Widespread contamination of ground and surface water with nitrate (NO3-) and perchlorate (ClO4 -) has been recorded in many US states. Nitrate and perchlorate are soluble anions that are known to affect human health. This dissertation presents the results of three studies of biological reduction ClO4 - and NO3- using autotrophic bacteria. In the first study, hydrogenotrophic (H2 oxidizing) denitrifiers were inoculated into two hollow fiber membrane bioreactors (HFMB), which were set up in different configurations (I and II). In Configuration I, H 2 passed through the lumen of the fibers and nitrified water flowed through the shell. In Configuration II, liquid flowed through the lumen and H2 through the shell. Complete denitrification was achieved in both systems with pH and biomass control at hydraulic retention times (HRT) of 8.3 and 1.5 hours for configurations I and II, respectively. Influent dissolved oxygen (DO) did not inhibit denitrification. The second study investigated reduction of NO3- and ClO4- in ion exchange (IX) brines using halophilic-hydrogenotrophic bacteria in a HFMB (Configuration II). Continuous operation of the HFMB resulted in partial denitrification (30%) of the brines. Batch HFMB operation resulted in average removal efficiencies of 30% and 42% for NO3- and ClO4-, respectively. The third study investigated ClO4- reduction using Sulfur Utilizing Perchlorate Reducing Bacteria (SUPeRB). SUPeRB cultures reduced 5-20 mg/L ClO4- to < 0.5 mg/L at varying salinities (0-30 g/L NaCl). Perchlorate (8-0.01 mg/L) reduction was achieved in packed bed reactors (PBR) inoculated with SUPeRB and filled with S° pellets and crushed oyster shells at empty bed contact times of 8-13 hours for low and high ClO4- concentrations, respectively. Decreased ClO4- removal efficiency was observed at increased recirculation velocity and with small S0 particle sizes. Influent DO or NO3- did not inhibit overall ClO4- removal.

No description available.

<p> As reuse of municipal water resource recovery facility (WRRF) effluent becomes vital to augment diminishing fresh drinking water resources, concern exists that conventional barriers may prove deficient and the upcycling of contaminants of emerging concern (CECs) could prove harmful to human health and aquatic species if more effective and robust treatment barriers are not in place. </p><p> There are no federal Safe Drinking Water Act (SDWA) regulations in place specifically for direct potable reuse (DPR) of WRRF effluent. Out of necessity, some states are developing their own DPR reuse regulations. Currently, reverse osmosis (RO) is the default full advanced treatment (FAT) barrier for CEC control. However, the potential exists for tight thin-film composite (TFC) nanofiltration (NF) membranes to provide acceptable CEC rejection efficacies for less capital, operations and maintenance (O&amp;M), energy, and waste generated. </p><p> Recognizing the inherent complexity of CEC rejection by membranes, this research program was designed to elucidate the vital predictive variables influencing the rejection of 96 CECs found in municipal WRRF effluents. Each of the CECs was cataloged by their intended use and quantitative structure activity relationship (QSAR) properties, and measured in secondary effluent samples from WRRFs in Texas and Oklahoma. These secondary effluent samples were then processed in bench-scale, stirred, dead-end pressure cells with water treatment industry-specified TFC NF and RO membranes. </p><p> A multi-level, multi-variable model was developed to predict the probable rejection coefficients of CECs with the studied NF membrane. The model was developed from variables selected for their association with known membrane rejection mechanisms, CEC-specific QSAR properties, and characteristics of the actual solute matrix. R statistics software version 3.1.3 was utilized for property collinearity analysis, outlier analysis, and regression modeling. The Pearson correlation method was utilized for selection of the most vital predictor variables for modeling. The resulting Quantitative Molecular Properties Model (QMPM) predicted the NF rejection CECs based on size, ionic charge, and hydrophobicity. Furthermore, the QMPM was verified against a CEC rejection dataset published by an independent study for a similar commercially available TFC NF membrane.</p>

