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  • 1
    Publication Date: 2018-09-24
    Description: Water, Vol. 10, Pages 1315: Developing an EFDC and Numerical Source-Apportionment Model for Nitrogen and Phosphorus Contribution Analysis in a Lake Basin Water doi: 10.3390/w10101315 Authors: Hui Bai Yan Chen Dong Wang Rui Zou Huanzhen Zhang Rui Ye Wenjing Ma Yunhai Sun The numerical source-apportionment model is an efficient and useful method for analyzing water-quality responses to nutrient loading in rivers and lakes. In this study, the Environmental Fluid Dynamic Code (EFDC) and numerical source-apportionment model were applied to Lake Bali in Jiujiang City, China to predict the contributions of various pollution sources to the lake at any time and position. We calibrated and validated the model by comparing its predictions with observed hydrodynamic and water-quality parameters from 2014 to 2015. Application of the calibrated model to simulate water-quality responses to a pollution source showed that the contribution of a pollution source to water quality in the lake has strong spatial heterogeneity. The results provide useful information for the optimization of pollution load reduction in Lake Bali and can be used to determine the most effective implementation of its pollution-control plan. The model built in this study can also be used for pollution source-apportionment in other urban lakes and is superior to other traditional source-apportionment models.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 2
    Publication Date: 2018-09-24
    Description: Water, Vol. 10, Pages 1316: Greener Method for the Removal of Toxic Metal Ions from the Wastewater by Application of Agricultural Waste as an Adsorbent Water doi: 10.3390/w10101316 Authors: Rabia Baby Shaikh Bullo Saifullah Fawad ur Rehman Ruqia Iqbal Shaikh The presence of inorganic pollutants such as metal ions (Ni2+, Pb2+, Cr6+) in water, probably by long-term geochemical changes and from the effluents of various industries, causes diseases and disorders (e.g., cancer, neurodegenerative diseases, muscular dystrophy, hepatitis, and multiple sclerosis). Conventional methods for their removal are limited by technical and economic barriers. In biosorption, low-cost and efficient biomaterials are used for this purpose. In this study, Brassica Campestris stems from the agriculture waste and has been used for the removal of Ni2+, Cr6+ and Pb2+ ions from an aqueous solution containing all the ions. Effect of different parameters, e.g., pH, contact time, metal ion initial concentration, adsorbent dose, agitation rate and temperature were analyzed and optimized. The adsorbent worked well for removal of the Pb2+ and Cr6+ as compared to Ni2+. The atomic absorption spectrophotometer (AAS) and FTIR investigation of adsorbent before and after shows a clear difference in the adsorbent capability. The highest adsorption percentage was found at 98%, 91%, and 49% respectively, under the optimized parameters. Furthermore, the Langmuir isotherm was found better in fitting to the experimental data than that of the Freundlich isotherm.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 3
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1314: Analysis of Soil Erosion Induced by Heavy Rainfall: A Case Study from the NE Abruzzo Hills Area in Central Italy Water doi: 10.3390/w10101314 Authors: Tommaso Piacentini Alberto Galli Vincenzo Marsala Enrico Miccadei Soil erosion induced by heavy rainfall deeply affects landscape changes and human activities. It depends on rainfall distribution (e.g., intensity, duration, cumulative per event) and is controlled by the interactions between lithology, orography, hydrography, land use, and vegetation. The Abruzzo piedmont coastal hilly area has been affected by several heavy rainfall events in the last decades. In this work, we investigated three ~1-day heavy rainfall (>35 mm/h and 100–220 mm/day) events in 2007, 2011, and 2012 that occurred in the clayey hilly coastal NE Abruzzo area, analyzing cumulative rainfall, intensity, and duration while mapping triggered geomorphological effects (soil erosion and accumulation) and evaluating average erosion. The analysis provides contributions to a soil erosion assessment of clayey landscapes that characterizes the Adriatic hilly area, with an estimation of rainfall-triggering thresholds for heavy soil erosion and a comparison of erosion in single events with rates known in the Mediterranean area. The triggering threshold for heavy soil erosion shows an expected value of ~100–110 mm. The estimated average soil erosion is from moderate to high (0.08–3.08 cm in ~1-day heavy rainfall events) and shows a good correlation with cumulative rainfall and a poor correlation with peak rainfall intensity. This work outlines the strong impact of soil erosion on the landscape changes in the Abruzzo and Adriatic hilly areas.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 4
