Impact of Operational and Design Parameters on Natural Organic Matter Removal and its Correlation with NDMA Precursor Removal or Formation during Biofiltration in Drinking Water Treatment

NOM is a complex mixture of organic compounds that are present in all natural waters and is mainly originating from plant and aquatic organism degradation products. Therefore, the specific composition of NOM is site-specific. Removing NOM during drinking water treatment is very beneficial, since NOM not only causes aesthetic problems, such as taste, odour, and colour problems, but also impacts other treatment processes. NOM, for examples, causes increased coagulant and disinfectant demands; contributes to corrosion and bacterial regrowth throughout the distribution system; transports metals and hydrophobic chemicals; and interferes in adsorption processes of other contaminants. However, one of the most important points for removing NOM is that NOM fractions have been identified as being precursors to potentially carcinogenic disinfection by-products (DBPs). The goal of this research was to identify the impact of different operational, design, and water quality parameters on the characteristics and removal of NOM fractions during bench-scale and pilot-scale biofilter columns at different drinking water treatment plants (DWTPs). Parameters investigated in bench-scale biofilter columns at three different facilities (Facilities B, I, and L) include: water sources, media acclimated/operated in different water sources, and pre-ozonation. During these bench-scale experiments, three different biofilter media (from Facilities B, I, and L media) were tested simultaneously at each of the three facilities. Also, two different pilot-scale experiments were carried out, one at Facility C, which investigated the following parameters: media type, backwash type, and ammonia addition. The other pilot-scale experiment was at Facility Q, which investigated the following parameters: full-scale treatment processes prior to biofiltration, media type, backwash type, and backwash frequency. At both the pilot-scale facilities, the biofilter profiles and kinetics of the NOM fraction removals for the different parameters were also investigated. Lastly, the NOM fraction removals from both the bench-scale and pilot-scale experiments were correlated to the NDMA precursor removals or formations. The NOM fractions in this research were characterized by using two relatively new NOM characterization techniques: LC-OCD and fluorescence excitation emission matrix (FEEM). LC-OCD separates NOM into five different fractions based on molecular weight size, and these fractions are: biopolymers (BP), humics (HS), building blocks (BB), low molecular weight (LMW) acids/humics, and LMW neutrals. FEEM detects molecules that contain fluorophores and it can therefore identify three different fractions: humic acids (HA), fulvic acids (FA), and protein-like materials. Furthermore, the NDMA concentrations in this research was analysed using a measuring technique called uniform formation condition (UFC). UFC mimics average chloramination conditions used at DWTPs across North America. The bench-scale experiments at Facilities B, I, and L showed that when all the different media acclimated/operated in different water sources were fed the same water source they behaved very similarly in terms of NOM fraction removal and water sources therefore matters. However, when the same media was fed the water sources from each of these facilities, then there were barely any similarities and the media acclimated/operated in different water sources therefore barely had any influence. Also, the pre-ozonation at Facility B improved the NOM fraction removals when combined with the bench-scale biofiltration columns. The pilot-scale experiments at Facilities C and Q showed that powdered activated carbon (PAC) drastically removed various NOM fractions, it, for example, successfully removed more than 83% of BP. Also, granular activated carbon (GAC) media was the media type that had the best removals of various NOM fractions at both pilot-scale facilities. At facility C, the chloraminated backwashed columns had higher removals of DOC (4.3 percentage points higher), BP (20 percentage points higher), LMW acids/humics (3.9 percentage points higher), and LMW neutrals (11 percentage points higher) than the GAC control columns. However, at Facility Q there were no noticeable differences between backwash types or backwash frequencies on the NOM removals, due to low removals at most sampling events. These low removals made it difficult to assess conclusively the influence from these parameters on NOM fraction removals. At Facility C, only DOC, BP, and HS relatively fitted the kinetics models, and the best data fit was for BP. At Facility Q, BP during phase 1 and DOC for only one column during phase 2 poorly fitted the kinetics models. However, there were no clear trends regarding which reaction order fitted each fraction removal the best. The reason is that the change in the coefficients of determination (R2 coefficients) only marginally changed from 0th to 2nd order model. Also, these poor fits between NOM fraction removals and kinetics models is due to, for example, only 4-5 data points for each profile and only low removals across the biofilters. For the NDMA UFC, pre-ozonation at facility B also substantially reduced NDMA UFC, and pre-ozonation combined with biofiltration had the lowest NDMA UFC concentrations. Softening also substantially increased NDMA UFC at the full-scale treatment process at Facility Q. Last, there was a statistically significant correlation between higher protein-like materials intensities as measured by FEEM in the biofilter influents and higher NDMA UFC concentrations in the biofilter influents. The same was also observed for the biofilter effluents. This research provides greater insight into NOM fraction removals, biofiltration performance, and the correlation between NOM and NDMA UFC. Although the results might be site-specific, these results indicated that to optimize the NOM fraction removals at a DWTP PAC, pre-ozonation, and GAC media in the biofilters should be employed. Also, to minimize NDMA precursor formation during drinking water treatment, pre-ozonation prior to the biofilters should be employed, but softening should be avoided. These findings provide insight to municipalities, consultants, and staff members at DWTPs on some operational and design parameters that should be taken into consideration when designing or upgrading a DWTP

