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Danielle Barnhill

Undergraduate Major: Environmental Engineering

Future Plans: Environmental Engineering Ph.D

Danielle Barnhill

Danielle Barnhill was born and raised in Pensacola, Florida. She was awarded an Associate of Arts in Pre-Engineering from Pensacola State College. She is currently pursuing a bachelor's degree in Environmental Engineering at the University of Central Florida. She plans to pursue her Ph.D. focusing on the intersection of urban infrastructure and the environment. With these goals in mind, she plans to make her career a narrative of sustainability and resilience in the face of climate change.

Compatibility of Dual-Disinfection in a Disinfection System

Conducted at University of Central Florida as part of the McNair Scholars Program

Mentor: Dr. Steven J. Duranceau, P.E., Associate Professor- UCF Department of Civil Environmental and Construction Engineering

Abstract: The City of Sarasota currently treats and produces its own drinking water, disinfecting using free chlorine. However, in emergency situations, it may become necessary to use water from neighboring chloraminated systems through the use of existing interconnects. One concern in using the potable water from neighboring systems is the compatibility of the two different disinfectants in the distribution systems. This research was conducted to identify and report the effects of mixing free chlorine with chloramines in the City of Sarasota's distribution system. The concentrations of free ammonia, monochloramine, free chlorine, and total chlorine were monitored to assess the compatibility of blending the water systems. Breakpoint chlorination curves were developed for multiple interconnections to determine the chlorine demand to reach breakpoint at each location. Data showed a chlorine demand of 4 mg/L was required before breakpoint occurs. To adhere to the regulatory limit of 4 mg/L on chlorine injection it was recommended that the interconnections be modified with chlorine and ammonia injection system and that should an emergency situation occur the city should temporarily convert to a chloramine system in the interconnect service area.

Screening the Toxicity of Phosphorous-Removal Adsorbents Using A Bioluminescence Inhibition Test 

Conducted at the University of Central Florida

Mentor: Dr. Steven J. Duranceau, P.E., Associate Professor- UCF Department of Civil Environmental and Construction Engineering

Abstract: When found in excess, phosphorus (P) has been linked to surface water eutrophication. As a result, adsorbents are now used in P remediation efforts. However, possible secondary toxicological impacts on the use of new materials for P removal from surface water have not been reported. This study evaluated the toxicity of adsorbent materials used in the removal of P from surface water including: fly ash, bottom ash, alum sludge, a proprietary mix of adsorbents, and a proprietary engineered material. Toxicity screening was conducted by performing solid-liquid extractions (SLEs) followed by the bacterial bioluminescence inhibition test with a Microtox® M500. Of the materials tested, the samples extracted at lower pH levels demonstrated higher toxicity. The material exhibiting the most toxic response was the iron and aluminum oxide coated engineered material registering a 66–67% 15-min EC50 level for pH 4 and 5 SLEs, respectively. However, for SLEs prepared at pH 7, toxic effects were not detected for this engineered material. Fly ash and bottom ash demonstrated between 82 and 84% 15-min EC50 level, respectively, for pH 4 SLE conditions. Dried alum sludge and the proprietary mix of adsorbents were classified as having.