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Approximately six billion gallons of drinking water are lost through distribution systems every day across the United States. In Philadelphia alone, an estimated 22 million gallons per day (MGD) of water is unaccounted for. This constitutes 25% of drinking water produced each day. Water is lost through distribution networks due to various reasons, such as erroneous meter readings, inaccurate billing, and physical damage to the infrastructure. According to the Philadelphia Water Department's Water Audit, water losses in the year 2010 amounted to over $30 million. Not only does "unaccounted-for water" cost the city of Philadelphia millions of dollars every year, it could also be affecting the quality of our drinking water; undetected leaks could potentially allow pathogens to enter the pipes and contaminate the network's water. This risk is magnified in periods of high flow demands such as during fire emergencies. Currently, the City utilizes many methods for detecting and repairing leaks including acoustic leak detection methods. However, these methods are not fast and not very effective in large diameter pipes. This thesis proposes a method for leak detection that utilizes hydraulic modeling and pressure management in the water distribution network to find the source of leaks as quickly and efficiently as possible causing less water to be wasted. Millions of dollars worth of wasted water could be saved while protecting the quality of our water from contamination. / Civil Engineering

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This study investigates the removal of natural organic matter (NOM) by alum coagulation, and the effect of ozonation on this process. The objectives of the research were: (1) to determine various properties of NOM that are important for its interaction with alum, and the effect of ozone on these properties, (2) to determine the calcium and aluminum binding capacities of unozonated and ozonated NOM, (3) to determine the sorption capacity of unozonated and ozonated NOM on aluminum hydroxide flocs, and (4) to use the data thus obtained to describe NOM removal by alum coagulation, and the effect of ozonation on this process. For the purpose of this research, NOM from a eutrophic raw water source (Forge Pond, Granby, MA) was isolated and fractionated into eight fractions based on relative hydrophobicity and acidity. The fractions isolated were: fulvic acid (FA), humic acid (HA), weak hydrophobic acids (WHYA), hydrophilic acids (HAA), hydrophobic bases (HYB), hydrophilic bases (HYB), hydrophobic neutrals (HYN), and hydrophilic neutrals (HN). The objectives of the research were met with a series of carefully controlled experiments conducted with raw water and the above fractions. It was postulated that the interactions between charged functional groups on NOM molecules and coagulants was responsible for the removal of NOM by alum coagulation. Two mechanisms for such removal are charge neutralization/precipitation and adsorption of NOM on aluminum hydroxide flocs. The acidic NOM fractions (FA, HA, WHYA and HAA) were negatively charged at all pH values, and hence interacted well with the positively charged aluminum hydroxide particles. Of all the NOM fractions isolated, the humic fractions (FA and HA) exhibited best adsorption on aluminum hydroxide flocs. The basic and neutral fractions (HB, HYB, HN and HYN) had little or no charge, and hence exhibited poorer adsorption than the acidic fractions. Calcium and aluminum complexation studies showed that the negative charge on most acidic fractions were only partially neutralized due to metal complexation. The charge on the basic and neutral fractions, on the other hand, were completely neutralized by metal complexation. Thus it was concluded that the charge neutralization/precipitation mechanism of NOM removal was only important for the basic and neutral fractions. Ozonation increased the charge of all NOM fractions. The adsorption of the acidic fractions on aluminum hydroxide flocs either remained unchanged or decreased upon ozonation. Hydrophilic neutrals (HN) on the other hand showed increased adsorption on aluminum hydroxide flocs on ozonation. It was also shown that in the case of Forge Pond water, increased NOM removal on ozonation may only be obtained if ozone is allowed to react with the non humic components of the NOM exclusively.

The primary goal of this dissertation project has been the study of metal affinity interactions in metal recovery and bioremediation. During the first part of this research a mathematical model that describes the affinity partitioning of metal ions in aqueous two-phase systems was derived. The model has been used to calculate complex formation constants between metal ions in solution and affinity ligands, satisfactorily describing their partition behavior. Simulation using this model shows the great effect that pH has on the partitioning of metal ions suggesting better conditions for the separation. Work on metal affinity interactions has led to the pursuit of characterization studies of metal uptake by microorganisms of relevance in bioremediation. The methanotrophic bacterium M. trichosporium 0B3b a mutant culture (PP358) that expresses soluble methane monooxygenase (sMMO) independent of the external copper concentration have been the subject of this research. Knowledge of substances and/or mechanisms that are involved in the copper uptake by M. trichosporium 0B3b will greatly facilitate application of this or like species to the bioremediation of hazardous waste. Specifically, the role of an extracellular copper-binding biochelator (CBL) in copper uptake by Methylosinus trichosporium 0B3b has been investigated. Experiments included the identification and physical characterization of the biochelator and elucidation of the environmental factors that affect its production. The biochelator is apparently an aromatic, low-molecular weight, hydrophobic molecule with high affinity and selectivity for copper. Results indicate that the mutation in PP358 is unrelated to possible defects in biochelator functionality and strongly suggest that the CBL is directly involved in the copper acquisition mechanism of this methanotroph. Finally, an existing colorimetric method currently used in the qualitative determination of sMMO has been modified and improved to provide additional quantitative information. Until now, the instability of one of the products of the reaction on which the current method is based has precluded the effective use of the assay as a quantitative tool. Stabilization of the compound of interest has been achieved, allowing the successful quantification of sMMO activity from M. trichosporium 0B3b and propane monooxygenase activity from the propane oxidizer M. vaccae JOB5.

