Electrochemical struvite precipitation from digestate with a fluidized bed cathode microbial electrolysis cell
KAUST Grant NumberKUS-I1-003-13
Permanent link to this recordhttp://hdl.handle.net/10754/598139
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AbstractMicrobial electrolysis cells (MECs) can be used to simultaneously convert wastewater organics to hydrogen and precipitate struvite, but scale formation at the cathode surface can block catalytic active sites and limit extended operation. To promote bulk phase struvite precipitation and minimize cathode scaling, a two-chamber MEC was designed with a fluidized bed to produce suspended particles and inhibit scale formation on the cathode surface. MEC operation elevated the cathode pH to between 8.3 and 8.7 under continuous flow conditions. Soluble phosphorus removal using digester effluent ranged from 70 to 85% with current generation, compared to 10-20% for the control (open circuit conditions). At low current densities (≤2mA/m2), scouring of the cathode by fluidized particles prevented scale accumulation over a period of 8 days. There was nearly identical removal of soluble phosphorus and magnesium from solution, and an equimolar composition in the collected solids, supporting phosphorus removal by struvite formation. At an applied voltage of 1.0V, energy consumption from the power supply and pumping (0.2Wh/L, 7.5Wh/g-P) was significantly less than that needed by other struvite formation methods based on pH adjustment such as aeration and NaOH addition. In the anode chamber, current generation led to COD oxidation (1.1-2.1g-COD/L-d) and ammonium removal (7-12mM) from digestate amended with 1g/L of sodium acetate. These results indicate that a fluidized bed cathode MEC is a promising method of sustainable electrochemical nutrient and energy recovery method for nutrient rich wastewaters. © 2014 Elsevier Ltd.
CitationCusick RD, Ullery ML, Dempsey BA, Logan BE (2014) Electrochemical struvite precipitation from digestate with a fluidized bed cathode microbial electrolysis cell. Water Research 54: 297–306. Available: http://dx.doi.org/10.1016/j.watres.2014.01.051.
SponsorsThe authors thank Henry Gong from the materials characterization lab at Penn State for assisting in ICP sample analysis. Award KUS-I1-003-13 from the King Abdullah University of Science and Technology (KAUST) supported this research.
CollectionsPublications Acknowledging KAUST Support
- Phosphate recovery as struvite within a single chamber microbial electrolysis cell.
- Authors: Cusick RD, Logan BE
- Issue date: 2012 Mar
- Modeling phosphorus removal and recovery from anaerobic digester supernatant through struvite crystallization in a fluidized bed reactor.
- Authors: Rahaman MS, Mavinic DS, Meikleham A, Ellis N
- Issue date: 2014 Mar 15
- Removal and recovery of phosphorus as struvite from swine wastewater using microbial fuel cell.
- Authors: Ichihashi O, Hirooka K
- Issue date: 2012 Jun
- Assessing struvite precipitation in a pilot-scale fluidized bed crystallizer.
- Authors: Iqbal M, Bhuiyan H, Mavinic DS
- Issue date: 2008 Nov
- Concurrent hydrogen production and phosphorus recovery in dual chamber microbial electrolysis cell.
- Authors: Almatouq A, Babatunde AO
- Issue date: 2017 Aug