result in incomplete removal of the contaminated sediments and that sediment suspension and the release of pores waters during dredging will produce harbor water contaminant concentrations that would require the treatment of large volumes of water. In addition, no remedial work can start until a site for the dredged material can be found. The local community inquired whether in situ burial of the sediments and abandonment of the harbor would provide safe disposal. Removing the sediment by conventional dredging methods would leave approximately 5% of the contaminants in the harbor and result in possible mobilization of the contaminants so that a method of further isolating the contaminants in place is investigated. The use of a geotextile (filter fabric) is central to the concept of being able to consolidate the sediment in place by decreasing the water content of the sediment during the application of fill material while confining the contaminated sediment.
Solidification of Dried Borate Waste with Polyester
Authors: Kim H-Y , Kim K-H , Park H-H , Suh I-S
Published: March 2009

An effective method to dry the sludge produced in a reaction between the evaporator concentrates of a pressurized water reactor (PWR) and calcium oxide (CaO) has been sought. The optimum reaction condition in this study for avoiding the adhesion of dried products to the heating wall of a dryer and for preventing the agglomeration of dried products was found to be about 0.75 mol ratio of CaO/boric acid (H3BO3). In this condition the dried products were porous spheres, and their true density was 2.04 × 103 kg/m3.

In the immersion test of the solidified forms with unsaturated polyester in deionized water for 520 days, the weight change of the solidified forms was not more than 1%, and their volume change was negligible. The specific gravity of the solidified form containing 40% by weight of dried products was 1.45 and increased to 1.55 with an increase of the dried products to 50% by weight. The compressive strength of a solidified form in the above range was increased from 139.3 to 162.8 MPa. The effective diffusion coefficients in the 18-month leaching test for Cs-137 and Co-60 were 2.08 × 10-15 m2/s and 3.30 × 10-19 -2.26 × 10-18 m2/s, respectively.
The Development of Cement Formulations for Radioactive Waste Encapsulation
Authors: Lee DJ , Fenton A
Published: March 2009

Cement formulations that have been developed in the United Kingdom (UK) for treating radioactive wastes are described. Primarily, blends of ordinary Portland cement with ground granulated blast furnace slag or pulverized fuel ash have been shown to possess adequate processing performance and product properties when used to encapsulate a wide range of radioactive wastes. The versatility of these formulations is demonstrated by reference to the key process and product properties necessary to meet identified criteria for disposal of radioactive wastes. In particular, the development of the strength, structure, and the solid and liquid phases with time is discussed. An illustration is given of the selection and development of a cementation process for immobilization of Winfrith reactor waste sludges.
Field Demonstration of In Situ Grouting of Radioactive Solid Waste Burial Trenches with Polyacrylamide
Authors: Spalding BP , Fontaine TA
Published: March 2009

Demonstrations of in situ grouting with polyacrylamide were carried out on two undisturbed burial trenches and one dynamically compacted burial trench in Solid Waste Storage Area (SWSA) 6. The injection of polyacrylamide was achieved quite facilely for the two undisturbed burial trenches, and the trenches were filled with grout at typical pumping rates of 95 L/min in several batches injected over several days. The compacted burial trench, however, failed to accept grout at more than 1.9 L/min even when pressure was applied. Consequently, burial trenches that have been stabilized by dynamic compaction appear to have a permeability too low to be considered groutable. The water table beneath the burial trenches did not respond to grout injections, indicating a lack of hydrologic connection between fluid grout and the water table, which would have been observed if the grout failed to set. Because grout set times were adjusted to less than 60 min, the lack of hydrologic connection was not surprising. Postgrouting penetration testing revealed that the grout had improved the stability of the burial trenches from further subsidence from only 26 to 79% of that measured in the undisturbed soil formation. In situ permeation tests on the grouted trenches have indicated a significant reduction in hydraulic conductivity of the trench contents from a mean of 2.1 × 10-3 to 1.85 × 10-5 cm/s. Preliminary observations indicate that grouting with polyacrylamide is an excellent method for both improved stability and hydrologic isolation of radioactive waste and its incidental hazardous constituents.
Stabilization/Solidification of Metal-Contaminated Soils: Two Case Histories
Authors: Kleppe JH , Otten MT , Finn JT
Published: March 2009

This paper describes treatability studies, design, and remediation for the stabilization of contaminated soil at two hazardous waste sites in Washington State. In both sites, the soil was contaminated with metals. The study of stabilization/solidification included bench-scale treatability studies, preparation of plans and specifications for the remediation, and monitoring stabilization remediation. This paper presents the results of the above work with focus on practical, regulatory, and performance aspects of the stabilization. The effect of stabilization agents on the leaching of metals and the relation of the leaching results to applicable regulations are discussed.

