bluuebunny/crossref_metadata_2025 huggingface dataset:
Opportunities for further progress of sociological studies about doctors and medical students
Authors: Molnár Regina , Győrffy Zsuzsa
Published: October 2012

Introduction: The fundamental purpose of sociological studies is to explore social problems which should be also in focus when examining doctors and medical students. In addition to fact findings, published reports may raise awareness toward these issues. Aim: The authors formulate a possible change of the research approach exploring possibilities to move forward with special focus on the health status among doctors, the role-conflict among female doctors and the professional socialisation among medical students. Methods: Secondary analysis of published studies among health care professionals. Results: Almost all published papers convey the conflict of being a physician in some aspect, but they fail to explore issues related to professional success, protective factors, resources and conflict management modes. Conclusion: In addition to exploration of risk factors, future studies should promote medical identity, should call attention to existing positive examples and should provide hints to cope with challenging issues in order to achieve a successful medical career. Orv. Hetil., 2012, 153, 1738–1744.
The AIC model selection method applied to path analytic models compared using a d‐separation test
Authors: Shipley Bill
Published: October 2012

Classical path analysis is a statistical technique used to test causal hypotheses involving multiple variables without latent variables, assuming linearity, multivariate normality, and a sufficient sample size. The d‐separation (d‐sep) test is a generalization of path analysis that relaxes these assumptions. Although model selection using Akaike's information criterion (AIC) is well established for classical path analysis, this model selection technique has not yet been developed for d‐sep tests. In this paper, I explain how to use the AIC statistic for d‐sep tests, give a worked example, and include instructions (supplemental material) to implement the analysis in the R computing language.
Nursing Leadership in Disaster Preparedness and Response
Authors: Knebel Ann R. , Toomey Lauren , Libby Mark
Published: October 2012

Nurses serve as leaders in disaster preparedness and response at multiple levels: within their own homes and neighborhoods, at disaster scenes, and the workplace, which can vary from a health care facility, in the community, or at the state, national, or international level. This chapter provides an overview on theories of leadership with a historical context for nursing leadership; setting the context for nursing leadership in disaster preparedness and response. Although few research studies exist, there are numerous examples of nurses who provide leadership for disaster preparedness and response. To define the current state of the science, the research studies cited in this chapter are supplemented with case studies from particular disasters. The major finding of this review is that nursing leadership in disaster preparedness and response is a field of study that needs to be developed.
A Logical and Progressive Approach to Computed Tomography–Guided Implantology
Authors: Califano Joseph V. , Rosenfeld Alan , Mandelaris George
Published: October 2012

Focused Clinical Question: What are the important factors contributing to the success of computed tomography (CT)–guided implantology, and how might this technology best be incorporated into practice?

Summary: CT‐guided implantology has provided an opportunity to more completely assess and plan the surgical placement of dental implants. This technology allows viewing of both anatomic and prosthetic information preoperatively in an interactive format. A precise plan can be developed and transferred to the surgery with a computer‐generated surgical template. In addition, it facilitates preoperative collaboration among the restoring dentist, laboratory technologist, surgeon, and patient that establishes treatment goals and expectations. There are several types of guides that may be used in CT‐guided implantology, with each having different levels of guidance. A logical and progressive approach to implementing CT‐guided technology in practice involves a gradual increase in complexity while minimizing risk during the learning curve. Each case can be evaluated, planned, and suited to the patient's needs, as well as the clinician's preference, experience, and risk tolerance.

Conclusions: Incorporating technological advances, such as CT‐guided implantology, into clinical practice requires cooperative and collaborative input of all those responsible for patient care. Each clinician must determine the most appropriate diagnostic approach for a given situation. Success in CT interpretation and guided surgery execution is proportional to experience and detail in planning. This paper provides some guidelines and options to incorporate such technology into practice and suggests a logical and progressive approach to ensure success.
Antibiotic Susceptibility of Periodontal Enterococcus faecalis
Authors: Rams Thomas E. , Feik Diane , Mortensen Joel E. , Degener John E. , van Winkelhoff Arie J.
Published: October 2012

Background: Enterococcus faecalis may contribute to periodontal breakdown in heavily infected subgingival sites, particularly in patients responding poorly to mechanical forms of periodontal therapy. Because only limited data are available on the antimicrobial sensitivity of enterococci of subgingival origin, this study evaluates the in vitro antibiotic susceptibility of E. faecalis isolated from periodontitis patients in the United States.

Methods: Pure cultures of 47 subgingival E. faecalis clinical isolates were each inoculated onto specially prepared broth microdilution susceptibility panels containing vancomycin, teicoplanin, and six oral antibiotics of potential use in periodontal therapy. After incubation in ambient air for 18 to 20 hours, minimal inhibitory drug concentrations were determined using applicable Clinical and Laboratory Standards Institute criteria and interpretative guidelines. The organisms were additionally evaluated for in vitro resistance to metronidazole at 4 μg/mL.

Results: Periodontal E. faecalis exhibited substantial in vitro resistance to tetracycline (53.2% resistant), erythromycin (80.8% resistant or intermediate resistant), clindamycin (100% resistant to 2 μg/mL), and metronidazole (100% resistant to 4 μg/mL). In comparison, the clinical isolates were generally sensitive to ciprofloxacin (89.4% susceptible; 10.6% intermediate resistant) and 100% susceptible in vitro to ampicillin, amoxicillin/clavulanate, vancomycin, and teicoplanin.

