Three‐chamber Bioelectrochemical System for Biogas Upgrading and Nutrient Recovery

Abstract

Abstract Here, an innovative three‐chamber bioelectrochemical system configuration is proposed to combine COD, CO 2 and NH 4 + removal into a single device. In the proposed process, while COD oxidation and CO 2 reduction occurred, respectively, in the anodic and cathodic chamber, the consequent current generation promoted the migration of target ionic species towards an intermediate accumulation chamber, across cation and anion exchange membranes, respectively. Under this configuration, COD removal proceeded in the anode chamber with an average removal rate of 841 mgCOD L −1 d −1 while the cathode was able to remove 2.1 gCO 2 L −1 d −1 and produce 60 meq L −1 d −1 of CH 4 . Around 90% of the removed CO 2 was contained in the concentrated spill (at around 20 g L −1 of bicarbonate), which was recovered from the intermediate accumulation chamber and also contained the removed nitrogen as ammonium ion (around 32% removal and around 4‐fold concentration with respect to the anode influent). Methane generation allowed a partial recovery of energy of overall energy consumption costs of both COD and CO 2 removal. This study confirms the possibility to combine three processes into a single bioelectrochemical device.

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Identifiers

DOI

10.1002/fuce.201700048

Journal

Fuel Cells

Year

2017