Civil Engineering
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The Department of Civil Engineering has strong affiliation with the Western Transportation Institute (WTI) and the Center for Biofilm Engineering (CBE), a graduated NSF research center. The department is also affiliated with a Montana Department of Transportation Design Unit located on the MSU campus.
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Item Pharmaceutical impacts on aerobic granular sludge morphology and potential implications for abiotic removal(Elsevier, 2024-02) Bodle, Kylie B.; Kirkland, Catherine M.The goal of this study was to investigate abiotic pharmaceutical removal and abiotic pharmaceutical effects on aerobic granular sludge morphology. For 80 days, a pharmaceutical mixture containing approximately 150 μg/L each of diclofenac, erythromycin, and gemfibrozil was fed to an aerobic granular sludge sequencing batch reactor and granule characteristics were compared with those from a control reactor. Aqueous and solid phase pharmaceutical concentrations were monitored and staining was used to assess changes in biofilm structures. Solid phase pharmaceutical concentrations were elevated over the first 12 days of dosing; however, they then dropped, indicative of desorption. The lipid content in pharmaceutical-exposed granules declined by approximately half over the dosing period, though the relative concentrations of other key biofilm components (proteins, alpha-, and beta-polysaccharides) did not change. Batch experiments were conducted to try to find an explanation for the desorption observed, but reduced solid phase pharmaceutical concentrations could not be linked with the presence of common wastewater constituents such as ammonia or phosphate. Sorption of all three compounds was modeled best by the Henry isotherm, indicating that, even at 150 μg/L, granules’ sorption site coverage was incomplete. Altogether, this study demonstrates that simplified batch systems may not accurately represent the complex abiotic processes occurring in flow-through, biotic systems.Item Treatment performance and microbial community structure in an aerobic granular sludge sequencing batch reactor amended with diclofenac, erythromycin, and gemfibrozil(Frontiers Media SA, 2023-09) Bodle, Kylie B.; Mueller, Rebecca C.; Pernat, Madeline R.; Kirkland, Catherine M.This study characterizes the effects of three commonly detected pharmaceuticals—diclofenac, erythromycin, and gemfibrozil—on aerobic granular sludge. Approximately 150 µg/L of each pharmaceutical was fed in the influent to a sequencing batch reactor for 80 days, and the performance of the test reactor was compared with that of a control reactor. Wastewater treatment efficacy in the test reactor dropped by approximately 30-40%, and ammonia oxidation was particularly inhibited. The relative abundance of active Rhodocyclaceae, Nitrosomonadaceae, and Nitrospiraceae families declined throughout exposure, likely explaining reductions in wastewater treatment performance. Pharmaceuticals were temporarily removed in the first 12 days of the test via both sorption and degradation; both removal processes declined sharply thereafter. This study demonstrates that aerobic granular sludge may successfully remove pharmaceuticals in the short term, but long-term tests are necessary to confirm if pharmaceutical removal is sustainable.Item Flow-Control Plates to Manage Denil Fishways in Irrigation Diversions for Upstream Passage of Arctic Grayling(U.S. Fish and Wildlife Service, 2023-06) Plymesser, Kathryn; Blue, Tyler; Kappenman, Kevin M.; Blank, Matthew; Cahoon, Joel; Dockery, DavidSmall-stream irrigation diversions are key elements of many on-farm irrigation systems but can act as barriers to aquatic species. Denil fishways have been installed at irrigation diversion structures throughout the Big Hole River watershed in Montana to provide upstream passage for a population of Arctic Grayling Thymallus arcticus. When stream flows are low and irrigation demand is high, irrigators look for ways to maintain adequate diversion, but doing so may reduce the effectiveness of the fishways. In response, agencies and irrigators have proposed flow-control plates placed at the upstream end of fishways. We conducted laboratory-based fishway efficiency experiments with Arctic Grayling placed in an open-channel flume fitted with a Denil fishway and three flow plates. Of the total 200 fish that we used, the fishway entrance attracted 154 fish and we counted these fish as participants. We operated the fishway under varying flow conditions using three flow-control plate treatments and a control to investigate 1) the extent to which each treatment