bluuebunny/crossref_metadata_2025 huggingface dataset:
Geospatial hazard modeling for the delineation of flash flood-prone zones in Wadi Dahab basin, Egypt
Authors: Abuzied Sara M. , Mansour Basma M. H.
Published: October 2018

This study delineated flash flood hazard zones leading to vast destruction to infrastructure, property, and loss of life. An integrated approach using remote sensing and geographic information systems was applied to reveal flash flood-prone zones. The study approach evaluated topographic, geologic, and hydrologic factors holistically to assess these hazard zones. The morphometric characteristics of Wadi Dahab sub-basins were supported by topographic, geologic, and hydrologic information. Data from Shuttle Radar Terrain Mission and Operational Land Imager imagery were analyzed to characterize hydrological morphometrics, lithology, soil types, and land use. A Natural Resources Conservation Service model was selected to calculate runoff depth at ungauged watersheds. A spatially distributed unit hydrograph was adopted to create the flow time and runoff velocity. The Flashflood Hazard Model was developed by spatial integration of all contributing factors. An analytical hierarchy process was adopted for the logic ranking of the effective factors. The flash flood hazard map classifies Wadi Dahab basin into five relative hazard zones: very high, high, moderate, low, and very low. The highly hazardous zones are distributed at the downstream of Wadi Dahab basin corresponding to steep topography and Precambrian rocks. The hazard map was validated using the flash flood markers defined from field observations.
Analyzing multi-variate water quality signals for water quality monitoring station placement in water distribution systems
Authors: Sankary Nathan , Ostfeld Avi
Published: October 2018

Placing fixed water quality monitoring stations in a water distribution system can greatly improve the security of the system via prompt detection of poor water quality. In the event that a harmful substance is injected into a water distribution system, large populations can be put at risk of exposure to the contaminant. Promptly detecting the presence of a contaminant will reduce the number of people put at risk of exposure. However, to protect against a wide variety of possible contaminants, a water quality monitoring station will need to identify contamination via recognition of anomalous changes in a suite of surrogate water quality indicators (chlorine, pH, etc.). This work attempts to place water quality monitoring stations within the water distribution at locations that best detect contamination events via surrogate water quality signals. Networks of water quality monitoring stations are designed to minimize the population affected prior to contamination event detection, and simultaneously minimize the expected number of false positive detections, under uncertain water quality conditions. Solutions generated in this study are compared to solutions designed via classical detection methods. Results show the sensor networks designed without consideration to detection via surrogate water quality parameters have higher false positive detection rates.
Emergency response in water, sanitation and hygiene to control cholera in post-earthquake Nepal in 2016
Authors: Sekine Kazutaka , Roskosky Mellisa
Published: October 2018

After the 2015 earthquake in Nepal that killed approximately 9,000 people, the country faced an increased risk of cholera outbreaks due to extensive destruction of water and sanitation infrastructure and massive displacement. The disaster revealed long-standing weaknesses in water and sanitation systems in the country. Anticipating a cholera outbreak in 2016, UNICEF, Johns Hopkins University, and the Group for Technical Assistance partnered to support the Government of Nepal to ensure a safe water supply and improve sanitation and hygiene. This article discusses challenges, gaps, lessons learned and recommendations that were drawn from the authors' experience in cholera prevention and control in post-earthquake Nepal. Challenges identified include lack of regular water quality testing and monitoring, inconsistent use of point-of-use water treatment products, and lack of a fast-track mechanism for rapid response. The article argues for building a resilient water and sanitation system to secure sustainable and equitable access to safe drinking water.
Assessing peri-urban sanitation quality using a theoretically derived composite measure in Lusaka, Zambia
Authors: Tidwell James B. , Chipungu Jenala , Chilengi Roma , Aunger Robert
Published: October 2018

Despite ongoing debates about what constitutes adequate sanitation, there is a lack of sanitation quality measures that are theoretically grounded in ways that allow empirical comparisons of quality across different types of sanitation. The Healthy Sanitation Framework (HSF) was developed to capture universal aspects of sanitation quality from a public health perspective. From this, the Peri-Urban Healthy Toilet Index (PUHTI) was created for measuring on-site, peri-urban sanitation quality. This PUHTI score was used to assess sanitation quality in a peri-urban area in Lusaka, Zambia. The HSF identified five categories for capturing sanitation quality: hygiene, use, sustainability, desirability, and accessibility. A composite index derived from these categories had high reliability and plausible validity, despite barriers to rigorously evaluating validity. Applying the PUHTI tool showed that while 87% of toilets were classified as ‘improved, but shared,’ there were frequent concerns about doors that could not be locked, dirty user interfaces, unhygienic containment, limited emptyability, and lack of handwashing facilities. The HSF allows granular measures of sanitation quality to be developed in any setting using a reproducible and theoretically grounded process. However, lack of a unified basis on which to compare different types of sanitation overall or evidence to compare within narrower categories currently limits comparisons across types of sanitation.
Engaging field staff in strategic asset management
Authors: Bakir Patricia , Raine Cameron
Published: October 2018

