Summary of Studies and Current Work for

Kerry J. Howe, Fiessinger Scholarship Winner 1998

(Dr. Kerry J. Howe received his Ph.D. in Environmental Engineering at the University of Illinois in August 2001; he accepted a faculty position at the University of Albuquerque, New Mexico, in 2002.)

(Final report - summer 2002)

EREF's first Fiessinger Scholar, Kerry J. Howe, finished his Ph.D. in environmental engineering at the University of Illinois at Urbana-Champaign in August of 2001.  His doctoral thesis won an honor award in the University Research category of the Excellence in Environmental Engineering competition sponsored by the American Academy of Environmental Engineers.  The results of his research were presented in the journal Desalination and at several conferences, both nationally and internationally, and were featured in the cover article of the journal Environmental Science and Technology.  He is now working as an assistant professor in the Civil Engineering department at the University of New Mexico in Albuquerque, NM.  He is teaching classes in water treatment processes and starting a research program focused on membrane filtration and other water and industrial waste treatment processes.

(Previous report - summer 2001)

My doctoral research investigated the impact of coagulation as pretreatment to low-pressure membrane processes.  This research has the potential to have a significant impact on the production of municipal drinking water in the United States.  Microfiltration and ultrafiltration physically strain microorganisms such as Cryptosporidium parvum and Escherichia coli from water.  These technologies provide a higher level of treatment than conventional water filtration systems and can prevent waterborne illness, such as the cryptosporidiosis outbreak in Milwaukee, Wisconsin in 1993, when 400,000 people became ill after drinking tap water.  Membrane filters, however, are susceptible to fouling, which can reduce the flow of water through the system and drive up treatment costs.  Dissolved organic matter has been identified in previous research as a prime cause of fouling, but the mechanisms responsible for organic fouling have been unclear.

Coagulation is commonly used in conventional water filtration systems.  Chemical coagulants are added to water, which causes a floc to form that can be easily separated from water.  Particles and organic matter are bound in the floc and separated from the water.  This research demonstrated that coagulation could remove components in natural waters that cause membrane fouling.  As a result, membrane performance improved.  The relative importance of various membrane characteristics was evaluated, and the optimal conditions for which coagulation can improve membrane operation were determined.

In addition, the research identified specific components in natural waters that are primarily responsible for membrane fouling.  Very small colloidal matter was found to impact membrane performance more than other components in natural waters.  Identification of the primary foulants is a critical step in developing a fundamental understanding of the origin of membrane fouling.  With this understanding comes the ability to develop more efficient treatment processes.  There is widespread interest in combining coagulation and membrane filtration in the United States, and water treatment plants have recently started installing systems that take advantage of this combination of processes.