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Full-Text Articles in Environmental Engineering
Effects Of Disinfectants On The Formation Of Aldehydes, Megan Dutra
Effects Of Disinfectants On The Formation Of Aldehydes, Megan Dutra
Environmental & Water Resources Engineering Masters Projects
Disinfection by-products have been the subject of intense study in the water treatment community due to the established adverse health effects of many known by-products and the postulated adverse health effects of many other known and unknown by-products. Aldehydes are one such group of by-products, containing compounds of both known and postulated health effects. This thesis explores the formation of simple alkyl aldehydes due to different disinfectants; these relationships are important because they can aid in determining possible by-product formation of potentially harmful substances with a particular disinfectant or disinfectant combination. Compounds such as these biodegrade easily, presenting a potential …
Occurrence, Formation And Persistence Of Halobenzoquinones: A Case Study On 2, 6 -Dichloro-1, 4 -Benzoquinone, Aarthi Mohan
Occurrence, Formation And Persistence Of Halobenzoquinones: A Case Study On 2, 6 -Dichloro-1, 4 -Benzoquinone, Aarthi Mohan
Environmental & Water Resources Engineering Masters Projects
Halobenzoquinones (HBQs) constitute an emerging class of potentially carcinogenic disinfection by-products (DBPs). Given that HBQs are not measured in routine analysis of drinking water, there is little data on their occurrence in the USA. The presence of 2, 6-dichloro-1, 4-benzoquinone (2, 6-DCBQ) in US drinking water facilities was investigated in 8 utilities to provide an initial assessment of occurrence and fate in relation to the regulated DBPs. Point of entry (POE) and distribution system (DS) samples with DCBQ concentrations greater than the 90th percentile values were from treatment plants that used free chlorine. Across distribution systems, DCBQ exhibited decreasing concentrations …
Stream Temperature Modeling: A Modeling Comparison For Resource Managers And Climate Change Analysis, Lynn Brennan
Stream Temperature Modeling: A Modeling Comparison For Resource Managers And Climate Change Analysis, Lynn Brennan
Environmental & Water Resources Engineering Masters Projects
In the Northeast U.S. increasing stream temperatures due to climate change pose a serious threat to cool and cold water fish communities, as well as aquatic ecosystems as a whole. In this study, three stream temperature models were implemented for two different case-study basins in the Northeast Climate Science Center region. Two coupled hydrology-stream temperature (physical) models were used: VIC-RBM and SWAT-Ficklin et al. (2012). The third model implemented was a nonlinear regression (statistical) model developed by Mohseni et al. (1998). Metrics were developed to assess these models regarding their prediction skill, data input requirements, spatial and temporal resolutions, and …
Effects Of Sulfidation And Natural Organic Matter On The Deposition Of Silver Nanoparticles, Yunqui Chen
Effects Of Sulfidation And Natural Organic Matter On The Deposition Of Silver Nanoparticles, Yunqui Chen
Environmental & Water Resources Engineering Masters Projects
Environmental transformation through sulfidation and complexation with natural organic matter (NOM) are two major factors that may affect the fate and transport of silver nanoparticles (AgNPs) in the aquatic systems by changing their dissolution, deposition, and surface properties. To understand the impact of sulfidation and NOM on the aggregation and deposition of AgNPs, a combination of dynamic light scattering and quartz crystal microgravimetry with dissipation monitoring was used. Polyvinylpyrrolidone (PVP)-capped AgNPs that were modified through sulfidation and/or complexed with NOM had a greater extent of deposition than unmodified PVP-AgNPs. Specifically, the deposition extent of sulfidized AgNPs in the presence of …
Prioritizing Mitigation Of Road-Stream Crossings For Resident Aquatic Organisms By Accounting For Habitat Quantity, Quality, And Accessibility, Rachael L. Weiter
Prioritizing Mitigation Of Road-Stream Crossings For Resident Aquatic Organisms By Accounting For Habitat Quantity, Quality, And Accessibility, Rachael L. Weiter
Environmental & Water Resources Engineering Masters Projects
Road crossings and dams may act as barriers to movement for a wide range of aquatic organisms in lotic freshwater systems. Limited funding constrains the number of barriers that may be mitigated by repair or removal, so systematic methods of prioritization are needed for selecting barriers for mitigation. A new formulation is proposed that links the number of organisms in the watershed to the amount and quality of accessible habitat in order to quantify habitat connectivity of a watershed. The method is applied to a case study performed on the Upper West Branch of the Westfield River in Massachusetts, with …