Biological Decontamination of Water Using Non-Thermal Plasma Treatment

Abstract

The field of biological decontamination of water using non-thermal plasma formation is a novel and rapidly growing field due to its importance for environmental sustainability. The current method of decontaminating water is by adding chemicals that destroy harmful bacteria and viral pathogens. However, this has the risk of forming chemical byproducts that could also be harmful to humans. The way non-thermal plasma works is by ionizing gas and water molecules under pulsed electric fields. It results in shockwaves, reactive species like hydroxyl radicals, atomic oxygen and ozone; all of which aid in effectively killing the bacteria, rendering the water safe to drink and free of harmful byproducts. The plasma is generated in a reaction chamber by applying pulsed high voltage pulses of nano-second duration across two parallel strip electrodes. E. coligrown in Luria’s Broth was inoculated in to sterilized water which ran through the plasma chamber at 1 mL per minute. The obtained water was diluted and plated on agar plates. A control was conducted in order to study the effect of plasma. The obtained plates were incubated and the colony forming units (CFUs) were counted after incubation. The results obtained showed a 65% decrease from 244 CFUs to 89 CFUs significantly reducing the bacterial count from the control. The significance of an alternative decontamination method, both cost effective and safe will be an answer to the increasing scarcity of clean water all around the world. This method will especially be useful in developing countries.