Site A was a large manufacturing facility covering about 300 000 m2 (80 acres). Soil contamination included lead, chromium, and arsenic. The soil to be stabilized contained total concentrations of up to 19 000 mg/kg lead, 1600 mg/kg chromium, and 180 mg/kg arsenic; however, bulk soil samples obtained for this study contained unexpectedly lower concentrations of these metals. Extraction procedure toxicity (EP Tox) concentrations were below hazardous waste designation levels. Stabilization will be used on soil with total concentrations greater than 8000 mg/kg lead, 600 mg/kg chromium, and 100 mg/kg arsenic. Site B covered about 10 000 m2 (2 acres) and was used to repair and store machinery. As a result, the soil was contaminated with lead. The highest lead concentration was 17 000 mg/kg, with the corresponding EP Tox concentration of 300 mg/L. The selected remedial action was to remove the soil with lead over 500 mg/kg and place it in a solid waste landfill. In order for the soil to be classified as a solid waste, the leachable lead had to be less than 5 mg/L based on the EP Tox test.

At Site A, the stabilized soil had low compressive strengths, possibly due to petroleum contamination and natural organics in the soil. Leaching tests using a monolith showed that the leachate from the soil/cement specimen unexpectedly contained higher concentrations of chromium than the leachate from untreated soil. The relative amount of lead leached from soil/cement and untreated soil varied. The results for arsenic were inconclusive because of the low arsenic concentrations in the tested soils and leachates. At Site B, proprietary stabilization agents were successfully used to reduce leachability below hazardous waste levels as measured by EP Tox.
American Heroes
Authors: Tyree J. M.
Published: March 2009

An analysis of 2008 Hollywood superhero blockbusters. Iron Man and The Incredible Hulk are humorous and often light-hearted; but the latest Batman film, The Dark Knight, which reinvents The Joker in Heath Ledger's performance, is much more grim and morally complex—a dark entertainment for pessimistic times.
The Politics of Style in Miklós Jancsó's The Red and The White and The Lord's Lantern in Budapest
Authors: Strausz Laszlo
Published: March 2009

By comparing the design of Jancsó's mobile shots in a 1967 and a 1998 film, this essay analyzes the director's political commentary via the two films' visual style. The author argues that the filmmaker's construction of cinematic spaces is anchored to the critical depiction of dominant national ideologies.
Yasmin Ahmad's “Orked” Trilogy
Authors: Sim Gerald
Published: March 2009

Sepet (2004), the sequel Gubra (2006), and prequel Mukhsin (2006), directed by Yasmin Ahmad, narrate the three major relationships of Orked, a Muslim girl in Malaysia negotiating them at different points in her life. The essay considers Ahmad's cinephilia and sentimental style, and their relation to the trilogy's postcolonial themes.
Genetic variation in adipokine genes and risk of colorectal cancer
Authors: Pechlivanis Sonali , Bermejo Justo Lorenzo , Pardini Barbara , Naccarati Alessio , Vodickova Ludmila , Novotny Jan , Hemminki Kari , Vodicka Pavel , Försti Asta
Published: March 2009

Objective

Obesity has been related to an increased risk of colorectal cancer (CRC). Adipokines produced by the adipose tissue are directly linked to obesity and may thus contribute to the pathogenesis of CRC. We hypothesized that potentially functional polymorphisms in the adipokine genes leptin (LEP), leptin receptor (LEPR), resistin (RETN), and adiponectin (ADIPOQ) may be associated with CRC.

Design and methods

We studied the association of four putatively functional single nucleotide polymorphisms (SNPs) with CRC risk using a hospital-based study design with 702 cases and 752 controls from the Czech Republic. We used likelihood ratio tests to select the best model to represent the relationship between genotypes and risk of CRC. Age-adjusted odds ratios (ORs) under the best model were calculated for each SNP. Previous genotyping data on insulin (INS)-related genes were used to explore interactions between genes in obesity- and diabetes-related pathways by using two independent methods, logistic regression, and multifactor-dimensionality reduction.

Results

A trend to associate between the RETN SNP rs1862513 (C-420G) and CRC risk was observed (per allele OR 1.18, 95% confidence interval (0.99–1.40). Statistically, significant interactions were observed between the INS SNP rs3842754 (+1127INSPstI) genotypes and both the LEPR SNP rs1137101 (Q223R) and the ADIPOQ SNP rs266729 (C-11374G) genotypes.

