bluuebunny/crossref_metadata_2025 huggingface dataset:
Opioid receptor-dependent modulation of insulin-release in pancreatic beta-cells
Authors: Alok Paul  , Nuri Guven  , Nikolas Dietis
Published: February 2016

In this study we aimed to look at the effects of opioid-receptor selective agonists and antagonists on insulin secretion in the pancreatic β-cell line RIN-5F. Cells were treated for 24 hours with 1μM of selective agonists (DAMGO for MOP, DPDPE for DOP, U50488 for KOP) in the presence or absence of 10μM of selective antagonists (CTOP for MOP, naltrindole for DOP, norBNI for KOP). An enzyme-based immunoassay was used to detect the amount of insulin in the supernatant, using a standard curve generated from known concentrations of rat insulin. A trypan blue viability assay was performed to assess the toxicity of each treatment and the secreted insulin was expressed as per 103 viable cells. Treatment with DAMGO or DPDPE caused an increase in secreted insulin by 94.2% and 76.3% respectively, compared to the non-treated controls. Co-treatment of DAMGO and CTOP was able to cancel out the agonists’ effect. However, CTOP itself was able to increase insulin secretion by 72% when compared to control. These results suggest that opioid-induced insulin secretion may be based on G-protein independent mechanisms. In addition, none of the KOP-receptor selective ligands tested here were able to significantly affect insulin secretion compared to control, whereas naltrindole was highly toxic to pancreatic β-cells since it induced maximum cell death. Collectively, these findings suggest that MOP and DOP receptor-binding opioids might be more relevant in increasing insulin secretion from pancreatic β-cells than KOP receptor ligands.
An in vitro trial to study the effect of inclusion of different levels of coconut oil on sheep rumen methanogenesis and fermentation processes
Authors: Tisa Mukharji  , Aakash Srivastava  , Meera Srivastava
Published: February 2016

An in vitro trial was conducted in fermentation vessels under anaerobic conditions using composite feed-1 and composite feed-2 with inclusion of different levels of Coconut Oil (CO) along with buffered rumen liquor of sheep to observe the effects of oil on rumen methanogenesis and fermentation. The Composite Feed-1(CF-1) consisted of 40% of concentrate and Composite Feed-2 (CF-2) had 25 % of concentrate. The different levels of CO used were 0.5,1 and 2 µl/ml. Among the gas production and methane concentration parameters the inclusion of CO showed a significant decrease of 38.67%. A non significant effect on gas production was noted with the inclusion of CO in CF-2. Further, a decrease in total gas production and methane concentration was observed which was highly pronounced in CF-1 as compared to CF-2. The rumen digestibility by inclusion of CO in CF-1 and CF-2 decreased significantly (P < 0.01) from control. The inclusion of CO in CF-2 did not affect Ammonia Nitrogen (NH3 –N) concentration, while in CF-1 the CO inclusion increased the NH3 –N concentration. The inclusion of CO decreased the Total volatile fatty acid (TVFA) concentration significantly (P < 0.01). In both the diets namely CF-1 and CF-2 the A:P ratio was unaffected by CO inclusion. The inclusion of CO in CF-1 had a non significant effect in pH. However, the inclusion of CO in CF-1 and CF-2 decreased the protozoa number significantly (P < 0.01). Inclusion of oil tended to decrease Gas production (GP), Metabolizable energy (ME), Short Chain Fatty Acid (SCFA), True Degradability of Dry Matter (TDDM) and Microbial Biomass Production (MBP). The effect was more pronounced when CO level was 1.0µl/ml or higher. From the above gas production and fermentation parameters noticed in two diets CF-1 and CF-2 with inclusion of different levels of CO, it can be envisaged that increasing the proportion of concentrate in diets and using CO as a feed additive increases the rumen efficiency by reducing the methane concentration and gas production.
Refugee Resettlement Patterns and State-Level Health Care Insurance Access in the United States
Authors: Agrawal Pooja , Venkatesh Arjun Krishna
Published: February 2016

We sought to evaluate the relationship between state-level implementation of the Patient Protection and Affordable Care Act (ACA) and resettlement patterns among refugees. We linked federal refugee resettlement data to ACA expansion data and found that refugee resettlement rates are not significantly different according to state-level insurance expansion or cost. Forty percent of refugees have resettled to states without Medicaid expansion. The wide state-level variability in implementation of the ACA should be considered by federal agencies seeking to optimize access to health insurance coverage among refugees who have resettled to the United States.
Total Duration of Breastfeeding, Vitamin D Supplementation, and Serum Levels of 25-Hydroxyvitamin D
Authors: Darmawikarta Denise , Chen Yang , Lebovic Gerald , Birken Catherine S. , Parkin Patricia C. , Maguire Jonathon L.
Published: February 2016

Objectives. To determine the association between total breastfeeding duration and serum 25-hydroxyvitamin D (25-OHD) and to explore whether vitamin D supplementation influences this association.

Methods. We conducted a cross-sectional study of healthy children between September 2011 and August 2013 through the TARGet Kids! primary health care research network. Of the 4533 eligible children, we included only the 2508 who had 25-OHD measured. We assessed adjusted associations of total breastfeeding duration (in months) with serum 25-OHD and in supplemented versus nonsupplemented children, with the odds of 25-OHD less than 20 nanograms per milliliter.

