TITLE:
Wastewater Remediation Using Algae Grown on a Substrate for Biomass and Biofuel Production
AUTHORS:
James B. Houser, Mark E. Venable, Yosuke Sakamachi, Michael S. Hambourger, Jacob Herrin, Shea R. Tuberty
KEYWORDS:
Algae, Wastewater Remediation, CAFO, Eutrophication, Biomass Production, Biofuels
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.10,
July
30,
2014
ABSTRACT:
Surging oil, feed and fertilizer costs have impacted farmers particularly
hard. Farm-based, local sources of renewable energy could help reduce energy costs
for farmers and help develop rural-based processing and manufacturing of biofuel
to bolster rural economies. At the same time, nutrient contamination and eutrophication
from farming operations have become national problems. Algal-based bioprocessors
have the potential to address these problems simultaneously. At Appalachian State
University (Appstate) we set out to design, build and test a system that uses algae
to capture wastewater nutrients as well as excreted pharmaceuticals, while simultaneously
sequestering CO2, producing oil for conversion to biodiesel and feed
for livestock. There are a number of problems with current algae growth systems.
Algae grown in an open pond or raceway system are suspended in the water in the
presence of soluble and suspended waste making most of the current harvest techniques
problematic and expensive. Appstate designed algae troughs in which the algae are
immobilized on a solid substrate. The laboratory-scale prototype was constructed
of three-sided square plastic pipe open at the top. Inside the pipe, there was a
series of cloth filters supported by rigid flow-through baffles. Preliminary results
observed an average percent reduction of nitrate and phosphorous of 40 and 43, respectively,
from different initial nutrient concentrations. Near complete removal (~96%) of
estrogen was observed in 2-day trial experiments. In addition, effective increases
in algal biomass which can serve as both biofuel feedstock and livestock feed were
observed.