Conclusions

Our results suggest that variants in the adipokine genes may affect CRC risk in combination with variants in diabetes-related genes.
Molecular mechanisms by which hormones and cytokines regulate cell junction dynamics in the testis
Authors: Lui Wing-Yee , Lee Will M
Published: March 2009

Hormones and cytokines are known to regulate cellular functions in all tissues including testis. These two groups of biomolecules exert a broad spectrum of effects on various aspects of spermatogenesis. Among them, one of the regulatory effects on spermatogenesis is to modulate cell junction restructuring between Sertoli cells and between Sertoli and germ cells in the seminiferous epithelium. The restructuring of cell junctions is crucial to enable the migration of germ cells along the seminiferous epithelium from the basement membrane towards the tubular lumen, and at the same time for their attachment to Sertoli cells for support. This review will summarize the recent findings that focus on the role of hormones (FSH and testosterone) and cytokines (transforming growth factor-βs and tumor necrosis factor-α) on cell junction restructuring in the testis and the molecular mechanisms.
Effect of daidzein, 4-methylbenzylidene camphor or estrogen on gastrocnemius muscle of osteoporotic rats undergoing tibia healing period
Authors: Komrakova Marina , Werner Carsten , Wicke Michael , Nguyen Ba Tiep , Sehmisch Stephan , Tezval Mohammad , Stuermer Klaus Michael , Stuermer Ewa Klara
Published: March 2009

The effect of daidzein (D), 4-methylbenzylidene camphor (4-MBC) or estradiol-17β-benzoate (E2) on muscle of osteoporotic rats during fracture healing was studied. After performing a metaphyseal tibia osteotomy in 96 osteoporotic 5-month-old female Sprague–Dawley rats, they received daily 50 mg D, 200 mg 4-MBC or 0.4 mg E2 per kg body weight, or soy free (SF) diet up to 36 and 72 days. Mitochondrial activity, fiber area, and capillary density were analyzed in M. gastrocnemius. Osseous callus bridging of fracture was observed in half of the rats after 36 days. By day 72, fracture was healed in most of the animals. State 3 mitochondrial respiration significantly enhanced in E2, 4-MBC and D groups versus SF after 36 days (30, 32 and 32 vs 23 pmol O2/s per mg). It declined after 72 days, however, in E2 group it was still at a higher level versus SF (25, 23 and 21 vs 20 pmol O2/s per mg). Size of fast oxidative glycolytic (FOG) and fast glycolytic (FG) fibers, capillary density did not differ significantly between the groups, however, at day 36 an increase in D and 4-MBC groups was detectable. FOG diameter was 64, 66, 68, and 58 μm and FG diameter was 88, 98, 95, and 89 μm in SF, D, 4-MBC, and E2 groups. The ratio of capillaries to muscle fiber was 1.1, 1.4, 1.3, and 1.1 in SF, D, 4-MBC and E2 groups by day 36. D and 4-MBC react similar to estrogen thereby improving oxidative cell metabolism in severe osteoporotic rats. The level of mitochondrial activity was higher, though no significant morphological differences could be shown.
Modelling composite repairs to cracked metal structures
Authors: Roy M. , Lang C. , May I. M.
Published: March 2009

Composite patches (usually made from carbon-fibre reinforced plastic (CFRP)) are frequently used for localised structural strengthening. They can also be used to repair fatigue cracks in metallic structures in situations where welded repairs are unsuitable: for example, cracks in stress concentrations may re-appear soon after a welded repair is attempted. This application is, however, hampered by the difficulty of predicting the fatigue life extension produced by the repair. This paper presents work which shows that the growth of patched and unpatched fatigue cracks can be predicted using finite-element analysis, allowing the benefits of a potential patch repair to be quantitatively assessed. Simulations of the crack propagation are performed and show a good correlation with test results. The tested repair was successful in significantly reducing the fatigue crack growth rate.
A new approach to aerostatic analysis of long-span bridges
Authors: Ma H. , Su C. , Huang Z.
Published: March 2009

