bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Agronomic Practices on Phytoremediation of an Aged PAH‐Contaminated Soil
Authors: Olson Paul E. , Castro Ana , Joern Mark , DuTeau Nancy M. , Pilon‐Smits Elizabeth , Reardon Kenneth F.
Published: June 2008

Phytoremediation offers an ecologically and economically attractive remediation technique for soils contaminated with polycyclic aromatic hydrocarbons (PAHs). In addition to the choice of plant species, agronomic practices may affect the efficiency of PAH phytoremediation. Inorganic nutrient amendments may stimulate plant and microbial growth, and clipping aboveground biomass might stimulate root turnover, which has been associated with increases in soil microbial populations. To assess the influence of fertilization and clipping on PAH dissipation in a nutrient‐poor, aged PAH‐contaminated soil, a 14‐mo phytoremediation study was conducted using perennial ryegrass (Lolium perenne) as a model species. Six soil treatments were performed in replicate: unplanted; unplanted and fertilized; planted; planted and fertilized; planted and clipped; and planted, clipped, and fertilized. Plant growth, soil PAH concentrations, and the concentrations of total and PAH‐degrading microorganisms were measured after 7 and 14 mo. Overall, planting (with nearly 80% reduction in total PAHs) and planting + clipping (76% reduction in total PAHs) were the most effective treatments for increased PAH dissipation after 14 mo. Fertilization greatly stimulated plant and total microbial growth, but negatively affected PAH dissipation (29% reduction in total PAHs). Furthermore, unplanted and fertilized soils revealed a similar negative impact (25% reduction) on PAH dissipation after 14 mo. Clipping did not directly affect PAH dissipation, but when combined with fertilization (61% reduction in total PAHs), appeared to mitigate the negative impact of fertilization on PAH dissipation. Therefore, fertilization and clipping may be included in phytoremediation design strategies, as their combined effect stimulates plant growth while not affecting PAH dissipation.
Sorption of the Veterinary Antimicrobials Sulfadimethoxine and Ormetoprim in Soil
Authors: Sanders S. M. , Srivastava P. , Feng Y. , Dane J. H. , Basile J. , Barnett M. O.
Published: June 2008

Currently, limited research on the fate of antimicrobials in the environment exists, once they are discharged in human and animal wastes. Sorption of two antimicrobials, sulfadimethoxine (SDM) and ormetoprim (OMP), was investigated in two soils and sand using a series of batch experiments. Because OMP and SDM are often administered in combination, their sorption was also investigated in combination as co‐solutes. The rate of SDM and OMP sorption was rapid over the first few hours of the experiments, which then slowed considerably after 16 to 68 h. OMP sorption was enhanced at high concentrations when in combination with SDM, with linear sorption coefficients ranging from 1.3 to 58.3 L·kg−1 in the single solute experiments and 4.96 to 89.7 L·kg−1 in the co‐solute experiments. Sorption of OMP as a single solute seems to provide a better fit with the Freundlich equation, which became more linear (n approached 1) when SDM was present. Overall, SDM sorbed less than OMP in the two soils and sand. SDM linear sorption coefficients ranged from 0.4 to 25.8 L·kg−1 as a single solute and 2.5 to 22.1 L·kg−1 as a co‐solute. Sorption of SDM becomes more nonlinear (n < 1) when SDM is present in combination with OMP. Overall, sorption of both antimicrobials increased in the selected soils and sand as the organic matter, clay content, and cation exchange capacity increased. These experiments indicate relatively low sorption of SDM and OMP in natural soils, making them a potential threat to surface and ground water.
Nitrogen, Tillage, and Crop Rotation Effects on Nitrous Oxide Emissions from Irrigated Cropping Systems
Authors: Halvorson Ardell D. , Del Grosso Stephen J. , Reule Curtis A.
Published: June 2008

We evaluated the effects of irrigated crop management practices on nitrous oxide (N2O) emissions from soil. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0 to 246 kg N ha−1 during the 2005 and 2006 growing seasons. Cropping systems included conventional‐till (CT) continuous corn (Zea mays L.), no‐till (NT) continuous corn, NT corn–dry bean (Phaseolus vulgaris L.) (NT‐CDb), and NT corn–barley (Hordeum distichon L.) (NT‐CB). In 2005, half the N was subsurface band applied as urea‐ammonium nitrate (UAN) at planting to all corn plots, with the rest of the N applied surface broadcast as a polymer‐coated urea (PCU) in mid‐June. The entire N rate was applied as UAN at barley and dry bean planting in the NT‐CB and NT‐CDb plots in 2005. All plots were in corn in 2006, with PCU being applied at half the N rate at corn emergence and a second N application as dry urea in mid‐June followed by irrigation, both banded on the soil surface in the corn row. Nitrous oxide fluxes were measured during the growing season using static, vented chambers (1–3 times wk−1) and a gas chromatograph analyzer. Linear increases in N2O emissions were observed with increasing N‐fertilizer rate, but emission amounts varied with growing season. Growing season N2O emissions were greater from the NT‐CDb system during the corn phase of the rotation than from the other cropping systems. Crop rotation and N rate had more effect than tillage system on N2O emissions. Nitrous oxide emissions from N application ranged from 0.30 to 0.75% of N applied. Spikes in N2O emissions after N fertilizer application were greater with UAN and urea than with PCU fertilizer. The PCU showed potential for reducing N2O emissions from irrigated cropping systems.
The Determination of Carbon Dioxide Concentration Using Atmospheric Pressure Ionization Mass Spectrometry/Isotopic Dilution and Errors in Concentration Measurements Caused by Dryers
Authors: DeLacy Brendan G. , Bandy Alan R.
Published: June 2008

