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There are many reports indicating the presence of emerging contaminants such as: estrogen hormones, 1,4-dioxane and perfluoro-octanoic acids in the natural environment. Estrogen hormones are considered important emerging class of contaminants due to their endocrine disrupting effects. These compounds are invariably found in the environment originating mostly from natural sources. Trace concentrations of estrogen hormones (low µg/L concentrations) have been detected in municipal wastewater treatment plants and observed in receiving water bodies. 1,4-Dioxane (C4H8O2) is used as an organic solvent and solvent stabilizer numerous in chemical processes. The United States Environmental Protection Agency (US-EPA) has recognized 1,4-dioxane as a toxic chemical and a possible human carcinogen. 1,4-dioxane has been detected as a contaminant in the natural environment, drinking water supplies, superfund sites, public groundwater sources in the United States, Canada and Japan at concentrations greater than the permissible standards. Perfluorinated chemicals such as perfluoro-octanoic acid (PFOA) and perfluorooctane-sulfonate (PFOS) have been manufactured for use in a variety of industrial and consumer applications. Due to their environmental persistence, PFOAs have been detected in surface waters at a number of locations at concentrations ranging from pg/L to ng/L. Elevated concentrations of PFOAs have been measured in surface and ground waters near specific point sources. Through this project, successful attempts have been made for the destruction of emerging contaminants using ultrasound. This study deals with the optimization of various process parameters for the destruction of estrogen hormones. The influence of process parameters such as power density, reactor geometry, power intensity, ultrasound amplitude, and external mixing was investigated. Artificial neural network (ANN) approach was used to describe the interactions between optimized parameters. The important findings obtained in the present work for the optimized estrogen degradation can help tackle the challenges of scale up such as operational optimization and energy consumption. The effect of process conditions such as pH and presence of oxidizing agents on the ultrasonic destruction of 1,4-dioxane and PFOA was studied. Acidic conditions favored the destruction of both the compounds. The presence of activated sulfate radicals enhanced the reaction rate kinetics. An innovative technology using electric potential and ultrasound for the removal organic contaminants was developed. The existence of organic contaminants in ionic form under certain process conditions has led to the development of this technology. Applying a low electric potential across the probe enhances the mass transfer of the contaminants into effective reaction zone, thereby enhancing the total destruction. A two-fold increase in the reaction rates was observed. This study shows ultrasound as an efficient and effective treatment technology for the destruction of emerging contaminants. / Civil Engineering

The Deepwater Horizon (DWH) blowout, in the Gulf of Mexico, heavily contaminated miles of sandy beaches. Previous experience of petroleum contamination has shown that oil residues can persist in the sediments for decades. Biodegradation is the major mechanism of remediation regarding petroleum hydrocarbons. There is an urgent need to evaluate the competent indigenous microbial biomass in contaminated sediments if the risks posed by toxic oil residues, for the coastal ecosystem, are to be minimized. We report a field investigation during December 2010 and January 2011 regarding measurement of microbial activity in a sandy beach at the Bon Secour National Wildlife Refuge in Alabama. One transect of wells for sampling was installed in the beach; starting with multiport one, being most landward and thought to be least exposed to oil residue and ending with multiport four being the most seaward and exposed to the open waters of the Gulf of Mexico. Sediment samples were collected from different depths purposely chosen from above, inside, and below the oil layers for microbial analysis. Dissolved oxygen (DO) measurements were obtained and temperature was recorded while collecting the oxygen measurements. Pore water samples were collected for nutrient content and were monitored using the multiport sampling wells. Moisture content was analyzed from the sediments extracted at various depths at each well. pH and salinity were also analyzed for their contributing affect on the microbial community. Grain size distribution analyses were conducted on samples collected at all wells and at multiple depths to characterize the field study location. Results show that the bacterial biomass, as measured by Adenosine-5-triphosphate (ATP) and numbers of alkane and polycyclic aromatic hydrocarbon (PAH) degraders determined by Most Probable Number (MPN), are consistently higher in the sediment layers where oil had been detected. A very good correlation was observed among the relative abundance of bacteria in the different samples using MPN and ATP measurements. As expected, ATP based estimates of the microbial populations were two orders of magnitude higher than the alkane and PAH numbers determined by MPN, which reflect the non-cultivability of most environmental bacteria. The lower concentrations of PAH degraders than alkane degraders that were observed in this study are consistent with other studies, even though both populations are lower than in studies involving fresh oil trapped in beach or wetland sediments. PAHs (aromatics) are notoriously more resistant to biodegradation than alkanes, therefore allowing a lower number of biomass to grow using them. The overall smaller size of the bacterial numbers could be explained by the naturally occurring low-organic content of beach sand. On the other hand, this may be due to the highly weathered nature of the oil or it could reflect some other limitation. / Civil Engineering

