N, N Diethyl-P-Phenylene Diamine (DPD) Free/Total Chlorine, Coliform and Heterotrophic Bacterial Profile of Polyethylene Terephthalate (PET) and Sachet Water Sold Within and Around University of Benin Campus.

Abstract

Water quality, free/total chlorine (Cl₂) and bacteriological standard, determine the shelf life of water in the hands of the consumers. This study was carried out to determine the free/total chlorine, coliform and heterotrophic bacterial profile of Polyethylene Terephthalate (PET) and sachet water sold within and around the University of Benin Campus. PET/sachet water was randomly sampled from sales vendors and transported to the laboratory in ice condition for analysis. Standard microbiological methods were followed for the determination of the coliform and heterotrophic bacterial profile of the sampled water. The digital colorimeter methods with N, N Diethyl-P-Phenylene Diamine (DPD) pillow for free chlorine (DPD 1) and total chlorine (DPD 4) determination in water was used. The free chlorine from PET/sachet water samples of UNIBEN, Faithmark, Dandori and Olivia were < 0.1 mg/l, falling short of the recommended World Health Organization (WHO) and Center for Disease and Prevention (CDC) permissible limit (0.2 to 0.5 mg/l). The coliform bacterial counts from this study were recorded as <1.8 MPN, which is less than the WHO and CDC recommended permissible limit. Whereas, the Heterotrophic bacterial counts were well above the recommended limit (> 500 cfu/ml). A proper hygienic regime should be employed during the processing, packing, distribution and sales of PET/sachet water to eliminate high levels of heterotrophic bacteria, which may contaminate the water.