Water Resource Management Commons^™

Cyclic Heating To Inhibit Bacterial Growth In Activated Carbon Point-Of-Use Treatment Devices, Irwin Silverstein, Irvine W. Wei

Irvine W. Wei

The effectiveness of using heat treatment on a cyclic basis as a means of inhibiting bacterial growth in activated carbon point-of-use treatment devices was examined. Heat treated and non-heat treated devices were compared in a controlled experiment with respect to parameters such as standard plate count, total organic carbon, total residual chlorine and head loss. The results of the study indicated that cyclic heat treatment can inhibit bacterial growth on the surface of granular activated carbon without compromising total organic carbon and total residual chlorine removal efficiencies or accelerating head loss. Microbiological testing verified that the control device had become …

Advanced Chemical Oxidation Of 2,4,6-Trichlorophenol By Using Fenton's Reagent - Dechlorination And Toxicity Reduction, Kuang-Wei (Stone) Chen, Irvine W. Wei

Irvine W. Wei

Chlorinated phenols are priority pollutants, regulated by stringent discharge limits. The presence of chlorine increases the toxicity of these phenolic compounds and decreases their biodegradability. This study is to examine the removal of a priority chlorinated aromatic pollutant, 2,4,6-trichlorophenol (TCP), in aqueous solution by using Fenton's Reagent (a mixture of hydrogen peroxide and fenous iron catalyst), in terms of dechlorination and toxicity reduction. Test results indicate that the higher the molar ratio of H₂O₂ to TCP, the faster the release of chloride from TCP. However, the chloride released in all runs eventually approach the same level of theoretical chloride concentration, …

Climate Change Adaptation Chapter: Marshfield, Massachusetts, Joshua H. Chase, Jonathan G. Cooper, Rory Elizabeth Fitzgerald, Filipe Antunes Lima, Sally R. Miller, Toni Marie Pignatelli

Jonathan G. Cooper

Climate change, understood as a statistically significant variation in the mean state of the climate or its variability, is the greatest environmental challenge of this generation (Intergovernmental Panel on Climate Change, 2001). Marshfield is already being affected by changes in the climate that will have a profound effect on the town’s economy, public health, coastal resources, natural features, water systems, and public and private infrastructure. Adaptation strategies have been widely recognized as playing an important role in improving a community’s ability to respond to climate stressors by resisting damage and recovering quickly. Based on review of climate projections for the …

Climate Change Adaptation Chapter: Marshfield, Massachusetts, Joshua H. Chase, Jonathan G. Cooper, Rory Elizabeth Fitzgerald, Filipe Antunes Lima, Sally R. Miller, Toni Marie Pignatelli

Sally Miller

Climate change, understood as a statistically significant variation in the mean state of the climate or its variability, is the greatest environmental challenge of this generation (Intergovernmental Panel on Climate Change, 2001). Marshfield is already being affected by changes in the climate that will have a profound effect on the town’s economy, public health, coastal resources, natural features, water systems, and public and private infrastructure. Adaptation strategies have been widely recognized as playing an important role in improving a community’s ability to respond to climate stressors by resisting damage and recovering quickly. Based on review of climate projections for the …

First-Order Catchment Mass Balance During The Wet Season In The Panama Canal Watershed, Fred Ogden

Fred L. Ogden

Tropical hydrology is poorly understood for a number of reasons. Intense biological activity in the tropics introduces complexities to the hydrologic process. Bioturbation, rapid rates of decay, and intensive insect activity all tend to promote rapid flow paths in the upper soil. Aggressive weathering leads to clays depleted of light cations and deep soil profiles. Processes in the seasonal tropics are further complicated by seasonal transitions, and very large changes in catchment storage between seasons. Beginning in 2005, we installed a suite of hydrologic sensors in a 16.7 ha first-order catchment in the Panama Canal Watershed to observe hydrologic variables …

Exploring The Effects Of Aperture Size, Aperture Variability And Matrix Properties On Biocolloid Retention In A Single, Saturated Fracture, Margaret Burke

Sarah E Dickson

No abstract provided.

Determining Nutrient And Sediment Critical Source Areas With Swat: Effect Of Lumped Calibration, Ruoyu Wang

Ruoyu Wang

New Nanosystem Mixed Reactor For Urban Wastewater Treatment, Masoud Rastegar, Kamran Rahmati Shadbad

Masoud Rastegar

No abstract provided.

Mechanical Properties Of High Blaine Portland Cement, Masoud Rastegar, Kamran Rahmati Shadbad, Ali Hadidi

Masoud Rastegar

No abstract provided.

