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

Aims One of the consequences of taking ground water into surface is changing its chemicalquality, specially increasing the concentration of dissolved salts. This research was performedin order to analyze growth possibility of heterotrophic bacteria in the membrane of activedesalination plants in Kashan City, Iran.Instrument & Methods This descriptive cross-sectional study was done on water outputof 20 active desalination plants in 2013 in Kashan City, Iran and 200 specimens of input andoutput water was randomly extracted from desalination plants. Awareness and educationlevel of system operators, filter changing intervals, HPC of input and output water andchlorine concentration of input and output water were measured and recorded. Obtaineddata 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 levelof the plants (p<0.05). The mean number of HPC was decreased from 16.7±24.5CFU/ml ininput water to 14.4±23.7CFU/ml in output water which was not significant (p>0.05). Themean concentration of chlorine in samples of 20 desalination plants was 0.76±0.44mg/l ininput water and 0.64±0.52mg/l in output water (p>0.05). Level of awareness had significantrelation with the output water pollution with HPC (p<0.05) but their education level had nosuch relation (p>0.05).Conclusion The mean level of HPC pollution in output water of desalination plants of KashanCity, Iran, is much less than WHO standards.

کلیدواژه ها:

Osmosis ، Water Purification ، Biofilms ، Heterotrophic Growth