Conclusions: Tetracycline, erythromycin, clindamycin, and metronidazole revealed poor in vitro activity against human subgingival E. faecalis clinical isolates, and would likely be ineffective therapeutic agents against these species in periodontal pockets. Among orally administered antibiotics, ampicillin, amoxicillin/clavulanate, and ciprofloxacin exhibited marked in vitro inhibitory activity against periodontal E. faecalis, and may be clinically useful in treatment of periodontal infections involving enterococci.
Periodontal Disease and Pregnancy Hypertension: A Clinical Correlation
Authors: Pralhad Swati , Thomas Betsy , Kushtagi Pralhad
Published: October 2012

Background: Periodontal disease is thought to be associated with increased risk of systemic diseases and adverse pregnancy outcomes, including pregnancy hypertension (PH). The aim of the present study is to find the prevalence of periodontal disease in females with PH in a rural‐based medical institute.

Methods: The present case control study was performed with 200 females, 100 with PH and 100 without PH. Antenatal periodontal screening was performed within 72 hours of their hospital admission for delivery. The periodontal parameters assessed were oral hygiene index–simplified, gingival index, mean probing depth, and loss of attachment.

Results: Prevalence of periodontal disease was 65.5% and was significantly higher (P <0.0001) in females with hypertension (relative risk = 1.5; 95% confidence interval [CI] = 1.3 to 1.9). Socioeconomic status, education, occupation, and body mass index did not appear to influence the relationship between periodontal disease and PH on bivariate multiple logistic regression analysis. Nulliparous females were at higher odds to develop periodontal disease and PH (odds ratio = 1.7; 95% CI = 0.5 to 6.1). As the severity of periodontal disease increased from moderate to severe, the severity of hypertension also increased (r2 = 0.8 and 0.5 for moderate and severe periodontal disease, respectively).

Conclusion: Periodontal disease is more prevalent in females with PH.
Effectiveness of Periodontal Treatment to Improve Metabolic Control in Patients With Chronic Periodontitis and Type 2 Diabetes: A Meta‐Analysis of Randomized Clinical Trials
Authors: Sgolastra Fabrizio , Severino Marco , Pietropaoli Davide , Gatto Roberto , Monaco Annalisa
Published: October 2012

Background: It was recently suggested that scaling and root planing (SRP) may help to improve glycemic and metabolic control in patients with chronic periodontitis (CP) and type 2 diabetes mellitus (DM2); however, the effectiveness of SRP in this role remains unclear. This meta‐analysis assesses the effectiveness of SRP in improving glycemic and metabolic control in patients with CP and DM2.

Methods: A literature search of electronic databases was performed for articles published through May 16, 2012, followed by a manual search of several dental journals. A meta‐analysis was conducted according to the recommendations of the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA). Weighted mean differences (MDs) and 95% confidence intervals (CIs) were calculated for glycated hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), total cholesterol (TC), triglycerides (TG), and high‐ and low‐density lipoprotein cholesterol (HDL and LDL, respectively). All outcomes were evaluated as changes from baseline to the end of follow‐up. Heterogeneity was assessed with the χ2‐based Cochran Q test and I2 statistic. The level of significance was set at P <0.05.

Results: After the study selection process, five randomized clinical trials were included. Results of the meta‐analysis indicated that SRP was effective in the reduction of HbA1c (MD = 0.65; 95% CI 0.43 to 0.88; P <0.05) and FPG (MD = 9.04; 95% CI 2.17 to 15.9; P <0.05), but no significant differences were found in the reduction of TC, TG, HDL, or LDL. No evidence of heterogeneity was detected.

Conclusion: The meta‐analysis results seem to support the effectiveness of SRP in the improvement of glycemic control in patients with CP and DM2; however, future studies are needed to confirm these results.
A Randomized, Double‐Masked Clinical Trial Comparing Four Periodontitis Treatment Strategies: 1‐Year Clinical Results
Authors: Preus Hans R. , Gunleiksrud Therese Mehlum , Sandvik Leiv , Gjermo Per , Baelum Vibeke
Published: October 2012

Background: The benefit of full‐mouth disinfection (FDIS) over traditional scaling and root planing (SRP) remains equivocal, and it is not known whether the use of adjunctive antibiotics may enhance the effect of FDIS. The aim of the present study is to test the hypothesis that there is no difference in the 1‐year clinical outcome of therapy among groups of patients treated with conventional SRP performed over 2 to 3 weeks, or same‐day FDIS, with or without adjunctive metronidazole.

Methods: A total of 184 patients with moderate‐to‐severe periodontitis were randomly allocated to one of four treatment groups: 1) FDIS+metronidazole; 2) FDIS+placebo; 3) SRP+metronidazole; or 4) SRP+placebo. Recordings of plaque, bleeding on probing, probing depth (PD), and clinical attachment level (CAL) were carried out in four sites per tooth at baseline and at 3 and 12 months after treatment.