Adopting and implementing Strategic Asset Management (SAM) is a prerequisite to improving day-to-day management and long-term utility planning. Field-level employees play a key role in implementation of a SAM program and have to make often burdensome adjustments to their work processes to comply with newly instituted systems. They are not always consulted in planning and technology adoption. They frequently do not receive feedback or recognition for their contribution. Based on a water utility survey, the authors provide insights and recommendations on how to increase field staff commitment to SAM. They will utilize their results to conduct further research directly with field staff on their perceived role and what can be done to improve their adoption of SAM processes.
Remote sensing lake level fluctuations in response to a changing climate
Authors: Mutowo Godfrey
Published: October 2018

Lakes and reservoirs have long been regarded as a solution to the water problems of semi-arid regions, as well as a mitigation measure against the impacts of climate change and climate variability. However, the ability of these lakes to mitigate the impacts of climate change itself has largely been untested. In this study, we tested the utility of remote sensing in monitoring fluctuations in Lake Mutirikwi's surface area. Furthermore, we determined the nature and strength of the relationship between Lake Mutirikwi's surface area and annual rainfall total with a view to understanding the sensitivity of the lake volume to the main input of water in the lake – precipitation. Results of the study show that the volume of the lake fluctuated by between 1% and as much as 90% of the lake's capacity. We also found a significant relationship (r = 0.84, p = 0.002) between the surface area of the lake and the amount of rainfall received in the second half of the rainfall season. We conclude that Lake Mutirikwi is so sensitive to fluctuations in rainfall amounts that it does not offer much mitigation cover in the face of a changing and highly variable climate.
Structural analysis of the essential environmental factors associated with the marine meiofauna
Authors: Zhang Qingtian , Hu Guikun
Published: October 2018

A biogeochemical study was carried out from 2006 to 2007 in Bohai Bay, northern China, to investigate meiofauna and a number of environmental factors. A total of 18 environmental factors were selected to study their interrelations using Interpretive Structural Analysis. The results showed that these environmental factors could be divided into five levels according to their degree of impact; the results also showed clear links among these factors. The six factors designated as Level 1 included both biological and chemical factors. The other factors had indirect effects on meiofauna and affect these six factors in different ways. There was single factor, sediment grain size, in the fifth level. The structural analysis of the essential factors gave us more information than simple correlation analysis did. Both the water and sediment factors influenced the benthos community. The result is helpful in understanding the complex relationships between environmental factors, and could be used to grasp the main causes and their environmental linkages with further studies; it would be a good basis for integrative environmental management.
Water quality control plan with BATHTUB model for lake inflow rivers – a case study of total phosphorus in Northwest Lake Taihu, China
Authors: Xu Chen , Wan Rongrong , Yang Guishan , Lv Wen , Ma Qian , Li Bing
Published: October 2018

Total phosphorus (TP) standards for lakes differ from those for rivers in GB3838-2002. This disjunction may lead to the failure of lake-water quality improvement plans that control nutrient inputs from inflow rivers. With monthly monitoring data for the period 2009–2015, Northwest Lake Taihu was regarded as a case study and the BATHTUB model was utilised to simulate the correspondence between concentrations of TP in the lake and in its inflow rivers. A control plan for TP in Northwest Lake Taihu's inflow rivers is proposed. To guarantee the fulfillment of the control goals of TP in the lake, concentration of TP in the inflow rivers of North Zone, Zhushan Bay, Meiliang Bay and Gonghu Bay should be reduced by 50%, 58%, 18% and 11%, respectively, and TP flux loads should be maintained under 227.35, 173.39, 113.69 and 90.62 ta−1, respectively. Meanwhile, total TP influxes from Northwest Lake Taihu should be maintained under 604.63 ta−1. A control plan that is more restrictive than GB3838-2002 should be proposed to address the TP pollution of the lake. This research provides the foundation for quantifying reduction of the nutrient loading from the catchment and for maintaining Lake Taihu and other typical eutrophic lakes.
Water quality, availability, and acute gastroenteritis on the Navajo Nation – a pilot case-control study
Authors: Grytdal Scott P. , Weatherholtz Robert , Esposito Douglas H. , Campbell James , Reid Raymond , Gregoricus Nicole , Schneeberger Chandra , Lusk Tina S. , Xiao Lihua , Garrett Nancy , Bopp Cheryl , Hammitt Laura L. , Vinjé Jan , Hill Vincent R. , O'Brien Katherine L. , Hall Aron J.
Published: October 2018

The Navajo Nation includes approximately 250,000 American Indians living in a remote high desert environment with limited access to public water systems. We conducted a pilot case-control study to assess associations between acute gastroenteritis (AGE) and water availability, use patterns, and quality. Case patients with AGE and non-AGE controls who presented for care to two Indian Health Service hospitals were recruited. Data on demographics and water use practices were collected using a standard questionnaire. Household drinking water was tested for presence of pathogens, coliforms, and residual chlorine. Sixty-one subjects (32 cases and 29 controls) participated in the study. Cases and controls were not significantly different with respect to water sources, quality, or patterns of use. Twenty-one percent (n = 12) of study participants resided in dwellings not connected to a community water system. Eleven percent (n = 7) of subjects reported drinking hauled water from unregulated sources. Coliform bacteria were present in 44% (n = 27) of household water samples, and 68% (n = 40) of samples contained residual chlorine concentrations of <0.2 mg/L. This study highlights issues with water availability, quality, and use patterns within the Navajo Nation, including sub-optimal access to community water systems, and use of water hauled from unregulated sources.
An exploration of disinfection by-products formation and governing factors in chlorinated swimming pool water
Authors: Ilyas Huma , Masih Ilyas , van der Hoek Jan Peter
Published: October 2018