Discharge of many organic contaminants (OCs) to the environment from industries such as pharmaceuticals, pesticides, dyestuffs, and chemical intermediates is one of the major concerns to human health and the ecosystem due to their high toxicity. Existing water and wastewater treatment techniques were not specifically designed to remove OCs, and the elimination rate can vary from negligible to over 90%. Therefore, development of treatment technologies to efficiently remove OCs from water and wastewater effluents is required. Polymeric resins are an alternative for treatment since they can selectively target certain OCs as they can be custom-synthesized during polymerization by including desired functional groups to the matrix. However, additional efforts and cost are needed for the regeneration of the exhausted resins and recycling of the sorbed contaminants. Palladium based catalysts supported on polymeric resins are a promising method to overcome regeneration problems and convert contaminants to less toxic chemicals. The main goals of this research were to (1) develop predictive models for the sorption of cationic OCs by resins based on a mechanistic understanding of the sorption mechanisms of a range of cationic OCs on two cation exchange resins and (2) synthesize novel resin-based Pd catalysts to selectively remove two toxic contaminants, i.e., 4-chlorophenol and 4-nitrophenol, convert them to less toxic chemicals, and evaluate the possibility of in situ regeneration of the spent resins. The sorption study indicated that electrostatic (ion exchange) and nonelectrostatic (adsorption) interactions between nonpolar moieties of solute and sorbent have synergistic effects on sorption. It also established predictive models for estimating the sorbed concentrations of a target contaminant on a given resin at any environmentally relevant pH. Our findings point to the significant role of adsorption in the overall catalytic reactivity. The rate determining step (RDS) switched from adsorption to surface reaction with increasing concentration of the reactant. This observation was confirmed by good fitting of the reaction kinetics to the Langmuir-Hinshelwood model developed based on the respective RDS. Our results demonstrated that Pd-resin composites are advantageous to water treatment because they can avoid the conventional resin regeneration process and enable recycling of reaction products of smaller environmental impacts. / Civil Engineering

There are many reports indicating the presence of various emerging contaminants (ECs) in treated wastewater and other water sources. The detection of such contaminants in the environment and the ability of these contaminants to pose potential threats to the environment at very low concentrations have led to a need for more efficient treatment technologies. Cyclodextrins (CDs) have gained significant interest as an alternative adsorbent for water and wastewater treatment because of their unique physico-chemical characteristics and excellent selectivity towards organic compounds. The property of CD to form inclusion complexes with various molecules through host-guest interactions has made it a useful compound for the removal of a number of contaminants from water and wastewater. The overall goal of the study is to identify and develop a novel adsorbent for the removal of ECs of interest. The specific objectives are a) to synthesize various beta-cyclodextrin (BCD) based adsorbents by coating BCD onto different supports such as silica, filter paper, iron oxide, and zeolite, b) to perform batch and column experiments using the developed adsorbents, c) to evaluate the performance of the adsorbents in different water matrices such as MQ water, simulated wastewater in presence of humic acid, and real municipal wastewater, d) to study the regeneration potential of the adsorbents. In this research, various (BCD) based hybrid adsorbents were synthesized and their performances were evaluated based on the removal of selected ECs. At first, chemically bonded BCD onto silica particles as hybrid adsorbents were synthesized by using crosslinking agents and copolymers. Three different methods were used to synthesize 14 different BCD coated silica adsorbents. The adsorbent prepared by reacting BCD with hexamethylene diisocyanate (HMDI) as crosslinking agent and dimethyl sulfoxide (DMSO) as solvent showed best results in removing the ECs studied. The adsorbent showed more than 95% removal of 17β-estradiol (in single component) and more than 90% of most of the estrogens (mixture of 12), more than 99% of perfluorooctanoic acid (PFOA) (in single component) and more than 90% of most of the PFCs (mixture of 10), and a maximum of 90% removal in case of BPA. The adsorption capacity of the developed adsorbent was observed to be higher for the removal of 17β-estradiol and PFOA than that of commercially available activated carbon (F400) in MQ water. In order to represent the real environmental scenario, further batch experiments were conducted for the removal of two PFCs (PFOA and PFOS (perfluorooctane sulfonic acid)), 17β-estradiol, and BPA at environmentally relevant concentrations from wastewater. The adsorbent was effective in removing the ECs that were spiked in the secondary effluent of a municipal wastewater treatment plant. Furthermore, the adsorbent was successfully regenerated with methanol over four cycles without significant loss in its adsorption capacity for the removal of PFOA and estrogens. Ozonation as an alternative method of regeneration was also used and the process was