Results: No differences were observed in the mean CAL or PD values between the four experimental groups at baseline and 3 or 12 months post‐treatment. All four groups displayed significant improvements in all parameters. However, using absence of pockets ≥5 mm as the criterion for treatment success, the two groups receiving adjunctive metronidazole performed significantly better than the two placebo groups.

Conclusion: Metronidazole had a significant, adjunctive effect in patients with a metronidazole‐sensitive subgingival microbiota on the clinical parameters of CAL, PD, and absence of pockets ≥5 mm.
The Effects of a Novel Botanical Agent on Lipopolysaccharide‐Induced Alveolar Bone Loss in Rats
Authors: Lee Bo‐Ah , Lee Hwa‐Sun , Jung Young‐Suk , Kim Se‐Won , Lee Yong‐Wook , Chang Sun‐Hwa , Chung Hyun‐Ju , Kim Ok‐Su , Kim Young‐Joon
Published: October 2012

Background: The development of host‐modulatory agents with low risk of adverse effects has been needed to treat periodontitis, a chronic inflammatory disease. A botanical mixture of extracts from two natural substances, Panax notoginseng and Rehmannia glutinosa Libosch, was developed as a novel botanical agent synthesized with anti‐inflammatory effect. The aim of this study is to evaluate the effects of the botanical mixture on the release of inflammatory cytokines and its inhibitory effect on lipopolysaccharide (LPS)‐induced alveolar bone loss (ABL) in a rat model.

Methods: Cytotoxicity was assessed by 3‐(4,5‐dimethylthiazol‐2yl)‐5(3‐carboxymethoxyphenol)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium assay using human gingival fibroblast (hGF) and human periodontal ligament (hPDL) cells. Human acute monocytic leukemia cell line and hGF cells were cultured to assay tumor necrosis factor (TNF)‐α and interleukin (IL)‐6, respectively. Microcomputed tomography analysis and immunofluoresence analysis were performed to evaluate the efficacy of the botanical mixture to inhibit the destruction of alveolar bone and connective tissue in a rat model.

Results: The botanical mixture is cytotoxic at concentrations exceeding 2.5 mg/mL (P <0.05). Based on the results from cytotoxicity assay, it can be determined that the pharmacologic ranges of the botanical mixture to be used in all subsequent in vitro and in vivo experiments. The botanical mixture reduced the release of TNF‐α and IL‐6 from human monocytic cells and hGF cells in a dose‐dependent manner (P <0.05). The administration of the botanical mixture significantly reduced the alveolar bone loss in a rat model (P <0.05). In groups treated with the botanical mixture, matrix metalloproteinase (MMP)‐9 was detected along the alveolar bone crest (ABC), but not around the gingival connective tissue, while in the group with LPS‐induced ABL, pronounced expression of MMP‐9 around the ABC, periodontal ligament, and gingival connective tissue was found.

Conclusions: The botanical mixture showed a potential adjunctive effect in the treatment of periodontitis. However, the present findings are obtained in vitro and in a rat model, so further clinical study is needed for its clinical application.
A Novel Method for Quantifying Nitrous Oxide Reduction in Soil
Authors: Klefoth Roland , Oenema Oene , Willem van Groenigen Jan
Published: October 2012

Nitrous oxide is produced in soil by nitrifying and denitrifying microorganisms. Most of the N2O produced in soil is reduced to N2 in the final step of denitrification, and only a fraction is released into the atmosphere. No reliable methods exist, however, to quantify N2O reduction and its controlling parameters in soil. In this study, we investigated: (i) a novel method to quantify the reduction of N2O in soil as it diffuses upward; and (ii) the effects of soil moisture content on N2O reduction. We developed a setup where a silicone tube coil permeable to N2O linked to an N2O reservoir simulated a subsoil with a known, artificial N2O source. A soil core filled with repacked sandy soil (a Typic Endoaquoll) was placed on top of the silicone coil. Experimental treatments included water‐filled pore space (WFPS) levels of 60, 75, and 90%, as well as a quartz sand treatment at 90% WFPS that served as an abiotic control. Soil surface N2O emissions were measured for 21 d, and after the experiment, residual N2O in the system was determined. During the experiment, 41, 39, and 0% of the applied N2O was emitted as soil surface flux for the 60, 75, and 90% WFPS treatments, respectively. In the 90% WFPS treatment, 52% of applied N2O was reduced to N2. We conclude that our method enables us to quantify N2O reduction in soil columns. Our results further show that wet soils can be effective in reducing N2O to N2 during upward diffusion from the subsoil.
Radionuclide Transport in the Unsaturated Zone at Yucca Mountain, Nevada
Authors: Robinson Bruce A. , Houseworth James E. , Chu Shaoping
Published: October 2012