This paper investigates disinfection by-products (DBPs) formation and their relationship with governing factors in chlorinated swimming pools. The study compares concentrations of DBPs with WHO guidelines for drinking water quality recommended to screen swimming pool water quality. The statistical analysis is based on a global database of 188 swimming pools accumulated from 42 peer-reviewed journal publications from 16 countries. The mean and standard deviation of dichloroacetic acid and trichloroacetic acid were estimated as 282 ± 437 and 326 ± 517 μg L−1, respectively, which most often surpassed the WHO guidelines. Similarly, more than half of the examined pools had higher values of chloral hydrate (102 ± 128 μg L−1). The concentration of total chloramines (650 ± 490 μg L−1) was well above the WHO guidelines in all reported cases. Nevertheless, the reported values remained below the guidelines for most of the studied pools in the case of total trihalomethanes (134 ± 160 μg L−1), dichloroacetonitrile (12 ± 12 μg L−1) and dibromoacetonitrile (8 ± 11 μg L−1). Total organic carbon, free residual chlorine, temperature, pH, total nitrogen and bromide ions play a pivotal role in DBPs formation processes. Therefore, proper management of these governing factors could significantly reduce DBPs formation, thereby, contributing towards a healthy swimming pool environment.
Ultraviolet A and B wavelength-dependent inactivation of viruses and bacteria in the water
Authors: Mbonimpa E. G. , Blatchley E. R. , Applegate B. , Harper W. F.
Published: October 2018

UVA and UVB can be applied to solar disinfection of water. In this study, the inactivation and photoreactivation of viruses and bacteria in the UVA-B range were analyzed. MS2 and T4 bacteriophages, and Escherichia coli were used as surrogates to quantify dose-response behaviors. Inactivation in UVC was used to validate the methodology and to expand the inactivation action spectra. The results showed log-linear inactivation for MS2 and T4 in the 254–320 nm wavelength range. T4 inactivation was consistently faster than MS2 (except at 320 nm), and for both phages, inactivation decreased with increasing wavelength. The dose-response of bacteria exhibited a lag at low doses, possibly because the photons must strike a discrete number of critical targets before growth stops. A tail was present at high doses for some wavelengths, perhaps due to clumping or the presence of subgroups with higher resistance. The inactivation action spectra for bacteria exhibited a reduction in inactivation as wavelength increased. No bacterial inactivation was observed beyond 320 nm at doses applied. After inactivation at 297 nm (UVA), bacteria regained viability through photoreactivation, and repair increased with increase in photoreactivating light exposure time. This implies additional doses above inactivation thresholds are required to cause irreversible damage. These results are useful for designing solar disinfection systems.
Isolation and molecular identification of Acanthamoeba spp. from hot springs in Mazandaran province, northern Iran
Authors: Dodangeh Samira , Kialashaki Elham , Daryani Ahmad , Sharif Mehdi , Sarvi Shahabeddin , Moghaddam Yusef Dadi , Hosseini Seyed Abdollah
Published: October 2018

Acanthamoeba is a free-living protozoan that can be found in natural and artificial environments such as hot tubs, surface water and springs and can cause severe diseases including amoebic keratitis and granulomatous amoebic encephalitis. The present study was conducted owing to the lack of research regarding genotypes of Acanthamoeba in hot springs of Mazandaran province in northern Iran. Twenty-four water samples were collected from all hot springs in Mazandaran province. After filtration through nitrocellulose membrane, samples were cultured on non-nutrient agar medium enriched with TYIS-33. The cultures were microscopically examined for the presence of Acanthamoeba. Positive cultures were analysed by polymerase chain reaction (PCR) and genotypes were determined by targeting the 18 S rRNA gene. The pathogenic potential of all positive isolates was identified using thermotolerance and osmotolerance tests. Eleven (47.8%) samples were positive for Acanthamoeba. Based on sequencing analysis, 100% of isolates belonged to the T4 genotype. Thermo- and osmo-tolerance tests showed that four (36.3%) Acanthamoeba strains were highly pathogenic. According to our research, the occurrence of Acanthamoeba in recreational hot springs could be a hazard for high risk persons. Posting warning signs and regular monitoring of these waters by health planners may therefore be useful for decreasing Acanthamoeba spp. infections.
Storage of aerobic granular sludge embedded in agar and its reactivation by real wastewater
Authors: Cheng Yuanyuan , Xuan Xinpeng , Zhang Linan , Zhao Jue , Long Bei
Published: October 2018

