COMPARATIVE SURVEY OF CHEMICAL, PHYSICAL AND MICROBIAL EVALUATION OF COMMERCIAL BOTTLED MINERAL WATER, PACKAGE FILTRATION PLANT, WELL WATER AND TAP WATER

Abstract

Access to an improved drinking water supply is not only a basic need and precondition for a healthy life; it is also a human right. Beside official figures, there should be no doubt that the majority of the Pakistan's population is exposed to the hazard of drinking unsafe and polluted water. In an effort to improve this situation, many consumers in Pakistan have to turn to bottled water as a first alternative to drinking unfiltered well and tap water. Drinking bottled water reflects not just a certain way of life but a necessity and the only option for safe water in many areas of Pakistan. In this study, total twenty eight (28) samples were analyzed and divided into 4 groups. Group I comprised of ten (10) different available commercial bottled mineral water, Group Il consists of six (6) samples from different package filtration plants, Group Ill included six (6) samples of domestic tap water, and Group IV included six (6) samples of well water. All these samples were examined to evaluate their chemical, microbial and physical properties in order to assess their quality. A total of 21 parameters including 4 physical (color, turbidity, pH and conductivity), 17 chemical (arsenic, calcium, chloride, copper, chromium, fluorides, iron, magnesium, manganese, nitrates, nitrites, sulfates, zinc, total hardness, TOC (total organic carbon), TDS (total dissolved solids) and I microbial (Most Probable Number, MPN) were performed. Standard Methods and DR-2()10 Spectrophotometer were used to assess the above mentioned parameters. The results obtained were compared with World Health Organization (WHO) Standards. After gelting the results of all samples, statistical analysis was performed. SPSS software was used to conduct One-Way ANOVA, Tukey's Multiple Comparisons and Scheffé's Homogenous Subsets test. Sampling was divided into 3 separate batches. In each batch collection, single sample was collected from each source. So, in totality, each sample has been analyzed 3 times during the study in 3 different batches. Mean values of the dala obtained has been presented in chapter 4. On the basis of this study, it was evaluated that the physical and chemical parameters of majority of the samples collected, lies within the limits of WHO standards. Majority of the chernical parameters analyzed were below their respective drinking water standards for maximum admissible concentrations (MAC). Arsenic, Iron and Nitrites were found to be below detection limits in majority of the brands. Among the four (4) groups, Mineral water group (Group I) showed that majority of the parameters are within the WHO standards. Package Filtration plant group also showed that samples included in this group have very few parameters (color, water hardness and nitrites) that exceeded the limit of drinking water quality standards. Tap water samples did not show satisfactory results. Results of Color, pH, TOC, and water hardness of some samples indicated that these samples are not fit for the human consumption. Lastly, Well Water samples showed that results of color, turbidity, pH, TDS, magnesium, sulfates and water hardness of some samples were exceeding upper limits of WHO standards. Moreover, Copper and Nitrates were also detected in few sainples of this group which is quite harmful for the hurnan consumption. For Microbial analysis, MPN (Most Probable Number) test was performed and Mineral water brand group showed the best results except for a single brand, whose 6 tubes of MPN test out of 10 (6.9/100mL) were found to be positive . Hence this brand is unfit for human consumption. Samples taken from Package filtration plants showed that only I sample of Westridge was found to be contaminated. Its 4 MPN tubes out of 10 were found to be contaminated (5.1/100mL). Tap water samples showed poor results. Except 2 smnples, remaining samples were found to be heavily contaminated with fecal coliforms as their all tubes (10/10) gave positive MPN test (>23/l()()mL). All samples of Well water were found to be contaminated in both the presumptive and confirmative test for fecal coliforms (>23/10()mL). Hence these water samples are unfit for drinking purposes. Statistical analysis of the data generated also supported that bottled mineral water group is best for human consumption as results of this group are significantly different from the other 3 groups.