Research Topics
Department of Civil and Environmental Engineering
Ph.D. (1993) University of Illinois
Research Topics
Research Interests
I. Foaming in Activated Sludge Systems. The formation of a viscous, stable, foam layer on activated sludge aeration basin and final clarifier surfaces is a common problem for the activated sludge industry that has been linked to the presence of filamentous bacteria. This research will develop oligonucleotide probes target- ing the ribosomal RNA of filamentous microorganisms, which can be used as diagnostic tools to evaluate foaming problems without the prior cultivation of the foam-causing microorganisms. In addition, the research will test the performance of laboratory-scale activated sludge systems equipped with selectors. Population shifts of foam-causing microorganisms will be followed before, during, and after foaming episodes in these systems using ribosomal RNA-targeted oligonucleotide probes and related to operating conditions and system performance.
II. Biofilms are complex structures of microorganisms immobilized on a surface and embedded in an extracellular organic polymer matrix. Pathogens may grow or may be entrapped in biofilms that develop in drinking water distribution systems. Molecular techniques are being developed to detect and assess the viability of pathogens and indicator organisms in water samples from distribution systems. In addition, molecular techniques are being developed to visualize these microbes in biofilms and to study the microbial populations that constitute the biofilm. Pipes taken from existing distribution systems are being used to build laboratory scale systems that simulate distribution systems.
III. The anaerobic sequencing batch reactor (ASBR) is a new biological process for the conversion of organic wastes to biogas. The technical feasibility of ASBRs to stabilize swine waste has been demonstrated at Iowa State University. This research will evaluate possibilities to further reduce capital and operating costs of ASBR systems and to create an alternative added value to the system. The research will focus on seeding ASBRs with different sludges to reduce start-up periods, recovering nutrients from ASBR effluent, and reusing ASBR effluent as flush water.
IV. A sustainable process for sulfur recovery for the corn processing industry will be developed. The specific objectives are: (1) Establish a sulfur balance for representative corn wet milling plants. (2) Evaluate the potential of a novel anaerobic biological waste treatment process (Anaerobic Migrating Blanket Reactor, AMBR) to treat a sulfate-rich waste stream from a corn wet milling plant and to maintain stable operating conditions while treating a highly variable waste stream. Adopt a biological system to oxidize sulfide to elemental S that is compatible with the AMBR. Nucleic acid based techniques will be used to quantify microbial populations and help improve operating conditions.
Keywords: Fluorescence Microscopy, Image Analysis, Gas and/or Liquid Chromatography, Microbial Physiology, Biodegradation, Environmental Biotechnology