Aerobic granular sludge (AGS) was preserved using an agar embedding method to maintain its stability. No obvious damage was imposed on the granular appearance during 30 days of cold and dry storage, but the granular microstructure had an uneven surface with a large number of holes. The results were consistent with the extinction of microbial communities and the monitored consumption of extracellular polymeric substances, in which granular specific oxygen utilization rate and mixed liquor volatile suspended solids/mixed liquor suspended solids ratio, respectively, decreased by 72.4% and 62.5% during storage. A mass conversation calculation indicated that the loss of granular mass was 1.6393 g. An offensive odour was smelled during storage, and the results indicated that a material transformation and mitigation were involved between AGS and the gas phase. Although the granular structure was destroyed to a certain extent, no obvious damage was imposed on the granular skeleton during storage. After it was aerated again after a feeding with real wastewater, the residual skeleton served as a carrier for the rapid proliferation of microorganisms, and good granular properties were obtained after 11 days of reactivation.
Public health responses to toxic cyanobacterial blooms: perspectives from the 2016 Florida event
Authors: Metcalf James S. , Banack Sandra Anne , Powell James T. , Tymm Fiona J. M. , Murch Susan J. , Brand Larry E. , Cox Paul Alan
Published: October 2018

In June 2016, massive cyanobacterial blooms occurred in the St. Lucie River in Florida, caused by nutrient and cyanobacterial-laden water releases from Lake Okeechobee. We independently collected and analyzed bloom material for cyanotoxin diversity and concentrations. The concentrations of microcystins, potent hepatotoxins, present in the bloom material greatly exceeded World Health Organization Guideline Values for drinking and recreational water. We also detected the neurotoxins anatoxin-a(S) and β-N-methylamino-L-alanine (BMAA). The Florida State Governor declared a state of emergency, but many affected aquatic recreational areas in St. Lucie County remained open during the bloom event without adequate hazard notification to citizens. During the bloom event, issues with preparedness, communication, sampling, analysis, closures and contingencies were observed. We suggest better ways that cyanobacterial bloom events can be predicted, managed, and mitigated in the future throughout the world. As similar problems with cyanobacterial bloom frequency and occurrence present worldwide, understanding governmental responses to the 2016 Florida incident can help in the development of effective mitigation and management strategies for future bloom events.
Treaties can be a non-starter: a multi-track and multilateral dialogue approach for Brahmaputra Basin
Authors: Barua Anamika , Vij Sumit
Published: October 2018

Countries sharing the Brahmaputra River have for decades deliberated on formulating and implementing cooperative strategies to develop the potential of the basin. Yet, little progress has been made so far at the government-to-government track 1 level in achieving regional cooperation due to the diverse national interests of the riparian countries. This has led to tension and friction among co-riparian nations and mistrust at political level. Drawing from the Brahmaputra Dialogue, this paper aims to highlight the merit of multi-track and multilateral dialogue processes for building trust and confidence between the riparian countries – paving a way towards transboundary cooperation. The paper concludes that given the geo-politics and the national interests of each riparian nation, negotiation for a treaty for cooperation through track 1 diplomacy, in the Brahmaputra River Basin (BRB), is a non-starter. Multi-track and multilateral dialogues can provide a platform to pursue positive interactions and can be viewed as an extension to existing state-diplomacy in BRB, to bring about sustainable change in the basin management.
Examining the interaction of flood vulnerability determinants in Cambodia and Vietnam using partial least squares structural equation modeling
Authors: Ha Anh Hoang , Da Hanh Tran Minh , Thi Tuong Vi Nguyen , Shunbo Yao
Published: October 2018

The formation of vulnerability to natural hazards consists of many driving factors that represent multi-facets of the subjected system. However, the interactions among these components remain unclear and have not been clarified. Examining these internal relationships helps to improve the accuracy of vulnerability assessments and provides needed focus in flood management. This study employed partial least squares structural equation modeling (PLS-SEM) to discover the interrelationship of household flood vulnerability determinants in Cambodia's floodplain and Vietnam's Mekong River Delta. The results show that demographics and social capital have direct influences on flood exposure. In this paper, socioeconomic status can reduce flood effect levels through the mediation of coping capacity. In addition, heterogeneity was also observed between Vietnamese and Cambodian families, highlighting the influence of context on understanding social vulnerability. As the two countries are under threat from hydropower and climate change that profoundly affect flooding, flood management strategies should be improved. The study suggests that the focus should be placed with socioeconomic and coping capacity to sustainably strengthen resilience against flooding.
Methodology for the national water savings models– indoor residential and commercial/institutional products, and outdoor residential products
Authors: Schein Jonah , Chan Peter , Chen Yuting , Dunham Camilla , Fuchs Heidi , Letschert Virginie , McNeil Michael , Melody Moya , Price Sarah , Stratton Hannah , Williams Alison
Published: October 2018

Since 2006, the U.S. Environmental Protection Agency (EPA) has operated WaterSense® in partnership with manufacturers, utilities, and consumer groups. Similar to EPA's ENERGY STAR® role for energy-efficient products, WaterSense® employs a labeling system to identify water-efficient products, homes, and services. As of 2015, the WaterSense® program can claim credit for a total savings of 1.5 trillion gallons of water and $32.6 billion in consumer water and energy bills. Savings are tracked in the National Water Savings (NWS) model that combines innovative analyses with methodologies established in the energy sector. Merging life-cycle cost and national impact analysis models, the NWS model estimates savings from a bottom-up accounting method for individual products. The model extends those savings to the national level by employing parameters such as frequency of product use by number of people and building type, product lifetime, stock accounting, and market saturation. The NWS model tracks the water and consumer monetary savings of WaterSense-labeled products for residential and commercial water use both indoors and out.
Copula-based joint probability distribution of water supply and demand in Luhun irrigation district
Authors: Zhang Jinping , Shi Xixi , Li Jian , Li Fawen
Published: October 2018