Long-span bridges are prone to wind-induced response, and aerostatic analysis is a very important tool for predicting their behaviours under strong wind conditions. While there are many powerful commercial finite-element analysis software packages, the aerostatic stability analysis of long-span bridges cannot be conducted by using these packages because of the dependency of wind loading on the deformation of the bridge structure. To obtain accurate aerostatic analysis results, the effect of this type of ‘load non-linearity’ must be taken into account, and therefore special in-house computer programs are often required. This paper introduces a novel approach to the aerostatic stability analysis of bridge structures and presents a new algorithm based on the new approach. A commercial software package is chosen as the analysis engine and is integrated with new modules developed through application program interface (API). The aerostatic stability analysis of Hong Kong Ting Kau Bridge is conducted using this algorithm, illustrating the effectiveness of this approach. The new approach is expected to be applicable to other types of advanced analyses of structures.
Dose–response regressions for algal growth and similar continuous endpoints: Calculation of effective concentrations
Authors: Christensen Erik R. , Kusk Kresten O. , Nyholm Niels
Published: March 2009

We derive equations for the effective concentration giving 10% inhibition (EC10) with 95% confidence limits for probit (log-normal), Weibull, and logistic dose–response models on the basis of experimentally derived median effective concentrations (EC50s) and the curve slope at the central point (50% inhibition). For illustration, data from closed, freshwater algal assays are analyzed using the green alga Pseudokirchneriella subcapitata with growth rate as the response parameter. Dose–response regressions for four test chemicals (tetraethylammonium bromide, musculamine, benzonitrile, and 4-4-(trifluoromethyl)phenoxy-phenol) with ranges of representative slopes at 50% response (0.54–2.62) and EC50s (2.20–357 mg/L) were selected. Reference EC50s and EC10s with 95% confidence limits using probit or Weibull models are calculated by nonlinear regression on the whole dataset using a dose–response regression program with variance weighting and proper inverse estimation. The Weibull model provides the best fit to the data for all four chemicals. Predicted EC10s (95% confidence limits) from our derived equations are quite accurate; for example, with 4-4-(trifluoromethyl)phenoxy-phenol and the probit model, we obtain 1.40 (1.22–1.61) mg/L versus 1.40 (1.20-1.64) mg/L obtained from the nonlinear regression program. The main advantage of the approach is that EC10 or ECx (where x = 1–99) can be predicted from well-determined responses around EC20 to EC80 without experimental data in the low- or high-response range. Problems with the estimation of confidence interval for EClow,x (concentration predicted to cause x% inhibition) from algal growth inhibition also are addressed. Large confidence intervals may be the result of experimental error and lack of a well-defined reference response value.
Trout density and health in a stream with variable water temperatures and trace element concentrations: Does a cold-water source attract trout to increased metal exposure?
Authors: Harper David D. , Farag Aïda M. , Hogstrand Christer , MacConnell Elizabeth
Published: March 2009

A history of hard-rock mining has resulted in elevated concentrations of heavy metals in Prickly Pear Creek (MT, USA). Remediation has improved water quality; however, dissolved zinc and cadmium concentrations still exceed U.S. Environmental Protection Agency water-quality criteria. Physical habitat, salmonid density, fish health, and water quality were assessed, and metal concentrations in fish tissues, biofilm, and macroinvertebrates were determined to evaluate the existing condition in the watershed. Cadmium, zinc, and lead concentrations in fish tissues, biofilm, and invertebrates were significantly greater than those at the upstream reference site and an experimental site farther downstream of the confluence. Fish densities were greatest, and habitat quality for trout was better, downstream of the confluence, where water temperatures were relatively cool (16°C). Measures of fish health (tissue metal residues, histology, metallothionein concentrations, and necropsies), however, indicate that the health of trout at this site was negatively affected. Trout were in colder but more contaminated water and were subjected to increased trace element exposures and associated health effects. Maximum water temperatures in Prickly Pear Creek were significantly lower directly below Spring Creek (16°C) compared to those at an experimental site 10 km downstream (26°C). Trout will avoid dissolved metals at concentrations below those measured in Prickly Pear Creek; however, our results suggest that the preference of trout to use cool water temperatures may supersede behaviors to avoid heavy metals.
A fish bioassay to evaluate the toxicity associated with the ingestion of benzo[a]pyrene-contaminated benthic prey
Authors: Couillard Catherine M. , Laplatte Benjamin , Pelletier Émilien
Published: March 2009