reduced flow compared to the control, and 2) the extent to which each treatment impacted passage success of Arctic Grayling relative to the control. We measured passage success as the ratio of the number of fish that fully ascended the fishway treatment to the number of participant fish attracted to the fishway treatment. One of the three plates, the Denil slot treatment, showed no evidence of reducing either flow or passage success. Another plate, the standard treatment, showed no evidence of reducing flow but moderate evidence of reducing passage success (P = 0.03). The only treatment to significantly reduce water flow rate was the narrowed Denil slot treatment and there was no evidence this treatment reduced passage in comparison to the control. Over all trials, water flow rate through the Denil fishway had a strong positive influence on fish passage success.Item Impact of deicing salts on pervious concrete pavement(Frontiers Media SA, 2023-06) Feng, Lichao; Zhang, Yongran; Wang, Xiaowei; Mery, Stephene; Akin, Michelle; Li, Mengchao; Xie, Ning; Li, Zhenming; Shi, XianmingTwo pervious concrete projects (named as SR28 and SR431), with the same mixture design but different winter maintenance activities, were included in this research. Both projects are located in the Lake Tahoe area, Nevada, United States. Testing results indicated that the mechanical properties were significantly higher in SR28 cored samples than the ones in SR431. It was found that the SR28 pieces have fewer air voids, while the SR431 samples have higher water absorption and hydraulic conductivity, and the SR28 samples show fare better performance against repeated freezing and thawing cycles than the SR431 ones. scanning electron microscope pictures of crack surfaces in cores taken from SR28 indicate that the cement binder phase has been largely retained. However, in the coring sample of SR431, needle-shaped residues can be seen within the cement binder phase and an abundance of precipitated micro-sized crystalized particles can be observed. On a micrometer scale, the μCT examination reveals that the porosity of SR28 samples is significantly less than that of SR431. The analyzing results give a clue to demonstrate the durability of pervious concrete pavement can be attributed to the construction quality control, maintenance activity, or the weather and locations of the field sites.Item High-Level Assessment ofStatewide GNSS-RTN Business Models(2023-06) Al-Kaisy, Ahmed; Raza, SajidThe applications of geospatial technologies and positioning data embrace every sphere of modern-day science and industry where geographical positioning matters. Among all other fields, geospatial technology plays a remarkable role in the transportation sector and has the potential to play an even more critical role in future autonomous transportation systems. In this regard, the GNSS-Real-Time Network (GNSS-RTN) technology is promising in meeting the needs of automation in most advanced transportation applications. The GNSS-RTN is a satellite-based positioning system that uses a network of reference stations to provide centimeter-level accuracy in positioning data in real-time. The technical aspect and working technology of GNSS-RTN are widely studied, however, only limited research has been conducted on the various GNSS-RTN business models currently in use nationally and internationally. Therefore, this study aims at assessing the various GNSS-RTN business models currently used in practice as well as those that are deemed potentially viable but have not yet moved to practice. Eight different business models were cataloged and used in the current assessment. All business models were assessed using three criteria: state control, sustainability, and state/agency costs. The findings of this research are important in helping state agencies make informed decisions as they build, expand or manage their own GNSS-RTN systems.Item Pharmaceutical Sorption to Lab Materials May Overestimate Rates of Removal in Lab-Scale Bioreactors(Springer Science and Business Media LLC, 2022-11) Bodle, Kylie B.; Pernat, Madeline R.; Kirkland, Catherine M.Environmental contamination from pharmaceuticals has received increased attention from researchers in the past 20 years. As such, numerous lab-scale studies have sought to characterize the effects of these contaminants on various targets, as well as determine improved removal methods. Many studies have used lab-scale bioreactors to investigate pharmaceutical effects on wastewater bacteria, as wastewater treatment plants often act as reservoirs for pharmaceuticals. However, few—if any—of these studies report the specific lab materials used during testing, such as tubing