This paper presents a comprehensive treatment of large‐scale unsaturated zone (UZ) transport below the repository at the Yucca Mountain, Nevada, reporting on studies investigating the UZ as a component of the Lower Natural Barrier to radionuclide transport from the site. Regardless of the disposition of Yucca Mountain as the site for a nuclear waste repository, these studies and models of radionuclide transport through the UZ have relevance to the study of contaminant transport through deep vadose zones in general. For many radionuclides, including most strongly sorbing species, the Yucca Mountain UZ was found to prevent or substantially reduce the rate of movement of radionuclides to the accessible environment. The UZ radionuclide transport models developed for Yucca Mountain simulate the features and processes that influence the capability of the UZ below the repository to reduce the movement of radionuclides. Transport of radionuclides away from the repository depends on the rate and pathways of flow within the UZ, the retardation of radionuclides, and the rate of transport by colloids. Several basic processes affect radionuclide transport in the UZ, including the quantity of recharge and deep percolation of water, flow partitioning between fractures and rock matrix, diffusion of radionuclides from water flowing in fractures into the pores of the rock matrix, sorption of radionuclides onto rock or mineral surfaces, and colloid filtration. This paper summarizes the treatment of these and other processes, describing the experimental and observational basis for the models, conceptualizations, and predictions, and then presents some representative results.
Links Between Root Length Density Profiles and Models of the Root System Architecture
Authors: Pagès Loïc , Bruchou Claude , Garré Sarah
Published: October 2012

A lot of data is available in the literature on root length density profiles (i.e., root length per unit of soil volume versus soil depth), because they are a traditional way of representing root distribution in the field. In a complementary approach comprehensive models of the root system architecture are being developed, but the parameters required for these models are often difficult to assess in field conditions. In this paper, we bridge both approaches, empirical and comprehensive, by evaluating the capability of architectural models to simulate the observed diversity in root length distribution on the one hand and the possibility of estimating developmental parameters from root length density profiles on the other. For this purpose, we constructed a simple model with only six parameters, to represent the root system architecture. It reproduced a large diversity of root profiles comparable to observations reported in the literature and encompassing many different crops. The impact of each model parameter, as well as their interactions, on the shape of the profiles was quantified using a global sensitivity analysis. Finally, a statistical meta‐model was designed and estimated to simulate the same collection of profiles without intermediate simulating the whole architecture. The meta‐model allows for estimation of architectural parameters from profile shapes (inversion). Some architectural parameters could be estimated from the profiles with good accuracy, especially those quantifying the growth potential and gravitropism of individual roots, because of their specific impact on root length at a specific depth. But others (like inter‐branch distance, life duration), which modify root density in a more diffuse way throughout the profile, could not be identified correctly using this method. Additional data involving specific measurements are necessary to identify these last parameters.
Virtual Soils: Assessment of the Effects of Soil Structure on the Hydraulic Behavior of Cultivated Soils
Authors: Schlüter Steffen , Vogel Hans-Jörg , Ippisch Olaf , Bastian Peter , Roth Kurt , Schelle Henrike , Durner Wolfgang , Kasteel Roy , Vanderborght Jan
Published: October 2012

The hydraulic behavior of soil is determined by the spatial heterogeneity of its hydraulic properties. The interplay among parent material, pedogenesis, and tillage leads to characteristic structures in cultivated soils. Tillage‐induced features like a loosely aggregated seed bed, a compacted plow pan, and soil compaction beneath tractor ruts overlay natural features such as facies and horizons. Assessing the impact of such structural components on vadose zone hydrology requires an observation scale of several meters and a resolution in the range of centimeters, which is not feasible with experimental setups. An alternative solution is the generation of synthetic but realistic structures and their hydraulic properties as a basis for modeling the hydraulic behavior in response to different boundary conditions. With such “virtual soils” at hand, comparative studies are possible that help explore the relation between soil architecture and soil function. We developed a structure generator that provides great flexibility in the design of virtual soils with nested heterogeneity. Virtual soils with increasing complexity were generated to explore scenarios of precipitation and evaporation for a period of several months. The simulations demonstrated that the structure and the hydraulic properties close to the soil surface originating from tillage clearly govern atmospheric boundary fluxes, while the impact of heterogeneity on groundwater recharge is more complex due to threshold effects, hydraulic nonequilibrium, and the interaction with atmospheric forcing. A comparison with one‐dimensional, effective representations of these virtual soils demonstrated that upscaling of soil water dynamics becomes inaccurate when lateral fluxes become relevant at the scale of observation.
An Experimental Study of Diffusivity of Technetium‐99 in Hanford Vadose Zone Sediments
Authors: Mattigod Shas V. , Bovaird Chase C. , Wellman Dawn M. , Parker Kent E. , Wood Marc I.
Published: October 2012

One of the methods being considered at the Hanford site in the state of Washington for safely disposing of low‐level radioactive wastes (LLW) is to encase the waste in concrete and entomb the packages in the Hanford vadose zone sediments. The current plan for waste isolation consists of stacking low‐level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages with concrete. Any failure of the concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow or diffusion and move into the surrounding subsurface sediments. It is therefore necessary to conduct an assessment of the performance of the concrete encasement structure and the surrounding soil's ability to retard radionuclide migration. Because of their anionic nature in aqueous solutions, the radionuclides, 99Tc and 129I were identified as long‐term dose contributors in LLW. The leachability or diffusion of these radionuclide species must be measured to assess the long‐term performance of waste grouts when contacted with vadose zone pore water or groundwater. To supplement the previously obtained data, a set of experiments were conducted using 99Tc‐spiked concrete (with 0 or 4% metallic Fe additions) in contact with Hanford soil at extremely low moisture content (~1% by mass). The 99Tc diffusion profiles in the soil half‐cells were measured after a time lapse of ~1.9 yr and the diffusion coefficient was calculated to be ~1.0 × 10−9 cm2 s−1.
Enhancing oil-sorption performance of polypropylene fiber by surface modification via UV-induced graft polymerization of butyl acrylate
Authors: Li Shaoning , Wei Junfu , Wang Ao , Nie Yuexia , Yang Hang , Wang Lei , Zhou Bin
Published: October 2012

