Atmospheric Argon Plasma Jet for Post-Treatment of Biotreated Landfill Leachate

Post-treatment of biotreated landfill leachate by atmospheric non-thermal plasma jet was proposed. A parallel operation of three atmospheric non-thermal argon plasma jets was applied for leachate treatment with water sample in strong acidic condition $(\mathbf{pH} < 2)$. Three cases with different gap distances for 1.5, 3 and 4.5 cm were employed with a $4.5\ \mathbf{kV}_{\text{rms}}$ 50 Hz AC neon sign transformer power source for 60 minutes. In this time, the influence of electrode gap distance $(\text{G}_{\text{d}})$ of argon plasma jet on the degradation of refractory organic compounds in biotreated landfill leachate was observed. Some key parameters of water quality including pH, DO, temperature, COD and the macromolecules, such as humic and fulvic substances, were measured before and after treatment. The result showed that the maximum removal of COD (33.9%), fulvic (53.3 %), humic (32.2%), and visible humic substances (57.2%) was found with the operating condition in 4.5 cm $\text{G}_{\text{d}}$ case. It could be confirmed that atmospheric non-thermal Ar plasma had the potential to effectively reduce the refractory organic compounds in wastewater which could be exploited for post-treatment of biotreated landfill leachate.