I-Corps: Auto-flocculation technology for wastewater treatment

The broader impact/commercial potential of this I-Corps project is the development of wastewater treatment technology. Currently, wastewater treatment plants (WWTPs) consume greater than a third of the energy used by the municipality, with aeration operation utilizing up to 80% of this energy. WWTPs also are one of the largest greenhouse gas emitters with their direct emissions estimated at 1.6% of global inventory.

The proposed technology uses auto-flocculation to enhance primary clarification of wastewater treatment, a basic unit operation in all wastewater treatment applications. Enhancing primary clarification by using the proposed auto-flocculation technology may reduce organic and nutrient loading to secondary treatment processes. Therefore, the technology has the potential to reduce treatment infrastructure outlay, energy cost for aeration in activated sludge, and carbon footprint of wastewater treatment.

This I-Corps project is based on the development of auto-flocculation technology for enhanced primary clarification in wastewater treatment. Currently, in primary clarification, particles are removed by gravity-based sedimentation from the bulk water. The efficacy of this primary treatment process is typically about 50%.

Following primary clarification, wastewater is subjected to secondary treatment, such as activated sludge, requiring intense infrastructure requirements, high energy use, and greenhouse gas emissions. In addition, enhanced primary treatment of wastewater often requires conditioning chemicals, which is unsustainable and often compromises downstream bioprocesses, and/or significant retrofitting of conventional clarifiers.

However, wastewater possesses significant self-aggregating potential, which is currently unrealized in conventional wastewater treatment. The proposed auto-flocculation process does not require chemicals nor clarifiers' retrofit but employs agitation of wastewater prior to clarification, which enables 80-90% of primary treatment efficacy. Greater capture of carbon rich solids by the proposed auto-flocculation technology at the primary treatment stage is expected to render wastewater treatment plants with a path toward carbon neutral industry.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.