Emily Miller presents her final oral defense on May 11

BSPH Senior Honors Research Thesis
Emily C. Miller

Comparison of low-pressure membrane processes (MF vs. UF) as pretreatment methods for subsequent virus removal by high-pressure membranes for wastewater reuse
(Under the direction of Dr. Francis DiGiano)

Wastewater reuse for offers great potential for water conservation. Potable, indirect potable, and non-potable reuse applications are a particularly salient issue in arid and semi-arid regions like the southwestern United States. According to Professor Takashi Asano (2002b), “water reuse has been dubbed as the greatest challenge of the 21st century as water supplies remain finite and water demands increase because of escalating populations and per capita consumption.” Membrane treatment after secondary biological treatment of wastewater encourages reuse in both small, decentralized systems as well as in large centralized systems. However, only a few studies have assessed the efficacy of microbial removal (especially of viruses). This study is unique because: (1) virus removals were assessed in both low-pressure membrane units, in which the pore size would be considered too large to affect high rejection, and in subsequent high- pressure membrane units that are known to achieve high virus removals and (2) removals are measured under field conditions in a large-scale pilot plant treating secondary effluent in Greensboro, NC. The pilot plant includes the following treatment schemes: (1) microfiltration (MF) followed by either a nanofiltration (NF) or one of two different types of RO, and (2) a parallel treatment system consisting of an ultrafiltration (UF) unit that precedes the same three types of high -pressure units. The efficacy of MF and UF as pretreatment for these high-pressure technologies and differences in virus removal among the three different high-pressure units are compared.

Committee:
Advisor: Dr. Fran DiGiano
Readers: Dr. O. “Chip” Simmons
Dr. Fred Pfaender

For further information please contact Rebecca Riggsbee Lloyd by email at Rebecca_Lloyd@unc.edu