Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 14 of 14 for “"low DO"”.
-
Characterizing Kinetic Shifts in Nitrifying, Denitrifying, and Phosphorus Removing Biomass Adapting to Low DO
Low dissolved oxygen (DO) biological nutrient removal (BNR) is becoming a viable option to improve the energy efficiency of BNR. To properly model and design BNR processes for low DO operation, it is critical to fully understand how nitrifier, denitrifier, and polyphosphate accumulating organism …
-
Optimizing Enhanced Biological Phosphorus Removal at WRRFs: Impact of Low DO Operation and Full-Scale Strategies
… 69 percent decrease in average dissolved oxygen (DO) concentrations, alongside a 53 percent reduction in average effluent total phosphorus (TP) concentrations from 2019 to 2023. This improvement in effluent quality coincided with the elimination of metal salt addition in 2023. Batch tests …
-
Development of Low Energy Aeration System For Enhanced Biological Phosphorus Removal (EBPR)
… has grown in importance. Most of the research done on EBPR process was focusing on continued aeration, the effect of intermittent aeration is not widely researched. Thus, this research aims to overcome the previously mentioned challenges towards achieving stable EBPR process through different …
-
The Respiratory Physiology and Energy Metabolism of Freshwater Mussels and Their Responses to Lack of Oxygen
… important for establishing the dissolved oxygen (DO) requirements of freshwater mussels, determining the metabolite(s) indicative of environmental stress, and interpreting environmental conditions based on physiological indicators of mussels. Three studies were undertaken to address these …
-
Effects of Hypoxia on Embryonic Development and Hatching in Two Ambystoma and Two Rana Species
The concentration of dissolved oxygen (DO) available to amphibian embryos fluctuates widely and is often quite low. I investigated the effects of low DO (hypoxia) on embryonic development and hatching of two Ambystoma and two Rana species. In Ambystoma, hypoxia resulted in slowed development, …
-
Algal and protozoan response to Holocene climate change and anthropogenic impact: a case study from Sluice Pond, MA
… specimens of cellulosic thecae are attributed to low dissolved oxygen (DO) in the basin. The fossil protozoan record supports the interpretation- thecamoebians were unable to colonize the basin until the middle Holocene and only became abundant when the drought-induced lowstand oxygenated the …
-
Development of Kinetic Parameterization Methods for Nitrifying Bacteria using Respirometry
… how nitrifiers react when exposed to low DO conditions could provide a greater understanding of low DO operations in full-scale biological wastewater treatment. Previous methods to observe nitrifier oxygen kinetics do exist in literature, however they are inefficient and labor …
-
Modelling and control of an activated sludge process using ASM2d and taking into account sludge floc distribution effects
… sludge process sometimes needs to operate at low dissolved oxygen concentrations. The ASM2d model describes the activated sludge process, if nitrification and denitrification occur during different phases in a sequencing batch reactor (SBR). Despite the widespread study of enhanced biological …
-
The effects of carpet dye on the Bagmati River
… indicator, total chromium, dissolved oxygen (DO) and chemical oxygen demand (COD). Total chromium was measured both in samples from the Bagmati River and in dye samples. All four dyes tested contained chromium. Three of them contained high levels of chromium (1,200 - 2,400ppm). The highest …
-
A bio-indicator assessment towards the rehabilitation of the Stiebeuel River, Franschhoek, South Africa
… the biodiversity of species and organisms, following a rehabilitation intervention. It was investigated how nature, in the form of biodiversity of diatoms and macro-invertebrates, were observed in the Stiebeuel River when a range of habitats were created and restored through the replanting of …
-
Design and testing of an integrated catalytic membrane reactor for deoxygenating water using hydrogen for down-hole injection and process applications.
… obtained from the sea contains dissolved oxygen (DO) and is considered to be undesirable for use in down-hole water injection or other process applications. The presence of DO leads to corrosion and other related problems and hence the need for its removal. Various methods are in place for sea …
-
Metal fluxes across the sediment water interface in a drinking water reservoir
… water degrade water quality by affecting taste, odor, and color. Under oxic conditions (dissolved oxygen (DO) >2 mg/L), Fe and Mn are rarely present in soluble form in natural waters, as they occur as insoluble, oxidized minerals in sediments. However, the development of low DO concentrations in …
-
Rainbow Trout (Oncorhynchus mykiss) Summer Habitat Use in Lake Spokane, Washington
… and prefer water temperatures < 20 °C and DO levels ≥ 5.0 mg/L. The overarching goal of this study is to document Rainbow Trout movements in an environment that experiences oxygen stress and high water temperatures not meeting preferred levels. Lake Spokane is a 38.62 km long reservoir on …
-
Evaluation Of Nitrification Kinetics For A 2.0 MGD IFAS Process Demonstration
… in the basin, and after temperatures dropped below 20 °C, AOB activity in the fixed film phase made up 75% of the total activity in the IFAS basin. During the warmest period of the summer, the media still retained more than 60% of the total NOB activity, and more than 90% of the total NOB …