Results. Each 1-month increase in total breastfeeding duration was associated with a 0.12 nanograms per milliliter lower median serum 25-OHD (95% confidence interval [CI] = –0.21 ng/mL, –0.02 ng/mL) among children who were not supplemented. The odds of serum 25-OHD less than 20 nanograms per milliliter increased by 6% (odds ratio [OR] = 1.06; 95% CI = 1.03, 1.10) for every 1-month increase in total breastfeeding duration among nonsupplemented children. The interaction between vitamin D supplementation, duration of breastfeeding, and median serum 25-OHD was statistically significant (P = .04).

Conclusions. Breastfed children who were not supplemented, particularly those breastfed more than 1 year, appear to have lower vitamin D status. Vitamin D supplementation may mitigate this risk. These findings support recommendations for supplementation during breastfeeding of any duration.
Causes and Disparities in Death Rates Among Urban American Indian and Alaska Native Populations, 1999–2009
Authors: Jacobs-Wingo Jasmine L. , Espey David K. , Groom Amy V. , Phillips Leslie E. , Haverkamp Donald S.
Published: February 2016

Objectives. To characterize the leading causes of death for the urban American Indian/Alaska Native (AI/AN) population and compare with urban White and rural AI/AN populations.

Methods. We linked Indian Health Service patient registration records with the National Death Index to reduce racial misclassification in death certificate data. We calculated age-adjusted urban AI/AN death rates for the period 1999–2009 and compared those with corresponding urban White and rural AI/AN death rates.

Results. The top-5 leading causes of death among urban AI/AN persons were heart disease, cancer, unintentional injury, diabetes, and chronic liver disease and cirrhosis. Compared with urban White persons, urban AI/AN persons experienced significantly higher death rates for all top-5 leading causes. The largest disparities were for diabetes and chronic liver disease and cirrhosis. In general, urban and rural AI/AN persons had the same leading causes of death, although urban AI/AN persons had lower death rates for most conditions.

Conclusions. Urban AI/AN persons experience significant disparities in death rates compared with their White counterparts. Public health and clinical interventions should target urban AI/AN persons to address behaviors and conditions contributing to health disparities.
Human Papillomavirus Vaccination in the United States: Uneven Uptake by Gender, Race/Ethnicity, and Sexual Orientation
Authors: Daniel-Ulloa Jason , Gilbert Paul A , Parker Edith A.
Published: February 2016

Objectives. To assess national differences in human papillomavirus (HPV) vaccine uptake among young adults in the United States by gender, race/ethnicity, and sexual orientation.

Methods. We tested group differences in initiation and completion of the HPV vaccine series (i.e., 3 doses) by Rao–Scott χ2 test among 6444 respondents aged 18 to 30 years from the 2013 National Health Interview Survey.

Results. Among men, 5% reported receiving the HPV vaccine, with no differences in uptake by race/ethnicity or sexual orientation. By contrast, 30% of the women reported receiving the HPV vaccine, with women of color having lower odds of initiating and completing the vaccine series compared with White women.

Conclusions. In the United States, HPV vaccine rates are lagging in men and show disparities among women. Increasing HPV vaccine uptake and series completion among women of color and all men may provide considerable long-term public health benefits.
Yield Differences Influenced by Distance from Riparian Buffers and Conservation Reserve Program
Authors: Udawatta Ranjith P. , Gantzer Clark J. , Reinbott Timothy M. , Wright Ray L. , Pierce Robert A.
Published: February 2016

Riparian buffers (RB) and the Conservation Reserve Program (CRP) can improve water and soil quality. However, these practices can reduce crop yields, especially at the tree/CRP‐crop interface. The objective of this study was to quantify yield differences in a no‐till corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation with a multi‐species RB, CRP, and riparian with root pruning (RRP). Crop yields were determined in triplicate plots by rows from 2007 to 2010. Regression analysis was used to evaluate yield differences among years and distances from the tree/CRP‐crop interface and RRP. Corn yield at 0.76‐m was 97, 97, 65, and 66% lower than the yield at 9‐m away from the interface in 2007, 2008, 2009, and 2010, respectively for RB. Averaged across 4 yr corn yields at 0.76 m was 61, 74, and 81% of that at 3, 6, and 9 m. The CRP had no effect on corn yields. Effects of RB and CRP were not significant for soybean. The RRP showed increasing yield for rows from the tree interface for corn and soybean. The distance explained 21 to 60% and 15 to 52% of the yield variations in corn and soybean, respectively, with the RRP treatment. Results are applicable only to the studied distances. Results of the study suggest selection of a less sensitive crop such as soybean for use with RB in the first 9 m (12 rows), or use of CRP to generate additional income and ecosystem services to offset any loss in grain.

Core Ideas

This manuscript evaluated riparian buffer, CRP, and riparian with root pruning on corn and soybean yields for 4 years.

Riparian with root pruning significantly reduced crop yields near the buffer/crop border. The CRP effect was not significant.