The potential of the copula method to construct the joint probability distribution of three hydrological variables characterizing water supply and demand (WSD) is explored for the Luhun irrigation district of China. The marginal distributions of rainfall, reference crop evapotranspiration (ET0) and irrigation water are simulated by the corresponding best-fitting cumulative distribution functions. Furthermore, the correlations between every pair of variables are quantified. On this basis, the two-dimensional joint distributions of rainfall and (ET0) (representing natural WSD), and irrigation water and (ET0) (representing man-made WSD), and the three-dimensional joint distribution of rainfall, irrigation water, and (ET0) (representing natural–man-made WSD) are established. The results reveal that the best-fitting marginal distributions for rainfall and (ET0) and irrigation water are the normal distribution and the Weibull distribution. Moreover, for rainfall and (ET0), the Student's t copula is applied to obtain the joint distribution, while the corresponding copula for (ET0) and irrigation water is the Clayton copula. Finally, the three-dimensional Student's t copula is selected to explore the dependence structure among rainfall, irrigation water, and (ET0). Therefore, these joint distributions provide an efficient approach to assess water shortage risks in the irrigation district.
Fiber filter built with polypropylene fibers applied to water clarification
Authors: Morita Alice K. M. , Reali Marco A. P.
Published: October 2018

Flexible fiber filters are recently developed modular filtration units which have been applied to wastewater and water treatments, satisfactorily removing solids even when operated at high application rates. In this paper, polypropylene fibers, in lieu of the commonly used polyamide fibers, were tested for constructing filtration modules containing parallel fibers. The studied fibers were analyzed by means of scanning electronic microscopy and through solubility assays in hydrochloric acid and sodium hydroxide, aiming to evaluate the risks of using them as filtering media. Three polypropylene filters with different lengths (25, 60, and 100 cm) were constructed and fed with the same raw synthetic water. In-line coagulation was applied by addition of aluminum sulfate (22.5 mg·L−1) and filtration rates from 20 to 80 m·h−1 were evaluated. Filtrates with less than 0.5 NTU could be produced by both 60 and 100 cm filters, operating at 80 m·h−1. High filtration rates, as well as significant backwashing water and air flows, could be applied to flexible fiber filters made of polypropylene, which shows their promising applications.
Possibilities to use the meta model and classical approaches to evaluate the impact of hydraulic conditions in prediction of the critical submergence depth ratio
Authors: Poursorkhabi Ramin Vafaei , Ghasempour Roghayeh
Published: October 2018

One of the hydraulic phenomena that mainly occurs during the water withdrawal process of channels is the formation of vortices that can cause many problems for the hydro-mechanical facilities of intakes. In the current study, classical models and meta model approaches (i.e. Support Vector Machine and Gene Expression Programming) were applied to evaluate the impact of pipe diameter and hydraulic condition changes in prediction of the critical submergence depth ratio in horizontal intakes. In this regard, two types of critical submergence experiments, based on bottom clearance, were considered (i.e. c = 0 and c = d/2, in which c and d are the bottom clearance and diameter of the intake, respectively). Different models were developed and tested using experimental data series. The results indicated that in modeling the critical submergence depth ratio, meta model approaches led to better predictions compared to the classical approaches. It was observed that the developed models for the state of c = d/2 yielded better results. According to the outcome of sensitivity analysis, the ratio of velocities in the intake pipe and channel (Vi/Vc) had a key role in the modeling. It was also found that intake pipe diameter affected the critical submergence depth ratio in intake pipes. Increasing pipe diameter caused a decrease in model accuracy.
Predicting the relative energy dissipation of hydraulic jump in rough and smooth bed compound channels using SVM
Authors: Saghebian Seyed Mahdi
Published: October 2018

Channels with different shapes and bed conditions are used as useful appurtenances to dissipate the extra energy of a hydraulic jump. Accurate prediction of hydraulic jump energy dissipation is important in design of hydraulic structures. In the current study, hydraulic jump energy dissipation was assessed in channels with different shapes and bed conditions (i.e. smooth and rough beds) using the support vector machine (SVM) as an intelligence approach. Five series of experimental datasets were applied to develop the models. The results showed that the SVM model is successful in estimating the relative energy dissipation. For the smooth bed, it was observed that the sloping channel models with steps performed more successfully than rectangular and trapezoidal channels and the step height is an effective variable in the estimation process. For the rough bed, the trapezoidal channel models were more accurate than the rectangular channel. It was found that rough element geometry is effective in estimation of the energy dissipation. The result showed that the models of rough channels led to better predictions. The sensitivity analysis results revealed that Froude number had the more dominant role in the modeling. Comparison among SVM and two other intelligence approaches showed that SVM is more successful in the prediction process.
Dynamic air supply models add realism to the evaluation of control strategies in water resource recovery facilities
Authors: Juan-García Pau , Kiser Mehlika A. , Schraa Oliver , Rieger Leiv , Corominas Lluís
Published: October 2018