<p> Over the past decade, there has been a revival in algal research and attempts at large scale cultivation for bioenergy production. Among various types of microalgae culturing systems, Open Raceway Ponds (ORP) are considered as an economic system for large-scale microalgae cultivation. In order to improve the algal growth and productivities in ORPs, it is very important to understand the effects of design parameters and operating conditions on mixing and light distribution patterns. The goal of this dissertation was to develop computational tools and experimental techniques to assess key variables that affect algal growth and productivity, and to improve microalgal cultivation in ORPs. The effects of major parameters on growth, were investigated and the optimum C. vulgaris growth condition was determined at 52 W/m2, 24&deg;C, and pH of 7.4, using Response Surface Methodology. The C. vulgaris grown in swine wastewater with 102 mg/L nitrogen and 76 mg/L phosphorus at the optimum environmental condition achieved the average growth rate of 0.16 g/L/day, compared to 0.19 g/L/day for its growth in the modified Bold's medium with 100 mg/L nitrogen and 53 mg/L phosphorus, at the same condition. Results indicated that at NC weather conditions, C. vulgaris grown in swine wastewater in a pond with 0.3 m medium depth, can reach a biomass and lipid productivity of 80 and 20 tons/hectare/year, respectively, at the harvesting cell density of 0.1 g/L. However, the algal productivity decreased significantly with the increase of harvesting cell density. A specific growth rate model of C. vulgaris was generated as a function of light intensity, temperature and pH. A Computational Fluid Dynamics (CFD) model was developed to simulate the multiphase flow in ORPs to investigate the effects of operational conditions on biomass concentration and light intensity distribution. Operating large scale ORPs at 0.2 m/s inlet velocity resulted in a significant decrease in dead zone areas in comparison with 0.1 m/s. However, further increase in velocity to 0.3 m/s did not make significant changes. CFD models were then integrated with the growth kinetic model to simulate the dynamic growth of C. vulgaris in ORPs. The predicted algal growth and productivity well agreed with those measured values. The predicted average algal productivities for the 3-week cultivation of C. vulgaris in the lab-scale ORPs were 7.34, 7.4, and 7.46 g/m2/day for medium depths of 0.20, 0.25, and 0.30 m, respectively, which well agreed with the measured values of 6.78, 7.23 and 7.39 g/ m2/day for medium depths 0.20, 0.25, and 0.30 m, respectively. Simulations were conducted to study different harvesting methods. The average algal productivity for the 3-week cultivation in the ORP with 0.2 m depth by harvesting 50% algae at the target 0.2 g/L cell density was 10.5 g/m2/day, which was 54.7% higher than 6.78 g/ m2/day for the 3-week cultivation under the same condition without harvesting. The average algal productivity decreased with the increase of harvesting cell density.</p>

Thesis (Ph.D.)--Syracuse University, 2008. / "Publication number: AAT 3323075."

<p> Chemical and petrochemical industries produce substantial amounts of wastewater every day. This wastewater contains organic pollutants such as benzene, toluene, ethylbenzene and xylenes (BTEX) that are toxic to human and aquatic life. Ordered Mesoporous Carbon (OMC), an adsorbent that possesses the characteristics of an ideal adsorbent was investigated to understand its properties and suitability for BTEX removal. Adsorption isotherms, adsorption kinetics, the effects of BTEX initial concentrations, and temperatures on the adsorption process were studied. The OMCs were characterized using surface area and pore size analyzer, transmission electron microscopy (TEM), elemental analysis, thermogravimetric analysis (TGA), and fourier transform infrared spectroscopy (FTIR). The results suggested that the Langmuir isotherm and pseudo-second-order models described the experimental data. The thermodynamic parameters, Gibbs free energy (&Delta;G), the enthalpy change (&Delta;H), and the entropy change (&Delta;S) of adsorption indicated that the adsorption processes were physical, endothermic, and spontaneous. In addition, OMC had 27% higher total adsorption capacities compared to GAC. Physical modifications on OMC were performed by varying the ratios of boric acid to sucrose. The BTEX adsorption capacities were improved from 8% to 15% with the addition of boric acid. The highest total adsorption capacity was 116.6 mg g^-1 using OMC-2. Chemical modification of OMC using citric acid showed increase in adsorption capacity by 21.7% compared to OMC-2.</p><p>

<p> Requirements engineers who try to design sustainable systems may have to compromise when it comes to different environmental impacts. For example, compact fluorescent lamps contain mercury, a dangerous material. But these lamps also save energy. They reduce consumption at the expense of introducing toxic substances into the environment. To deal with these trade-offs, researchers have developed weighting metrics to account for every type of impact in a single assessment. However, the weights have the potential to direct the system design toward neglecting lowly weighted environmental concerns. </p><p> This study aims to clarify the effects of different weighting configurations. The project employs a mixing triangle that weights three different areas of environmental impact against each other. It then compares the effects of an application service provider to the effects of a system that uses locally hosted software. The comparison uses multiple weighting configurations.</p>