In order to improve oil sorption performances, polypropylene (PP) fiber was modified through graft polymerization with butyl acrylate (BA) initiated by ultraviolet (UV) radiation in isopropanol/water mixture solution. Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM) and specific surface area were used to characterize the chemical and morphological changes of the PP fiber surface. Static contact angle (CA) measurements showed that the hydrophilicity of original PP fiber was enhanced after graft polymerization. The grafted fiber exhibited an excellent oil-sorption, oil-retention performance, fast saturation-sorption rate and superior reusability of oil. When the grafting degree was 15.55%, the maximum oil-sorption capacity reached 18.35 g/g, while the oil-sorption capacity of original PP fiber was only 11.54 g/g. After the tenth cycle of reuse, the grafted fiber sorbent assembly only lost 30% of its virgin sorption capacity.
Sustainable nitrogen removal by denitrifying anammox applied for anaerobic pre-treated potato wastewater
Authors: Mulder A. , Versprille A. I. , van Braak D.
Published: October 2012

The feasibility of sustainable nitrogen removal was investigated in a two stage biofilm configuration consisting of a MBBR (Moving Bed Biofilm Reactor) and a Deamox reactor (Biobed-EGSB). The MBBR is used for nitrification and the denitrifying ammonium oxidation (Deamox) is aimed at a nitrogen removal process in which part of the required nitrite for the typical anammox reaction originated from nitrate. Anaerobic pre-treated potato wastewater was supplied to a MBBR and Deamox reactor operated in series with a bypass flow of 30%. The MBBR showed stable nitrite production at ammonium-loading rates of 0.9–1.0 kg NH4-N/m3 d with ammonium conversion rates of 0.80–0.85 kg NH4-N/m3 d. The nitrogen-loading rate and conversion rate of the Deamox reactor were 1.6–1.8 and 1.6 kg N/m3 d. The maximum ammonium removal capacity in the Deamox reactor was 0.6 kg NH4-N/m3 d. The removal efficiency of soluble total nitrogen reached 90%. The Deamox process performance was found to be negatively affected during decline of the operating temperature from 33 to 22 °C and by organic loading rates with a chemical oxygen demand (COD)/NO2-N ratio >1.
Spectrophotometric determination of trace amounts of phosphate in water and soil
Authors: Ganesh S. , Khan Fahmida , Ahmed M. K. , Velavendan P. , Pandey N. K. , Kamachi Mudali U.
Published: October 2012

A simple spectrophotometric method has been developed for the determination of phosphate dissolved in soil and water. The method is based on the formation of phosphomolybdate with added ammonium molybdate followed by reduction with hydrazine in acidic medium. Orthophosphate and molybdate ions condense in acidic solution to give molybdophosphoric (phosphomolybdic) acid, which upon selective reduction (perhaps with hydrazinium sulphate) produces a blue colour, due to molybdenum blue of uncertain composition. The intensity of blue colour is proportional to the amount of phosphate. If the acidity at the time of reduction is 0.5 M in sulphuric acid and hydrazinium sulphate is the reductant, the resulting blue complex exhibits maximum absorption at 830 nm. The system obeys Lambert–Beer's law at 830 nm in the concentration range of 0.5–5 μg/mL of phosphate with a relative standard deviation (RSD) of 0.1% and correlation coefficient of 0.99. Molar absorptivity was determined to be 2.9 × 104 L mol–1 cm–1 at 830 nm. The method is also applicable for the determination of phosphate in nuclear reprocessing plants, medical science, clinical science, agriculture, metallurgy and environmental science.
Degradation of bromamine acid by nanoscale zero-valent iron (nZVI) supported on sepiolite
Authors: Fei Xuening , Cao Lingyun , Zhou Lifeng , Gu Yingchun , Wang Xiaoyang
Published: October 2012

Sepiolite, a natural nano-material, was chosen as a carrier to prepare supported nanoscale zero-valent iron (nZVI). The effects of preparation conditions, including mass ratio of nZVI and activated sepiolite and preparation pH value, on properties of the supported nZVI were investigated. The results showed that the optimal mass ratio of nZVI and sepiolite was 1.12:1 and the optimal pH value was 7. The supported nZVI was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS), and furthermore an analogy model of the supported nZVI was set up. Compared with the nZVI itself, the supported nZVI was more stable in air and possessed better water dispersibility, which were beneficial for the degradation of bromamine acid aqueous solution. The degradation characteristics, such as effects of supported nZVI dosage, initial concentration and initial pH value of the solution on the decolorization efficiency were also investigated. The results showed that in an acidic environment the supported nZVI with a dosage of 2 g/L showed high activity in the degradation of bromamine acid with an initial concentration of 1,000 mg/L, and the degree of decolorization could reach up to 98%.
Ecophysiological role and function of uncultured Chloroflexi in an anammox reactor
Authors: Kindaichi Tomonori , Yuri Shota , Ozaki Noriatsu , Ohashi Akiyoshi
Published: October 2012