This paper introduces the application of a fully dynamic air distribution model integrated with a biokinetic process model and a detailed process control model. By using a fully dynamic air distribution model, it is possible to understand the relationships between aeration equipment, control algorithms, process performance, and energy consumption, thus leading to a significantly more realistic prediction of water resource recovery facility (WRRF) performance. Consequently, this leads to an improved design of aeration control strategies and equipment. A model-based audit has been performed for the Girona WRRF with the goal of providing a more objective evaluation of energy reduction strategies. Currently, the Girona plant uses dissolved oxygen control and has been manually optimised for energy consumption. Results from a detailed integrated model show that the implementation of an ammonia-based aeration controller, a redistribution of the diffusers, and the installation of a smaller blower lead to energy savings between 12 and 21%, depending on wastewater temperature. The model supported the development of control strategies that counter the effects of current equipment limitations, such as tapered diffuser distribution, or over-sized blowers. The latter causes an intermittent aeration pattern with blowers switching on and off, increasing wear of the equipment.
Fabrication of Fe3O4/MgAl-layered double hydroxide magnetic composites for the effective removal of Orange II from wastewater
Authors: Zhu Bo , Chen Lixian , Yan Tianyi , Xu Jiangyan , Wang Yanyu , Chen Min , Jiang Hongmei
Published: October 2018

A facile approach has been developed to construct a composite of magnetic Fe3O4 (MNPs) and regular hexagon Mg-Al layered double hydroxide (MNPs/MgAl-LDH) via a two-step hydrothermal method combined with the urea hydrolysis reaction for the removal of Orange II. The scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy results showed MNPs and MgAl-LDH have been combined successfully, providing the combination of the superior properties of fast separation and high adsorption capacity. The pH values, contact time, initial dye concentration and temperature were investigated in detail. The kinetics and isotherm study showed the adsorption of Orange II on MNPs/MgAl-LDH obeyed the pseudo-second-order and Langmuir model respectively and the adsorption processes were spontaneous and endothermic in nature. Also, some coexisting anions such as Cl−, NO3−, CO3− and SO42− had no significant effect on the removal of Orange II. The mechanism study revealed that the adsorption of Orange II on MNPs/MgAl-LDH mainly involves surface adsorption through electrostatic force and the layer anion exchange. Moreover, Orange II could be desorbed from MNPs/MgAl-LDH using 100 mg L−1 NaOH and used for four cycles without any adsorption performance loss, demonstrating MNPs/MgAl-LDH prepared in this work could be used as a cost-effective and efficient material for the removal of Orange II.
Effects of sulfamethoxazole on the denitrifying process in anoxic activated sludge and the responses of denitrifying microorganisms
Authors: An Yonglei , Qin Xueming
Published: October 2018

The presence of antibiotics in municipal wastewater is bound to affect the anoxic denitrifying process in anoxic activated sludge (AAS). This study investigated the effects of sulfamethoxazole (SMZ) on the denitrifying process in AAS and the responses of denitrifying microorganisms. The results showed that SMZ could decrease the speed of nitrate removal significantly when the concentration of SMZ was lower than 10 mg/L, and the removal of nitrate would be completely inhibited when SMZ concentration was higher than 100 mg/L. Weak alkaline condition would enhance the inhibition effect of SMZ on removal of nitrate in the anoxic bioreactor. The results of high-throughput sequencing and qPCR (quantitative polymerase chain reaction) showed that 100 mg/L of SMZ did not decrease the total abundance of denitrifying microorganisms. However, the relative expression levels of key denitrifying genes NirS and NosZ in AAS treated by 100 mg/L of SMZ versus the raw AAS without SMZ was only 0.030 and 0.036. Therefore, the inhibitory mechanism of SMZ on the denitrifying process in AAS was denoted by an effective inhibition to the expressions of denitrifying genes, rather than a decrease in the total abundance of denitrifying microorganisms.
Survival of ESKAPE pathogen Acinetobacter baumannii in water of different temperatures and pH
Authors: Dekic Svjetlana , Hrenovic Jasna , Ivankovic Tomislav , van Wilpe Erna
Published: October 2018

Bacterium Acinetobacter baumannii is an emergent pathogen associated with nosocomial infections, which can be also found in natural waters. The impact of ecological factors on A. baumannii is insufficiently investigated. The aim was to examine the influence of temperatures (−20 to 80 °C) and pH values (2 to 12) on the survival of environmental and clinical isolates of A. baumannii in nutrient-deprived spring water (SW) and nutrient-rich diluted nutrient broth during 5 months. A. baumannii successfully survived at −20 to 44 °C and neutral pH for 5 months, which is consistent with the persistence of this pathogen in the hospital environment. At temperatures 50 to 80 °C the survival of A. baumannii ranged from 5 days to 5 min. The pH 2 was the most lethal with survival time up to 3 hours, suggesting that acidic conditions are promising for disinfection of water contaminated with A. baumannii. Although the type of media was not statistically significant for long-time survival, the extensively resistant or pandrug-resistant isolates survived better in SW than susceptible or multidrug-resistant isolates. Two distinct colony phenotypes were recorded at extreme temperatures and pH values. The results of this study provide insight into the behaviour of this emerging pathogen in the environment.
Electroflotation of oily wastewater using stainless steel sponge electrodes
Authors: Genc A. , Goc S.
Published: October 2018

