Anaerobic Pre-Treatment for an Algae-based Wastewater Treatment System

"Removing nutrients, such as nitrogen and phosphorus, is an increasingly-important objective of wastewater treatment in order to reduce the impacts of nutrient pollution on waterways. Current technologies to remove these nutrients can be capital intensive, require dangerous chemical inputs and have high operational costs. Our company, Algal Scientific, has developed an innovative nutrient treatment system that sequesters nitrogen and phosphorus from the wastewater into the biomass of specially-selected algal species. This technology differs from the current nutrient treatment technologies that rely on bacterial-mediated conversion of soluble nitrogen into nitrogen gas and a separate chemical and/or biological precipitation of phosphorus. Our algae-based process not only reduces capital and operating costs but also provides new environmental benefits including reduced energy consumption and the production of a high-value algal biomass that can be converted into useful products such as bioenergy and biofertilizer. The main objective of the proposed research is to determine whether an anaerobic pre-treatment step can condition certain waste streams to help optimize our current algae-based treatment process. The proposed research utilizes both flask-scale and benchtop-scale experiments to determine which operating parameters of the anaerobic pre-treatment process result in the best nutrient removal performance by our established downstream algae-based process. We expect these experiments to demonstrate an increase in the availability of nitrogen and phosphorus for algal sequestration, which would allow us to decrease the water residence time of our entire wastewater treatment process. This improvement alone would substantially decrease operating and capital costs and allow us to remove nutrient more cost-effectively. During Phase II, we will scale up the anaerobic pre-treatment process developed in Phase I to a flow rate capable of supplying “pre-treated” wastewater effluent to our company’s pilot and demonstration-scale operations. We already have one on-site pilot plant (100 liters bioreactors) operation with our current technology and we expect to have a 50,000 liter per day demonstration-scale operation installed by the end of 2010 and our first commercial-scale operation (>1 million liters per day) installed by the end of 2012. If the Phase II research demonstrates that our proposed pre-treatment process provides a new cost-savings, then we will then integrate the process into our commercial scale design. While wastewater nutrient regulations will drive the implementation of our system across the country, we expect of help customers achieve compliance and at the same time save money, reduce energy costs and produce a valuable renewable biomass byproduct. "