Anaerobic Digestion Research at Univ. of Mass.
Research at UMass Amherst has the potential to advance sustainability in wastewater treatment...
At UMass Amherst, Dr. Chul Park is leading two areas of research that have the potential to advance the sustainability of wastewater treatment. One pilot system is reducing wastewater solids by 70%. The other is looking at whether microalgae can provide greater biomass and bioenergy potential for use in co-digestion systems. Dr. Park and one of his students will be presenting their research at the North East Residuals & Biosolids Conference in November (see above).
In a basement beneath the Amherst wastewater treatment plant, Dr. Park and his graduate students have constructed a small pilot plant that is demonstrating 70% solids reduction through repeated cycling of wastewater solids through a high-rate anaerobic side stream reactor. The repeated cycling results in solids retention times of more than 100 days, but has not significantly affected solids dewatering capability or effluent quality. "We have had nice cooperation from the Amherst facility," notes Dr. Park. "We appreciate their support."
Meanwhile, back at the lab, Meng Weng and others are growing lots of microalgae, trying to find the best species for growing biomass on wastewater solids. The concept of a closed loop of energy production is developing: algae growth is accelerated by growing it on anaerobic digestor sludge centrate. The algae are then co-digested with waste-activated solids, and the CO2 produced from using the resulting biogas for energy is returned, with the centrate, to help grow more algae. More work is needed to understand if algae are as robust and resilient a biological tool as traditional wastewater treatment microorganisms. But, if they are, their more rapid growth and higher lipid content make them a better choice for energy production.
Dr. Park has been an assistant Professor in the Department of Civil and Environmental Engineering at UMass, Amherst since 2007. He took his PhD at Virginia Tech, working with Dr. John Novak.