title: Algal-based, single-step treatment of urban wastewaters.
abstract: Currently, urban wastewaters (UWW) laden with organic carbon (BOD) and nutrients (ammoniacal nitrogen, N, and phosphates, P) are treated in multi-stage, energy-intensive process trains to meet the mandated discharge standards. This study presents a single-step process based on mixotrophic metabolism for simultaneous removal of carbon and nutrients from UWWs. The proposed system is designed specifically for hot, arid environments utilizing an acidophilic, thermotolerant algal species, Galdieria sulphuraria, and an enclosed photobioreactor to limit evaporation. Removal rates of BOD, N, and P recorded in this study (14.93, 7.23, and 1.38 mg L(-1) d(-1), respectively) are comparable to literature reports. These results confirm that the mixotrophic system can reduce the energy costs associated with oxygen supply in current UWW treatment systems, and has the potential to generate more energy-rich biomass for net energy extraction from UWW.
authors.affiliation: Civil Engineering Department, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Henkanatte-Gedera
authors.affiliation: Civil Engineering Department, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: T
authors.initials: T
authors.lastname: Selvaratnam
authors.affiliation: Energy Engineering Laboratory, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: N
authors.initials: N
authors.lastname: Caskan
authors.affiliation: Civil Engineering Department, New Mexico State University, Las Cruces, NM 88003, USA. Electronic address: nkhandan@nmsu.edu.
authors.forename: N
authors.initials: N
authors.lastname: Nirmalakhandan
authors.affiliation: Molecular Biology Program, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: W
authors.initials: W
authors.lastname: Van Voorhies
authors.affiliation: Energy Engineering Laboratory, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Lammers
mesh_terms: D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D002244:Carbon / Q000032:analysis; D002947:Cities; D009584:Nitrogen / Q000032:analysis / Q000302:isolation & purification; D010710:Phosphates / Q000302:isolation & purification; D010758:Phosphorus / Q000032:analysis; D058433:Photobioreactors; D000461:Rhodophyta / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D002244:Carbon; D009584:Nitrogen; D010710:Phosphates; D010758:Phosphorus; D062065:Wastewater
keywords: Galdieria sulphuraria; Mixotrophic metabolism; Nutrient removal; Organic removal; Wastewater treatment