Effect Of Spontaneous Gas Expansion And Mobilization On The Aqueous-Phase Concentrations Above A Dense Non-Aqueous Phase Liquid Pool., Kevin G. Mumford, James Smith, Sarah E. Dickson

Sarah E Dickson

This paper presents a framework to quantify the overall variability of the model estimations of Total Polychlorinated Biphenyls (Total PCBs) concentrations in the Niagara River on the basis of the uncertainty of few model parameters and the natural variability embedded in some of the model input variables. The results of the uncertainty analysis are used to understand the importance of stochastic model components and their effect on the overall reliability of the model output and to evaluate multiple sources of uncertainty that might need to be further studied. The uncertainty analysis is performed using a newly developed point estimate method, …

Degradation Of Organic Pollutants In Domestic Wastewaters By Concrete Plates Containing Of Photocatalyst Nanoparticles, Masoud Rastegar

Masoud Rastegar

No abstract provided.

A Method For Computing Infiltration And Redistribution In A Discretized Moisture Content Domain, Fred L. Ogden

Fred L. Ogden

A new one-dimensional infiltration and redistribution method is proposed as an alternative to the Richards equation (RE) for coupled surface and subsurface models. The proposed method discretizes soil water content into hypothetical hydraulically interacting bins. The entry and propagation of displacement fronts in each bin are simulated by means of explicit infiltration and drainage approximations based on capillary and gravitational driving forces. Wetting front advances within bins create water deficits that are satisfied by capillary-driven interbin flow. The method inherently provides numerical stability by precluding the need to directly estimate nonlinear gradients through numerical schemes. Comparisons of the performance of …

Runoff Production In The Upper Rio Chagres Watershed, Panama, Fred Ogden

Fred L. Ogden

Runoff production in tropical watersheds is governed by a wide variety of potential sources and there have been few rigorous studies to date. The 414 km2 upper Río Chagres basin offers a unique opportunity to better understand the runoff production mechanisms in tropical watersheds through data analysis and modeling with rainfall and runoff data. Flow data and tipping bucket rain gage data are available at both the basin outlet (Chico gage) and for an 80.6 km2 internal basin location (Piedras gage). Modeling is performed using the Sacramento Soil Moisture Accounting Model (SAC-SMA), calibrated using data from 2000 and verified using …

Numerical Investigation Of Saturated Source Area Behavior At The Small Catchment Scale, Fred L. Ogden

Fred L. Ogden

The objective of this research is to explore the relationship between small catchment properties and the temporal growth and decay of saturated source areas (SSA). A simple physics-based hydrologic model, which we call the Sandbox model, is developed for this purpose. A thorough sensitivity analysis is undertaken to evaluate model response to variations in model parameters. Sandbox model output is compared to that from the semi-distributed conceptual model, TOPMODEL, a model with a wide spread acceptance. Plotting the temporal evolution of the extent of saturated source area versus catchment average soil water content dur- ing a number of wetting and …

Green And Ampt Infiltration With Redistribution, Fred L. Ogden

Fred L. Ogden

Distributed, physically based watershed and irrigation advance models require robust infiltration estimation capabilities. The empirical Green and Ampt (GA) equation of infiltration is a popular method for estimating infiltration. The GA parameters have physical basis and considerable prior research has focused on relating these parameters to soil textural classification. However, the original GA method is limited in that it is applicable only for a single ponding period. An explicit Green and Ampt redistribution (GAR) technique is developed herein to estimate interstorm redistribution of soil water and allow multiple ponding simulations using the GA methodology. Soil water redistribution during interponding periods …

Strength Of Bentonite Water-Well Annulus Seals In Confined Aquifers, Fred Ogden

Fred L. Ogden

The advantages of bentonite clay for sealing applications are well known. Bentonites have extremely low permeability, do not affect formation water chemistry, and have the ability to swell and deform in response to subsurface changes. The major limitation on the applicability of bentonite for water well annulus sealing is strength. Strength tests conducted in a physical model of a water well identified the expected magnitude of shear strength for several commercially available bentonite well-sealing products. The dependence of bentonite strength in the annulus of a water well on both setting time and borehole geometry is discussed. Force balance calculations for …

Setting Time Effects On Bentonite Water-Well Annulus Seals, Fred L. Ogden

Fred L. Ogden

Shear strength tests are conducted in a model of a water well on four, commercially available, granular bentonite well sealing products. The time dependency of annulus seal shear strength and resistance to piping is examined. Dry bentonite samples are placed through water in the annular space between the casing and borehole and allowed to set for a specified time. Pressure is applied at a constant rate to one end of the clay seal until shear or piping failure occurs. Pressure and seal displacement data are recorded on a digital data acquisition system. Annulus seal strength and resistance to piping increase …