An atmospheric pressure ionization mass spectrometry/isotopically labeled standard (APIMS/ILS) method has been developed for the determination of carbon dioxide (CO2) concentration. Descriptions of the instrumental components, the ionization chemistry, and the statistics associated with the analytical method are provided. This method represents an alternative to the nondispersive infrared (NDIR) technique, which is currently used in the atmospheric community to determine atmospheric CO2 concentrations. The APIMS/ILS and NDIR methods exhibit a decreased sensitivity for CO2 in the presence of water vapor. Therefore, dryers such as a nafion dryer are used to remove water before detection. The APIMS/ILS method measures mixing ratios and demonstrates linearity and range in the presence or absence of a dryer. The NDIR technique, on the other hand, measures molar concentrations. The second half of this paper describes errors in molar concentration measurements that are caused by drying. An equation describing the errors was derived from the ideal gas law, the conservation of mass, and Dalton's Law. The purpose of this derivation was to quantify errors in the NDIR technique that are caused by drying. Laboratory experiments were conducted to verify the errors created solely by the dryer in CO2 concentration measurements post‐dryer. The laboratory experiments verified the theoretically predicted errors in the derived equations. There are numerous references in the literature that describe the use of a dryer in conjunction with the NDIR technique. However, these references do not address the errors that are caused by drying.
Evidence for Struvite in Poultry Litter: Effect of Storage and Drying
Authors: Hunger Stefan , Sims J. Thomas , Sparks Donald L.
Published: June 2008

The use of spectroscopic techniques (especially phosphorus‐31 nuclear magnetic resonance [31P‐NMR] and X‐ray absorption near edge structure spectroscopy) has recently advanced the analysis of the speciation of P in poultry litter (PL) and greatly enhanced our understanding of changes in P pools in PL that receive alum (aluminum sulfate) to reduce water‐soluble P and control ammonia emissions from poultry houses. Questions remain concerning changes of P species during long‐term storage, drying, or after application of PL to cropland or for other uses, such as turfgrass. In this study, we investigated a set of six PL samples (of which three were alum‐amended and three were unamended) that had been characterized previously. The P speciation was analyzed using solid‐state 31P‐NMR spectroscopy, and the mineralogy was analyzed by powder X‐ray diffraction (XRD) after storing the samples moist and dried for up to 5 yr under controlled conditions. The magnesium ammonium phosphate mineral struvite was identified in all but one PL samples. Struvite concentrations were generally lower in dried samples (≤14%) than in samples stored moist (23 and 26%). The moist samples also had higher concentrations of phosphate bound to aluminum hydroxides. Solid‐state NMR spectroscopy was in general more sensitive than XRD in detecting and quantifying P species. Although phosphate associated with calcium and aluminum made up a large proportion of P species, they were not detected by XRD.
Simulated Effects of Sulfur Deposition on Nutrient Cycling in Class I Wilderness Areas
Authors: Elliott Katherine J. , Vose James M. , Knoepp Jennifer D. , Johnson Dale W. , Swank Wayne T. , Jackson William
Published: June 2008

We predicted the effects of sulfate (SO4) deposition on wilderness areas designated as Class I air quality areas in western North Carolina using a nutrient cycling model (NuCM). We used three S deposition simulations: current, 50% decrease, and 100% increase. We measured vegetation, forest floor, and root biomass and collected soil, soil solution, and stream water samples for chemical analyses. We used the closest climate stations and atmospheric deposition stations to parameterize NuCM. The areas were: Joyce Kilmer (JK), Shining Rock (SR), and Linville Gorge (LG). They differ in soil acidity and nutrients, and soil solution and stream chemistry. Shining Rock and LG have lower soil solution base cation and higher acidic ion concentrations than JK. For SR and LG, the soil solution Ca/Al molar ratios are currently 0.3 in the rooting zone (A horizon), indicating Al toxicity. At SR, the simulated Ca/Al ratio increased to slightly above 1.5 after the 30‐yr simulation regardless of S deposition reduction. At LG, Ca/Al ratios ranged from 1.6 to 2.4 toward the end of the simulation period, the 100% increase scenario had the lower value. Low Ca/Al ratios suggest that forests at SR and LG are significantly stressed under current conditions. Our results also suggest that SO4 retention is low, perhaps contributing to their high degree of acidification. Their soils are acidic, low in weatherable minerals, and even with large reductions in SO4 and associated acid deposition, it may take decades before these systems recover from depletion of exchangeable Ca, Mg, and K.
In Situ Accumulation of Copper, Chromium, Nickel, and Zinc in Soils Used for Long‐term Waste Water Reclamation
Authors: Lin Chunye , Negev Ido , Eshel Gil , Banin Amos
Published: June 2008