This study investigated (1) the volatilization and biodegradation removal rates of volatile organic compounds (VOCs) in a membrane bioreactor (MBR), and (2) impacts of biomass and soluble organics characteristics on membrane fouling. A laboratory-scale MBR was operated to treat synthetic wastewater containing acetaldehyde, butyraldehyde and vinyl acetate. In Phase I, the organic loading rates were varied from 1.06 to 2.98 kg chemical oxygen demand (COD) m-3 d-1. In Phase II, the dissolved oxygen (DO) concentrations were varied from 0.2 to 5.4 mg L-1. Total VOC removal rates were greater than 99.75 percent at all organic loading rates. Volatilization removal rates were achieved as low as 0.78 percent for acetaldehdyde, 1.27 percent for butyraldehyde, and 0.59 percent for vinyl acetate. Biomass stabilization status had a significant effect on volatilization. Under unstable conditions, 85 percent of vinyl acetate was volatilized. Regardless of the DO concentrations, total and biodegradation removal rates were greater than 99.7 and 95.9 percent. When the DO concentrations were increased, the volatilization rate increased. The experimental data were close to VOC emission modeling results using an analytical model and TOXCHEM+. The biomass showed a non-Newtonian and pseudoplastic flow behavior. The average particle diameter was less than 10 µm. Few filamentous bacteria were observed, leading to weak and fragile microbial flocs. The microorganisms were dispersed freely as small clumps or individual cells. The total organic carbon (TOC) and COD concentration in the bound extracellular polymeric substances (EPS) increased linearly with viscosity. The membrane permeate flux was inversely proportional to mixed liquor volatile suspended solids (MLVSS) concentration, viscosity, and total bound EPS concentration. The cake resistances were approximately 95 percent of the total membrane resistances. Soluble organics had a greater impact on cake layer formation under DO limited conditions, when soluble organics contained a larger amount of high molecular weight compounds. The bound EPS concentration had a greater influence on membrane filtering resistance than the molecular weight fraction of EPS. It is confirmed that confocal laser scanning microscopy (CLSM) could be a promising tool to visualize and map the biofouled membrane.

<p>Seasonal road design in mountainous terrain consists of four main phases: route selection, field investigation, surveying, and analysis. The first phase, route selection, consists of two parts: selecting control points at strategic locations, and then determining potential routes between those points. Two geographic information system (GIS) geoprocessing automations were developed to aid a road planner in determining routes between control points. Both automations utilized Environmental Systems Research Institute&rsquo;s (ESRI) ArcGIS software package. The first method developed was the least cost path method, which makes use of ArcGIS&rsquo;s cost path tool to find a route between points following a gradual slope. The second automation was the side hill method, which utilized a variety of ArcGIS tools to maintain a uniform grade along the side of a hill between two points. The two methods were compared and contrasted based on control point locations. The least cost path method was determined to be preferable for main thoroughfares along flat valleys and ridge lines, while the side hill method was preferable for secondary roads that could be used to access steeper ground. It was concluded that the two methods can save time and increase accuracy of GIS road features for land managers planning new seasonal roads. </p>

<p> In a large-scale outdoor, airborne, hazardous materials (HAZMAT) incident, such as ruptured chlorine rail cars during a train derailment, the local Incident Commanders and HAZMAT emergency responders must obtain accurate information quickly to assess the situation and act promptly and appropriately. HAZMAT responders must have a clear understanding of key information and how to integrate it into timely and effective decisions for action planning. This study examined the use of HAZMAT plume modeling as a decision support tool during incident action planning in this type of extreme HAZMAT incident. The concept of Situation Awareness as presented by Endsley's dynamic situation awareness model contains three levels: perception, comprehension and projection. It was used to examine the actions of incident managers related to adequate data acquisition, current situational understanding, and accurate situation projection. Scientists and engineers have created software to simulate and predict HAZMAT plume behavior, the projected hazard impact areas, and the associated health effects. Incorporating the use of HAZMAT plume projection modeling into an Incident Action Plan may be a complex process. The present analysis employed a mixed qualitative and quantitative methodological approach and examined the use and limitations of a "HAZMAT Plume Modeling Cycle" process that can be integrated into the incident action planning cycle. HAZMAT response experts were interviewed using a computer-based simulation. One of the research conclusions indicated the "HAZMAT Plume Modeling Cycle" is a critical function so that an individual/team can be tasked with continually updating the hazard plume model with evolving data, promoting more accurate situation awareness.</p>