Evaluation of the action of photosensitizers immobilized on chitosan in photodynamic inactivation of Escherichia coli bacteria present in drinking water

• Grant number: 10/04569-0
• Support type: Scholarships in Brazil - Master
• Effective date (Start): April 01, 2011
• Effective date (End): March 31, 2012
• Field of knowledge: Engineering - Biomedical Engineering - Bioengineering
• Principal researcher: Janice Rodrigues Perussi
• Grantee: Cintia Ramos Camargo
• Home Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 98/14270-8 - Center for Optical and Photonics Science, AP.CEPID

Abstract

Urbanization and the fast growth of population have brought disastrous consequences for the environment; pollution and contamination of oceans, rivers and groundwater are one of them. Water is an important environment for development of life, so the elimination of harmful substances and microorganisms in water is of great importance. Water purification is usually a chemical process, for which chlorine, hypochlorites, chloramines, chlorine dioxide, bromine and ozone are used to damage the cell wall of microorganisms. However, analysis of water treated by these methods revealed the formation of by-products which are regarded as toxic and as potentially carcinogenic. Thus, replace these chemical methods with more ecologically friendly disinfection methods is a necessity. Through a process called Photodynamic Inactivation, microorganisms can be inactivated using a photosensitizing substance followed by irradiation with visible light in an appropriate wavelength. In this project, Photodynamic Inactivation will be used for water disinfection using photosensitizers immobilized in heterogeneous phase in order to eliminate the microorganisms. For disinfection experiments under laboratory conditions, the microorganism to be inactivated will be the bacteria Escherichia coli employing photosensitizers immobilized in chitosan membranes. Photosensitive molecules are a derivative of chlorin e-6, phthalocyanines and hypericin, all synthesized in Brazil. Furthermore, to reproduce a real situation of disinfection of water, a water reactor will be used. Water disinfection using photosensitizers has important practical applications, such as disinfection of water tank of hospitals, dental offices, daycare centers and schools. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

. Development of chitosan membranes with photosensitizers incorporated aiming water disinfection. 2012. Master's Dissertation - Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) São Carlos.