Environmental Engineering Commons^™

Understanding N-Nitrosodimethylamine Formation In Water: Chloramine Chemistry, Kinetics, And A Proposed Reaction Pathway, Huong Thu Pham

Graduate Theses and Dissertations

The formation of N-nitrosodimethylamine (NDMA) in drinking water systems is a concern because of its potential carcinogenicity and occurrence at toxicologically relevant levels. The postulated mechanism for NDMA formation involves a substitution between dichloramine and amine-based precursors to form an unsymmetrical dimethylhydrazine (UDMH), which is then oxidized by ground-state molecular oxygen to form NDMA. However, this latter reaction is spin forbidden, thus likely occurs at a slow rate. It is hypothesized that the reaction between monochloramine and hydroxylamine (a nitrification product) may form an intermediate, which is involved in the NDMA formation pathway. This intermediate may also be generated from …

Total N-Nitrosamine Precursor Adsorption With Carbon Nanotubes: Elucidating Controlling Physiochemical Properties And Developing A Size-Resolved Precursor Surrogate, Erin Needham

Graduate Theses and Dissertations

As drinking water sources become increasingly impaired with nutrients and wastewater treatment plant (WWTP) effluent, formation of disinfection byproducts (DBPs) – such as trihalomethanes (THMs), dihaloacetonitriles (DHANs), and N-nitrosamines – during water treatment may also increase. N-nitrosamines may comprise the bulk of the chronic toxicity in treated drinking waters despite forming at low ng/L levels. This research seeks to elucidate physicochemical properties of carbon nanotubes (CNTs) for removal of DBP precursors, with an emphasis on total N-nitrosamines (TONO).

Batch experiments with CNTs were completed to assess adsorption of THM, DHAN, and TONO precursors; physiochemical properties of CNTs were quantified through …

Trihalomethane, Dihaloacetonitrile, And Total N-Nitrosamine Precursor Adsorption By Carbon Nanotubes: The Importance Of Surface Oxides And Pore Volume, Erin Needham

Graduate Theses and Dissertations

As drinking water sources become increasingly impaired, enhanced removal of natural organic matter (NOM) may be required to curb formation of disinfection byproducts (DBPs) upon chlor(am)ination. While carbon nanotubes (CNTs) can adsorb NOM, their properties for DBP precursor adsorption have not been elucidated. Nine types of CNTs were assessed for trihalomethane (THM), dihaloacetonitrile (DHAN), and total N-nitrosamine (TONO) precursor adsorption. Batch isotherm experiments were completed with lake water and, to simulate an impaired condition, effluent from a wastewater treatment plant (WWTP). Adsorption varied with CNT type and dose, with TONO precursors having the highest percent removals from WWTP effluent (up …

Effect Of High Cationic Flocculant On Anaerobic Digestion Of Municipal Wastewater., Prathap D. John

Electronic Theses and Dissertations

Anaerobic digestion (AD) of municipal sludge is a widely used stabilization process at municipal wastewater treatment plants. It is highly effective in reducing sludge volume and produces methane gas which is used as fuel in the wastewater plant. Following digestion sludge is sent to a centrifuge to separate the solids from the liquids. Louisville MSD adds flocculent to material in the centrifuge to better coagulate the solids, thereby aiding in separation of the solids from the liquids. The potential for further AD, COD reduction, and methane generation of the liquid effluent from the centrifuge was unknown, particularly in regards to …

Analysis Of Lid Implementation To Combat Flooding And Erosion At The University Of Arkansas Campus, Madison E. Crowl

Biological and Agricultural Engineering Undergraduate Honors Theses

The city of Fayetteville, Arkansas has experienced rapid urbanization throughout recent years as it continues to grow. Within the city, the University of Arkansas has been constantly expanding, with increased impervious surfaces as more parking lots and facilities are built. This has caused issues including flooding and stream bank erosion, specifically in Mullins Creek, which receives runoff from a large part of campus. A portion of the creek was restored, but there are still downstream issues. Low Impact Development (LID) is a type of green infrastructure that has been shown to decrease runoff and increase infiltration. EPA SWMM, a hydrologic …

Passive Solar Distillation Of Acid Rock Drainage, Stephanie Shreve, Luke Galuska, Anna Stoller, Alex Raney, Agustin Caceres, Caitlyn Chambers, Chris Graham, Devin Hazlett