Results of the study imply the importance of land management practices for production and environmental benefits.
Polymer‐Coated Urea Improved Corn Response Compared to Urea‐Ammonium‐Nitrate When Applied on a Coarse‐Textured Soil
Authors: Maharjan Bijesh , Ferguson Richard B. , Slater Glen P.
Published: February 2016

Increasing economic and environmental concerns in corn (Zea mays L.) production have prompted the need for improved N management. In this study, effects of two N sources [urea‐ammonium‐nitrate (UAN) and polymer‐coated urea (PCU)] on corn response were evaluated at different N rates over three site‐years. An additional N treatment of split‐applied UAN (UAN‐SP) based on the University of Nebraska‐Lincoln recommendation algorithm was also included. Leaf chlorophyll was indirectly measured using a chlorophyll meter at different corn growth stages for all N treatments to determine in‐season corn N status. Both PCU and UAN‐SP increased grain yield compared to UAN, even when the UAN rate was higher than that of PCU or UAN‐SP. The PCU treatment applied at 168 kg N ha−1 was as effective as UAN‐SP applied at ∼200 kg N ha−1. At early growth stages, leaf chlorophyll was higher in a dry year than in wet years, when more N loss was likely. At different growth stages taken individually or together, chlorophyll meter readings were significantly correlated to grain yield. Temporal N release from PCU in the conditions of this study was not an issue, as shown by the consistently greater chlorophyll meter readings in PCU treatments than in UAN treatments, regardless of interannual climatic variations. These results indicate that PCU consistently performed better than UAN.
QTLs for Early Tiller Production and Relationships with Rapid Seedling Growth and Increased Panicle Number in Rice
Authors: Pinson Shannon R. M. , Jia Yulin
Published: February 2016

Tiller number (TN) is a key determinant of final grain yield in the small grains crops, including rice (Oryza sativa L.), and is desired to enhance competition with weeds. Quantitative trait loci (QTLs) associated with TN were mapped within a set of recombinant inbred lines developed from a cross between the low‐tillering tropical japonica cultivar ‘Kaybonnet‐lpa1‐1’ and the high‐tillering, high‐yielding, early‐maturing indica cultivar ‘Zhe733’ using data collected from greenhouse potted plants evaluated weekly. Relationships between the five identified TN QTLs and related traits including panicle number (PN), flag leaf number, seedling leaf number (SLN), and earliness of tiller production were also evaluated. The three TN QTLs that were linked with early tiller emergence were also associated with PN; two additional TN not associated with PN were also identified. All five TN QTLs were also SLN QTLs, though other loci affecting SLN were also identified. Several of the TN and SLN QTLs identified using data from young plants (e.g., ≤6 wk after planting) were not detectible in data collected just before or after heading. The three TN QTLs also associated with PN showed stronger effects (higher logarithm of the odds ratios and additive effects) on TN as observed in seedling stages than on final TN at heading time, and their effects diminished over time to the point that they were not always detectible in TN data collected at or after heading. However, the three TN QTLs that were also PN QTLs were robust enough that they were detected in the less intensive (one‐fourth the labor and resources) Arkansas trials, where tillers were counted from two single‐plant replications just twice, at 6 wk after planting and after heading. The three loci associated with both TN and PN are the TN loci most likely to increase rice yield, and the markers presently found linked to them can be used for marker assisted breeding.
Experimental Studies and Model Analysis of Noble Gas Fractionation in Porous Media
Authors: Ding Xin , Kennedy B. Mack , Evans William C. , Stonestrom David A.
Published: February 2016

Core Ideas

Ambient noble gases in porous media fractionate from through‐flow of other gases.

CO2 fluxes and noble‐gas fractionation are measured in simple sandbox experiments.

Modeled fractionation provides indirect proxy, e.g., of steady CO2 leakage fluxes.

The noble gases, which are chemically inert under normal terrestrial conditions but vary systematically across a wide range of atomic mass and diffusivity, offer a multicomponent approach to investigating gas dynamics in unsaturated soil horizons, including transfer of gas between saturated zones, unsaturated zones, and the atmosphere. To evaluate the degree to which fractionation of noble gases in the presence of an advective–diffusive flux agrees with existing theory, a simple laboratory sand column experiment was conducted. Pure CO2 was injected at the base of the column, providing a series of constant CO2 fluxes through the column. At five fixed sampling depths within the system, samples were collected for CO2 and noble gas analyses, and ambient pressures were measured. Both the advection–diffusion and dusty gas models were used to simulate the behavior of CO2 and noble gases under the experimental conditions, and the simulations were compared with the measured depth‐dependent concentration profiles of the gases. Given the relatively high permeability of the sand column (5 × 10−11 m2), Knudsen diffusion terms were small, and both the dusty gas model and the advection–diffusion model accurately predicted the concentration profiles of the CO2 and atmospheric noble gases across a range of CO2 flux from ∼700 to 10,000 g m−2 d−1. The agreement between predicted and measured gas concentrations demonstrated that, when applied to natural systems, the multi‐component capability provided by the noble gases can be exploited to constrain component and total gas fluxes of non‐conserved (CO2) and conserved (noble gas) species or attributes of the soil column relevant to gas transport, such as porosity, tortuosity, and gas saturation.
Is swimming in recreational water associated with the occurrence of respiratory illness? A systematic review and meta-analysis
Authors: Mannocci Alice , La Torre Giuseppe , Spagnoli Alessandro , Solimini Angelo G. , Palazzo Caterina , De Giusti Maria
Published: February 2016