Household survey to evaluate the Zambia-led Prevention Initiative: Baseline report

With an estimated HIV prevalence of 14.3 percent among men and women age 15–49, Zambia is one of the sub-Saharan African countries most affected by the HIV and AIDS pandemic. The Zambia-led Prevention Initiative Program (ZPI) was developed by a consortium led by FHI360, with the Population Council as the evaluation partner. This study determined baseline levels of key indicators related to HIV, gender-based violence, and reproductive health. Additionally, the baseline findings provide critical insights into key areas for interventions in Zambia and highlights variability in the populations across provinces and between males and females that provide valuable guidance for programming

Further studies on <i>Tabanus claripennis</i> (Bigot) with special reference to the morphology and biology of the pre-imago stages

Se realiza la descripción de larvas de Tabanus claripennis (Bigot) halladas en La Plata (R. A.) y de las pupas obtenidas en el laboratorio.Larvae of Tabanus claripennis (Bigot) collected in La Plata (R. A.) and the pupae thus obtained in the laboratory are described with special reference to the biological characteristics of the pre-imago stages.Facultad de Ciencias Veterinaria

Further studies on <i>Tabanus claripennis</i> (Bigot) with special reference to the morphology and biology of the pre-imago stages

Se realiza la descripción de larvas de Tabanus claripennis (Bigot) halladas en La Plata (R. A.) y de las pupas obtenidas en el laboratorio.Larvae of Tabanus claripennis (Bigot) collected in La Plata (R. A.) and the pupae thus obtained in the laboratory are described with special reference to the biological characteristics of the pre-imago stages.Facultad de Ciencias Veterinaria

Inclusion of an Introduction to Infrastructure Course in a Civil and Environmental Engineering Curriculum

Civil infrastructure refers to the built environment (sometimes referred to as public works) and consists of roads, bridges, buildings, dams, levees, drinking water treatment facilities, wastewater treatment facilities, power generation and transmission facilities, communications, solid waste facilities, hazardous waste facilities, and other sectors. Although there is a need to train engineers who have a holistic view of infrastructure, there is evidence that civil and environmental engineering (CEE) programs have not fully addressed this increasingly recognized need. One effective approach to address this educational gap is to incorporate a course related to infrastructure into the curriculum for first-year or second-year civil and environmental engineering students. Therefore, this study assesses the current status of teaching such courses in the United States and identifies the incentives for, and the barriers against, incorporating an introduction to infrastructure course into schools’ current CEE curricula. Two distinct activities enabled these objectives. First, a questionnaire was distributed to CEE programs across the United States, to which 33 responses were received. The results indicated that although the majority of participants believe that offering such a course will benefit students by increasing the breadth of the curriculum and by providing a holistic view of CEE, barriers such as the maximum allowable credits for graduation, the lack of motivation within a department—either because such a course did not have a champion or because the department had no plans to revise their curriculum—and a lack of expertise among faculty members inhibited inclusion of the course in curricula. Second, three case studies demonstrating successful inclusion of an introduction to infrastructure course into the CEE curriculum were evaluated. Cases were collected from Marquette University, University of Wisconsin-Platteville, and West Point CEE programs, and it was found that the key to success in including such a course is a motivated team of faculty members who are committed to educating students about different aspects of infrastructure. The results of the study can be used as a road map to help universities successfully incorporate an introduction to infrastructure course in their CEE programs

