| 2015-present |
Director, NEWT ERC |
Rice University, Houston, TX |
| 2004-present |
G.R. Brown Professor |
Rice University, Houston, TX |
| 2004-present |
CEE Dept. Chair |
Rice University, Houston, TX |
| 2001-2003 |
Professor |
The University of Iowa, Iowa City |
| 1999 |
Visiting Professor |
EAWAG, Switzerland |
| 1998-2003 |
Associate Director |
Center for Biocatalysis & Bioprocessing |
| 1997-2001 |
Associate Professor |
The University of Iowa, Iowa City |
| 1993-1997 |
Assistant Professor |
The University of Iowa, Iowa City |
| 1985-1988 |
Environ. Engineer |
Tetratech Inc., San Bernardino, CA |