Chemical Engineering Undergraduate Honors Theses

Arkansas Razorback Distillers (A.R.D.) has developed a passive solar distillation system for treating acid rock drainage (ARD) from legacy (i.e., abandoned) mines. The solar still addresses the need to reduce both the metal sulfate contaminants as well as the acidity of acid rock drainage. During the design phase, A.R.D. addressed the need for the system to be low cost, simple, and effective for general use as well as a specified location. To demonstrate the applicability of the solar still, A.R.D. used the Freeport McMoRan Inc. Copper Queen legacy mine in Bisbee, Arizona, as a base case scenario. The mine was …

Evaluation Of Phosphorous Removals By Biochar Supported Nano-Scale Zero-Valent Iron, Maria S. Rossetti

Chemical Engineering Undergraduate Honors Theses

This study evaluated the effectiveness of biochar-supported nano-scale zero-valent iron (nZVI/BC) in removing phosphorus (P) from water. Samples of nZVI/BC were prepared using aqueous nanoparticles synthesis techniques, and were mixed with a stock phosphorus solution. To determine P reductions water samples were tested for P content using the ascorbic acid method. This procedure was repeated for samples of stock P solution, zero-valent iron (ZVI), biochar, and ZVI/BC. nZVI/BC reduced P content by 86% whereas ZVI, biochar, and ZVI/BC removed 6%, -23%, and 17% respectively. This suggests that nZVI/BC has the potential to be an effective method of stormwater remediation.

Impacts Of Ozone Dose And Empty Bed Contact Time On Bulk Organic Removal And Disinfection Byproduct Mitigation In Ozone-Biofiltration Systems, Mayara Aquino

UNLV Theses, Dissertations, Professional Papers, and Capstones

In areas where water shortages have compromised water supplies, potable reuse is a promising solution. However, additional research is needed to identify and/or optimize cost-effective treatment technologies to demonstrate compliance with potable reuse regulations. Treatment trains employing reverse osmosis (RO) and advanced oxidation, a combination known as ‘full advanced treatment’ (FAT), are required by the California Division of Drinking Water (CDDW) for surface water augmentation and direct injection of recycled water into local aquifers. A maximum concentration of 0.5 mg/L of wastewater-derived total organic carbon (TOC) is also required by CDDW in all groundwater recharge applications. This appears to be …

Pharmaceuticals And Personal Care Products In An Effluent-Dominated Stream: Seasonal Variability And Downstream Fate, Bradley R. Buswell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pharmaceuticals and personal care products (PPCPs) consist of a large group of compounds including medicines, lotions, soaps, shampoos, and even flame retardants and insect repellants. After use, PPCPs often enter waste streams that are directed to municipal wastewater treatment plants (WWTPs). Due to inefficient removals in conventional wastewater treatment processes, WWTP discharges into streams and rivers are a major source of PPCPs to the environment.

The East Canyon Water Reclamation Facility (ECWRF) is a WWTP in Park City, Utah. After treatment, the ECWRF effluent is discharged into a small constructed wetland area before it enters East Canyon Creek. Due to …

Smartvid.Io, Purdue Ect Team

ECT Fact Sheets Archive

The collection, organization, and retrieval of industrial media is a pervasive challenge that is especially glaring for companies in the AEC industry. Construction projects often generate large volumes of pictures & videos from the field for tracking progress and communicating between engineers, contractors, and subcontractors. It is not uncommon for field personnel to capture hundreds of photos per week on any given jobsite.

Smartvid.io is a cloud-based software solution designed for the specific needs of industrial media. The application’s internal deep-learning engines, collectively nicknamed VINNIE (for ‘Very Intelligent Neural Network for Insight and Evaluation’), use speech and image recognition to …

Hillman Composite Beam (Hcb®), Purdue Ect Team

ECT Fact Sheets Archive

The Hillman-Composite Beam (HCB®), is an innovative structural member for use in highway and railroad bridges as well as marine facilities. The HCB is essentially a lightweight reinforced concrete beam strengthened and protected by a corrosion-resistant and resilient Fiberglass Reinforced Polymer (FRP) shell.

The beam is comprised of three main components, a concrete arch (compression reinforcement), an FRP bottom flange encapsulating steel strands tying the ends of the arch together (tension reinforcement) and the FRP shell. Galvanized Rebar “shear connectors” are used to make the beam composite with the concrete deck in the same manner as pre-stressed concrete beams.