We studied the long‐term in situ accumulation of Cu, Cr, Ni, and Zn in the soil profile of a large‐scale effluent recharge basin after 24 yr of operation in a wastewater reclamation plant using the Soil Aquifer System approach in the Coastal Plain of Israel. The objective was to quantify metals accumulation in the basin's soil profile, clarify retention mechanisms, and calculate material balances and metal removal efficiency as the metal loads increase. Effluent recharge led to measurable accumulation, relative to the pristine soil, of Ni and Zn in the 0‐ to 4‐m soil profile, with concentration increases of 0.3 to 1.3 mg kg−1and 2.9 to 6.4 mg kg−1, respectively. Copper accumulated only in the 0‐ to 1‐m top soil layer, with concentration increase of 0.28 to 0.76 mg kg−1Chromium concentration increased by 3.1 to 7.3 mg kg−1in the 0‐ to 1‐m horizon and 0.9 to 2.3 mg kg−1at deeper horizons. Sequential selective extraction showed Cu tended to be preferentially retained by Fe oxides and organic matter (OM), Cr by OM, Ni by OM, and carbonate and Zn by carbonate. The average total retained amounts of Cu, Cr, Ni, and Zn were 0.7 ± 1.0, 13.6 ± 4.8, 4.3 ± 3.6, and 28.7 ± 5.4 g per a representative unit soil slab (1 m2× 4 m) of the basin, respectively. This amounts to 3.6 ± 4.9%, 79.5 ± 28.0%, 8.0 ± 6.9%, and 9.3 ± 1.8% of the Cu, Cr, Ni, and Zn loads, respectively, applied during 24 yr of effluent recharge (total of ∼1880 m effluent load). The low long‐term overall removal efficiency of the metals from the recharged effluent in the top horizon may be due to the metals' low concentrations in the recharged effluent and the low adsorption affinity and retention capacity of the sandy soil toward them. This leads to attainment of a quasi‐equilibrium and a steady state in element distribution between the recharged effluent solution and the soil after few years of recharge and relatively small cumulative effluent loadings.
Fungicide Leaching from Golf Greens: Effects of Root Zone Composition and Surfactant Use
Authors: Larsbo Mats , Aamlid Trygve S. , Persson Lave , Jarvis Nick
Published: June 2008

Soil water repellency in golf putting greens may induce preferential “finger flow,” leading to enhanced leaching of surface applied fungicides. We examined the effects of root zone composition, treatment with a non‐ionic surfactant, and the use of the fungicide iprodion or a combination of azoxystrobin and propiconazole on soil water repellency, soil water content distributions, fungicide leaching, and turf quality during 1 yr. Soil water repellency was measured using the water drop penetration time (WDPT) test and tension infiltrometers. Our study was made on a 3‐yr‐old experimental green seeded with creeping bentgrass (Agrostis stolonifera L.) ‘Penn A‐4’ at Landvik in southeast Norway. The facility consists of 16 lysimeters with two different root zone materials: (i) straight sand (1% gravel, 96% sand, 3% silt and clay, 4 g kg−1 organic matter) (SS) and (ii) straight sand mixed with garden compost to an organic matter content of 21 g kg−1 (Green Mix [GM]). Surfactant treatment resulted in 96% lower average WDPTs at 1 cm depth, three times higher water infiltration rates at the soil surface, and reduced spatial variation in soil water contents. Fungicide leaching was close to zero for the GM lysimeters probably due to stronger sorption. Concentrations in the drainage water from SS lysimeters often exceeded surface water guideline values for all three fungicides, but surfactant treatment dramatically reduced fungicide leaching from these lysimeters. In autumn and winter, surfactant‐treated plots were more infected with fungal diseases probably because of higher water content in the turfgrass thatch layer.
Evaluation of the Host‐Specificity and Prevalence of Enterococci Surface Protein (esp) Marker in Sewage and its Application for Sourcing Human Fecal Pollution
Authors: Ahmed W. , Stewart J. , Powell D. , Gardner T.
Published: June 2008

The suitability of the enterococci surface protein (esp) marker to detect human fecal pollution was evaluated by testing 197 fecal samples from 13 host groups in Southeast Queensland, Australia. Overall, this marker was detected in 90.5% of sewage and septic system samples and could not be detected in any fecal samples from 12 animal host groups. The sensitivity of the esp primer to detect the human‐specific esp marker in sewage and septic samples was 100 and 67%, respectively. The overall specificity of this marker to distinguish between human and animal fecal pollution was 100%. Its prevalence in sewage was also determined by testing samples from the raw sewage, secondary effluent, and treated effluent of a sewage treatment plant (STP) over five consecutive days. Of the 15 samples tested, 12 (80%) were found to be positive for this marker. In contrast, it was not found in three samples from the treated effluent and these samples did not contain any culturable enterococci. The PCR limit of detection of this marker in freshwater samples was up to dilution 1 × 10−4 and the number of culturable enterococci at this dilution was 4.8 × 101 ± 7.0 × 10° colony forming unit (CFU). The utility of this marker was evaluated by testing water samples from three non‐sewered catchments in Pine Rivers in Southeast Queensland. Of the 13 samples tested, eight were positive for this marker with the number of enterococci ranging between 1.8 × 103 to 8.5 × 103 CFU per 100 mL of water. Based on the results, it can be concluded that the esp marker appears to be sewage specific and could be used as a reliable marker to detect human fecal pollution in surface waters in Southeast Queensland, Australia.
Fate of Arsenic in Swine Waste from Concentrated Animal Feeding Operations
Authors: Makris Konstantinos C. , Quazi Shahida , Punamiya Pravin , Sarkar Dibyendu , Datta Rupali
Published: June 2008