This study represents the first systematic review and meta-analysis conducted to assess the association between swimming in recreational water and the occurrence of respiratory illness. Most studies focus their attention on gastrointestinal illnesses occurring after exposure to microbial polluted water. Fourteen independent studies that included 50,117 patients with significant heterogeneity (I2 = 95.3%) were reviewed. The meta-analysis reports that people exposed to recreational water (swimmers/bathers) present a higher risk of respiratory illness compared to non-swimmers/non-bathers [relative risk (RR) = 1.63 (confidence interval at 95% [95% CI]: 1.34–1.98)]. This percentage increases if adjusted RR by age and gender [RR = 2.24 (95% CI: 1.81–2.78)] are considered. A clear association between swimming in recreational water and the occurrence of respiratory illness was found. The surveillance of water quality monitoring systems is crucial not only for gastrointestinal illness, but also for respiratory ones.
Fate of major compounds in source-separated urine
Authors: Udert K.M. , Larsen T.A. , Gujer W.
Published: February 2016

Urine separation is a promising alternative to present-day waste water management. It can help to manage our nutrient flows in a sustainable way. Currently, techniques are being developed to recycle and treat source-separated urine. These techniques, however, must consider the spontaneous processes that change the separated urine. The initial cause of changes is the contamination with microorganisms, which can hardly be avoided in urine-collecting systems. The most important transformation processes are microbial urea hydrolysis, mineral precipitation and ammonia volatilisation. Additionally, a variety of microorganisms may grow in source-separated urine, because the content of biodegradable organic compounds is very high. These microorganisms may also include pathogens. In this paper we give an overview of the effects that the spontaneous transformation processes may have. We focus on nitrogen, phosphorus, magnesium, calcium, potassium, sulphur, organic substances, pathogens and the buffering capacity. The discussion is based on own experiences and literature reviews. This overview will help to develop appropriate technologies for urine recycling.
Observations on ozone treatment of excess sludge
Authors: Yin J.
Published: February 2016

We regret that the list of authors' addresses for this paper was printed with an incorrect mailing address introduced for the corresponding author, J. Yin; the correct details are as given here.
Partitioning of heavy metals in sub-surface flow treatment wetlands receiving high-strength wastewater
Authors: Wojciechowska Ewa , Gajewska Magdalena
Published: February 2016

The retention of heavy metals at two pilot-scale treatment wetlands (TWs), consisting of two vertical flow beds (VSSF) followed by a horizontal flow bed (HSSF) was studied. The TWs received high-strength wastewater: reject waters from sewage sludge centrifugation (RW) and landfill leachate (LL). The concentrations of the metals Fe, Mn, Zn, Al, Pb, Cu, Cd, Co, and Ni were measured in treated wastewater, substrate of the beds and in plant material harvested from the beds (separately in above ground (ABG) parts and below ground (BG) parts). The TWs differed in metals retention. In the RW treating TW the metal removal efficiencies varied from 27% for Pb to over 97% for Fe and Al. In the LL treating system the concentrations of most metals decreased after VSSF-1 and VSSF-2 beds; however, in the outflow from the last (HSSF) bed, the concentrations of metals (apart from Al) increased again, probably due to the anaerobic conditions at the bed. A major removal pathway was sedimentation and adsorption onto soil substrate as well as precipitation and co-precipitation. In the LL treating facility the plants contained substantially higher metal concentrations in BG parts, while the upward movement of metals was restricted. In the RW treating facility the BG/ABG ratios were lower, indicating that metals were transported to shoots.
Performance comparison between two equal stabilization ponds operating with and without sludge layer
Authors: Rodrigues V. A. J. , Possmoser-Nascimento T. E. , Dias D. F. C. , Passos R. G. , von Sperling M. , Vasel J. L.
Published: February 2016

Stabilization ponds are a highly appropriate system for treating sewage in small to medium size communities. However, sludge accumulation at the pond bottom occurs with the passage of time, reducing the net pond volume, which, in principle, could affect its performance. The objective of this paper is to compare the behaviour of two equal ponds in parallel treating the same flow of municipal wastewater from an upflow anaerobic sludge blanket reactor in Brazil. Each pond treated a population equivalent of around 125 inhabitants. One pond had approximately 40% of its net volume occupied by sludge after 11 years of operation, while the other pond had previously undergone complete desludging. The study covers the removal of biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), nitrogen fractions and coliforms. Owing to the presence of a sludge layer, the theoretical hydraulic retention time (HRT) was lower in the pond without sludge. For BOD, COD, SS and Escherichia coli there were no significant differences (Wilcoxon matched-pairs test) between both ponds. The pond without sludge had significantly better removal efficiencies in terms of total Kjeldahl nitrogen and ammonia-N. The sludge layer probably allowed the occurrence of removal mechanisms that compensated for the reduction caused in the HRT.
Depression storage capacities of different ideal pavements as quantified by a terrestrial laser scanning-based method
Authors: Nehls T. , Menzel M. , Wessolek G.
Published: February 2016

