Can Algae Solve a POTW's Nitrogen Removal Dilemma

With the requirements to meet total nitrogen allocations for the James River in Virginia and the Chesapeake Bay, the Hopewell Regional Wastewater Treatment Facility (HRWTF) struggles to define a cost effective biological nutrient removal (BNR) system. Because a conventional BNR system to treat the primarily industrial wastewater would cost the locality approximately 75 million, HRWTF began seeking other alternatives to obtain compliance with its nitrogen allocation.Hearing and reading articles about the potential of algae to remove nitrogen from wastewater and provide a “green” by-product for use as an energy source was intriguing. Further investigation into this possibility revealed little information into the success of an algae treatment system and actually generated more questions than answers. After soliciting and receiving proposals, HRWTF selected the Algaewheel system to conduct a demonstration project. After several startup problems were overcome, consistent operation began in June 2010.This paper will provide the results of the demonstration project to date. Data on operation of the algae treatment system are presented as well as lessons learned in the operation. The potential of using the Algaewheel as a full scale system will also be discussed.