R. Ryan Dupont

An in situ instrumentation bundle was designed for inclusion in monitoring wells that were installed at the Wasatch Trailer Sales site in Layton, Utah, to evaluate in situ air sparging (IAS) and in-well aeration (IWA). Sensors for the bundle were selected based on laboratory evaluation of accuracy and precision, as well as consideration of size and cost. SenSym pressure transducers, Campbell Scientific, Inc. (CSI) T-type thermocouples, and dissolved oxygen (DO) probes manufactured by Technalithics Inc. (Waco, Texas), were selected for each of the 27 saturated zone bundles. Each saturated zone bundle also included a stirring blade to mix water near the DO probe. A Figaro oxygen sensor was included in the vadose zone bundle. The monitoring wells were installed by direct push technique to minimize soil disruption and to ensure intimate contact between the 18 inch (46 cm) long screens and the soil. A data acquisition system, comprised of a CSI 21X data logger and four CSI AM416 multiplexers, was used to control the stirring blades and record signals from more than 70 in situ sensors. The instrumentation performed well during evaluation of IAS and IWA at the site. However, the SenSym pressure transducers were not adequately temperature compensated and will need to be replaced.

Grease, oil, hydrocarbon residues, heavy metals, and surfactants are all present in car wash wastewater (CWW), which all can have detrimental effects on the environment and human health. This study was designed to assess CWW treatment using an upgraded physical technique combined with a range of conventional and more sustainable coagulants. Physical treatment effectively lowered the oil and grease (O&G) and chemical oxygen demand (COD) of the CWW by 79 ± 15% and 97 ± 1.6%, respectively. Additional treatment was provided using chemical coagulation–flocculation–settling. In jar test studies, humic acid (HA) and alum were found to provide significantly higher turbidity removal, 79.2 ± 3.1% and 69.8 ± 8.0%, respectively, than anionic polyacrylamide (APA), 7.9 ± 5.6% under influent turbidity values from 89 to 1000 NTU. Overall physical/chemical treatment of CWW yielded 97.3 ± 0.8% COD removal, and 99.2 ± 0.4% O&G removal using HA and alum. Due to the numerous problems created when using ...

Egypt's ability to fulfill present and forecast water demands must be improved urgently. The Nile River feeds Egypt's industrial and agricultural sectors with 55.5 cubic kilometers of fresh water every year and drinking water for the inhabitants. It provides 95 percent of the country's accessible water, 85 percent of it used for agricultural purposes. Most Egyptian water program graduates lack the necessary skills to meet Egypt's present and future water needs despite this urgent necessity. To adequately serve the stakeholders of the water industry in Egypt, water programs must evolve. Universities should look not only at what is being taught but also at how it is being taught. To address this, and as part of the United States Agency for International Development funded “Center of Excellence in Water,” the most demanded skills required by industry were solicited so that curriculum revisions and delivery methods can be implemented to prepare students with these necessary skills. This paper presents the results of a survey to solicit non-academic professionals’ expectations for water graduates in Egypt. Data were collected from 48 water professionals and resource management specialists. To prepare a water graduate valued by industry, the water curriculum should be modified to deliver the skills necessary to meet the demands of the Egyptian water sector. The survey results may have applications for water science and engineering worldwide.

Results of a five-year research study on natural attenuation processes in a wetland, located downgradient of a sour gas processing plant in central Alberta, Canada, show that natural attenuation may present a favourable remedial solution. Both free-phase and dissolved phase condensate have been discharging to the wetland since 1984. This condensate is primarily composed of C5 to C12 hydrocarbons, including BTEX compounds. The condensate enters the base of the wetland at 1 m below ground surface, resulting in contamination of the wetland peat and underlying clay till. The lateral extent of contamination in the wetland has remained stable, and apparent free product thickness and BTEX concentrations have decreased over time. Sorption, aerobic biodegradation, volatilization, and anaerobic biodegradation were identified as active attenuation processes at this site. Sorption and desorption processes were evaluated by laboratory testing of site soils using 14C-benzene. Linear sorption coefficients (Kd) for the surface and subsurface peat were similar (4.48-4.62 l/kg), while the Kd for the underlying silt was 0.096 l/kg. The significantly higher Kd values for the peat are attributed to the peat's higher organic content (40%), relative to the clayey silt (1%). No significant resistance to desorption was observed, however, indicating that benzene would remain mobile and bioavailable over time. Aerobic biodegradation and volatilization appear to be the main removal processes. They are enhanced by a seasonal drop in the water level from surface down to 1 m depth, resulting in an aerobic unsaturated zone. Respiration testing in the peat indicates a significant aerobic biodegradation rate of 27 mg/kg/day, equating to an estimated hydrocarbon removal rate of 5 kg/day across the 3600 m2 plume area. Surface vapour measurements indicate hydrocarbon volatilization is occurring at a rate of 3 x 10(-4) kg/m2/day, equating to a mass removal of 1 kg/day across the plume. Anaerobic biodegradation is occurring primarily in the clayey silt, based on geochemical indicator parameters, microbial analyses, and soil vapour sampling. Overall, natural attenuation appears to be a feasible remedial solution for this wetland, by providing continued removal and degradation of condensate components before they reach the downgradient surface water receptor.

ABSTRACT: Plants are known to take up pollutants from water and soil. The metal concentration of stormwater runoff is relatively low compared to industrial waste and mine tailings, however, continual runoff accumulation in constructed wetland (CW) and bioretentioin (BR) system soils is expected to result in soil metal levels that may become human health concerns in the foreseeable future. Davis et al. (2003) used nationally averaged stormwater metal concentrations, and estimated that continual pollutant accumulation from runoff will exceed EPA regulatory limits for soil contamination after 15-20 years of deposition. Research focusing on the phytoextraction potential of plants at these low-level contamination conditions is vital to slow and potentially prevent metal accumulation, and the resulting creation of hazardous sites. Two studies in Cache Valley, Utah quantified differences in biomass production and uptake of copper (Cu), zinc (Zn), and lead (Pb) from stormwater runoff by pla...