Swine diets are often supplemented by organoarsenicals, such as 3‐nitro‐4‐hydroxyphenylarsonic acid (roxarsone) to treat animal diseases and promote growth. Recent work reported roxarsone degradation under anaerobic conditions in poultry litter, but no such data exist for swine wastes typically stored in lagoons nearby concentrated animal feeding operations (CAFOs). The objectives of this study were to: (i) characterize a suite of swine wastes collected from 19 randomly selected CAFOs for soluble arsenate [As(V)], arsenite [As(III)], dimethylarsenic acid (DMA), monomethylarsonic acid (MMA), 3‐amino‐4‐hydroxyphenylarsonic acid (3‐HPPA), p‐arsanilic acid, and roxarsone, and (ii) determine the geochemical fate of roxarsone in storage lagoons nearby CAFOs. Swine waste suspensions were spiked with roxarsone and incubated under dark/light and aerobic/anaerobic conditions to monitor roxarsone degradation kinetics. Arsenic speciation analysis using liquid chromatography and inductively coupled plasma mass spectrometry (LC‐ICPMS) illustrated the prevalence of As(V) in swine waste suspensions. Roxarsone underwent degradation to either organoarsenicals (3‐HPPA) or As(V) and a number of unidentified metabolites. Roxarsone degradation occurred under anaerobic conditions for suspensions low in solids content, but suspensions higher in solids content facilitated roxarsone degradation under both anaerobic and aerobic conditions. Increased solids content enhanced roxarsone degradation kinetics under aerobic conditions. According to current waste storage and sampling practices, arsenic in swine wastes stored in lagoons has been overlooked as a possible environmental health issue.
Application of Flow Field‐Flow Fractionation and Laser Sizing to Characterize Soil Colloids in Drained and Undrained Lysimeters
Authors: Gimbert Laura J. , Haygarth Philip M. , Worsfold Paul J.
Published: June 2008

This paper reports the use of a new technique, flow field‐flow fractionation (FlFFF), for the characterization of soil sampled under grassland. FlFFF can be used to determine the fine colloidal material in the <1 μm fraction obtained by gravitational settling of 1% m/v soil suspensions. The aim of this work was to determine the potential of FIFFF to characterize soil colloids in drained and undrained field lysimeters from soil cores sampled at different depths. Two different grassland lysimeter plots of 1 ha, one drained and one undrained, were investigated, and the soil was sampled at 20‐m intervals along a single diagonal transect at three different depths (0–2, 10–12, and 30–32 cm). The results showed that there was a statistically significant (P = 0.05) increase in colloidal material at 30‐ to 32‐cm depth along the transect under the drained lysimeter, which correlates with disturbance of the soil at this depth due to the installation of tile drains at 85‐cm depth backfilled to 30‐cm depth with gravel. Laser sizing was also used to determine the particles in the size range 1 to 2000 μm and complement the data obtained using FlFFF because laser sizing lacks resolution for the finer colloidal material (0.1–1.0 μm). The laser sizing data showed increased heterogeneity at 30‐ to 32‐cm depth, particularly in the 50 to 250 μm size fraction. Therefore FIFFF characterized the finer material and laser sizing the coarser soil fraction (<2000 μm) at depth in drained and undrained grassland. This is of importance as colloidal material is more mobile than the larger material and consequently an important vector for contaminant transport from agricultural land to catchments.
Hydrogeological Study of an Anti‐Tank Range
Authors: Mailloux Michel , Martel Richard , Gabriel Uta , Lefebvre René , Thiboutot Sonia , Ampleman Guy
Published: June 2008

The Arnhem Anti‐Tank Range (Canadian Forces Base [CFB] Valcartier, Canada, in operation since the 1970s) has been characterized, including the drilling, installation, and characterization of 25 wells and a ground‐penetrating radar survey. The observed particular features of this site include highly variable flow velocities (from < 3 to 1200 m/yr) and transient flow regime in the regional aquifer below the contaminant source zone of the impact area, sharp flow direction shifts, discontinuous stratigraphy and a local perched aquifer. A transient ground water flow model permitted us to understand how the complex hydrogeological setting shapes contaminant transport in the regional aquifer. The model explains the highly variable energetic material (EM) concentrations measured in the plume with peaks associated to spring and to a lesser extent to fall recharge events. As a conclusion from this work, the authors suggest that the characterization of contaminant sources on slopes should extend over all seasons to be sure to detect potential transient flow conditions and variable contaminant concentrations.
Recovery of nutrients from sewage sludge – Results of the European research-project SUSAN
Authors: Adam C. , Kley G. , Simon F.-G. , Lehmann A.
Published: June 2008