Rainfall partition on paved urban surfaces is governed to a great extent by depression storage. This is especially the case for small rainfall events, which are often ignored in urban hydrology. If storage, infiltration and evaporation (important for urban heat island mitigation), rather than storm water run-off, are of interest, high-resolution simulations with exact values for depression storage capacities are required. Terrestrial laser scanners deliver fast, high-resolution surveys of pavement surface morphology. The depression storage capacity can be quantified from 3D points by generating digital elevation models and applying cut-and-fill algorithms in a geographic information system. The method was validated using a test model. It was possible to quantify depressions with a depth of at least 1.4 × 10−3 m and a surface of at least 15 × 10−6 m2 with an uncertainty below 30%. Applying this method, the depression storage capacities for 11 ideal, typical pavement designs were found to vary from 0.07 to 1.4 mm. Realistic urban pavements must also be surveyed, as cracks and puddles from their use history can have a major impact on the depression storage capacities and thus on infiltration, evaporation and, finally, the annual run-off.
Effects of influent fractionation, kinetics, stoichiometry and mass transfer on CH4, H2 and CO2 production for (plant-wide) modeling of anaerobic digesters
Authors: Solon Kimberly , Flores-Alsina Xavier , Gernaey Krist V. , Jeppsson Ulf
Published: February 2016

This paper examines the importance of influent fractionation, kinetic, stoichiometric and mass transfer parameter uncertainties when modeling biogas production in wastewater treatment plants. The anaerobic digestion model no. 1 implemented in the plant-wide context provided by the benchmark simulation model no. 2 is used to quantify the generation of CH4, H2 and CO2. A comprehensive global sensitivity analysis based on (i) standardized regression coefficients (SRC) and (ii) Morris' screening's (MS's) elementary effects reveals the set of parameters that influence the biogas production uncertainty the most. This analysis is repeated for (i) different temperature regimes and (ii) different solids retention times (SRTs) in the anaerobic digester. Results show that both SRC and MS are good measures of sensitivity unless the anaerobic digester is operating at low SRT and mesophilic conditions. In the latter situation, and due to the intrinsic nonlinearities of the system, SRC fails in decomposing the variance of the model predictions (R2 < 0.7) making MS a more reliable method. At high SRT, influent fractionations are the most influential parameters for predictions of CH4 and CO2 emissions. Nevertheless, when the anaerobic digester volume is decreased (for the same load), the role of acetate degraders gains more importance under mesophilic conditions, while lipids and fatty acid metabolism is more influential under thermophilic conditions. The paper ends with a critical discussion of the results and their implications during model calibration and validation exercises.
Anaerobic biodegradability of fish remains: experimental investigation and parameter estimation
Authors: Donoso-Bravo Andres , Bindels Francoise , Gerin Patrick A. , Vande Wouwer Alain
Published: February 2016

The generation of organic waste associated with aquaculture fish processing has increased significantly in recent decades. The objective of this study is to evaluate the anaerobic biodegradability of several fish processing fractions, as well as water treatment sludge, for tilapia and sturgeon species cultured in recirculated aquaculture systems. After substrate characterization, the ultimate biodegradability and the hydrolytic rate were estimated by fitting a first-order kinetic model with the biogas production profiles. In general, the first-order model was able to reproduce the biogas profiles properly with a high correlation coefficient. In the case of tilapia, the skin/fin, viscera, head and flesh presented a high level of biodegradability, above 310 mLCH4 gCOD−1, whereas the head and bones showed a low hydrolytic rate. For sturgeon, the results for all fractions were quite similar in terms of both parameters, although viscera presented the lowest values. Both the substrate characterization and the kinetic analysis of the anaerobic degradation may be used as design criteria for implementing anaerobic digestion in a recirculating aquaculture system.
Characterization of modified PVDF membrane by gamma irradiation for non-potable water reuse
Authors: Lim Seung Joo , Kim Tak-Hyun , Shin In Hwan
Published: February 2016

Poly(vinylidene fluorine) (PVDF) membranes were grafted by gamma-ray irradiation and were sulfonated by sodium sulfite to modify the surface of the membranes. The characteristics of the modified PVDF membranes were evaluated by the data of Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscope (FE-SEM), the contact angle of the membrane surface and the water permeability. From the results of FT-IR, XPS and FE-SEM, it was shown that the modified membranes were successfully grafted by gamma-ray irradiation and were sulfonated. The content of oxygen and sulfur increased with the monomer concentration, while the content of fluorine sharply decreased. The pore size of the modified membranes decreased after gamma-ray irradiation. The contact angle and the water permeability showed that the hydrophilicity of the modified membranes played a role in determining the membrane performance. The feasibility study of the modified PVDF membranes for using non-potable water reuse were carried out using a laboratory-scale microfiltration system. Grey wastewater was used as the influent in the filtration unit, and permeate quality satisfied non-potable water reuse guidelines in the Republic of Korea.
Leaching behavior of total organic carbon, nitrogen, and phosphorus from banana peel
Authors: Jiang Ruixue , Sun Shujuan , Xu Yan , Qiu Xiudong , Yang Jili , Li Xiaochen
Published: February 2016

