A hybrid electrocoagulation-adsorption process for fluoride removal from semiconductor wastewater

• Main Authors: Ajien, A.A (Author), Amri, N. (Author), Ballinger, B. (Author), Ismail, N.F (Author), Jalil, S.N.A (Author)
• Format: Article
• Language: English
• Published: Institute of Physics Publishing 2019
• Subjects: Activated carbon; Adsorption; Coagulation; Concentrated wastewater; Efficiency; Electro coagulations; Fluoride concentrations; Fluorine compounds; Nanostructured materials; Parameter combination; Removal efficiencies; Semiconductor processing; Semiconductor wastewater; Synthetic waste water; Wastewater treatment
• Online Access: View Fulltext in Publisher; View in Scopus

 Semiconductor processing facilities regularly emit wastewater with fluoride concentrations exceeding 100 mg/L which can cause major health issues in the local population. This research aims to address this issue by optimising an electrocoagulation-adsorption (EC-AD) process using two aluminium electrodes and activated carbon. The applied voltage (5, 15, and 20V) and adsorbent dosage (0.20, 0.50, and 1.00g) parameters were varied to treat a synthetic wastewater solution containing 100 mg/L of fluorine. It was found that fluoride removal efficiencies are significantly affected by the adsorbent dosages and applied voltages used. Increasing the applied voltage from 5V to 20V increased the removal efficiency from 37.55% to 64.25% for 0.2g adsorbent dosage and from 33.85% to 67.25% for 0.5g dosage. After all the parameter combinations were tested, an applied voltage of 20V and an adsorbent dosage of 0.50g produced the maximum fluoride removal efficiency. These parameter values thus define the optimal conditions for the EC-AD process to reduce fluoride from highly concentrated wastewater. The AD, EC, and hybrid EC-AD process achieved fluoride removal efficiencies of 2.86%, 41.13%, and 67.25% respectively from synthetic wastewater. Therefore, it was showed that the combination EC-AD process performs better than adsorption (AD) or electrocoagulation (EC) processes used in isolation. © Published under licence by IOP Publishing Ltd.