A bioassay was developed to assess the toxic effects of ingested prey contaminated by polycyclic aromatic hydrocarbons (PAHs) using the teleost Fundulus heteroclitus as a predator and the polychaete Nereis virens as a benthic vector. Ten groups of nine male adult Fundulus were exposed for 21 d to 10 different diets of Nereis contaminated with benzo[a]pyrene (BaP) by spiking dead Nereis with BaP (spiked Nereis [SN] diets, 0–26 μg of BaP per gram dry wt) or by exposing living Nereis to a diet, to sediments, or to both contaminated with BaP (exposed Nereis [EN] diets, 0–16 μg/g dry wt). Another group was exposed to commercial fish food, used as reference diet. Condition and prevalence of histopathological changes were not affected. Exposure to the SN diets containing at least 3.5 μg of BaP per gram dry weight caused an induction of ethoxyresorufin-O-deethylase activity in the intestine but not in the liver. In contrast, fish exposed to the highest doses (≥13.4 μg of BaP per gram dry wt) had increased cellular proliferation rate in the liver but not in the intestine. Quantifiable levels of free BaP tetrol–like metabolites were detected in the bile of fish exposed to diets containing more than 6.8 μg/g dry weight of BaP, and exhibited a dose–response relationship in fish exposed to SN diets. For a similar dose of BaP, EN and SN diets had similar effects. Thus, the BaP metabolic products that could have been produced in Nereis apparently did not contribute to the biomarkers responses. This bioassay can be applied to a variety of prey contaminated naturally or experimentally with PAHs. The present study supports the use of intestinal biomarkers, in addition to hepatic biomarkers, in environmental monitoring to assess the impact of dietary exposure to PAHs.
Degradation and ecotoxicity of the biomedical drug artemisinin in soil
Authors: Jessing Karina K. , Cedergreen Nina , Jensen John , Hansen Hans C. B.
Published: March 2009

The plant Artemisia annua L. is cropped in many countries for production of the antimalarial drug artemisinin. Artemisinin is phytotoxic and has insecticidal activity. Large-scale cultivation of A. annua may cause transfer of artemisinin to soil and, hence, may affect both soil organisms and the aquatic environment if the compound is leachable. In the present study, a new method for extraction of artemisinin from soil was developed, and field concentrations and degradation kinetics of artemisinin in sandy and loamy soils were measured. The soil concentrations in a Danish A. annua field were up to 11.7 mg/kg. The degradation kinetics could be modeled as the sum of two first-order reactions, a fast initial degradation followed by a reaction that was 11- to 25-fold slower. It took at least 35 d before artemisinin could not be detected (<0.36 mg/kg) at 20°C, classifying artemisinin as being relatively persistent in the environment. Combined with its water solubility of 49.7 ± 3.7 mg/L, this makes it potentially leachable. In soil, artemisinin repelled the earthworm (Eisenia fetida; the 10 and 50% effect concentrations [EC10s and EC50s, respectively] were 5.24 ± 2.64 and 21.57 ± 4.73 mg/kg, respectively) and inhibited growth of lettuce (Lactuca sativa L.; EC50, 2.48 mg/kg). Springtails (Folsomia candida) were not affected in the tested concentration range of 1 to 100 mg/kg. Artemisinin had toxicity to the freshwater algae (Pseudokirchneriella subcapitata; EC50, 0.24 ± 0.01 mg/L) and duckweed (Lemna minor; EC50, 0.19 ± 0.03 mg/L) similar to that of the commercial herbicide atrazine. Based on the presented data, the risks of adverse environmental effects because of cultivation of A. annua are high and comparable to those when using commercial pesticides.
Characterization of ontogenetic changes in gene expression in the fathead minnow (Pimephales promelas)
Authors: Johns Sonia M. , Kane Michael D. , Denslow Nancy D. , Watanabe Karen H. , Orlando Edward F. , Villeneuve Dan L. , Ankley Gerald T. , Sepúlveda Maria S.
Published: March 2009

