Removal of Salicylic Acid from Aqueous Solutions Using Various Electrodes and Different Connection Modes by Electrocoagulation

摘要

Removal of salicylic acid (SA) from aqueous solutions using hybrid aluminum and iron electrodes(eight different combinations) and three different connection modes (monopolar parallel (MP-P),Monopolar series (MP-S) and bipolar series (BP-S)) by electrocoagulation was investigated in thisstudy. The effects of electrocoagulation parameters such as hybrid electrode combination, initial pH,current density, initial salicylic acid concentration, air injection flow, solution conductivity andconnection mode on SA and COD removal efficiencies were evaluated. Optimum operationalconditions at 10 min operating time were found to be as: Al-Al-Al-Al (anode-cathode-anode-cathode)2 electrode combination, the initial pH of 6, current density of 50 A/m , salicylic acid concentration of100 mg/L, air injection mode of 2 L/min and connection mode of monopolar series (MP-S). Underthese conditions, removal efficiencies for salicylic acid and COD were respectively observed as 95.1%and 85.97%. Moreover, the UV absorbance was determined before and after the treatments byelectrocoagulation (EC) process. The operating costs including electrodes, energy and chemicals were3 calculated as 0.0156 m . Sludge generation of EC process was also analyzed by scanning electronmicroscope (SEM) imaging, Fourier Transform Infrared Spectroscopy (FT-IR), XRD (X- raydiffraction) and amorphous Al hydroxides were encountered in the sludge. As to conclude,electrocoagulation through different electrode combinations and connections modes was found to bequite efficient for removal of salicylic acid from aqueous solutions.