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1313: Modified U-Tube for Ruling out Naked DNA Transfer during Conjugation and Application in Antibiotic Resistance Genes Transfer Research Water doi: 10.3390/w10101313 Authors: Ning Zhang Xiang Liu Bing Li Limei Han Xuejiao Ma Fanbin Meng Miao Li Antibiotic resistance is currently a major global public health issue. In particular, the emergence and transfer of antibiotic resistance genes (ARGs) is a matter of primary concern. This study presented a method for ruling out the transfer of naked DNA (plasmid RP4 lysed from donor cells) during the cell-to-cell conjugation, using a modified “U-tube”. A series of gene transfer assays was conducted in both flask and modified U-tube, using Pseudomonas putida KT2440 (P. putida (RP4)) harboring the RP4 plasmid as the donor strain, Escherichia coli (E. coli, ATCC 25922) in pure culture as sole recipient, and bacteria from reclaimed water microcosms as multi-recipients. The verification experiments showed that the U-tube device could prevent direct contact of bacteria without affecting the exchange of free plasmid. In the experiments involving a sole recipient, the transconjugants were obtained in flask samples, but not in modified U-tube. Furthermore, in experiments involving multi-recipients, transfer of naked DNA in the modified U-tube accounted for 5.18% in the transfer frequency of the flask transfer experiment. The modified U-tube proved to be useful for monitoring the interference of naked DNA in the research of conjugative transfer and calculating the exact conjugative transfer rate. This device is identified as a promising candidate for distinguishing different gene transfers in practical application because of its convenient use and easy and simple manufacture.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 5
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1312: Effectiveness of Contour Farming and Filter Strips on Ecosystem Services Water doi: 10.3390/w10101312 Authors: John Ng’ang’a Gathagu Khaldoon A. Mourad Joseph Sang The failing ecosystem services in Thika-Chania catchment is manifested in the deterioration of water quality, sedimentation of reservoirs, and subsequent increase in water treatment costs due to high turbidity. The services can be restored by implementing relevant soil and water conservation practices to enhance flow regulation and control sediment yield. The impacts of contour farming and filter strips on water and sediment yield were evaluated using Soil Water and Assessment Tool (SWAT), Texas A&M University, USA. Sediment calibration and validation was achieved using data obtained from a bathymetric survey. Model parameters were adjusted to simulate the conservation impacts of contour farming and filter strips. Results indicated the average annual sediment yield as 22 t/ha at the outlet of the catchment and average annual surface runoff of 202 mm. The simulation results showed that filter strips of 5 m width would reduce the average annual sediment yield from the catchment by 54%. The efficacy of filter strips in reducing sediment yield was observed to increase with increasing filter width. Three-meter filter strips and contour farming reduced the average annual sediment yield at catchment outlet by 46% and 36%, respectively. It was concluded that the implementation of contour farming and filters strips reduced sediments by 63% from the base value. Water yield at the sub-basin level was only influenced by contour farming. The total water yield at the catchment outlet experienced no significant change.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 6
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1310: Increasing Energy Efficiency in Water Collection Systems by Submersible PMSM Well Pumps Water doi: 10.3390/w10101310 Authors: Marcus Beck Alexander Sperlich Ricardo Blank Eckehard Meyer Ralf Binz Mathias Ernst Water collection based on groundwater abstraction has a high energy consumption that depends primarily on the operation and performance of submersible well pumps. The fact of the matter is that these machines still work with a global energy efficiency of less than 50%, and further investigations of the energy aspects in well pumps are needed. The present study introduces measures to increase the global efficiency of submersible well pumps linked to electrical energy savings. Common submersible pumps with asynchronous motors (ASMs) were compared with innovative permanent magnet synchronous motor (PMSM) technology in real well fields in Berlin and Hamburg waterworks. This study confirms that PMSM pumps showed a 6.8%-points higher global efficiency compared to ASM pumps at optimal working points. The investigation of the impact of well field operation on local pump efficiency offers an additional increase in the global efficiency. In this context, the influence of variable speed control on the global efficiency and the energy consumption was analyzed. Global efficiencies of over 70%, and potential energy savings of up to 20%, were determined for the speed-controlled PMSM pump. This offers water suppliers new incentives to optimize their water collection systems for less energy consumption.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 7
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1308: Impact of Uncertainty of Floodplain Digital Terrain Model on 1D Hydrodynamic Flow Calculation Water doi: 10.3390/w10101308 Authors: Adam Kiczko Dorota Mirosław-Świątek This study investigates the effect of the Digital Terrain Model (DTM) uncertainty effect on the output of a 1D flow model. The analysis is performed for the lowland river Biebrza, covered with dense wetland vegetation, with a high uncertainty of terrain elevations. The DTM uncertainty is modeled in two ways: (1) accounting for the uncertainty spatial dependency on the basis of the correlogram function and (2) neglecting the correlation of the elevation points. The model explanation of water levels improves when elevation uncertainty is being included. Without the elevation uncertainty, the model provided a good fit only for peak flows, with uncertainty also representation of lower flows is better. It was shown that the correlation of the elevation uncertainty had a noticeable effect on the modeling outcomes, especially for near bankfull flows, where for the uncorrelated case water levels were underestimated by 5 cm, comparing to the correlated case. The effect was also present for inundation extents, obtained by an interpolation of computed water levels. The correlation of the elevation uncertainty strongly affects estimates of standard deviations of computed water levels, which were almost twice smaller when correlation was neglected. In the result, only when the correlation of the elevation uncertainty was included, it was possible to obtain confidence bands that enclosed observation points.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 8