Recently, researchers have begun looking at changes in gene expression in the fathead minnow (Pimephales promelas) after contaminant exposure as a way to develop biomarkers of exposure and effects. However, the bulk of this research has been conducted on adults, with few studies focusing on early life stages. Expression of selected genes important in growth, development, and reproduction in teleosts was quantified by quantitative polymerase chain reaction during different developmental time periods (from 0 to 28 d postfertilization [dpf]). Over the developmental period studied, there was a significant up-regulation of growth hormone mRNA and no significant changes in the expression of insulin-like growth factor 1. Thyroid hormone receptors A and B were detected in 4 dpf embryos and their expression stayed relatively constant. The variation in cytochrome P45019A mRNA expression was large during the first week of development, returning to 0 dpf expression levels thereafter. Estrogen receptor 2B was up-regulated during the first three weeks postfertilization, returning to prehatch values by 28 dpf. Expression of hydroxysteroid dehydrogenase 3B and steroidogenic acute regulatory protein increased after the third or fourth week postfertilization, respectively. Vitellogenin exhibited a large degree of variation within time points, especially after day 15, and a significant up-regulation for this gene was observed at 7 and 10 dpf. Knowledge of the normal changes in gene expression during embryo and larval development will allow for better experimental design and selection of suitable biomarkers when testing the potential toxicological effects of contaminants in this model fish species.
Trends in Perinatal and Infant Health Disparities Between Rural American Indians and Alaska Natives and Rural Whites
Authors: Baldwin Laura-Mae , Grossman David C. , Murowchick Elise , Larson Eric H. , Hollow Walter B. , Sugarman Jonathan R. , Freeman William L. , Hart L. Gary
Published: March 2009

Objectives. We examined disparities in perinatal care, birth outcomes, and infant health between rural American Indian and Alaska Native (AIAN) persons and rural Whites over time.

Methods. We compared perinatal and infant health measures for 217 064 rural AIAN births and 5 032 533 rural non-Hispanic White births.

Results. Among American Indians and Alaska Natives, unadjusted rates of inadequate prenatal care (1985–1987, 36.3%; 1995–1997, 26.3%) and postneonatal death (1985–1987, 7.1 per 1000; 1995–1997, 4.8 per 1000) improved significantly. However, disparities between American Indians and Alaska Natives and Whites in adjusted odds ratios (AORs) of postneonatal death (1985–1987, AOR = 1.55; 95% confidence interval [CI] = 1.41, 1.71; 1995–1997, AOR = 1.46; 95% CI = 1.31, 1.64) and adjusted risk ratios (ARRs) of inadequate prenatal care (1985–1987, ARR = 1.67; 95% CI = 1.65, 1.69; 1995–1997, ARR = 1.84; 95% CI = 1.81, 1.87) persisted.

Conclusions. Despite significant decreases in inadequate prenatal care and postneonatal death among American Indians and Alaska Natives, additional measures are needed to close persistent health gaps for this group.
Enhanced biological phosphorus removal in the retrofitting from an anoxic selector to an anaerobic selector in a full-scale activated sludge process in Singapore
Authors: Cao Y. , Ang C. M. , Chua K. C. , Woo F. W. , Chi H. , Bhawna B. , Chong C. T. , Ganesan N. , Ooi K. E. , Wah Y. L.
Published: March 2009

This paper presents the investigation results of retrofitting an anoxic selector to an anaerobic selector through stepwise reduction of air supply in a full-scale activated sludge process with a focus on enhanced biological phosphorus removal (EBPR). The process experienced gradual shift from a Ludzack-Ettinger (LE) to an anaerobic-anoxic-oxic (A2O) process and subsequently, an anaerobic-oxic (A/O) process. The major findings are: (i) the average influent-based PO43−-P release in the anaerobic selector compartment was 16.3 mg P l−1 and that in the secondary clarifier was 1.7 mg P l−1. 75% of the SCOD and 93% of the acetic acid in the primary effluent were taken up in the anaerobic selector compartment, respectively; (ii) PO43−-P uptake contributed by both aerobic and denitrifying phosphorus accumulating organisms (DPAOs) occurred mainly in the first and second aerobic lanes together with simultaneous nitrification and denitrification (SND) while there was not much contribution from the last aerobic lane; (iii) The average PO43−-P concentration of the final effluent was 2.4 mg P l−1 corresponding to a removal efficiency of 85%; (iv) the SVI was satisfactory after retrofitting; and (v) the increase of NH4+-N in the final effluent from the commencement to the completion of the retrofitting resulted in an approximate 40–50% reduction in oxygen demand and a significant aeration energy saving was achieved.
Urban water management in cities: historical, current and future regimes
Authors: Brown R. R. , Keath N. , Wong T. H. F.
Published: March 2009