also very effective in regenerating the adsorbent over seven successive cycles for the removal of BPA and 17β-estradiol. The characterization of the adsorbents using FTIR, TGA, and TEM confirmed the coating of BCD onto silica particles. The TGA results showed high thermal stability of the adsorbent (upto 300oC). As an alternative to chemical impregnation, another method of synthesis was developed where various BCD based hybrid adsorbents were synthesized by physically impregnating hydroxypropyl BCD (hpBCD) polymer onto three different supports: iron oxides, zeolite, and filter paper. The hpBCD impregnated filter papers were synthesized by solvent evaporation method and different adsorbents were synthesized by varying the polymer loadings. The polymer loading was optimized based on the performance of the modified (polymer impregnated) filter paper in terms of its filtration capacity as well as adsorption capacity to remove PFOA and BPA. The magnetic adsorbent was prepared by mixing hpBCD polymer with iron oxide (Fe3O4) particles. It was observed that by increasing the mixing time of the support (Fe3O4) with the polymer from 48 to 96 hr, the adsorption capacity of the adsorbent (hpBCD polymer coated Fe3O4) could be significantly enhanced. The same approach was also used to synthesize hpBCD polymer coated zeolite adsorbent and both adsorbents (hpBCD/zeolite and hpBCD/Fe3O4) were effective in removing the selected ECs from MQ water, simulated water, and wastewater. / Civil Engineering

Plants are exposed to various environmental contaminants through irrigation with reclamation water and land application of municipal biosolids. Plants have been shown to take up contaminants from soil and groundwater, and to some extent, metabolize them in their tissues. These mechanisms have potential important implications for the environment and human health. First, as plants constitute the basis of the terrestrial food chain, accumulation of toxic chemicals or their metabolites inside plant tissues may lead to contamination of animals and humans. Second, the recognition of the capability of plants to take up and metabolize contaminants has led to the development of a plant-based remediation technology, referred to as phytoremediation. Phytoremediation is defined as the use of higher plants for the removal of environmental contaminants from soil and groundwater. Although phytoremediation is conceptually attractive as a green, environmental-friendly technology, the metabolism of xenobiotic compounds by plants is often slow and incomplete, possibly resulting in the accumulation of toxic pollutants and/or their metabolites inside plant tissues. Without further detoxification, phytoremediation may result in pollution transfer, potentially threatening the food chain, and eventually humans. Gaining further knowledge about the fate of environmental contaminants inside plant tissues is therefore of paramount importance for conducting environmental risk assessment and enhancing the efficiency of phytoremediation applications. It's an attractive concept today to cultivate plants on contaminated lands, in order to combine the benefits of phytoremediation with plant-based biofuel production. Unlike conventional plant bioenergy production, plant biomass grown on marginal contaminated soil will not compete with land for food production. However, the effect of contaminants on the plant biomass and bioenergy feedstock yield have received little attention. Molecular biology techniques, such as high-throughput gene expression analysis, constitute powerful tools to understand the molecular bases of the plant metabolism and response to environmental contaminants. The objective of this thesis is to understand the physiological and transcriptional responses of two model plants, thale cress (Arabidopsis thaliana) and soybean (Glycine max), exposed to various classes of contaminants, including silver nanoparticles (AgNPs), pharmaceuticals (zanamivir - ZAN and oseltamivir phosphate - OSP), explosives (2,4,6-trinitrotoluene - TNT), and polychlorinated biphenyls (PCBs). Detection of the contaminants inside plants tissues was performed using advance analytical methods, including inductively-coupled plasma - mass spectrometry (ICP-MS), gas-chromatography - mass spectrometry (GC-MS), and liquid-chromatography (LC-MS). The effects of contaminants on plants were assessed by recording various plant metrics, including biomass, root and shoot length, and soybean production. The transcriptional response of plants to exposure to selected contaminants (AgNPs, OSP, and ZAN) was investigated using whole-genome expression microarrays and reverse-transcription real-time (quantitative) PCR (RT-qPCR). In the first experimental phase of this research, the effects of AgNPs and soluble silver (Ag+) on A. thaliana plants were investigated. AgNPs are widely used nanomaterials, which have raised environmental concerns because of their toxicity to most living organisms, including plants. Exposure of hydroponic A. thaliana plants for 14 days to 20-nm AgNPs resulted in a slight increase of the biomass at low concentrations (1.0 and 2.5 mg / L) and a significant decrease of the biomass at higher concentrations (5.0 to 100 mg / L). Exposure to Ag+ for 14 days resulted in a significant reduction of the biomass after 14 days at concentration at and above 5.0 mg / L. Genome-wide expression microarrays revealed that exposure of A. thaliana to AgNPs and Ag+ at the concentration of 5 mg / L for 14 days resulted in differential expression of many genes involved in the plant response to stress and to biotic and abiotic stimuli. Although distinct gene expression patterns developed upon exposure to AgNPs and Ag+, a significant overlap of differentially expressed genes was observed between the two treatments, suggesting