The coexistence of uncultured heterotrophic bacteria belonging to the phylum Chloroflexi has often been observed in anaerobic ammonium oxidation (anammox) reactors fed with synthetic nutrient medium without organic carbon compounds. To determine if coexisting Chloroflexi in anammox reactors scavenge organic matter derived from anammox bacterial cells, the present study was conducted to investigate the substrate uptake pattern of the uncultured Chloroflexi present in an anammox reactor and to clarify if they take up microbial products derived from anammox bacterial cells. To accomplish this, combined microautoradiography and fluorescence in situ hybridization (MAR–FISH) was conducted. Phylogenetic analysis revealed that 36% of the clones analyzed in this study were affiliated with Chloroflexi. The sequence similarities to Anaerolinea thermophila and Caldilinea aerophila within the phylum Chloroflexi were only 81.0–88.7% and 80.3–83.8%, respectively. The uncultured Chloroflexi were found to incorporate sucrose, glucose, and N-acetyl-glucosamine. The 14C-tracing experiment revealed that the uncultured Chloroflexi were clearly MAR-positive, indicating the utilization of decaying anammox bacterial cell materials. Taken together, these results indicate that coexisting uncultured Chloroflexi in anammox reactors scavenge organic compounds derived from anammox bacterial cells.
Lead isotopes as a tracer of Pb origin in the sediments from Beijiang River, South China
Authors: Gao Bo , Liang Xirong , Zhou Huaidong , Tu Xianglin
Published: October 2012

Concentrations and enrichment of heavy metals were determined in sediments collected from Beijiang River, South China. The Pb isotopic compositions in these sediment samples were also employed to effectively identify metal pollution sources. According to the measured Pb concentrations, the total Pb concentrations in sediments varied from 62.1 to 1,152.5 μg/g, with an average concentration of 249.6 μg/g. The assessment by Geoaccumulation Index indicates that Pb is at the ‘strongly contaminated’ level, indicating that the Pb pollution was mainly due to anthropogenic inputs. The observed isotopic ratios varied from 1.174 to 1.204 for 206Pb/207Pb, 2.452 to 2.478 for 208Pb/207Pb, 18.404 to 18.937 for 206Pb/204Pb, 15.631 to 15.790 for 207Pb/204Pb, 38.455 to 39.121 for 208Pb/204Pb. The majority of these ratios are lower than those reported for natural geological sources, especially for sediments collected from a smelter. Significant correlation between Pb concentration and isotopic ratios suggested possible binary mixing of Pb. Combined with Pb concentration and enrichment levels, our results show that Pb pollution in the sediments of Beijiang River was mainly derived from anthropogenic sources. The mining activities and metal smelting processing was the main source of Pb pollution in this region.
Bioaccumulation and primary risk assessment of persistent organic pollutants with various bivalves
Authors: Takabe Yugo , Tsuno Hiroshi , Nishimura Fumitake , Tanii Nobuo , Maruno Hirofumi , Tsurukawa Masahiro , Suzuki Motoharu , Matsumura Chisato
Published: October 2012

Field surveys on persistent organic pollutant (POP) bioaccumulation were conducted with oysters, clams and scallops whose consumption amount accounted for large shares in the total consumption of shellfish in Japan. There was no numerical difference in bioaccumulation characteristics between oysters, clams, scallops, Corbicula and Mytilus galloprovincialis. Therefore, it was clear that the bioaccumulation characteristics in oysters, clams and scallops, which are important for food, could be ascertained by using the monitoring results with Corbicula and M. galloprovincialis which are easily sampled in various water areas in the world. Non-cancer risk (hazard quotient, HQ) and cancer risk (excess cancer risk, ΔR) via shellfish ranged from 10−8 to 10−4 and from 10−11 to 10−7, respectively, at sampling points, which showed the risks of POP exposure via shellfish to be low enough. However, concerning the intake of other food, the importance of dieldrin monitoring should be suggested in Japan. Based on these results, the effectiveness of primary risk assessment could be suggested for screening chemicals whose preferential monitoring is needed.
Synthesization, characterization and adsorption properties of sulfonic cellulose
Authors: Shi Wenjian , Zhou Yan , Zhang Yuanzhang , Li Liang , Yang Qinlin
Published: October 2012

