Analysis the Existence of Heterotrophic Bacteria in Active Water Desalination Plant Output of Kashan City, Iran

Document Type : Original Article


1 Social Determinants of Health (SDH) Research Center” and “Environmental Health Department, Health Faculty”, Kashan University of Medical Sciences, Kashan, Iran

2 Biostatistics & Public Health Department, Health Faculty, Kashan University of Medical Sciences, Kashan, Iran

3 Health, Safety & Environment Faculty, Shahid Beheshti University of Medical Sciences, Tehran, Iran

4 English Translation Studies Department, Foreign Language Faculty, Isfahan Branch, Islamic Azad University, Isfahan, Iran


Aims One of the consequences of taking ground water into surface is changing its chemical
quality, specially increasing the concentration of dissolved salts. This research was performed
in order to analyze growth possibility of heterotrophic bacteria in the membrane of active
desalination plants in Kashan City, Iran.
Instrument & Methods This descriptive cross-sectional study was done on water output
of 20 active desalination plants in 2013 in Kashan City, Iran and 200 specimens of input and
output water was randomly extracted from desalination plants. Awareness and education
level of system operators, filter changing intervals, HPC of input and output water and
chlorine concentration of input and output water were measured and recorded. Obtained
data were analyzed statistically with SPSS 18 software using one-way ANOVA, Chi-square,
McNemar and one-sample T tests.
Findings There was a significant relation between the interval time and output HPC level
of the plants (p<0.05). The mean number of HPC was decreased from 16.7±24.5CFU/ml in
input water to 14.4±23.7CFU/ml in output water which was not significant (p>0.05). The
mean concentration of chlorine in samples of 20 desalination plants was 0.76±0.44mg/l in
input water and 0.64±0.52mg/l in output water (p>0.05). Level of awareness had significant
relation with the output water pollution with HPC (p<0.05) but their education level had no
such relation (p>0.05).
Conclusion The mean level of HPC pollution in output water of desalination plants of Kashan
City, Iran, is much less than WHO standards.