that AgNP-induced stress originated partly from silver toxicity and partly from nanoparticle-specific effects. In the second experimental phase of this research, the effects of the antiviral drugs, OSP and ZAN, on A. thaliana were investigated using an approach similar as the one described above. OSP and ZAN are pharmaceutical drugs that currently constitute the last line of defense against influenza infection. These drugs have been widely detected in wastewater effluents, especially during the influenza season, and they have the potential to contaminate agricultural plants through irrigation and land application of biosolids. Exposure of A. thaliana to OSP showed a significant decrease in the plants biomass at the concentrations of 20 and 100 mg / L, although no significant effect on the biomass was recorded upon exposure to ZAN (up to 100 mg / L), suggesting low acute toxicity of these compounds on plants. On the other hand, Arabidopsis exposure to OSP and ZAN at 20 mg / L resulted in significant transcriptional changes, including up- and down-regulation of many genes involved in the plant response to oxidative stresses and response to stimuli. Comparison with an Arabidopsis gene expression database (Genevestigator), revealed that many genes significantly up- and down-regulated by exposure to OSP and/or ZAN were similarly affected by exposure to biotic and abiotic stresses, toxic chemicals, and hormonal stimuli, suggesting that OSP and ZAN have negative chronic effects on plant health. The third experimental phase of this thesis focuses on the effects of two important persistent pollutants, TNT and PCBs, on the growth of soybean plants, with the objective of assessing the potential of using energy crops for the combined benefit of land remediation and biofuel (biodiesel) production. Explosives, such as TNT, are common toxic contaminants frequently observed at explosive manufacturing sites and military training ranges. PCBs are ubiquitous and toxic contaminants that are found in virtually every compartment of the environment. Short-term growth inhibition tests conducted with TNT and selected PCBs (e.g., 2,4'-dichlorobiphenyl - 2,4'-DCB) showed that these compounds exerted no or mild observable effects on plant growth even when applied at very high concentrations (i.e., 100 to 250 mg / kg soil, respectively). Analysis of TNT and 2,4'-DCB in exposed plant tissues showed average concentrations of 30 - 40 ng/g of TNT and 9,000 to 17,000 ng/g of 2,4'-DCB, which is consistent with biotransformation of TNT inside plant tissues. On the other hand, long-term exposure experiments show that exposure to TNT significantly affected soybean growth and production of bean in TNT-exposed plants (25 - 50 mg / kg soil). Exposure to TNT resulted in a significant decrease of the biomass of harvested beans after 120 days, which may have important consequences on the yield of biodiesel obtained from plants grown on contaminated land. Soybean were then exposed to 2,4'-DCB and its major transformation products, 4-OH-2,4'-DCB). Although high concentrations of the parent PCB (100 and 200 mg / kg) resulted in significant decrease of the biomass, high concentrations of the OH-metabolite resulted in increase of the plant biomass. Future research work will include the determination of the molecular bases of the effects - both positive and negative - of TNT, PCBs, and OH-PCBs on soybean plants and beans. / Civil Engineering

The focus of this research was to assess the performance of bioswales in mitigating and treating stormwater runoff from highways and to identify critical parameters that influence the load of pollutants from the drainage area. These bioswales are located in Philadelphia and are part of a project initiated by the Pennsylvania Department of Transportation to upgrade a major roadway (Interstate 95) running through the area. The work included sampling and laboratory analysis of runoff water from 9 storm events to characterize concentrations of contaminants coming from the highway and going in to the bioswales. For one storm event, sampling of vadose-zone and ponded water was included to assess how contaminants move or are retained within the bioswale. The various contaminants include solids, nutrients and metals, which have all been shown to be parameters of concern when dealing with stormwater runoff from highways. In addition, a simulated runoff test was performed to assess the potential risk of a very large storm in mobilizing contaminants within the bioswale. Stepwise linear regression in IBM SPSS was used to analyze the runoff data collected. Characteristics of the rainfall (antecedent dry period, total rainfall, rainfall intensity) were selected as potential explanatory variables to predict contaminant concentration or load. Results of the runoff characterization showed contaminant concentrations that fell within range of literature values from a similar drainage area. Estimated annual loads of contaminants were also in range of what has been observed for highway runoff. Vadose-zone and ponded water sampling showed removal of ammonia, total phosphorus and chemical oxygen demand and build-up of nitrate, total nitrogen and TKN. The build-up was likely due to lack of ion interaction with soil particles, which caused the contaminants to remain in the water. Simulated runoff testing showed no potential for contaminant mobilization within the bioswale but did indicate potential areas of contaminant buildup via observation of a dye tracer. Stepwise linear regressions performed in SPSS showed total rainfall as the most significant predictor of suspended solid, nitrate and total phosphorus load in the bioswales. Results also indicate that there are significant differences between the loads observed for the two bioswales monitored. / Civil Engineering