Drawing from three phases of a social research programme between 2002 and 2008, this paper proposes a framework for underpinning the development of urban water transitions policy and city-scale benchmarking at the macro scale. Through detailed historical, contemporary and futures research involving Australian cities, a transitions framework is proposed, presenting a typology of six city states, namely the ‘Water Supply City’, the ‘Sewered City’, the ‘Drained City’, the ‘Waterways City’, the ‘Water Cycle City’, and the ‘Water Sensitive City’. This framework recognises the temporal, ideological and technological contexts that cities transition through when moving towards sustainable urban water conditions. The aim of this research is to assist urban water managers with understanding the scope of the hydro-social contracts currently operating across cities in order to determine the capacity development and cultural reform initiatives needed to effectively expedite the transition to more sustainable water management and ultimately to Water Sensitive Cities. One of the values of this framework is that it can be used by strategists and policy makers as a heuristic device and/or the basis for a future city state benchmarking tool. From a research perspective it can be an underpinning framework for future work on transitions policy research.
Health risk assessment of organic pollutants in Jiangsu Reach of the Huaihe River, China
Authors: Wang B. , Yu G. , Yu Y. J. , Huang J. , Hu H. Y. , Wang L. S.
Published: March 2009

In order to evaluate the potential health risk to local public caused by water pollution in Jiangsu reach of the Huaihe River, various organic pollutants, including Polycyclic Aromatic Hydrocarbons (PAHs), Organochlorine Pesticides (OCPs) and some other Semi-Volatile Organic Compounds (SVOCs), were determined. Preliminary health risk assessment (HRA) was performed by calculating the probability that the concentrations of detected compounds exceeded HHCWO (Human Health Criteria for Consumption of Water and Organism) after Kolmogorov-Smirnov test. The probabilities of posing a risk higher than 10−6 for most potential carcinogens were greater than 0.5, and some even approximated 1. Further HRA for potential carcinogens was performed based on Monte Carlo simulation. Cumulative Risk Probability (CRP) was introduced to characterize risk. The result showed that 3,3′-dichlorobenzidine posed the highest risk. PAHs with 4 ∼ 6 rings and some OCPs, such as heptachlorepoxide, aldrin and o,p′-DDT, also posed relatively high risk. Generally, there was a high level of heath risk in the study area. The study validated the high cancer incidence rate in areas along the Huaihe River.
Municipal wastewater treatment through an aerobic biofilm SBR integrated with a submerged filtration bed
Authors: Yang Kai , He Jiajie , Dougherty Mark , Yang Xiaojun , Li Lu
Published: March 2009

A biofilm reactor and a gravitational filtration bed were integrated as a sequencing batch reactor (SBR) to aerobically treat a municipal wastewater. Polyacrylonitrile balls (50 mm diameter, 90% porosity) were filled into the upper part of the SBR as biofilm attaching materials and anthracite coal (particle size ∼1.17 mm) was placed into the lower part as filter media. The SBR was aerated during filling and reaction phases, followed by a 10 min discharge phase during which the wastewater went through the filtration bed without aeration. The SBR was tested with raw wastewater from a municipal WWTP in Wuhan, China from July 2006 to January 2007, during both a warm season and a cold season. The SBR showed a capability to accept COD and turbidity fluctuations in the receiving wastewater. Seasonal influence on COD and nitrogen removal by the biofilm reactor was significant. Nitrogen and phosphorus removals were limited by COD levels in the wastewater. The filtration process removed considerable COD, nitrogen, phosphorus, and turbidity. The overall SBR effluent quality consistently satisfied the national secondary effluent discharge standard of China, except for total phosphorus. An anaerobic phase before the aerobic reaction is proposed to improve phosphorus and nitrogen removal. The filter normally required a backwash every seven days and the water needed for backwash was less than 4% of the wastewater treated by the SBR. This experiment provides information needed for further investigation to improve performance of the SBR.
Decomposition of 1,4-dioxane by photo-Fenton oxidation coupled with activated sludge in a polyester manufacturing process
Authors: So M. H. , Han J. S. , Han T. H. , Seo J. W. , Kim C. G.
Published: March 2009

The cyclic ether 1,4-dioxane is a synthetic industrial chemical that is used as a solvent in producing paints and lacquers. The EPA and the International Agency for Research on Cancer(IARC) classified 1,4-dioxane as a GROUP B2(probable human) carcinogen. 1,4-dioxane is also produced as a by-product during the manufacture of polyester. In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, Korea was investigated regarding the release of high concentrations of 1,4-dioxane (about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2010). A 10 ton/day pilot-scale treatment system using photo-Fenton oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2800 ppm H2O2 and 1,400 ppm FeSO4 were maintained along with 10 UV-C lamps (240 μW/cm2) installed and operated continuously during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L where TOC concentration in the effluent had been moreover increased due to decomposed products such as aldehydes and organic acids. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane and their by-products (i.e., TOC). As a result, 1,4-dioxane in the effluent has been decreased as low as 0.5 mg/L. The optimal conditions for the activated sludge process that were obtained are as follows: DO, 3-3.5 mg/L; HRT, 24 h; SRT 15 d; MLSS, 3,000 mg/L. Consequently, photo-Fenton oxidation coupled with activated sludge can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.
Optimization of biological wastewater treatment conditions for 1,4-dioxane decomposition in polyester manufacturing processes
Authors: Han J. S. , So M. H. , Kim C. G.
Published: March 2009

