Jornal Europeu de Biologia Experimental Acesso livre

Abstrato

Survey of heterotrophic bacteria population changes in Kerman drinking water distribution system and GIS zoning

Jalal Ghorbani, Shala Moradianfard, ParvizReisi and Mohsen Shehni Gheysari

One of the effective methods for water quality monitoring in drinking water distribution system is heterotrophic bacteria population count. The aim of this descriptive and analytical study was done at July 2010 to June 2011 was survey of the Kerman city (in Kerman province, center of Iran) drinking water distribution system monitoring, the variation of heterotrophic bacteria population and related parameters such as Turbidity, pH, residual free chlorine and Temperature. According to population amount and density of Kerman city, 74 sampling points of Kerman drinking water distribution system was selected and samplings were performed monthly. In all points, HPC, pH turbidity, residual free chlorine were measured according to standard methods for water and wastewater examinations. The obtained results were analyzed by SPSS software and zoning of variations was done on Kerman map by GIS. The annual average of HPC, residual free chlorine, temperature, turbidity and pH were respectively 19.8 cfu/ml, 0.42 mg/L, 24.9 °C, 0.58 NTU and 7.57. ANOVA analysis showed that between average of HPC, residual free chlorine, temperature and turbidity at different months and seasons there are significant differences ,also Correlation test showed that a significant relatives between studied parameters was obtained by Pearson's coefficient(Pvalue<%5). Data zoning showed high amount of HPC at network blind spots that it's related to low residual free chlorine concentration and high turbidity. The average of HPC, pH, turbidity and residual free chlorine in Kerman drinking water distribution system are in line with WHO standards. In blind spots and terminal points of Kerman drinking water distribution system, measured residual free chlorine is lower than WHO standards. At summer, lower pressure of distribution system was created negative pressure, external material entrance and turbidity increasing that is enhanced negative effects that must be considered.