A novel integrated electrochemical process for urban wastewater reuse is proposed, comprising an electrodisinfection-electrocoagulation process with aluminium bipolar electrodes.
This Spanish work describes a novel integrated electrochemical process for urban wastewater regeneration. This electrochemical cell makes it possible to carry out simultaneously two different electrochemical processes: electrodisinfection (ED) and electrocoagulation (EC).
The electrochemical cell consists of a boron-doped diamond (BDD) or dimensionally stable anode (DSA) as the anode, stainless steel (SS) as the cathode, and a perforated aluminium plate, which behaves as a bipolar electrode, between the anode and cathode.
In particular, the treatment of urban wastewater with different anodes and different operating conditions is studied.
First, to check the process performance, experiments with synthetic wastewaters were carried out, showing that it is possible to achieve 100% turbidity removal by the electrodissolution of the bipolar electrode.
Next, the effect of current density and anode material were studied during the ED–EC process with actual effluents. The results show that it is possible to remove Escherichia coli and turbidity simultaneously from an actual effluent from a wastewater treatment facility (WWTF).
The use of BDD anodes allows complete removal of E. coli at an applied electric charge of 0.0077 Ah/dm3 when working at a current density of 6.65 A/m2.
On the other hand, with DSA anodes the current density necessary to achieve total E. coli removal is higher (11.12 A/m2) than that required with BDD anodes.
Finally, the influence of cell flow path and flow rate were studied. The results show that the performance of the process strongly depends on the characteristics of the initial effluent (E. coli concentration and Cl−/NH4+ initial ratio), and that a cell configuration cathode (inlet)–anode (outlet) and a higher flow rate enhance turbidity removal from the treated effluent.