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1309: Performance of Earthworm-Enhanced Horizontal Sub-Surface Flow Filter and Constructed Wetland Water doi: 10.3390/w10101309 Authors: Rajendra Prasad Singh Dafang Fu Jing Jia Jiaguo Wu In this study, the performance of the horizontal sub-surface flow filter (HSSFF) and constructed wetland (HSSFCW) experimental units enhanced with earthworms was investigated for the treatment of construction camp sewage wastewater. All the experimental units (filter and constructed wetland) were filled with the same filler except Eisenia foetida earthworms and Lolium perenne Linn plants. The performance of the earthworm-enhanced filter (EEF) and the earthworm-enhanced constructed wetland (EECW) was compared to that of the blank filter (BF) units. The results revealed that the removal efficiencies for chemical oxygen demand (COD), NH4+-N, total nitrogen (TN) and total phosphorus (TP) in EEF were higher than the BF unit. In order to optimize the operating conditions, the experiments were conducted in three different water levels. The results revealed that the removal efficiencies of EEF for these pollutants are the highest in experimental conditions no. 2 (water level ~30 cm; HRT ~3 days; hydraulic load ~4.05 cm/day; and Inflow discharge ~0.27 L/h). Compared to the EEF and BF units, the EECW has higher removal efficiency for COD and TN and has more stable performance than the filters. This work will aid the design and improvement of filters and CWs for treatment of effluent wastewater from construction camps. The selection of appropriate hydraulic parameters and experimental conditions could be very beneficial in achieving the goal of implantation of low impact development (LID).
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 9
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1311: Season-Dependent Hedging Policies for Reservoir Operation—A Comparison Study Water doi: 10.3390/w10101311 Authors: Nikhil Bhatia Roshan Srivastav Kasthrirengan Srinivasan During periods of significant water shortage or when drought is impending, it is customary to implement some kind of water supply reduction measures with a view to prevent the occurrence of severe shortages (vulnerability) in the near future. In the case of operation of a water supply reservoir, this reduction of water supply is affected by hedging schemes or hedging policies. This research work aims to compare the popular hedging policies: (i) linear two-point hedging; (ii) modified two-point hedging; and, (iii) discrete hedging based on time-varying and constant hedging parameters. A parameterization-simulation-optimization (PSO) framework is employed for the selection of the parameters of the compromising hedging policies. The multi-objective evolutionary search-based technique (Non-dominated Sorting based Genetic Algorithm-II) was used to identify the Pareto-optimal front of hedging policies that seek to obtain the trade-off between shortage ratio and vulnerability. The case example used for illustration is the Hemavathy reservoir in Karnataka, India. It is observed that the Pareto-optimal front that was obtained from time-varying hedging policies show significant improvement in reservoir performance when compared to constant hedging policies. The variation in the monthly parameters of the time-variant hedging policies shows a strong correlation with monthly inflows and available water.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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  • 10
    Publication Date: 2018-09-23
    Description: Water, Vol. 10, Pages 1307: Removal of Nutrients, Sediment, and Heavy Metals by a Stormwater Treatment Train; a Medium-Density Residential Case Study in Southeast Queensland Water doi: 10.3390/w10101307 Authors: Darren Drapper Andy Hornbuckle Urban stormwater runoff from a medium-density residential development in southeast Queensland has been monitored in the field since November 2013. A treatment train installed on the site includes rainwater tanks collecting roofwater, 200-micron mesh baskets installed in grated gully pits, and two 850-mm-high media filtration cartridges installed in an underground 4-m3 vault. The site has been monitored over a 4.5-year period. Removal efficiencies were observed at this site for the regulated pollutants; the corresponding values for total suspended solids (TSS), total phosphorus (TP), and total nitrogen (TN) for the pit baskets were 61%, 28%, and 45%, respectively. The cartridge filters removed 78% of TSS, 59% of TP, 42% of TN, 40% of total copper, and 51% of total zinc. As the measured influent TSS and TP concentrations to the cartridge filters were low when compared to industry guidelines, the U.S. field dataset was truncated to anticipated guideline levels, confirming results at 90% for TSS and 76% for TP. The total gross pollutant generation rate from the medium-density residential catchment was observed to be 0.24 m3/Ha/year, with a corresponding air-dried mass of 142.5 kg/Ha/year. Less than 2% of the gross pollutant mass was anthropogenic. This paper concludes that the treatment train, and in particular the media filter, provides good removal of total copper and total zinc as well as TSS, TP, and TN from urban stormwater runoff, with higher inlet concentrations producing better performance. Field test data from 58 months of operation and standard maintenance suggests that breakthrough of TSS and TP has not occurred yet.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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