In this study, emulsified oil removals have been studied electrochemically by using stainless steel sponge electrode beds. A first-order electroflotation model was developed and the model estimation were consistent with the experimental results. It was found out that the mean electroflotation rate constant was mainly a function of the voltage applied to the electrode beds. In addition, the properties of intermediate materials (electrical conductivity) placed between the anode and cathode electrode beds strongly affected removal yields. For the initial concentration of 57,150 mg/L, the chemical oxygen demand (COD) removal was obtained as 85% under the conditions of voltage gradient 15 V. The experiments were also performed by varying the electrode bed lengths. Even though higher oil yields were obtained at 27 cm bed length, similar oil yields were also obtained at 18 cm bed length, especially after 60 min, with less energy consumption. Therefore, the optimum electrode bed length was concluded to be 18 cm.
Результати лікування постраждалих із незрощеннями великогомілкової кістки після переломів з використанням оцінних шкал
Authors: Rushay A.K. , Bebykh O.R. , Buglak A.I.
Published: October 2018

Авторами наведено результати лікування 32 постраждалих із незрощеннями великогомілкової кістки. Отримано добрі результати. Об’єм лікувального комплексу та можливий прогноз отриманих результатів здійснювався із застосуванням оцінної шкали Non-Union Scoring System. З урахуванням тих же показників був обраний і спосіб фіксації уламків кільцевими фіксаторами. Отримані результати ви­значалися з використанням оцінних анатомо-функціональних шкал Любошиця — Меттіса — Шварцберга та Karlstrom — Olerud. Використання оцінних шкал стандартизувало оцінку отриманих результатів, дало можливість порівняти ефективність різних методів лікування. Порівняння показників оцінних шкал Любошиця — Меттіса — Шварцберга та Karlstrom — Olerud довело їх схожість, відсутність значних розбіжностей в оцінці, що свідчить про можливість порівняння результатів лікування, здійснених за різними шкалами.
Критерії прогнозу ефективності лікування гастроезофагеальної рефлюксної хвороби в дітей шкільного віку
Authors: Nyankovskyy S.L. , Horodylovska M.I.
Published: October 2018

Одним із важливих аспектів підвищення ефективності лікування дітей із гастроезофагеальною рефлюксною хворобою (ГЕРХ) є індивідуалізація його проведення. Остання неможлива без розробки предикторів ефективності лікування хворих. Проведене дослідження встановило, що найбільш високе прогностичне значення для прогнозу ефективності лікування хворих дітей із ГЕРХ мають дані щодо лікування на амбулаторному етапі, ендоскопічне та морфологічне дослідження, загальний аналіз крові та біохімічні показники. Розроблений прогностичний алгоритм має високу (≥ 95 %) вірогідність і дозволяє клініцисту здійснювати прогноз ефективності лікування хворих дітей із ГЕРХ. У разі несприятливого прогнозу (задовільний результат лікування) можна персоніфікувати лікування шляхом нейтралізації контрольованих несприятливих прогностичних факторів конкретного хворого і, таким чином, підвищити його ефективність.
Порушення мікробіоти дихальних шляхів у дітей з респіраторними захворюваннями (літературний огляд)
Authors: Koreniuk O.S.
Published: October 2018

У статті наведено дані вітчизняної та зарубіжної літератури про мікробіоценози організму людини у нормі та патології. Розглянуто етапи заселення респіраторного тракту мікрофлорою у різні періоди дитячого віку. Представлені дані численних досліджень мікробіоти легень порівняно з мікробіоценозом верхніх дихальних шляхів. Наведені експериментальні дані, що підтверджують наявність мікрофлори у легенях здорової людини та прямий взаємозв’язок між мікробіотою верхніх і нижніх дихальних шляхів. Одним із найважливіших факторів, що визначають стан мікробіоти легень, є мікроаспірація. Показано значення мікробіоценозів відкритих порожнин організму для формування мукозального імунітету. Викладено наукову концепцію щодо алгоритму функціонування колонізаційної резистентності слизових організму. Розглянуто методику оцінки мікробіоценозу носоглотки та визначення ступеня дисбіозу. Особливу увагу приділено стану мікробіоти верхніх і нижніх відділів респіраторного тракту у дітей, які часто хворіють, а також дітей із рецидивуючими та хронічними захворюваннями органів дихання. Показано, що виявлення збудника в посіві матеріалу з верхніх і нижніх дихальних шляхів не обов’язково свідчить про його роль як збудника гострого бронхолегеневого захворювання. Необхідна оцінка ступеня вираженості дисбіозу. Однак тривала персистенція інфекційного збудника у пацієнтів з гострими бронхолегеневими захворюваннями може привести до дисбалансу імунної реактивності і формування хронічного бронхолегеневого запального процесу. Підвищена колонізація дихальних шляхів у пацієнтів з хронічними респіраторними захворюваннями є істотним чинником ризику, що сприяє розвитку загострень. Відзначено, що моніторинг етіологічно значущих штамів мікроорганізмів у пацієнтів з гострою та хронічною бронхолегеневою патологією є необхідним для удосконалення патогенетичної тактики лікування та профілактики формування хронічних станів.
Сучасне уявлення про роль мутацій протеїнів сурфактанту в формуванні інтерстиціальних захворювань легень у новонароджених і немовлят
Authors: Logvinova O.L. , Gonchar M.A.
Published: October 2018

