Disinfection Of Reverse Osmosis Water By Atmospheric Plasma Rich In Oh Radical

Abstract

Reverse osmosis water is one of the main components of hemodialysis treatment and its chemical and microbiological qualities are vital to avoid additional risks to the patient. A study conducted in the United States between 2009-2011 showed a mortality rate of patients in the first 180 days of dialysis, due to infections, of around 9.6% 1. The technology of non-thermal plasmas, operated under atmospheric pressure, is gaining a potential approach in the eradication and control of bacterial and fungal contamination 2. The aim of this work is to evaluate the efficiency of different atmospheric plasma jet on the disinfection of reverse osmosis water contaminated with standard strains ATCC (American Type Culture Collection) of Escherichia coli(10798), Proteus Mirabilis(35659) and Klebsiella pneumoniae(31488). In the methodology, were prepared bacterial inoculums with reverse osmosis water on the 0.5 of Mac Farland scale. The samples were divided into three groups: (A) control; (B) treated with 5L / min plasma of Argon and water vapor; (C) treated with 5L / min plasma of Argon and hydrogen peroxide. Treatments were performed in triplicate for 10 minutes and at a distance of 1 cm between the nozzle and the liquid surface. A gliding arc discharge reactor was used to generate the plasma jet. For the analysis of the plasma, we used the optical emission spectroscopy (OES) technique, in order to characterize its chemistry. The two plasma compositions used were efficient in the disinfection of the reverse osmosis water contaminated with the different microorganisms, reaching 99.9% reduction of CFU / mL. OES spectra show an increase of 2 orders of magnitude in the OH intensity.