The solvent stabilizer 1,4-dioxane could have harmful effects on an ecosystem. The discharge limit of 1,4-dioxane in a body of water will be regulated at 5 mg/L in Republic of Korea. Thus, the currently operating activated sludge used in the manufacture of polyester should be properly treated to meet the regulations. Accordingly, the removal rate of 1,4-dioxane and its microbial properties was assessed at K, H and T corporations. The highest removal efficiencies were recorded at H. However, the concentration of 1,4-dioxane in the effluent of T exceeded the criterion. In addition, a microbial degradation test was conducted on 100 mg/L of 1,4-dioxane inoculated with the activated sludge from each of the three corporations. After 7 days, the 1,4-dioxane was completely removed with the H sludge and efficiencies were 67% in the T sludge and 52% in the K sludge. These results confirm that the biodegradability of 1,4-dioxane may vary in relation to the microbial properties. The microbial diversity of activated sludge of each company was therefore investigated by 16S rDNA cloning methods. In conclusion, the activated sludge of H is the most effective for the biodegradation of 1,4-dioxane. This fact is of significant concern for the industrial sector.
Effects of Search Timing on Innovation: The Value of Not Being in Sync with Rivals
Authors: Katila Riitta , Chen Eric L
Published: March 2009

This paper investigates the effects on product innovation of firms' search to innovate, taking into account how a firm's search relates to that of its competitors. Drawing on organizational learning theory, we hypothesize that search timing relative to competitors matters and test two seemingly contradictory views: that competitors take away the exclusivity of search and therefore suppress innovation or, in contrast, sharpen and validate the focal firm's search and thus promote innovation. Our analysis of 15 years of longitudinal data on 124 Japanese, European, and U.S. industrial automation organizations reconciles these views. Results show that firms introduce more new products if they search after their competitors do, and they introduce more innovative new products if they search ahead of their competitors. The most innovative firms combine these two approaches, bridging their own and their rivals' hitherto isolated clusters of knowledge, but avoid engaging in learning contests in which they search at the same time as their rivals. The key insight for innovating firms, then, is not necessarily to strive to perform as well as possible in absolute terms, but to be different from the competition.
When Competence Is Irrelevant: The Role of Interpersonal Affect in Task-Related Ties
Authors: Casciaro Tiziana , Lobo Miguel Sousa
Published: March 2009

This paper examines the role of a person's generalized positive or negative feelings toward someone (interpersonal affect) in task-related networks in organizations. We theorize that negative interpersonal affect renders task competence virtually irrelevant in a person's choice of a partner for task interactions but that positive interpersonal affect increases a person's reliance on competence as a criterion for choosing task partners, facilitating access to organizational resources relevant to the task. Using social psychological models of interpersonal perception and hierarchical Bayesian models, we find support for this theory in social network data from employees in three organizations: an entrepreneurial computer technology company, staff personnel at an academic institution, and employees in a large information technology corporation. The results suggest that competence may be irrelevant not just when outright dislike colors a relationship. Across organizational contexts and types of task-related interaction, people appear to need active liking to seek out the task resources of potential work partners and fully tap into the knowledge that resides in organizations. We discuss contributions of our study to research on the interplay of psychological and structural dimensions of organizational life.
The Causes and Consequences of the Initial Network Positions of New Organizations: From Whom Do Entrepreneurs Receive Investments?
Authors: Hallen Benjamin L.
Published: March 2009

This paper examines the mechanisms by which new organizations establish their initial network positions, or sets of network ties from which their future tie networks evolve. I develop hypotheses from two competing logics, one based on the effects of previously developed network ties and the human capital of a new organization's founders and the other based on the effects of a new organization's early accomplishments. I test these logics in a study of 92 Internet security ventures forming ties by receiving investments from venture capitalists and other investment organizations between 2000 and 2005. In contrast to how the network positions of established organizations evolve, I find that new organizations forming their first ties early obtain their initial network positions through their founders' ties and human capital, while new organizations forming their first ties later achieve their initial network positions through their organizational accomplishments.