title: Enhancement of the performance of a combined microalgae-activated sludge system for the treatment of high strength molasses wastewater.
abstract: The treatment of molasses wastewater, by a combined microalgae-activated sludge process, for the simultaneous organics and total nitrogen reduction, was examined. Further enhancement of the performance of the combined process was accomplished, by means of biofilm carriers or electrocoagulation. A LED light tube was immersed into the reactor tank aiming to enhance the growth of photosynthetic microalgae, while in a similar unit, biofilm carriers were added to the system, representing a moving bed bioreactor. Exposure of the activated sludge biocommunity to light source, resulted in the growth of microalgae and photoreactors exhibited higher removal rates of total nitrogen and nitrates. However, operation at longer times resulted in low effluent quality due to the presence of microalgae cells as a result of high growth rates, and potential light shading effect. Nevertheless, the moving bed system was more beneficial than the single photoreactor, as biofilm carriers provided a self cleaning capacity of the light source, reducing the effect of microalgae deposition. Advanced treatment of the biological effluents, by electrocoagulation, increased even more the process efficiency: the combined photobioreactor and electrocoagulation process resulted in about 78% COD removal and more than 35% total nitrogen removal in the effluent, where nitrates represented almost the single form of total nitrogen.
authors: Department of Food Technology, Alexander Technological Education Institute of Thessaloniki, Sindos, GR-57400 Thessaloniki, Greece. Electronic address: ktsiopts@gmail.com.
authors: Costas
authors: C
authors: Tsioptsias
authors: Department of Food Technology, Alexander Technological Education Institute of Thessaloniki, Sindos, GR-57400 Thessaloniki, Greece.
authors: Gesthimani
authors: G
authors: Lionta
authors: Department of Food Technology, Alexander Technological Education Institute of Thessaloniki, Sindos, GR-57400 Thessaloniki, Greece.
authors: Andreas
authors: A
authors: Deligiannis
authors: Department of Food Technology, Alexander Technological Education Institute of Thessaloniki, Sindos, GR-57400 Thessaloniki, Greece.
authors: Petros
authors: P
authors: Samaras
mesh_terms: D018441:Biofilms; D057919:Biological Oxygen Demand Analysis; D004564:Electrocoagulation; D004867:Equipment Design; D058086:Microalgae / Q000254:growth & development; D008965:Molasses; D009566:Nitrates / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D058433:Photobioreactors; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater
chemical_list: D009566:Nitrates; D009584:Nitrogen; D012722:Sewage; D062065:Wastewater
keywords: Activated sludge; Electrocoagulation; Microalgae; Molasses wastewater; Moving bed photobioreactor