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Omaha, NE, United States

von Stackelberg N.O.,Environmental Engineer | Neilson B.T.,Utah State University
Journal of Water Resources Planning and Management | Year: 2014

Stakeholder involvement in watershed management decisions remains challenging, particularly when one is relying upon modeling efforts as one of the primary means to understand and communicate the complicated processes controlling a natural riverine system. To determine how to meet the instream water quality standards as required by the total maximum daily load (TMDL) program, a QUAL2Kw water quality model was developed and calibrated for the Jordan River, Utah. To improve transparency, increase stakeholder engagement, and reach agreement more effectively, a collaborative approach was taken to calibrate the model that included Utah Division of Water Quality (UDWQ) staff, consultants, key stakeholder representatives, and independent experts. The study reach of the Jordan River flows 83 km from Utah Lake to the Great Salt Lake through the urbanized Salt Lake Valley in Utah. Several segments of the river have been listed by UDWQ as impaired for a number of constituents, but the present effort focuses on the dissolved oxygen (DO) impairment. In cooperation with stakeholder groups, four seasonal synoptic sampling surveys and additional research studies were conducted for use in calibrating and validating the model. The collaborative calibration process involved many meetings and workshops where model performance was iteratively evaluated in order to reach consensus on model inputs and parameterization. The end result of the collaborative calibration of the QUAL2Kw model was the development of a scientifically defensible tool used to establish a consensus that decomposition of organic matter and poor reaeration are the primary causes of the DO impairment in the Jordan River. Without the collaborative approach to calibration, agreement regarding the causes of water quality impairments would not likely have occurred. While clearly improving stakeholder believability in the model, a comparison of the collaborative calibration model performance to an autocalibrated version demonstrated that both approaches resulted in similar predictive accuracy. © 2014 American Society of Civil Engineers. Source


Stewart B.A.,Tetra Tech Inc. | New C.W.,Environmental Engineer | Hosni A.A.,Water Science Technologies | Dvorak B.I.,University of Nebraska - Lincoln
Journal of Environmental Engineering (United States) | Year: 2013

This study evaluated the system performance in terms of sorbent usage rate (SUR) of single column, two-column parallel, and lead-lag configurations, both with and without bypass blending, based on two normalized parameters describing the breakthrough profile (mass transfer zone length to lag ratio, or MTZ:Lag) and treatment objective (C/Co). The pore surface diffusion model was used to simulate a range of single compound scenarios to develop a framework for comparing configurations. From this analysis, regions on a MTZ:Lag versus C/Co plot could be identified in which particular configurations yielded the lowest system SUR. At low MTZ:Lag ratios, bypass blending (single column or lead-lag operation) offered significant improvements because of the ability to bypass untreated flow and reduce sorbent bed mass. However, at low target C/Co values, bypass offered little improvement. Lead-lag without bypass performed best at high MTZ:Lag ratios by passing the mass transfer zone through two columns in series. At high MTZ:Lag ratios and high target C/Co values, two-column parallel configurations yielded significant benefits by blending high and low concentration effluents and improving sorbent utilization. © 2013 American Society of Civil Engineers. Source


Mujiburrehman K.,Environmental Engineer
Water and Energy International | Year: 2014

The advent of satellite-based elevation dataset acquired by Shuttle Radar Topography Mission (SRTM) made new and novel techniques possible to model hydrological process in midsize to large scale watersheds. This application is important in regions with poor photogrammetric coverage and land use in appropriate scale like Mumbai. Watershed parameters include slope, area, perimeters and mean elevation are derived from SRTM dataset. SRTM-DEM (digital elevation model) can be used for extracting watershed parameters with a reasonable degree of accuracy. In this study, drainage analysis will be performed on a terrain model for Mumbai area draining into Mithi River. The Arc Hydro tool and HecGeoHMS extension into ArcMap 10.1 are used to derive several data sets that collectivity describe the drainage patterns of the Mithi River catchment. Raster analysis is performed to generate data on flow direction, flow accumulation, stream definition, stream segmentation, and watershed delineation. These data are then used to develop a vector representation of catchments and drainage lines from selected points. The utility of Arc Hydro tools is used to develop attributes that can be useful in hydrologic modeling. The main data is the DEM with 3 arcs second to get as much accurate results as could. The obtained catchment of Mithi River is verified with Google earth. The obtained river and its tributaries are found to be matching with Google earth. © 2014, Central Board of Irrigation and Power. All rights reserved. Source


Guner Y.,Environmental Engineer | Kayhan F.E.,Marmara University | Balkis N.,Istanbul University | Aksu A.,Istanbul University | Kaymak G.,Sakarya University
Pakistan Journal of Zoology | Year: 2016

The aim of this study was to determe cadmium and lead concentrations in the whole soft tissue of the black mussels (Mytilus galloprovincialis Lamarck, 1819) (n=60) caught from Pendik district coasts of Istanbul, Turkey. According to legal standards of Turkish Food Codex (TFC) and United Nations Environment Programme (UNEP) standards the level of Cd was low white that of Pb was high. The highest Pb concentration found in the whole soft tissue of mussels at S4 was 8.66 (February), 6.64 (January), 4.72 ppm Pb (July 2011) whereas in S5 it is 8.66 (November), 8.14 (February), 6.64 (October), 4.57 ppm (June 2012). Copyright 2016 Zoological Society of Pakistan. Source


McAllister C.D.,Southeast Missouri State University | Ortiz A.Y.,Southeast Missouri State University | Southards T.J.,Environmental Engineer
Proceedings of the Institution of Civil Engineers: Water Management | Year: 2015

This study examines the ability of in-service domestic wastewater treatment facilities, as opposed to controllable laboratory experiments, to remove ammonia utilising recirculating sand filters (RSFs). Permitted facilities in Missouri, USA, are required to regularly sample, analyse and report discharged water quality. The Missouri Department of Natural Resources stores the results in a central database, which was queried and analysed to assess the performance of these facilities in both the summer and winter seasons and to determine if a correlation exists between ammonia removal and flow capacity. The RSFs were found to discharge ammonia under 44 mg/l 95% of the time in winter and under 30 mg/l in summer. No correlation between performance and flow was found. The results of the study suggest that RSF technology is presently unable to treat ammonia in domestic wastewater to meet acceptable water quality standards for surface discharge. ©.ICE Publishing: All rights reserved. Source

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