Municipal sewage sludge is a carrier of nutrients – most important phosphorus (P) – but also contains organic pollutants and heavy metals. A two steps thermal treatment based on 1. mono-incineration of sewage sludge under destruction of organic pollutants and 2. thermochemical treatment of the resulting ashes to remove heavy metals and increase P-bioavailability is suggested by the authors. The process aims at P-fertilisers production from sewage sludge. Seven sewage sludge ashes of different origin and composition and one residue from gasification of sewage sludge were thermochemically treated. The raw ashes were mixed with a chlorine donor (e.g. MgCl2) and thermally treated in a gas tight lab-scale rotary furnace. The distributions of the heavy metals between solid and gas phase were determined. The heavy metals concentrations of the treated ashes matched the legislative limits in most cases. The products from thermochemical treatment are suited raw materials for P-fertiliser production. Relevant process parameters such as temperature, type and concentration of Cl-donor and retention time were optimised for the thermochemical treatment step.
Anaerobic digestion enhanced by thermal hydrolysis: First reference BIOTHELYS® at Saumur, France
Authors: Chauzy Julien , Cretenot Didier , Bausseron Anne , Deleris Stéphane
Published: June 2008

Veolia Water has developed during these last years its own THP (Thermal Hydrolysis Process) named BIOTHELYS® in order to enhance MAD (mesophilic anaerobic digestion) of municipal or industrial sludge. The first reference BIOTHELYS® has been installed at Saumur in France, an extended aeration biological nutrient removal facility, and commissioned in April 2006. The thermal hydrolysis of dewatered sludge is realised by steam injection at a temperature of 160°C for duration of circa 30 minutes. The THP reactors are paired in order to recover flash steam and heat sludge economically. The MAD of hydrolysed sludge is done within a HRT of 15 days and reaches volatile reduction of more than 45% on extended aeration biological sludge. BIOTHELYS® turns the MAD of extended aeration biological sludge into a very attractive solution while producing green energy with biogas. MAD is thus no more only reserved for mixed sludge but also for pure biological sludge when using THP.
Sludge management systems for urban wastewater treatment plants – A tool for the decision makers
Authors: Duarte E.C.N.F. , Martins M.B.O. , Trindade C.P. , Ribeiro I.
Published: June 2008

The main goal of the work developed is to present the results from a set of studies conducted in different regions of Portugal where a conceptual model of sludge management was applied. In order to achieve the objective of the use of organic resources on land, all the partnerships (producers, users, authorities, regulators) should be convince that the sludge/biosolid is safe, sustainable, trusted and welcome. The selection of the use/disposal method or management system was based on technical factors such as, local geography, climate, land use, availability or disposal sites and regulatory constrains, giving also emphasis to the local traditions, personnel experience and public opinion. The wide spread of different WWTP by region in study (size, treatment process and local specific parameters) led us to the construction of hypothetical sludge management scenarios. The decision depends on several factors, namely, economical, environmental, logistical, energy recovery and land use. This tool can be used, not only for the region in study, but also for different municipalities, although it should be adapted to the different “municipality specific” and “site specific” parameters. The results were thoroughly analysed to identify parameters that could have a potential influence on the results.
Technical and scientific monitoring of the large-scale seaborne technology at the WWTP Gifhorn
Authors: Günther L. , Dockhorn T. , Dichtl N. , Müller J. , Urban I. , Phan L. C. , Weichgrebe D. , Rosenwinkel K. H. , Bayerle N.
Published: June 2008

The Seaborne process separates nutrients from the sewage sludge and produces a high quality fertilizer without heavy metals or organic pollutants. A first large-scale pilot plant with a modified Seaborne Technology was built on the wastewater treatment plant (WWTP) of Gifhorn in Germany. The plant was established in the year 2005 and the start-of-operation phase is being monitored technically and scientifically. The priority objective of the technical and scientific monitoring is to determine the efficiency of the process. This includes monitoring of resource consumption as well as the quality and quantity of the produced fertilizer. Furthermore the influence of this technology on the operation of the WWTP will be investigated. Another question to be answered is the profitability of the recycling process and a possible transferability to other WWTPs.

Mass balances of nutrient and pollutant streams established before start-of-operation will be used as reference values for comparing future results. In addition, organic and inorganic pollutant concentrations in the digested sludge were determined before the sludge was fed to the Seaborne process. The obtained reference values will then be compared with the measuring results obtained under operation of the Seaborne process. Thus load redistribution in the material flows of the WWTP will be determined. Since so far, no stable operation of the large-scale Seaborne Technology has been achieved, it has not been possible to carry out the measuring programme. Therefore reference values for nutrient streams obtained from the primary mass balances, were used to calculate expected mass balances after implementing the Seaborne Technology to the WWTP, in order to be able to estimate possible future load redistribution in the material flows of the WWTP.
Recycling of water treatment sludges in municipal wastewater treatment plants – a practical example
Authors: Klinksieg K. , Dockhorn T. , Dichtl N.
Published: June 2008

Full-scale and lab-scale research experiments were conducted to determine the phosphorous precipitation efficiency of iron hydroxide sludge from drinking water treatment. During full-scale investigations at a wastewater treatment plant, ferric sludge was added to the inflow of the primary settling tank in a first experimental phase and to the inflow of the aeration tank in a second phase. In the outflow of the mechanical stage and in the outflow of the biological stage, a reduction of the PO4-P concentrations could be observed. The concentration of COD, the SVI and the filament abundance were not changed significantly by adding the ferric sludge to the wastewater treatment plant. In lab tests, improved precipitation efficiency of the ferric sludge could be achieved by using anaerobic conditions and acid pulping. The research showed that the wastewater treatment process can benefit from the reuse of ferric sludge from drinking waterworks and that this also presents an inexpensive recycling option for these sludges.
Wastewater biosolids as an environmentally sustainable resource: Keys to success
Authors: LeBlanc Ronald J. , Allain Conrad J. , Laughton Peter J.
Published: June 2008

