Mohammad Ali Zazouli - Department of Environmental Health, School of Health and Health Sciences Research Center, Mazandaran University of MedicalSciences, Sari, Iran
Marjan Safarpour - Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
Farzaneh Veisi - Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
Mahdieh Alam Gholilou - Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran

Background & Aims of the Study: The heterotrophic bacteria are widely used as awater microbial pollution index for drinking water. The aim of this study was toinvestigate the effect of metallic nanoparticles such as Zero Valent Iron (ZVI),Titanium dioxide (TiO2) and Zinc oxide (ZnO) on Heterotrophic Bacteriainactivation in well water.Materials & Methods: We performed an experimental-laboratory study that the effect ofnanoparticles type Zero valent iron (ZVI), Titanium Dioxide (TiO2) and Zinc oxide (ZnO))in constant contact time (30 min) and nanoparticles dose (1 g/L) was investigated onheterotrophic bacteria inactivation.Results: The results showed that TiO2 was detected more effective than ZnO and ZVI. TheHPC inactivation after 30 min of retention time by TiO2, ZnO and ZVI nanoparticles were71.5, 50 and 36.4 as percent, respectively. The maximum bacteria inactivation was 98.82%in the presence of TiO2 nanoparticles.Conclusions: It is concluded that nanoparticles used in this study could be effectively usedto increase the efficiency of removing heterotrophic bacteria from water and can beconsidered for microorganisms’ inactivation.

Water DisinfectionWater microbiologyTitanium dioxideZinc oxideBacteriaHeterotrophic BacteriaIran