Use of an Algal Turf Scrubber ®to Reduce Nutrient Loadings and ProduceBiofuel at a Wastewater Treatment Planton Jamaica Bay New York CityPeter I. May, Ph.D.Biohabitats Senior Environmental ScientistRestore America’s Estuaries, Galveston, TexasNovember 16, 2010
What is an Algal Turf Scrubber®?• A culture unit for attached algae• The algae remove nitrogen and phosphorus from anywater source• The algae is regularly recovered and processed• Recovery of algal biomass maintains the culture units in anaccelerated growth phase• Nutrients are continuously recovered and removed fromthe treatment unit
Algal Turf Scrubber®Project Historyand Timeline
Algal Turf Scrubber®Early Stage Development1970s – 1980s
Patterson ATS(1995-1996)Stanislaus County, CA0.2 MGD x 500’
HMI Aquaculture ATS(2000-2002)Okeechobee County, FL30 MGD x 220’
S-154 ATS with WHS Pre-Treatment (2003-2004)Okeechobee County, FL1-6 MGD x 300’
Taylor Creek ATS(2007-2009)Okeechobee County, FL15 MGD x 300’
Egret Marsh ATS(2010)Indian River County, FL10 MGD x 575’
Algal Turf Scrubber® SystemsPilot and Full Scale Locations
Algal Turf Scrubber® Research• Smithsonian Institution• US Department of Agriculture• Statoilhydro• University of Maryland• Constellation Energy• University of Florida• William and Mary•Virginia Institute of Marine Science• University of Western Michigan• University of Arkansas• University of Georgia
Algal Turf Scrubber® Design
Algal Turf Scrubber® DesignSystem InflowWater is surged down the sloped floway in a pulsing motion.The pulsing surge stimulates algal growth.
Algal Turf Scrubber® DesignAlgal Turf FlowayThe algal turf biomass is recovered on a 7-14 day cycle usingHydroMentia’s proprietary harvest design. The recovered algalbiomass contains excess nutrients removed from the water.
Algal Turf Scrubber® DesignBiomass ProductionAlgal turf or dense mats of simple algae are cultivated on the surface ofthe floway. As the algae grow, they remove nutrient pollutants(phosphorous and nitrogen) from the water.
Algal Turf Scrubber® DesignCentralized Biomass RecoveryHarvested algae is conveyed by the water via a concrete flume to acentralized recovery facility.
Algal Turf Scrubber® DesignCentralized Biomass Recovery System
Algal Turf Scrubber® DesignCentralized Biomass RecoveryThe harvested algae is removed from the water with a Flex Rake.
Algal Biomass Products
Algal Biomass ProductsBiofuel ProductionOmega 3sCompost/Organic FertilizerLivestock Feed
Algal Turf Scrubber®Technology Advantages
Algal Turf Scrubber® Water TreatmentStrategic Advantages:• High Level Treatment Capabilities –Restoration to Background Levels• Lower Treatment Costs• Reduced Land Requirements• Revenue Generating Byproducts
LOWER TREATMENT COSTS - NitrogenTypical Nitrogen Reduction Unit Costs to Comply withTMDLs in the Lower St Johns River WatershedSource: CH2MHill, 2007. LSJR Main Stream Nutrient TMDLAlgal TurfScrubber®25 15-60 Assumes direct treatment of impaired surface water orUltra-AWT treatment of wastewaterSource: HydroMentia, Inc.
LOWER TREATMENT COSTS - Phosphorus HydroMentia. April 2005. Single Stage Algal Turf ScrubberPresent Worth Cost & By-Product Market Analysis. (TPIN=200ppb, TPOUT=146 ppb, 27.0% Removal, 56,000 AF/yr)$70.00$62.00 USACE, SFWMD, HDR. October 2003. Lake OkeechobeeWatershed Project Draft PIR, Water Quality Treatment Ranking(TPIN=261 ppb, TPOUT=100 ppb, 61.6% Removal, 97,500AF/yr)50-yr Present Worth Cost ($/lb P-Removed)$60.00$50.00$40.00$30.00$20.00$10.00$28.68$0.00Treatment Wetland - PhosphorusAlgal Turf Scrubber® - PhosphorusIn order to compare the cost of the ATS to the cost of treatmentwetlands, each system’s capital costs, operating costs and amounts ofphosphorus removed over a 50-year period are discounted to presentworth.
REDUCED LAND REQUIREMENTS – Phosphorus800800Phosphorus Areal Removal Rate (lbs/acre/yr)70060050040030020010010Treatment Wetlands200Algal Turf Scrubber300Low Nutrient Source WaterHight Nutrient Source Water
REDUCED LAND REQUIREMENTS – Nitrogen70006500Nitrogen Areal Removal Rate (lbs/acre/yr)600050004000300020001000150Treatment Wetlands1000Algal Turf Scrubber5000Low Nutrient Source WaterHight Nutrient Source Water