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Polyethylene pipes and epoxy or polyurethane linings are increasingly used in drinking water infrastructure. As a recent introduction to the water industry, there are still many unknowns about how polymers will behave in the distribution system specifically relating to sorption and desorption of chemical contaminants. This study is in response to a spill of 4-methylcyclohexane methanol (MCHM) that occurred in January 2014 contaminating the drinking water of nine counties in West Virginia. This study investigated sorption and desorption of the odorous chemical MCHM into polymer drinking water infrastructure and granular activated carbon (GAC). Experiments for sorption of non-polar toluene and polar 1-butanol were conducted as a comparison for MCHM sorption. Additionally, a brief odor analysis was done on the ability of activated carbon to remove odor from contaminated water and on leaching of MCHM from pipe material into clean water. The results show that MCHM diffusion and solubility in polyethylene pipe materials is low. Solubility in polyethylene ranged from 0.003-0.008 g/cm3 and was more similar to the polar contaminant n-butanol than the non-polar contaminant toluene. Desorption experiments indicated that MCHM sorbed to polyethylene diffused back into water at levels that produced odor. MCHM diffused very quickly into epoxy; its solubility was similar to polyethylene pipe. MCHM caused the polyurethane lining to swell and deform. Granular activated carbon effectively sorbed MCHM to below its odor threshold. The sorption properties of MCHM indicate the potential for contamination of infrastructure and the desorption indicates subsequent recontamination of drinking water. / Master of Science

The frequent use of high-density polyethylene pipes over the last decades has been possible because these pipes are lightweight, corrosion resistant, unlikely to have leaks, and are low cost. The chain structure of the polymer, the extrusion and cooling conditions, the resulting morphology and the ambient conditions all play an important role in the pipe's performance. A new generation of high density polyethylene resins has improved the performance of pipes, but brought new challenges to their testing and characterization. There is a need to understand the rheological behavior of the resins, their processing, and their associated properties in a finished pipe. The rheological behavior of the resins was studied to characterize the effect of high molecular weight tails in a bimodal molecular weight distribution. The use of cone-and-plate and parallel-plate geometries in a rheometer provided simple flow that characterized the steady and dynamical response of the polymer melts. The rheological measurements detected differences in the resins: the resin with higher molecular weight tail showed increased zero shear-rate viscosity, a much slower relaxation of stresses and a resin that more readily deviates from linear viscoelastic behavior. The rheology of the resins allowed modeling their flow through different extrusion dies. The flow channels for pipe dies are thick, so velocities and shear rates are low. Using a different die had a larger impact in shear rates and stresses compared to using different resins. The resin with higher molecular weight shows much higher shear stresses for the same die and temperature, which makes processing harder. The flow of a fluid through a pipe causes constant stress, which at long enough times is one the reasons for pipe failure. Tests that characterize the service lifetime of pipes take long times and are expensive. Dynamical mechanical analysis allows characterizing the viscoelastic properties of the pipe and creep testing confirms that shift factors work for viscoelastic properties measured inde-pendently. For the characterized pipes, one hour of testing at 80 °C is equivalent to a month of test-ing at 25 °C. This works characterizes pipes made from two resins and two different dies. The meas-urements showed that the pipes were statistically the same. / Doctor of Philosophy / The use of high-density polyethylene pipes has thrived over the last decades. This has been possible because these pipes are lightweight, corrosion resistant, unlikely to have leaks, and are low cost. The structure of the polymer and the manufacturing process both affect the pipe's performance. A new generation of high density polyethylene resins has improved the performance of the pipes, but brought new challenges to their testing and characterization. There is a need to understand the flow characteristics of the resins and their properties as a finished pipe. The flow behavior of the polymers in simple geometries gave insights into the polymer's structure. A higher molecular weight resin showed increased resistance to flow and deviated from ideal behavior more readily. These flow characteristics let one model certain aspects of the manufacturing process. Pipe manufacturing is a slow process because of the high resistance to flow of the polymer. Changing the processing equipment, and to a minor degree changing the resins, had an important impact in the manufacturing process. The tests that characterize the service lifetime of pipes take long times and are expensive. When pipes have fluids flowing at high pressures, it takes decades for them to fail. There are viscoelastic tests that allow much quicker characterization of pipes and help predict their long term behavior. This works characterizes pipes made from two resins and two different dies. This works characterizes pipes made from two resins and two different dies. The measurements showed that the pipes were statistically the same.

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Yes / This paper describes the design, development, deployment and performance assessment of a prototype system for monitoring the 'health' of a water distribution network based on the temperature distribution and time-dependent variations in temperature across the network. It has been found that the water temperature can reveal unusual events in a water distribution network, indicated by dynamic variations in spatial temperature differential. Based on this indication it is shown how patterns of changes in the water temperature can be analysed using AQUIS pipeline distribution software and used in conjunction with hydraulic (e.g. flow and pressure) sensors to indicate the state of ¿health¿ of the network during operation.

[pt] Neste trabalho é estudado o problema do chicoteamento de tubulações de alta energia após a ruptura em guilhotina. O modelo físico é representado por uma viga em balanço sujeita à ação de uma força impulsiva aplicada em sua extremidade livre, e por um suporte projetado para absorver a máxima energia cinética associada ao tubo. O método de análise é baseado na teoria de Bernoulli para hastes retas em combinação com a lei momento-curvatura bi-linear para o tubo. A viga é discretizada em elementos finitos uni-dimensionais, e a solução das equações do movimento são obtidas através do procedimento passo-a-passo para a discretização temporal (Newmark). O suporte tem comportamento rígido-plástico. São investigadas as influencias da folga entre o tubo e o suporte, e da relação momento-curvatura na resposta dinâmica do problema. / [en] The dynamic behavior of a cantilever beam simulating a pipe after full rupture at a given cross-section is investigated. This problem, know as pipe whip, has to be analysed within the frame of plastic deformations. The physical model is represented by a cantilever, subjected to a step- load at the free end, and a support designed to absorb the maximum possible kinect energy of the tube generated by suddenly applied force. The analysis is performed using the Bernoulli theory for straight beams, assuming for the moment-curvature relation a bi-linear law. The beam is discretized into finite elements and the time integration is done througth a step-by-step integration technique (Newmark). The support is assumed to follow a rigid plastic constitutive relation. The influence of the gap between the support and the pipe in the dynamic response is investigated, the momento-curvature relations as well.