The paper traces the success of a large Canadian wastewater utility that has dealt with the issue of biosolids management and recycling to the extent that it now has more demand for its biosolids than it produces. The Greater Moncton Sewerage Commission's (GMSC) problem is not one of disposing of biosolids, but one of determining which product and uses will be best for the environment as well as being most sustainable and cost effective in the long term. Wastewater treatment and the management of the sludge or biosolids produced are global issues, with growing challenges, that must address the concerns of all of the stakeholders, including the facility administrators and operators, regulators and elected officials, the scientific community, wastewater generators, taxpayers and the general public. The failure to take into consideration the concerns of all of the stakeholders including the lack of meaningful communication with the public has resulted in predictable but preventable problems, including the banning of scientifically acceptable biosolids recycling options in different countries. Consequently, a successful and viable wastewater treatment and biosolids recycling management plan requires a "big picture" view and a sustainable approach, which takes into consideration the concerns of all stakeholders. The paper will deal with key issues to the success of an environmentally sustainable biosolids management programme.
Sludge minimization by disintegration at different wastewater treatment plants
Authors: Luning Luchien , Roeleveld Paul , Claessen Victor W.M.
Published: June 2008

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).
Tendencies and Overview on the Nutrient Recovery from Sewage Sludge in Germany
Authors: Weidelener Alexander , Antakyalı Demet , Krampe Jörg
Published: June 2008

The critics against the land use of sewage sludge in Germany lead the research institutions to investigate methods for nutrient recovery. Current research proved that the nutrients such as nitrogen or phosphorus can be recovered. Though, the costs still must be reduced to compete with the conventional production using fresh raw material. Recovery products are not listed in current legislations concerning fertiliser use, therefore the land use of the recovered products require some legislative replenishments.

The paper portrays the current situation concerning the above discussions with an overview on the actual recovery technologies
DROUGHT MANAGEMENT AND CUSTOMER SERVICE
Authors: Zubizarreta Juan
Published: June 2008

Madrid Region comprises nearly 6 million inhabitants of which the vast majority is supplied with water by the Canal de Isabel II. The last drought season occurred in the years 2005 – 2006 and it was considered just as bad as the one experienced eleven years before.

The effective management of an imminent threat of water shortage, which usually results from such drought, was made possible through the creation of a Special Office. Its main task was to coordinate all the efforts and activities necessary in order to prevent the shortage problem from becoming a serious threat and developing into a region-wide crisis.

Some of those efforts and activities were focused directly on Customer Service. As such, the paper deals with some of those non-technical activities made to handle the drought situation and the experiences acquired in managing a potential crisis.
Public private partnership for efficient and sustainable water supply development in Indonesia
Authors: Hoogsteen Karst Jan , van der Kolff Gerard , Ruijter Josien A.
Published: June 2008

More than 90% of the water supply companies in Indonesia are in serious trouble and face bankruptcy. Water services are poor and the situation is worsening. The critical condition of the water companies is due to several factors, amongst others the lack of know-how in the company, the political influence in human resource management and on water price. These factors prevented the introduction of sound economical principles for the daily management. As the income of the company did not cover all costs, service hours were reduced and finally led to the negative spiral resulting in the current troublesome situation.

Water supply company Drenthe (WMD), together with local Indonesian Government and central Government in the Netherlands, developed a long-term public-private partnership approach for the development of water supply companies in Eastern Indonesia.

Customer relations and introduction of new billing procedures are of highest importance for the success of the approach. The new water companies can only operate successfully when the willingness to pay is restored and when the cash flow is secured. Important elements in this field are the introduction of a computer system supporting the monthly billing system and an innovative pilot with digital water meters.
Integrated Operations and Management of Wastewater Treatment Facilities in the Upstream Areas of Dams
Authors: Han Geung Jeon , Cho Ju Young , Kim Young Ju
Published: June 2008

Most of the wastewater treatment facilities in the upstream areas of dams in Korea are small and scattered and the local governments of these areas are financially very poor as well. Owing to these characteristics, though they directly impact the quality of water resources, operations and management of these facilities have been non effective. So, in this research, Korea Water Resources Corporation (K-water) has tried to integrate operations and management (O&M) of wastewater treatment facilities in these areas to maximize operating efficiency. Although there have been some difficulties measuring effects of an integrated system, we could see many positive consequences including operating cost reduction, effluent quality and process efficiency elevation, and customer service improvement in the centralized O&M.
PRIVATE WATER STORAGE TANKS: EVALUATING THEIR INEFFICIENCIES
Authors: Cobacho Ricardo , Arregui Francisco , Cabrera Enrique , Cabrera Enrique
Published: June 2008

