Atrazine removal from river water using direct current and solar-powered electrocoagulation

Atrazine is one of the most frequently found pesticides in groundwater and surface water. Under natural light, the half-life of this herbicide in aqueous medium is around 250 days. Atrazine has shown the potential to alter food webs, decrease diversity, and can interfere with species composition. In the current study, electrocoagulation powered by solar energy was used to eliminate atrazine from the aqueous solution. Aluminum and copper electrodes were used to investigate the effect of different operating parameters such as contact time (10-60 min), applied voltage (5-25 V), initial pH (3-11) of the feed water, types and concentration of supporting electrolyte like NaCl, Na₂SO₄ (100-500 mg/L) on the removal of atrazine. The loss of electrode mass and sludge generation were also evaluated. The effect of the initial concentration of atrazine was observed in the range of 3-15 mg/L. The pH of feed water solutions in all the experiments increased, indicating the necessity for neutralization after electrocoagulation.

The possible mechanisms of atrazine removal were explored using several techniques such as X-ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopic analysis. The particle size, surface structure, and shape of dried sludge particles were analyzed using a scanning electron microscope. The energy consumption and operating cost calculations of the electrocoagulation process infer that this technique is not energy-demanding. Kinetic analysis demonstrated that atrazine removal followed first-order rate kinetics. Removal of atrazine from real river water matrices was also assessed in the current research. Current work indicated that solar-powered electrocoagulation is a promising approach for the elimination of atrazine in the treatment of water and wastewater in decentralized mode.