Influence of the cell design in the electroremoval of PPCPs from soil slurry

The effluent from wastewater treatment plants (WWTPs) have been extensively reused for various purposes in many regions of the world, including landscape and agricultural irrigation. However, the elimination of pharmaceuticals and personal care products (PPCPs) in conventional WWTPs is not complete and consequently they may be present in effluent which, can be used for soil irrigation. This work discusses the efficiency of electro based processes, applied to soil slurry aiming PPCPs removal. Three different cell designs were tested, with three-, two- and one-compartment(s) (3C-, 2C- and 1C-cell, respectively). In the case of the 3C- and 2C-cells, ion exchange membranes were used for compartment division. Three PPCPs with different physical and chemical characteristics were studied: bisphenol A (BPA), 17α-ethinyloestradiol (EE2) and oxybenzone (MBPh). All experiments were carried out for 3 days with a current density of 0.02 mA cm⁻². After the electro based experiments, 44%–100% of the three contaminants were removed (mobilized and/or degraded) from the soil slurry. The highest removal rates (>83%) were achieved for BPA and EE2. BPA and MBPh were mainly mobilized towards an anode compartment, whereas EE2 was mainly degraded. Among all the tested cell designs, 1C-cell showed a broader range to contaminants removal from soil through electrodegradation. The 1C-cell also presents the main advantage of degrading the PPCPs of removing and accumulating them in another compartment, where degradation might not occur.