Evaluating the drinking waters microbial flora of reverse osmosis treatment systems in kashan city during summer and autumn (2015)

摘要

According to the various difficulties of Distillation desalination system,currently the membrane technology such as Reverse Osmosis (RO) is more useful. High concentration of dissolve solids in supplying water resources in Kashan caused a bad taste and reduced the consumer’s desire for using such water,and often they used treated water in a way that at the conducting time of this study,20 centers treated the water by RO method in the city. Therefore,this study evaluated the microbial flora of produced drinking water of RO treatment system in Kashan city during summer and autumn 2015. In this study the census method have used and the sampling have done from all the RO water treatment centers of the city. Three input,output and after storage,samples have taken. The evaluation of the temperature,residual chlorine,TDS,the storage time,and RO membrane operation time in samples have done. The HPC test has done on the samples in the laboratory and the positive plates have identified in terms of bacterial spices. The tests have repeated in four months of the year from July to October. The results showed 95% residual chlorine in the input samples and the HPC test for these samples showed no contamination. The sample contamination after treatment and the tank were 8 and 15% respectively. In addition,the most contamination level have related to September,which the samples temperature in this month reach its highest level. The Pearson coefficient results showed that there was a significant relation between the Heterotroph colonies number and the residual chlorine and temperature parameters,which was consistent with Karami et al. in Kermanshah and Dobaradaran et al. in Esfahan studies. In addition,there was a significant relation between the Heterotroph colonies number and storage time and RO membrane operation time.