Skip to main content


PhD, Environmental Science and Technology: University of Maryland
BS, Biochemistry, Cell and Molecular Biology: Drake University


Freddy Witarsa,PhD, has always been interested in understanding how nature can be incorporated into our daily lives to solve current problems. He majored in Biochemistry, Cell and Molecular Biology at Drake University to gain in-depth understanding of how cells and living organisms function before pursuing his PhD in Environmental Science and Technology at the University of Maryland. During his years at University of Maryland, he became especially interested in the field of ecological engineering or design that applies ecological principles for designing technology and systems that provide values to both humans and the environment.

During the years, Witarsa has been involved with the following projects:
1.) Anaerobic digestion that converts dairy, poultry and human manure into renewable energy in the form of methane-enriched biogas.
2.) Algal flow way that removes excess nutrients from water bodies, reducing eutrophication while producing algal biomass.
3.) Combined anaerobic digestion and nutrient capture technology that can produce renewable energy from poultry litter, reduce nutrients runoff and produce re-saleable fertilizer.
4.) Using systems approach to assess the sustainability of anaerobic digesters.

At Colorado Mesa University, Witarsa teaches Introduction to Environmental Science, Renewable Energy, Ecological Design, and Systems Thinking in Environmental Science. He is also interested in working with students to apply ecological engineering and systems approach to promote healthy and sustainable communities.

View Witarsa's curriculum vitae

Published Work

Hassanein, A., Witarsa, F., Guo, X., Liang, Y., Lansing, S., Qiu, L., 2017. Next generation digestion: complementing anaerobic digestion (AD) with a novel microbial electrolysis cell (MEC) Design. International Journal of Hydrogen Energy (In Press).

Witarsa, F., Lansing, S., Yarwood, S., Gonzalez Mateu, M., 2016. Incubation of innovative methanogenic communities to seed anaerobic digesters. Applied Microbiology and Biotechnology 100, 9795-9806.

Wang, Y., Witarsa, F., 2016. Application of Contois, Tessier, and first-order kinetics for modeling and simulation of a composting decomposition process. Bioresource Technology 220, 384-393.

Witarsa, F., Lansing, S., 2015. Quantifying methane production from psychrophilic laboratory-scale anaerobic digestion of separated and unseparated dairy manure. Ecological Engineering 78, 95-100.

Hassanein, A.A.M., Qiu, L., Pan, J., Ge, Y., Witarsa, F., Hassanain, A.A., 2015. Simulation and validation of a model for heating underground biogas digesters by solar energy. Ecological Engineering 82, 336-344.