Electrochemical technologies to reduce the environmental and sanitary impact of hospital urines

Resumen

The Doctoral Thesis entitled "ELECTROCHEMICAL TECHNOLOGIES TO REDUCE THE ENVIRONMENTAL AND SANITARY IMPACT OF HOSPITAL URINES" has developed a process based on electrochemical technologies to reduce the environmental and sanitary impact of hospital effluents through the direct treatment of hospital urine, due to its chemical and biological risk. 1) Firstly, a statistical and prevalence study was carried out to identify the main pathogens (fungi and bacteria) causing urinary tract infections in hospitalised patients of the Complejo Hospitalario Universitario de Albacete (Spain) as a case of study to clarify the real impact of urine to hospital wastewater. 2) The feasibility of electrodisinfection to treat hospital urine with biological risk was evaluated. This allowed to establish the best treatment point (as tertiary treatment of urban wastewater or as pre-treatment of the main source of contamination) to decrease the health and environmental hazard associated with ARB. The reduction of the potential chemical risk of urine during the disinfection process was also tested. 3) Different electrochemical reactors for pathogen removal in synthetic urine were studied to optimise the operating conditions and to evaluate the disinfection mechanisms involved (oxidising species: hypochlorite, chloramines, hydrogen peroxide and ozone) in the electrochemical disinfection process. 4) The synergies or antagonisms of the electrogenerated oxidants when coupling UV irradiation on the electrochemical disinfection process were considered. 5) The operating conditions of the selected electrochemical technology for the treatment of complex synthetic urine matrices (polymicrobial urines) were verified and adjusted. The denaturation of antibiotic resistance genes and the disinfection mechanisms of the electrogenerated oxidants were also studied. The results obtained allow postulating electrochemical technology as a promising alternative for the disinfection of real hospital urines, contributing to minimise the spread of both antibiotic-resistant bacteria and their resistance genes to other aquatic environments.