У статті наведено сучасне уявлення про компоненти сурфактанту, функції несироваткових протеїнів ­SP-A, SP-B, SP-C і SP-D. Описана історія відкриття спадкових дефіцитів протеїнів SP-B, SP-С та ABCA3. Авторами проаналізовано сучасну епідеміологію, клінічні та гістологічні особливості різних варіантів недостатності білків сурфактанту. Продемонстровано різні варіанти мутацій SFTPС, SFTPВ і ABCA3 та їх вплив на перебіг, клінічні прояви і наслідок інтерстиціального захворювання легень у дітей.
Современные аспекты выбора мукоактивной терапии кашля в педиатрической практике
Authors: Besh L.V. , Matsyura O.I.
Published: October 2018

В статье представлены основные подходы к назначению мукоактивной терапии кашля в педиатрической практике. Охарактеризованы одни из самых распространенных по применению у детей препараты амброксол и карбоцистеин и их комбинация. Проведен анализ собственных исследований эффективности трех мукоактивных средств: амброксола, карбоцистеина и их комбинации (Пектолван Ц) в лечении острых респираторных вирусных инфекций у детей в возрасте 2–6 лет, состояние которых сопровождалось продуктивным кашлем с вязкой, трудно отделяющейся мокротой. Доказано, что наиболее эффективным в таких случаях является комбинированный препарат Пектолван Ц.
Некоторые вопросы гидродинамики и энергетики циркуляторного и гемического звеньев системы транспорта кислорода (часть 1)
Authors: Mikhnevich K.G.
Published: October 2018

В 1-й части статьи рассмотрены закономерности движения жидкости по простой замкнутой циркуляторной гидродинамической системе. Обсуждено значение таких показателей, как давление и энергия движущейся жидкости, гидродинамическое сопротивление, влияние на них геометрии гидродинамического контура и характера нагнетательной функции насоса. Представлены модели нарушений кровообращения на примере простой замкнутой циркуляторной гидродинамической системы.
Вопросы тромбогеморрагических осложнений у больных раком эндометрия: что нового?
Authors: Tarabrin O.O. , Bobyr A.L. , Bosenko K.V. , Duzenko O.O.
Published: October 2018

Рак тела матки к концу прошлого столетия приобрел статус ведущей онкогинекологической патологии не только в экономически развитых странах, но и в странах третьего мира. В последние десятилетия начался постепенный и неуклонный рост заболеваемости раком тела матки, а вместе с тем и смертности от данной патологии. Известен факт, что между венозной тромбоэмболией и раком существует очень сильная связь. Пациенты со злокачественными новообразованиями имеют более высокую частоту тромбоэмболических осложнений. Активация механизмов сворачивания крови у больных раком — сложный и многофакторный процесс, связанный с характеристиками опухоли, клиническими стадиями, агрессивностью заболевания и дополнительными факторами, вызванными прогрессированием заболевания.
Поздние осложнения после классической флебэктомии в системе малой подкожной вены
Authors: Rogovoy N.A. , Yanushko V.A. , Turliuk D.V. , Klimchuk I.P. , Komissarov V.V. , Kulbeda D.S.
Published: October 2018

Предварительно был проведен ретроспективный анализ результатов хирургического лечения варикозной болезни нижних конечностей в системе малой подкожной вены (МПВ) на базе отделения сосудистой хирургии УЗ «4-я городская клиническая больница имени Н.Е. Савченко» г. Минска за 2009–2014 гг. Выявлено, что при классической флебэктомии у 13,9 % пациентов кроссэктомия МПВ выполнена с оставлением культи 20–35 мм. У 13,5 % МПВ удалена до подколенной складки, но далее продолжалась на бедро как проксимальная ветвь или вена Джиакомини с рефлюксом по последней. У 23,6 % МПВ удалена до средней трети голени, у 8,1 % — до высшей трети голени. У 40,9 % пациентов МПВ удалена на всем протяжении. Представлен клинический анализ двух случаев осложнений после флебэктомии в системе малой подкожной вены: пациент с тромбофлебитом культи МПВ и флотацией тромба в подколенную вену и пациент с артериовенозной фистулой подколенной области. Изложены симптоматика, клиническое течение данных видов осложнений, методы диагностики, профилактики венозного тромбоэмболизма и хронической сердечной недостаточности.
Стійка гіпоглікемія у новонародженого як рідкісний варіант прояву вродженого гіпотиреозу
Authors: Tantsіura L.D. , Kyselova I.V. , Stadnіk I.O.
Published: October 2018

Наведено випадок вродженого гіпотиреозу, який проявився стійкою гіпоглікемією, резистентною до внутрішньовенної корекції глюкозою. Персистуюча гіпоглікемія є рідкісним проявом вродженого гіпотиреозу, але при проведенні диференціальної діагностики гіпоглікемії розглядається оцінка функції щитоподібної залози. Причинами стійкої гіпоглікемії при вродженому гіпотиреозі можуть бути уповільнене поглинання глюкози клітиною, зменшення швидкості абсорбції глюкози в кишечнику, знижений кліренс інсуліну з крові, порушення глюконеогенезу.