Biological cycle determination of <i>Capillaria bursata</i>

Comprobada la parasitosis por Capillaria bursata, los autores logran reproducir la enfermedad en pollos mantenidos libres de toda infestación, dándoles a ingerir lombrices recogidas en el gallinero del que procedían las aves originalmente necropsiadas demostrando así el ciclo indirecto de este nematode y el papel de Eisenia sp. como hospedador intermediario.After the verification of the parasitic infection caused by Capillaria bursata the authors reproduced the disease in parasites free chicken, feeding the birds with earth worm collected from the poultry yard, where were the birds come from and necropsied. The workers demonstrated by this way the roll of Elsenia sp. as intermediary host of this nematode and its indirect biological cycle.Facultad de Ciencias Veterinaria

Duality violations and spectral sum rules

We study the issue of duality violations in the VV-AA vacuum polarization function in the chiral limit. This is done with the help of a model with an expansion in inverse powers of the number of colors, Nc, allowing us to consider resonances with a finite width. Due to these duality violations, the Operator Product Expansion (OPE) and the moments of the spectral function (e.g. the Weinberg sum rules) do not match at finite momentum, and we analyze this difference in detail. We also perform a comparative study of many of the different methods proposed in the literature for the extraction of the OPE parameters and find that, when applied to our model, they all fare quite similarly. In fact, the model strongly suggests that a significant improvement in precision can only be expected after duality violations are included. To this end, we propose a method to parameterize these duality violations. The method works quite well for the model, and we hope that it may also be useful in future determinations of OPE parameters in QCD.Comment: 29 pages, 9 figures, LateX file. Small changes to match journal versio

Human choriogonadotropin and epoetin alfa in acute ischemic stroke patients (REGENESIS-LED trial).

IntroductionPreclinical studies suggest that growth factors in the early days after stroke improve final outcome. A prior study found three doses of human choriogonadotropin alfa followed by three doses of erythropoietin to be safe after stroke in humans. A proof of concept trial (REGENESIS) was initiated but placed on regulatory hold during review of an erythropoietin neuroprotective trial. Due to financial constraints, the trial was largely moved to India, using lower erythropoietin doses, as the REGENESIS-LED trial.MethodsEntry criteria included National Institutes of Health Stroke Scale 8-20, supratentorial ischemic stroke, and 24-48 h poststroke at start of therapy. Patients were randomized to three QOD doses of subcutaneous human choriogonadotropin alfa followed by three QD doses of intravenous erythropoietin (three escalating dose cohorts, 4000-20,000 IU/dose) vs. placebo. Primary outcomes were safety and neurological recovery.ResultsThe study was halted early by the sponsor after 96 enrollees. There was no significant difference across treatment groups in the proportion of patients experiencing death, serious adverse events, or any adverse event. There was no significant difference in National Institutes of Health Stroke Scale score change from baseline to Day 90 between placebo and active treatment, whether active cohorts were analyzed together or separately, and no exploratory secondary measure of neurological recovery showed a significant difference between groups.DiscussionAdministration of human choriogonadotropin alfa followed by erythropoietin is safe after a new ischemic stroke. At the doses studied, placebo and active groups did not differ significantly in neurological recovery. Study limitations, such as the use of multiple assessors, differences in rehabilitation care, and being underpowered to show efficacy, are discussed

Cataloging-in-Publication Data Joint Bank-Fund Library

Managing volatile capital flows: experiences and lessons for Sub-Saharan African frontier markets / prepared by Trevor Alleyne [and eight others], under the guidance of Anne-Marie Gulde-Wolf. – Washington, D.C.: International Monetary Fund, 2014. pages.; cm Includes bibliographical references. ISBN: 978-1-61635-884-