The synthesization and characterization of a new environmental functional material–sulfonic cellulose – were studied in this paper. The preparation conditions were optimized through an orthogonal experiment. The modified cellulose was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The adsorption rules of cationic organic pollutants and heavy metal ions by this new material were discussed. Regeneration and recycling performances of the sulfonic cellulose were also investigated. At the temperature of 323 K, sulfonic cellulose was prepared by grafting 2-acrylamido-2-methylpropane sulfonic acid (AMPS) onto alkali-treated cellulose for 4 h with the employing of ceric ammonium nitrate as initiator. The mass ratio of AMPS to cellulose was 3:1 and the concentration of ceric ammonium nitrate was 63.8 mmol/L. The sulfur content of sulfonic cellulose was 7.32 wt%. The peaks of 1,303 and 1,159 cm−1 in IR suggested the existence of the sulfonic group in sulfonic cellulose. The XRD and SEM results showed that the crystallinity decreased while the specific surface area increased after modification. Batch adsorption results showed that sulfonic cellulose had a favorable adsorption capacity for model contaminants at pH 6.0–7.0. The adsorption process was endothermic and reached equilibrium in 180 min. The adsorption rules of cationic organic pollutants and heavy metal ions indicated that sulfonic cellulose had high adsorption capacity for the cationic dyes with a coplanar macromolecule structure and organic compounds carrying the amino group. Under room temperature, 1.0 mol/L HCl can be used as a desorption solution and the equilibrium adsorption capacity had little decrease (less than 7%) after six adsorption–desorption cycles.
The impact of Pleurotus ostreatus on organic matter transformation processes
Authors: Pisarek Izabella , Głowacki Mariusz , Czernia Małgorzata
Published: October 2012

This study showed the effect of Pleurotus ostreatus on the external organic matter (OM) transformation processes. The kinetics of these changes were determined. The experiment was conducted as 42-day pot experiment done in four combinations (with four replications). The four combinations of different substrates were: (1) organic, (2) composted hay, (3) organic soil + composted hay, (4) organic soil + composted hay + lead. The study results showed that P. ostreatus had the ability to transform external OM as well as metal–organic complexes. These transformations were reflected in the constant rate of characterized changes and correlation coefficients. The study also indicated the direction of the external OM transformation. The direction leads to the selective oxidation of aliphatic structures, and an increase in humic substances which are resistant to oxidation. The study also identified the negative impact of lead on the ability of P. ostreatus to transform humic substances. The impact of lead was expressed as the lower value of the rapid rate constant k1 in objects enriched with lead acetate.
Surveillance of human viral contamination and physicochemical profiles in a surface water lagoon
Authors: Fongaro G. , Nascimento M. A , Viancelli A. , Tonetta D. , Petrucio M. M. , Barardi C. R. M.
Published: October 2012

The present study evaluated the contamination of a surface water lagoon (Peri Lagoon) in Florianópolis, Santa Catarina, Brazil, by human adenovirus (HAdV), polyomavirus JC (JCPyV), hepatitis A virus (HAV) and rotavirus species A (RVA). Efforts were driven to determine the correlation between viral presence and the physicochemical parameters of the lagoon and measure the distribution of these viruses throughout the year (June 2010 to May 2011). A total of 48 samples were collected, concentrated and analyzed by qPCR (quantitative polymerase chain reaction). Approximately 96% of the samples were positive for HAdV (46/48), 65% were positive for RVA (31/48), 21% were positive for JCPyV (10/48) and 12% were positive for HAV (6/48). The presence of JCPyV was positively correlated with that of NO2−N, and also there was a positive correlation between the presence of each one of the viruses (HAdV, HAV and RVA) in winter. Samples from water dedicated for human consumption and recreation tested positive for HAdV by qPCR. These samples were also subjected to viral integrity and viability assays: 83% (10/12) contained intact viral particles and 66% (8/12) contained infectious particles. Our results demonstrate the release of human waste into water sources, justifying the urgent need to add viral parameters to water quality surveillance.
A focus on pressure-driven membrane technology in olive mill wastewater reclamation: state of the art
Authors: Ochando-Pulido J. M. , Martinez-Ferez A.
Published: October 2012

Direct disposal of the heavily polluted effluent from olive oil industry (olive mill wastewater, OMW) to the environment or to domestic wastewater treatment plants is actually prohibited in most countries, and conventional treatments are ineffective. Membranes are currently one of the most versatile technologies for environmental quality control. Notwithstanding, studies on OMW reclamation by membranes are still scarce, and fouling inhibition and prediction to improve large-scale membrane performance still remain unresolved. Consequently, adequately targeted pretreatment for the specific binomium membrane-feed, as well as optimized operating conditions for the proper membranes, is today's challenge to ensure threshold flux values. Several membrane materials, configurations and pore sizes have been elucidated, and also different pretreatments including sedimentation, centrifugation, biosorption, sieving, filtration and microfiltration, various types of flocculation as well as advance oxidation processes have been applied so far. Recovery of potential-value compounds, such as a variety of polyphenols highlighting oleuropein and hydroxytyrosol, has been attempted too. All this research should constitute the starting point to proceed with OMW purification beyond recycling for irrigation or depuration for sewer discharge, with the aim of complying with standards to reuse the effluent in the olive oil production process, together with cost-effective recovery of added-value compounds.
Urban water infrastructure asset management – a structured approach in four water utilities
Authors: Cardoso M. A. , Silva M. Santos , Coelho S. T. , Almeida M. C. , Covas D. I. C.
Published: October 2012

