Energy-efficient wastewater treatment via the air-based, hybrid membrane biofilm reactor (hybrid MfBR).
We used modeling to predict the energy and cost savings associated with the air-based, hybrid membrane-biofilm reactor (hybrid MfBR). This process is obtained by replacing fine-bubble diffusers in conventional activated sludge with air-supplying, hollow-fiber membrane modules. Evaluated processes included removal of chemical oxygen demand (COD), combined COD and total nitrogen (TN) removal, and hybrid growth (biofilm and suspended). Target concentrations of COD and TN were based on high-stringency water reuse scenarios. Results showed reductions in power requirements as high as 86%. The decrease mainly resulted from the dramatically lower air flows for the MBfR, resulting from its higher oxygen-transfer efficiencies. When the MBfR was used for COD and TN removal, savings up to US$200/1,000 m(3) of treated water were predicted. Cost savings were highly sensitive to the costs of the membrane modules and electrical power. The costs were also very sensitive to membrane oxidation flux for ammonia, and the membrane life. These results suggest the hybrid MBfR may provide significant savings in energy and costs. Further research on the identified key parameters can help confirm these modeling predictions and facilitate scale-up.
Department of Civil & Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556, USA E-mail: nerenberg.1@nd.edu; Department of Hydraulics and Environmental Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, 7820436 Santiago, Chile and Centro de Desarrollo Urbano Sustentable (CEDEUS). Pontificia Universidad Católica de Chile, Chile.
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Aybar
Department of Hydraulics and Environmental Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, 7820436 Santiago, Chile and Centro de Desarrollo Urbano Sustentable (CEDEUS). Pontificia Universidad Católica de Chile, Chile.
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Pizarro
CH2MHill, 4350 W. Cypress Street, Suite 600, Tampa, Florida 33607, USA.
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Boltz
Donohue & Associates, 3311 Weeden Creek Road, Sheboygan, WI 53081, USA.
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L
Downing
Department of Civil & Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556, USA E-mail: nerenberg.1@nd.edu.
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Nerenberg
D000388:Air; D018441:Biofilms; D003246:Conservation of Energy Resources; D008567:Membranes, Artificial; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods
D008567:Membranes, Artificial; D014874:Water Pollutants, Chemical