Private water storage tanks are often considered as very inefficient devices than can only be justified in systems that suffer frequent water service interruptions. This paper presents the results obtained after studying four different aspects of this question: the effect of this kind of tanks on water losses, unaccounted for water, time modulation curve and energy losses (other implications, such as those related to water quality deterioration, remain out of the scope of the study). Conclusions for each particular point will turn uneven, specially highlighting the effect on the meter global error and unregistered water. In any case, all four points, as well as several additional issues to be considered, are described and evaluated.
Knowledge, Beliefs, and Attitudes to Female Genital Mutilation (FGM) in Shao Community of Kwara State, Nigeria
Authors: Amusan O. A. , Asekun-Olarinmoye E. O.
Published: June 2008

To determine the level of knowledge, belief, and assess the attitude to female genital mutilation (FGM) and its complications in Shao community, Nigeria, a cross-sectional descriptive study with a health education intervention was used. A majority of respondents (99.5%) understood female circumcision to mean cutting off parts of the female genitals. There was a high level of knowledge regarding most of the complications of FGM as more than 50% of respondents knew at least four complications of FGM. Awareness of the global anti-FGM campaign was also high (78.8%). The most common reasons proffered for the practice of FGM were based on tradition or religion. Paternal grandfathers (50.0%) and fathers (21.0%) were cited as decision makers in the family most often responsible for requesting FGM. Post-intervention results showed that there was a statistically significant increase in the proportion of respondents who know more complications of FGM and who have no intention of circumcising future female children. Despite a high level of knowledge regarding the complications of FGM and a high level of awareness of the global campaign against it, there still exists a high prevalence of practice of FGM in this community. FGM remains a pressing human rights and public health issue. It is our recommendation that this health education intervention strategy be replicated nationwide especially using mass media.
Should My New Curing Light Be An LED?
Authors: Antonson S. A. , Antonson D. E. , Hardigan P. C.
Published: June 2008

Clinical Relevance

This study provides information concerning curing light unit purchase decision criteria and supporting evidence to compare various curing light units that are on the market.
Transdental Photo-activation Technique: Hardness and Marginal Adaptation of Composite Restorations Using Different Light Sources
Authors: Alves E. B. , Alonso R. C. B. , Correr G. M. , Correr A. B. , de Moraes R. R. , Sinhoreti M. A. C. , Correr-Sobrinho L.
Published: June 2008

Clinical Relevance

The association of transdental and direct photo-activation of composite restorations might improve marginal adaptation, while not being detrimental to composite hardness.
Influence of Er,Cr:YSGG Laser Treatment on Microtensile Bond Strength of Adhesives to Enamel
Authors: Cardoso M. V. , De Munck J. , Coutinho E. , Ermis R. B. , Van Landuyt K. , de Carvalho R. C. R. , Van Meerbeek B.
Published: June 2008

Clinical Relevance

Er,Cr:YSGG laser irradiation produced morphological alterations on enamel, which may adversely influence the bond strength of certain adhesives, depending on their approach and composition.
Repairing Ceramic Restorations: Final Solution or Alternative Procedure?
Authors: Reston E. G. , Filho S. C. , Arossi G. , Cogo R. B. , Rocha C. S. , Closs L. Q.
Published: June 2008

PURPOSE

This article provides an overview of dental ceramics. It addresses possible modes of failure and factors that may influence the decision to either repair or replace ceramic restorations. The authors' intention was to present ceramic repair as a reliable, low-cost, low-risk technique.
Influence of Cement Shade and Water Storage on the Final Color of Leucite-reinforced Ceramics
Authors: Karaagaclioglu L. , Yilmaz B.
Published: June 2008

Clinical Relevance

Luting cement under 0.8 mm thick leucite-reinforced ceramic changed the final color of the ceramic and could be seen by the human eye. Therefore, clinicians may prefer to use try-in pastes or polymerized luting composite shade guides to compensate for the change in color of definitive restorations, such as laminate veneers. The final color differences between ceramics luted with cements in A1 and A3 shades were not clinically perceivable at each measurement. Within the limitations of this study, changing the color of an IPS Empress laminate veneer restoration via the shade of the cement seems not to be a preferred method.
Work-Related Asthma in Automobile Spray Painters: Two Case Reports
Authors: Minov Jordan , Karadžinska-Bislimovska Jovanka , Vasilevska Kristin , Risteska-Kuc Snežana , Stoleski Sašo
Published: June 2008

Work-Related Asthma in Automobile Spray Painters: Two Case Reports

This report describes two patients who had developed asthma after working as automobile painters with isocyanate-based aerosol paint for two years or over. In both patients asthma was confirmed using the standard diagnostic procedure. One of the subjects was atopic. One was ex-smoker and the other had never smoked. Neither had a family history of asthma. The symptoms occurred after workplace exposure lasting two years in one patient and three in the other. As both reported work-relatedness of the symptoms, they underwent serial peak expiratory flow rate (PEFR) measurement and bronchoprovocation testing. Significant work-related changes in PEFR diurnal variations and in non-specific bronchial hyperresponsiveness (NSBH) were observed in one patient, suggesting allergic occupational asthma (OA), while the other patient was diagnosed work-exacerbated asthma (WEA). Our data confirm that spray painting is an occupation with increased risk of respiratory impairment and asthma.
Reduced-Dynamic Precise Orbit Determination for Low Earth Orbiters Based on Helmert Transformation
Authors: Chen Junping , Wang Jiexian
Published: June 2008