The leaching behavior of organic carbon and nutrient compounds from banana peel (BP) was investigated in batch assays with respect to particle size, contact time, pH value, and temperature. The granularity, contact time, pH, and temperature caused no significant effects on the leaching of total phosphorus (TP) from the BP. The maximum leached total nitrogen (TN) content was found at pH 5.0 and 90 minutes, while no significant effects were caused by the granularity and temperature. The maximum leached total organic carbon (TOC) content was found by using a powder of 40 mesh, 150 minutes and at pH 6.0, while the temperature had no effect on the TOC leaching. The proportions of the TN, TP, and TOC contents leached from the dried BP ranged from 33.6% to 40.9%, 60.4% to 72.7%, and 8.2% to 9.9%, respectively, indicating that BP could be a potential pollution source for surface and ground water if discharged as domestic waste or reutilized without pretreatment.
An ecological compensation standard based on emergy theory for the Xiao Honghe River Basin
Authors: Guan Xinjian , Chen Moyu , Hu Caihong
Published: February 2016

The calculation of an ecological compensation standard is an important, but also difficult aspect of current ecological compensation research. In this paper, the factors affecting the ecological–economic system in the Xiao Honghe River Basin, China, including the flow of energy, materials, and money, were calculated using the emergy analysis method. A consideration of the relationships between the ecological–economic value of water resources and ecological compensation allowed the ecological–economic value to be calculated. On this basis, the amount of water needed for dilution was used to develop a calculation model for the ecological compensation standard of the basin. Using the Xiao Honghe River Basin as an example, the value of water resources and the ecological compensation standard were calculated using this model according to the emission levels of the main pollutant in the basin, chemical oxygen demand. The compensation standards calculated for the research areas in Xipin, Shangcai, Pingyu, and Xincai were 34.91 yuan/m3, 32.97 yuan/m3, 35.99 yuan/m3, and 34.70 yuan/m3, respectively, and such research output would help to generate and support new approaches to the long-term ecological protection of the basin and improvement of the ecological compensation system.
Use of geological mapping tools to improve the hydraulic performance of SuDS
Authors: Bockhorn Britta , Klint Knud Erik Strøyberg , Jensen Marina Bergen , Møller Ingelise
Published: February 2016

Most cities in Denmark are situated on low permeable clay rich deposits. These sediments are of glacial origin and range among the most heterogeneous, with hydraulic conductivities spanning several orders of magnitude. This heterogeneity has obvious consequences for the sizing of sustainable urban drainage systems (SuDS). We have tested methods to reveal geological heterogeneity at field scale to identify the most suitable sites for the placement of infiltration elements and to minimize their required size. We assessed the geological heterogeneity of a clay till plain in Eastern Jutland, Denmark measuring the shallow subsurface resistivity with a geoelectrical multi-electrode system. To confirm the resistivity data we conducted a spear auger mapping. The exposed sediments ranged from clay tills over sandy clay tills to sandy tills and correspond well to the geoelectrical data. To verify the value of geological information for placement of infiltration elements we carried out a number of infiltration tests on geologically different areas across the field, and we observed infiltration rates two times higher in the sandy till area than in the clay till area, thus demonstrating that the hydraulic performance of SuDS can be increased considerably and oversizing avoided if field geological heterogeneity is revealed before placing SuDS.
Research on classified real-time flood forecasting framework based on K-means cluster and rough set
Authors: Xu Wei , Peng Yong
Published: February 2016

This research presents a new classified real-time flood forecasting framework. In this framework, historical floods are classified by a K-means cluster according to the spatial and temporal distribution of precipitation, the time variance of precipitation intensity and other hydrological factors. Based on the classified results, a rough set is used to extract the identification rules for real-time flood forecasting. Then, the parameters of different categories within the conceptual hydrological model are calibrated using a genetic algorithm. In real-time forecasting, the corresponding category of parameters is selected for flood forecasting according to the obtained flood information. This research tests the new classified framework on Guanyinge Reservoir and compares the framework with the traditional flood forecasting method. It finds that the performance of the new classified framework is significantly better in terms of accuracy. Furthermore, the framework can be considered in a catchment with fewer historical floods.
Assessment of LID practices for restoring pre-development runoff regime in an urbanized catchment in southern Finland
Authors: Guan Mingfu , Sillanpää Nora , Koivusalo Harri
Published: February 2016

This study quantifies the effects of common stormwater management techniques on urban runoff generation. Simulated flow rates for different low impact development (LID) scenarios were compared with observed flow rates during different urban construction phases in a catchment (12.3 ha) that was developed from natural forest to a residential area over a monitoring period of 5 years. The Storm Water Management Model (SWMM) was calibrated and validated against the observed flow rates in the fully developed catchment conditions, and it was then applied to parameterize the LID measures and produce scenarios of their hydrological impacts. The results from the LID scenarios were compared with the observed flow rates in the pre-development and the partially developed catchment conditions. The results show that LID controls reduce urban runoff towards the flow conditions in the partially developed catchment, but the reduction effect diminishes during large rainfall events. The hydrographs with LID are still clearly different from the observed pre-development levels. Although the full restoration of pre-development flow conditions was not feasible, a combination of several measures controlling both volumes and retention times of storm runoff appeared to be effective for managing the stormwater runoff and mitigating the negative impacts of urban development.
Novel diesel-oil-degrading bacteria and fungi from the Ecuadorian Amazon rainforest
Authors: Maddela N. R. , Masabanda M. , Leiva-Mora M.
Published: February 2016