Master of Science / Department of Biological & Agricultural Engineering / Kyle R. Douglas-Mankin / Sediment is considered as one of the important pollutant of concern in the U.S. In order to develop watershed management plans that address sediment pollution, it is essential to identify all sources of sediment in a watershed. The overall goal of this research is to quantify the total sediment from a watershed by integrating the outputs of three types of sediment sources: sheet and rill erosion, ephemeral gully erosion, and streambank erosion, that each operates at different spatial and temporal scales. This approach will be demonstrated in Black Vermillion River Watershed using AnnAGNPS (overland flow/erosion model), REGEM (ephemeral gully erosion model) and field measured values of streambank erosion. The study area includes three subwatersheds (Irish Creek, the Black Vermillion River Main Stem, and North Fork of the Black Vermillion), each monitored for continuous stream flow, base flow and event-based suspended sediment subwatershed export, annual streambank erosion, for 2 years. NASS land use, SSURGO soils data, 30-m DEMs, and local weather data were used to generate input data needed by the models. Stream monitoring data were used to calibrate the models. This paper will present results from independently calibrated and validated combinations of AnnAGNPS, REGEM, and filed measured streambank erosion. Our hypothesis is that use of separate models to simulate sediment load contributions for each sediment source will improve model agreement with measured watershed sediment yield data.

Within the context of potable reuse, there is a need for a more comprehensive examination of the quality of dissolved organic matter (DOM) in treated wastewater and the efficacy of different treatment schemes in removing or transforming DOM. In particular, there are significant information gaps regarding the character, fate, and health risks associated with effluent organic matter (EfOM). Two research goals guided this research. The first goal was to evaluate the efficacy of constructed wetlands for wastewater polishing in a hot, arid environment, from the perspective of season-dependent effects on DOM. To this end, behavior of organics was evaluated over a 22-month period during treatment in a local constructed wetlands facility. The second goal was to examine changes in character of EfOM that accompany passage through natural treatment systems (either constructed wetlands or soil aquifer treatment, SAT). This was accomplished via isolation and characterization of organics collected along flowpaths of these treatment systems. Wetland effluent concentrations of dissolved organic carbon (DOC) and nonbiodegradable DOC were positively correlated with temperature. That is, the highest concentrations occurred in summer and were attributed to the combined effects of evapotranspiration (ET) by wetland vegetation along with production of wetland-derived natural organic matter (NOM). There was little if any change in the hydrophobic-hydrophilic character of DOM attending wetland treatment. Biodegradation of labile EfOM combined with contribution of wetland-derived NOM resulted in modest (at best) changes in distribution of carbon moieties in hydrophobic (HPO) and hydrophilic (HPI) acid isolates. Aliphatic carbon decreased during wetland treatment. Elemental analysis suggested that microbial activity is the dominant process controlling the character of wetland-derived NOM. Reactivity of isolates in forming trihalomethanes (THMs) during chlorination increased as consequence of wetland treatment. Wetland-derived NOM was more reactive than EfOM in forming THMs. Uniform trends occurred among isolates of EfOM and wetland-derived NOM between biodegradability and THM production upon chlorination. Ultrahydrophilic EfOM was preferentially removed during vadose zone percolation of secondary effluent. The chemical character of EfOM (HPO- and HPI-acids) became more similar to NOM as a consequence of SAT. Genotoxicity of HPO-acids, on a per mass basis, increased after SAT.

This thesis focuses on the transport of mobilized contaminants in riverine sediments. A two-dimensional numerical model which simulates contaminant flux through the water column-benthic sediment interface in the presence of sediment bed forms has been constructed. Characteristics of the model include: hydrodynamics in the porous sediment modeled using the Darcy's Law; a sinusoidal pressure distribution used to describe the stream flow-induced pressure distribution that over sand dunes and ripples of sediment bed surfaces; and use of the hydraulic gradient of the stream flow to generate longitudinal underflow in the porous sediment bed. Numerical simulation results show that, depending on a number of environmental factors including depth of the hotspot, hydraulic conductivity, height of the bedforms, and other factors, the stream velocity can significantly affect the vertical flux (the flux of mobilized contaminants from the benthic sediment bed into the water column). In addition, the model results indicate that under certain environmental conditions, a significant amount of mobilized contaminant may be released from the benthic sediment into the water column. The model also predicts the distance downstream of the hotspot where the maximum net vertical flux is expected to appear A 2.1 meter laboratory flume filled with 3 mm glass beads and injected with a non-sorbing tracer was constructed to test the model predictions. The numerical model was calibrated with the flume study data and two model parameters, related to bed was calibrated with the flume study data and two model parameters, related to bed surface pressure and hydraulic gradient of overlying flow, were adjusted to complete the model calibration. The numerical model after calibration showed close agreement with the flume-generated experimental data Results of this effort verify that the model used is valid for predicting the mass flux between the water column and the sediment bed in the laboratory flume. The model developed here can be used as a planning tool for water quality management or, with modification, used within other models, such as Water Quality Analysis Simulation Program (WASP) / acase@tulane.edu