or pipette tip type. In this study, the pharmaceuticals erythromycin, diclofenac, and gemfibrozil were exposed to different micropipette tips, syringe filters, and tubing types, and losses over time were evaluated. Losses to tubing and syringe filters were particularly significant and neared 100%, depending on the pharmaceutical compound and length of exposure time. Results discussed herein indicate that pharmaceutical sorption to various lab supplies results in decreases to both dosed and quantified pharmaceutical concentrations. Studies that fail to consider this source of loss may therefore draw inaccurate conclusions about pharmaceutical effects or removal efficiencies.Item Mapping liquid water content in snow at the millimeter scale: an intercomparison of mixed-phase optical property models using hyperspectral imaging and in situ measurements(Copernicus Publications, 2022-01) Donahue, Christopher; Skiles, S. McKenzie; Hammonds, KevinIt is well understood that the distribution and quantity of liquid water in snow is relevant for snow hydrology and avalanche forecasting, yet detecting and quantifying liquid water in snow remains a challenge from the micro- to the macro-scale. Using near-infrared (NIR) spectral reflectance measurements, previous case studies have demonstrated the capability to retrieve surface liquid water content (LWC) of wet snow by leveraging shifts in the complex refractive index between ice and water. However, different models to represent mixed-phase optical properties have been proposed, including (1) internally mixed ice and water spheres, (2) internally mixed water-coated ice spheres, and (3) externally mixed interstitial ice and water spheres. Here, from within a controlled laboratory environment, we determined the optimal mixed-phase optical property model for simulating wet snow reflectance using a combination of NIR hyperspectral imaging, radiative transfer simulations (Discrete Ordinate Radiative Transfer model, DISORT), and an independent dielectric LWC measurement (SLF Snow Sensor). Maps of LWC were produced by finding the lowest residual between measured reflectance and simulated reflectance in spectral libraries, generated for each model with varying LWC and grain size, and assessed against the in situ LWC sensor. Our results show that the externally mixed model performed the best, retrieving LWC with an uncertainty of ∼1 %, while the simultaneously retrieved grain size better represented wet snow relative to the established scaled band area method. Furthermore, the LWC retrieval method was demonstrated in the field by imaging a snowpit sidewall during melt conditions and mapping LWC distribution in unprecedented detail, allowing for visualization of pooling water and flow features.Item Reanalysis of Polythermal Glacier Thermal Structure Using Radar Diffraction Focusing(American Geophysical Union, 2022-01) Delf, Richard; Bingham, Robert G.; Curtis, Andrew; Singh, Satyan; Giannopoulos, Antonios; Schwarz, Benjamin; Borstad, Chris P.Ground-penetrating radar (GPR) is widely used on polythermal glaciers to image bed topography and detect internal scatter due to water inclusions in temperate ice. The glaciological importance of this is twofold: bed topography is a primary component for modeling the long-term evolution of glaciers and ice sheets, and the presence of temperate ice and associated englacial water significantly reduces overall ice viscosity. Englacial water has a direct influence on radar velocity, which can result in incorrect observations of bed topography due to errors in depth conversion. Assessment of radar velocities often requires multi-offset surveys, yet these are logistically challenging and time consuming to acquire, hence techniques to extract velocity from common-offset data are required. We calculate englacial radar velocity from common offset GPR data collected on Von Postbreen, a polythermal glacier in Svalbard. We first separate and enhance the diffracted wavefield by systematically assessing data coherence. We then use the focusing metric of negative entropy to deduce a migration velocity field and produce a velocity model which varies spatially across the glacier. We show that this velocity field successfully differentiates between areas of cold and temperate ice and can detect lateral variations in radar velocity close to the glacier bed. This velocity field results in consistently lower ice depths relative to those derived from a commonly assumed constant velocity, with an average difference of 4.9 ± 2.5% of local ice depth. This indicates that diffraction focusing and velocity estimation are crucial in retrieving correct bed topography in the presence of temperate ice.