Isolating new diesel-oil-degrading microorganisms from crude-oil contaminated sites and evaluating their degradation capacities are vitally important in the remediation of oil-polluted environments and crude-oil exploitation. In this research, new hydrocarbon-degrading bacteria and fungi were isolated from the crude-oil contaminated soil of the oil-fields in the Amazon rainforest of north-east Ecuador by using a soil enrichment technique. Degradation analysis was tracked by gas chromatography and a flame ionization detector. Under laboratory conditions, maximum degradability of the total n-alkanes reached up to 77.34 and 62.62 removal ratios after 30 days of incubation for the evaporated diesel oil by fungi (isolate-1) and bacteria (isolate-1), respectively. The 16S/18S rDNA sequence analysis indicated that the microorganisms were most closely (99–100%) related to Bacillus cereus (isolate-1), Bacillus thuringiensis (isolate-2), Geomyces pannorum (isolate-1), and Geomyces sp. (isolate-2). Therefore, these strains enable the degradation of hydrocarbons as the sole carbon source, and these findings will benefit these strains in the remediation of oil-polluted environments and oil exploitation.
Degradation of ethylparaben under simulated sunlight using photo-Fenton
Authors: Zúñiga-Benítez Henry , Peñuela Gustavo A.
Published: February 2016

Ethylparaben (EPB) has been classified by different research groups as a potential endocrine-disrupting chemical, implying that it can potentially interfere with the normal balance of the endocrine system of living beings, which with its presence in different effluents, including drinking water, generates the need to seek methods that allow its removal from different water bodies. Advanced oxidation processes have been employed widely to remove organic compounds from different matrices. In this way, Fenton technology (process based on the reaction between ferrous ions and hydrogen peroxide) has been able to degrade different substrates, but due to the Fe2+ requirements to carry out the reaction optimally, combination of the conventional Fenton process with visible light radiation (photo-Fenton) is an alternative used in the treatment of pollution due to the presence of chemicals. In this way, the effectiveness of photo-Fenton on EPB degradation was assessed using a face-centered central composite experimental design that allowed assessment of the effects of Fe2+ and H2O2 initial concentrations on process. In general, results indicated that after 180 min of reaction almost all EPB was eliminated, the dissolved organic carbon in solution was reduced and the sample biodegradability index was increased.
Factors affecting population of filamentous bacteria in wastewater treatment plants with nutrients removal
Authors: Miłobędzka Aleksandra , Witeska Anna , Muszyński Adam
Published: February 2016

Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them – bulking and foaming of activated sludge.
Dynamic control of nutrient-removal from industrial wastewater in a sequencing batch reactor, using common and low-cost online sensors
Authors: Dries Jan
Published: February 2016

On-line control of the biological treatment process is an innovative tool to cope with variable concentrations of chemical oxygen demand and nutrients in industrial wastewater. In the present study we implemented a simple dynamic control strategy for nutrient-removal in a sequencing batch reactor (SBR) treating variable tank truck cleaning wastewater. The control system was based on derived signals from two low-cost and robust sensors that are very common in activated sludge plants, i.e. oxidation reduction potential (ORP) and dissolved oxygen. The amount of wastewater fed during anoxic filling phases, and the number of filling phases in the SBR cycle, were determined by the appearance of the ‘nitrate knee’ in the profile of the ORP. The phase length of the subsequent aerobic phases was controlled by the oxygen uptake rate measured online in the reactor. As a result, the sludge loading rate (F/M ratio), the volume exchange rate and the SBR cycle length adapted dynamically to the activity of the activated sludge and the actual characteristics of the wastewater, without affecting the final effluent quality.
Removal of 4-nitrophenol from aqueous solution by adsorption onto activated carbon prepared from Acacia glauca sawdust
Authors: Dhorabe Prashant T. , Lataye Dilip H. , Ingole Ramakant S.
Published: February 2016

The present paper deals with a complete batch adsorption study of 4-nitrophenol (4NP) from aqueous solution onto activated carbon prepared from Acacia glauca sawdust (AGAC). The surface area of the adsorbent determined by methylene blue method is found to be 311.20 m2/g. The optimum dose of adsorbent was found to be 2 g/l with 4NP uptake of 25.93 mg/g. The equilibrium time was found to be 30 minutes with the percentage removal of 96.40 at the initial concentration of 50 ppm. The maximum removal of 98.94% was found to be at pH of 6. The equilibrium and kinetic study revealed that the Radke–Prausnitz isotherm and pseudo second order kinetics model fitted the respective data well. In the thermodynamic study, the negative value of Gibbs free energy change (−26.38 kJ/mol at 30°C) and enthalpy change (−6.12 kJ/mol) showed the spontaneous and exothermic nature of the adsorption process.
The highest inhibition coefficient of phenol biodegradation using an acclimated mixed culture
Authors: Mohseni Mojtaba , Sharifi Abdar Payman , Borghei S. Mehdi
Published: February 2016