Water services are a strategic sector of large social and economic relevance. It is therefore essential that they are managed rationally and efficiently. Advanced water supply and wastewater infrastructure asset management (IAM) is key in achieving adequate levels of service in the future, particularly with regard to reliable and high quality drinking water supply, prevention of urban flooding, efficient use of natural resources and prevention of pollution. This paper presents a methodology for supporting the development of urban water IAM, developed during the AWARE-P project as well as an appraisal of its implementation in four water utilities. Both water supply and wastewater systems were considered. Due to the different contexts and features of the utilities, the main concerns vary from case to case; some problems essentially are related to performance, others to risk. Cost is a common deciding factor. The paper describes the procedure applied, focusing on the diversity of drivers, constraints, benefits and outcomes. It also points out the main challenges and the results obtained through the implementation of a structured procedure for supporting urban water IAM.
Assessment of the potential for biogas production from wheat straw leachate in upflow anaerobic sludge blanket digesters
Authors: Idrus S. , Banks C. J. , Heaven S.
Published: October 2012

Wheat straw is a major potential source of waste biomass for renewable energy production, but its high salt content causes problems in combustion. The salts can be removed by washing, but this process also removes a proportion of the organic material which could potentially be recovered by anaerobic digestion of the washwater leachate. This approach would maximise the overall energy yield in an integrated process in which washwater could be recycled after further desalting. Leachate from cold water washing with a chemical oxygen demand (COD) of 1.2 g l−1 was fed to mesophilic upflow anaerobic sludge blanket (UASB) digesters at a loading rate of 1 g COD l−1 day−1 to determine the energy yield and any detrimental effects of the leached salts on the process. The specific methane production was 0.29 l CH4 g−1 CODadded, corresponding to a COD removal rate of 84%. Light metal cations in the leachate, especially potassium, were found to accumulate in the digesters and appeared to have a synergistic effect up to a concentration of ∼6.5 mg K g−1 wet weight of the granular sludge, but further accumulation caused inhibition of methanogenesis. It was shown that gas production in the inhibited digesters could be restored within 12 days by switching the feed to a synthetic sewage, which washed the accumulated K out of the digesters.
Anaerobic/aerobic treatment of a petrochemical wastewater from two aromatic transformation processes by fluidized bed reactors
Authors: Estrada-Arriaga Edson B. , Ramirez-Camperos Esperanza , Moeller-Chavez Gabriela E. , García-Sanchez Liliana
Published: October 2012

An integrated fluidized bed reactor (FBR) has been employed as the treatment for petrochemical industry wastewaters with high organic matter and aromatic compounds, under anaerobic and aerobic conditions. The system was operated at hydraulic residence time (HRT) of 2.7 and 2.2 h in the anaerobic and aerobic reactor, respectively. The degree of fluidization in the beds was 30%. This system showed a high performance on the removal of organic matter and aromatic compounds. At different organic loading rates (OLR), the chemical oxygen demand (COD) removal in the anaerobic reactor was close to 85% and removals of the COD up to 94% were obtained in the aerobic reactor. High removals of benzene, toluene, ethylbenzene, xylenes, styrene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene and naphthalene were achieved in this study.
Water treatment using activated carbon supporting silver and magnetite
Authors: Valušová Eva , Vandžurová Anna , Pristaš Peter , Antalík Marián , Javorský Peter
Published: October 2012

Recent efforts in water purification have led to the development of novel materials whose unique properties can offer effective biocidal capabilities with greater ease of use and at lower cost. In this study, we introduce a novel procedure for the preparation of activated carbon (charcoal) composite in which magnetite and silver are incorporated (MCAG); we also describe the use of this material for the disinfection of surface water. The formation process of magnetic MCAG composite was studied using ultraviolet-visible spectroscopy. The results demonstrated the high sorption efficiency of AgNO3 to magnetic activated carbon. The antimicrobial capabilities of the prepared MCAG were examined and the results clearly demonstrate their inhibitory effect on total river water bacteria and on Pseudomonas koreensis and Bacillus mycoides cultures isolated from river water. The bacterial counts in river water samples were reduced by five orders of magnitude following 30 min of treatment using 1 g l−1 of MCAG at room temperature. The removal of all bacteria from the surface water samples implies that the MCAG material would be a suitable disinfectant for such waters. In combination with its magnetic character, MCAG would be an excellent candidate for the simple ambulatory disinfection of surface water.
Determination of the effect of wind velocity and direction changes on turbidity removal in rectangular sedimentation tanks
Authors: Khezri Seyed Mostafa , Biati Aida , Erfani Zeynab
Published: October 2012

In the present study, a pilot-scale sedimentation tank was used to determine the effect of wind velocity and direction on the removal efficiency of particles. For this purpose, a 1:20 scale pilot simulated according to Frude law. First, the actual efficiency of total suspended solids (TSS) removal was calculated in no wind condition. Then, the wind was blown in the same and the opposite directions of water flow. At each direction TSS removal was calculated at three different velocities from 2.5 to 7 m/s. Results showed that when the wind was in the opposite direction of water flow, TSS removal efficiency initially increased with the increase of wind velocity from 0 to 2.5 m/s, then it decreased with the increase of velocity to 5 m/s. This mainly might happen because the opposite direction of wind can increase particles’ retention time in the sedimentation tank. However, higher wind velocities (i.e. 3.5 and 5.5 m/s) could not increase TSS removal efficiency. Thus, if sedimentation tanks are appropriately exposed to the wind, TSS removal efficiency increases by approximately 6%. Therefore, energy consumption will be reduced by a proper site selection for sedimentation tank unit in water and waste water treatment plants.