Reduced-Dynamic Precise Orbit Determination for Low Earth Orbiters Based on Helmert Transformation

A model based on Helmert transformation is presented in reduced-dynamic Precise Orbit Determination(POD). As an implementation, a reduced-dynamic POD approach was developed. The approach includes two steps: firstly, kinematic POD and then reduced-dynamic POD. Based on the approach, a set of programs were developed. POD of CHAMP and GRACE was then carried out. Kinematic and reduced-dynamic POD for CHAMP and GRACE satellite over 2 weeks time show that reduced-dynamic orbits of CHAMP have a mean 3D RMS of 0.26 m compared to PSO orbit of GFZ, and the mean 3D RMS of GRACE-A has the same value compared to GNV1B orbit of JPL. The 3D RMS is reduced by up to 40% compared to kinematic solutions.
An Examination of Dynamic Capabilities: Is Evolutionary Theory Underdetermined?
Authors: Vassolo Roberto S. , Anand Jaideep
Published: June 2008

Firms frequently need to update their capabilities in changing environments but face significant barriers to accomplish this goal due to the stickiness of their routines, local search constraints, bounded rationality, uncertain imitability, and causal ambiguity. Under high levels of uncertainty, dynamic capabilities are often externally oriented, involving acquisitions and alliances. However, nonunique but competitive predictions about the behavior of these capabilities arise from the evolutionary theory. We test these competitive hypotheses analyzing portfolios of acquisitions and alliances made by pharmaceutical firms in search of portfolios of biotech capabilities. The analysis of portfolios enables us to better identify “common practices” in the pharmaceutical industry than using a transactional‐level focus. We develop implications for the evolutionary theory and for managerial practice.
Changes of the equilibrium-line altitude since the Little Ice Age in the Nepalese Himalaya
Authors: Kayastha Rijan Bhakta , P. Harrison Sandy
Published: June 2008

Changes of the equilibrium-line altitude (ELA) since the end of the Little Ice Age (LIA) in eastern Nepal have been studied using glacier inventory data. The toe-to-headwall altitude ratios (THARs) for individual glaciers were calculated for 1992, and used to estimate the ELA in 1959 and at the end of the LIA. THAR for debris-free glaciers is found to be smaller than for debris-covered glaciers. The ELAs for debris-covered glaciers are higher than those for debris-free glaciers in eastern Nepal. There is considerable variation in the reconstructed change in ELA (ΔELA) between glaciers within specific regions and between regions. This is not related to climate gradients, but results from differences in glacier aspect: southeast- and south-facing glaciers show larger ΔELAs in eastern Nepal than north- or west-facing glaciers. The data suggest that the rate of ELA rise may have accelerated in the last few decades. The limited number of climate records from Nepal, and analyses using a simple ELA–climate model, suggest that the higher rate of the ΔELA between 1959 and 1992 is a result of increased warming that occurred after the 1970s at higher altitudes in Nepal.
Mass budget of the grounded ice in the Lambert Glacier–Amery Ice Shelf system
Authors: Jiahong Wen , Yafeng Wang , Jiying Liu , Jezek Kenneth C. , Huybrechts Philippe , Csathó Beata M. , Farness Katy L. , Bo Sun
Published: June 2008

We used remote-sensing and in situ measurements of surface accumulation rate, ice surface velocity, thickness and elevation to evaluate the mass budgets of grounded ice-flow regimes that form the Lambert Glacier–Amery Ice Shelf system. Three distinct drainage regimes are considered: the western and eastern margins of the ice shelf, and the southern grounding line at the major outlet glacier confluence, which can be identified with drainage zones 9, 11 and 10 respectively of Giovinetto and Zwally (2000). Our findings show the entire grounded portion of the basin is approximately in balance, with a mass budget of –4.2±9.8 Gt a–1. Drainages 9, 10 and 11 are within balance to the level of our measurement uncertainty, with mass budgets of –2.5±2.8 Gt a–1, –2.6±7.8 Gt a–1 and 0.9±2.3 Gt a–1, respectively. The region upstream of the Australian Lambert Glacier basin (LGB) traverse has a net mass budget of 4.4±6.3 Gt a–1, while the downstream region has –8.9±9.9 Gt a–1. These results indicate that glacier drainages 9, 10 and 11, upstream and downstream of the Australian LGB traverse, are in balance to within our measurement error.
Snow avalanche mass-balance calculation and simulation-model verification
Authors: Sailer Rudolf , Fellin Wolfgang , Fromm Reinhard , Jörg Philipp , Rammer Lambert , Sampl Peter , Schaffhauser Andreas
Published: June 2008

Two-or three-dimensional avalanche-simulation models offer a wide range of applications; however, a challenging model-verification process is demanded, accompanied by a reliable determination of model-input parameters. We show that a verification process can be arranged with remote-monitoring data from an artificially triggered avalanche, leading to the calculation of avalanche mass balance. Two numerical methods are applied to increase the quality of the parameter fit and to reduce the number of simulations. The quality of the parameter fit is verified by comparing measured and simulated run-out lengths. In addition, a cross-check is performed using velocities derived from Doppler radar measurements.