In this study a membrane biological reactor (MBR) was operated at 25 ± 1 °C and pH = 7.5 ± 0.5 to treat synthetic wastewater containing high phenol concentrations. Removal efficiencies of phenol and chemical oxygen demand (COD) were evaluated at four various hydraulic retention times (HRTs) of 24, 12, 8, and 4 hours. The removal rate of phenol (5.51 kg-Phenol kg-VSS−1 d−1), observed at HRT of 4 h, was the highest phenol degradation rate in the literature. According to COD tests, there were no significant organic matter in the effluent, and phenol was degraded completely by mixed culture. Substrate inhibition was calculated from experimental growth parameters using the Haldane, Yano, and Edward equations. The results show that the Haldane equation is fitted to the experimental data in an excellent manner. Kinetic parameters were derived by nonlinear regression with a correlation coefficient (R2) of 0.974. The values for Haldane constants μmax, Ks, and Ki were 0.3085 h−1, 416 mg L−1 and 1,886 mg L−1, respectively. The Ki value is the highest value obtained for mixed cultures degrading phenol under batch conditions.
Treatment of hydraulic fracturing wastewater by wet air oxidation
Authors: Wang Wei , Yan Xiuyi , Zhou Jinghui , Ma Jiuli
Published: February 2016

Wastewater produced by hydraulic fracturing for oil and gas production is characterized by high salinity and high chemical oxygen demand (COD). We applied a combination of flocculation and wet air oxidation technology to optimize the reduction of COD in the treatment of hydraulic fracturing wastewater. The experiments used different values of flocculant, coagulant, and oxidizing agent added to the wastewater, as well as different reaction times and treatment temperatures. The use of flocculants for the pretreatment of fracturing wastewater was shown to improve treatment efficiency. The addition of 500 mg/L of polyaluminum chloride (PAC) and 20 mg/L of anionic polyacrylamide (APAM) during pretreatment resulted in a COD removal ratio of 8.2% and reduced the suspended solid concentration of fracturing wastewater to 150 mg/L. For a solution of pretreated fracturing wastewater with 12 mL of added H2O2, the COD was reduced to 104 mg/L when reacted at 300 °C for 75 min, and reduced to 127 mg/L when reacted at the same temperature for 45 min while using a 1 L autoclave. An optimal combination of these parameters produced treated wastewater that met the GB 8978-1996 ‘Integrated Wastewater Discharge Standard’ level I emission standard.
The kinetics for ammonium and nitrite oxidation under the effect of hydroxylamine
Authors: Wan Xinyu , Xiao Pengying , Zhang Daijun , Lu Peili , Yao Zongbao , He Qiang
Published: February 2016

The kinetics for ammonium (NH4+) oxidation and nitrite (NO2−) oxidation under the effect of hydroxylamine (NH2OH) were studied by respirometry using the nitrifying sludge from a laboratory-scale sequencing batch reactor. Modified models were used to estimate kinetics parameters of ammonia and nitrite oxidation under the effect of hydroxylamine. An inhibition effect of hydroxylamine on the ammonia oxidation was observed under different hydroxylamine concentration levels. The self-inhibition coefficient of hydroxylamine oxidation and noncompetitive inhibition coefficient of hydroxylamine for nitrite oxidation was estimated by simulating exogenous oxygen-uptake rate profiles, respectively. The inhibitive effect of NH2OH on nitrite-oxidizing bacteria was stronger than on ammonia-oxidizing bacteria. This work could provide fundamental data for the kinetic investigation of the nitrification process.
High strength distillery wastewater treatment by a PAC-MBR with low PAC dosage
Authors: Basu Subhankar , Kaushik Ankita , Saranya P. , Batra Vidya S. , Balakrishnan Malini
Published: February 2016

Augmentation of membrane bioreactors (MBRs) with activated carbon is established to offer several operational advantages. This work investigates the influence of low dosing (2 g/L) of powdered activated carbons (PACs) with different characteristics on the performance of MBR treating high strength molasses distillery wastewater containing difficult-to-biodegrade recalcitrant components. Two MBRs, augmented with different PACs, were operated in parallel over a period of 240 days and their performance monitored in terms of biomass growth, reduction in chemical oxygen demand (COD), sludge properties like extracellular polymeric substances content, filterability, and morphology. Removal of organics and coloring matter by adsorption, biodegradation and membrane filtration was estimated. Although adsorptive removal of color and COD is influenced by the properties of the PAC used, the performance of the PAC-MBRs was independent of PAC properties. Both PACs preferentially adsorbed the low molecular weight components in distillery wastewater. Retention by the membrane filter with the secondary cake layer contributed to reduction in color and COD of treated effluent. The findings indicate that low dosing with PAC adsorbing low molecular weight organics has a limited role in PAC-MBR treating distillery wastewater.