The …

Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their …

Industrial-Grade Monitoring Solution: Hoistcam, Purdue Ect Team

ECT Fact Sheets Archive

Safety and productivity are top priorities for contractors and industrial operations. Improving either makes a company more profitable and competitive. Technology advancements that can do both are important for every company to consider. HoistCam^TM industrial-grade video monitoring solutions can improve employees’ productivity and workplace safety in the construction industries. HoistCam also improves efficiency of operations and reduces job site accidents resulting in substantial cost savings to a contractor.

HoistCam™ is an integrated, wireless video system. The use of HoistCam eliminates blind lifts, blind spots and can share the live video with anyone, anywhere with solid security and easy control. …

The Sustainability Of Ion Exchange Water Treatment Technology, Adib Amini

USF Tampa Graduate Theses and Dissertations

This research investigated using a life cycle environmental and economic approach to evaluate IX technology for small potable water systems, allowing for the identification and development of process and design improvements that reduce environmental impacts and costs. The main goals were to evaluate conventional IX in terms of life cycle environmental and economic sustainability, develop a method for improving designs of IX systems from a environmental and economic sustainability standpoint, evaluate potential design improvements, and make the research findings accessible to water professionals through user-friendly tools and frameworks that take into account their feedback. This research provides an understanding, from …

Cwr 4812 Water Resources Design, Sarina Ergas

Service-Learning Syllabi

No abstract provided.

Remote Measurements Of Tides And River Slope Using An Airborne Lidar Instrument, Austin S. Hudson, Stefan A. Talke, Ruth Branch, Chris Chickadel, Gordon Farquharson, Andrew Jessup

Civil and Environmental Engineering Faculty Publications and Presentations

Tides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based …

Quantifying Cyanide Inhibition Of Nitrification And Developing Cost-Effective Treatment Processes, Germano M. Salazar-Benites

Civil & Environmental Engineering Theses & Dissertations

All wastewater treatment plants that operate multiple hearth furnaces (MHF) and are required to nitrify must manage the inhibitory effects of free cyanide (HCN, CN-) in the scrubber return flows due to inhibitory impacts on nitrifying bacteria.

HRSD Boat Harbor Treatment Plant (BHTP) a 25 MGD facility consisting of primary and secondary treatment, employs an anoxic selector process for nitrification and partial denitrification and operates a MHF. There is a desire to improve TN removal performance at BHTP due to an annual mass-based bubble permit limit on a combined discharge from seven HRSD plants, and there are no discharge limitations …

Investigating Geothermally-Sourced H2s Pollution In The Reykjavík Area: A Case Study Of Early March 2017., Shawnee Traylor

Independent Study Project (ISP) Collection

As geothermal energy becomes more widely implemented globally, it is critical to have an accurate assessment of the costs and benefits this technology may pose in order to plan, prevent, and mitigate pollution. Meteorological data sets from the Icelandic Met Office were analyzed in conjunction with hydrogen sulfide (H2S) levels in the Reykjavík area as a case study in the meteorological conditions leading to elevated H2S levels (>50 μg m-3) on March 1-3, 2017. Primary variables of interest were wind speed and direction, temperature, atmospheric stability, and humidity. Climate change is predicted to weaken the Gulf Stream, influencing all …

Hydrologic Response Caused By Wetland Expansion At Huntley Meadows Park In Hybla Valley, Virginia, Stephen Fraser Stone

OES Theses and Dissertations

The goal of this study was to understand the effects of wetland expansion across a watershed. The 2013 restoration and expansion of the wetlands at Huntley Meadows Park (Fairfax County, VA) performed by Wetland Studies and Solutions, Inc. provided the opportunity to study this process. The 630 ha park contains more than 364 ha of freshwater emergent and freshwater forested wetlands. The restoration and expansion project used a subsurface vinyl-piling dam that impedes groundwater flow leaving the wetland, thus expanding the existing pond and the surrounding wetland.

This study used a network of more than twenty monitoring instruments making observations …

Biosolids-Derived Biochar For Micropollutant Removal From Wastewater, Lee Kimbell

Master's Theses (2009 -)

Trace organic compounds including antibiotics, hormones, pharmaceuticals and personal care products are discharged to the environment with liquid and solid effluent streams from water resource recovery facilities. These compounds are referred to as micropollutants, and can have negative impacts in receiving waters. Current wastewater treatment processes are not specifically designed to remove micropollutants, and many of these compounds are recalcitrant to conventional treatment technologies. Triclosan (TCS) was selected as a representative micropollutant in this study due to frequent detection in liquid effluents, residual biosolids, and surface waters. Pyrolysis - the thermochemical decomposition of organic matter at elevated temperatures in the …