Degradation of imidacloprid pesticide in aqueous solution using an eco-friendly electrochemical process

Khadije Yari, Alireza Rahmani, Ghorban Asgari, Qasem Azarian, Amit Bhatnagar, Mostafa Leili
2017 DESALINATION AND WATER TREATMENT  
a b s t r ac t The aim of this study was to evaluate the efficiency of electrochemical degradation process in the removal of imidacloprid (IM), a pesticide, from aqueous solutions. Experiments were conducted using a batch glass reactor and two leads as anodes, and stainless steel electrode as a cathode. The influence of various experimental parameters including initial IM concentration (1-150 mg/L), pH (3-11), electrolysis time (20-120 min), current density (12.5-50 mA/cm 2 ) and NaCl
more » ... ion (4.28-26.74 mmol/L) were assessed to determine the optimum conditions. Scanning electron microscopy and X-ray diffraction analyses were used to study the type of materials formed on the electrode surfaces at the electrode preparation stage. The results from this investigation show that at pH = 5, current density = 25 mA/cm 2 , electrolysis time = 30 min, initial pesticide concentration = 100 mg/L and NaCl concentration = 10.69 mmol/L are optimum experimental conditions for achieving maximum IM and chemical oxygen demand (COD) removal from water. Accordingly, the maximum IM and COD removal efficiencies of 99.69% and 85.66% were achieved, respectively. At optimum conditions and applied voltage of 23.95 V, the electrical energy consumption was calculated about 5.35 kWh/kg COD. Based on the results, electrochemical degradation method was found to be a highly efficient technology in comparison with existing conventional methods and could be considered as a cost-effective method to remove IM from water and wastewater.
doi:10.5004/dwt.2017.21330 fatcat:sksp3buj3jgopbjmdo7n5rj3xy