Open Access. Powered by Scholars. Published by Universities.®

Environmental Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Environmental Engineering

Physical And Stochiometric Controls On Nutrient Uptake And Ecosystem Respiration In Contrasting Sites, Jancoba K. Dorley May 2024

Physical And Stochiometric Controls On Nutrient Uptake And Ecosystem Respiration In Contrasting Sites, Jancoba K. Dorley

Civil Engineering ETDs

Meteorological, hydrological, and biogeochemical processes naturally control stream ecosystems. These processes define the frequency and distribution of precipitation and the supply and demand of solutes and particles to support aquatic food chains through space and time. Studies have also found that stream ecosystems are also controlled by anthropogenic activities, which occur on a much shorter timescale. These anthropogenic activities affect stream ecosystems' structure and function from local to planetary changes to the environment. It is essential for scientists and engineers to understand the relationships between naturally occurring processes and those created by human activities for a better interpretation of stream …


Additive Manufacturing Of Engineered Cementitious Composites With Ultra-High Tensile Ductility, Amir Bakhshi Mar 2023

Additive Manufacturing Of Engineered Cementitious Composites With Ultra-High Tensile Ductility, Amir Bakhshi

Civil Engineering ETDs

One of the critical factors in the development of additive manufacturing in the construction industry is designing suitable materials for 3D printing applications. 3D concrete printing (3DCP) has gained significant attention due to the abundance and availability of concrete. However, concrete is a brittle material and, without proper reinforcement, cannot meet the requirements for structural purposes. Engineered Cementitious Composites (ECC), known for high ductility, and strain-hardening with low fiber contents, can potentially eliminate the need for steel reinforcement in 3D printing without any need for manual placement of reinforcement. A set of systematic tests on ECC mix designs' fresh and …


Application Of Cation Exchange And Nanofiltration To Treat Flue Gas Desulfurization Wastewater, Ayush R. Shahi Jul 2019

Application Of Cation Exchange And Nanofiltration To Treat Flue Gas Desulfurization Wastewater, Ayush R. Shahi

Civil Engineering ETDs

Flue gas emitted from coal-fired power plants is one of the major sources of sulfur and nitrogen oxides emissions to the atmosphere in the world today. Although coal use has decreased, it is still a major contributor to such emissions. The Clean Air Act in the United States established regulations for coal-fired power plants to limit SOx and NOx emissions into the atmosphere. To meet regulatory requirements, power plants have been using scrubbers to limit their air emissions. Flue-gas desulfurization (FGD) is a pollution prevention method that is employed to limit sulfur dioxide emissions directly in the environment …


Is Transportation Planning Effective? A Critical Review Of Long-Range Regional Transportation Planning In The United States, Razieh Nadafianshahamabadi Jul 2019

Is Transportation Planning Effective? A Critical Review Of Long-Range Regional Transportation Planning In The United States, Razieh Nadafianshahamabadi

Civil Engineering ETDs

The Federal-Aid Highway Act requires urban areas with a population greater than 50,000 to create Metropolitan Planning Organizations (MPOs) to ensure that funding for transportation projects and programs are based on a continuing, cooperative, and comprehensive planning process. A major responsibility of each MPO is the creation of a long-range transportation plan (LRTP) that addresses the transportation needs of a metropolitan region over the next twenty years or more. While long-range regional transportation planning goals have grown to include a wide range of concerns and technical methods for evaluating planning scenarios have advanced substantially over the past 50 years, there …


Comprehensive Silica Removal With Ferric Compounds For Industrial Wastewater Reuse, Ehren D. Baca Jun 2017

Comprehensive Silica Removal With Ferric Compounds For Industrial Wastewater Reuse, Ehren D. Baca

Civil Engineering ETDs

Cooling towers, integrated circuit (IC) manufacture and reverse osmosis (RO) generate copious amounts of wastewater high in colloidal and reactive silica inhibiting on-site or synergistic reuse. Silica present in cooling water can reach solubility limits via evaporation and form impervious scale on heat transfer surfaces that decreases efficiency. When water is treated by RO operating at high rejection, silica forms difficult-to-remove scale on the membrane feed side in the form of glassy patches and communities of aggregate particles, inhibiting aspirations for zero liquid discharge. Current methods for silica scale mitigation include abundant dosing with chemical antiscalents or complex operating schemes. …