Farooq Shaukat, Hashmi Imran, Qazi Ishtiaq A, Qaiser Sara, Rasheed Sajida
Institute of Environmental Science and Engineering, National University of Sciences and Technology, Rawalpindi, Pakistan.
Environ Monit Assess. 2008 May;140(1-3):339-47. doi: 10.1007/s10661-007-9872-2. Epub 2007 Nov 8.
The present study was undertaken to examine the drinking water quality of Rawal Treatment Plant, Rawalpindi and its distribution network by collecting samples from eight different locations. The aim was to determine potential relationship between the presence of microorganisms and chlorine residual in the distribution network. Quantification of chlorine residual, turbidity, standard plate count (SPC), fecal and total coliforms by Most Probable Number (MPN) was performed. Three different forms of chlorine were measured at each sampling station such as free chlorine, residual chlorine, chloramines and total chlorine residual. A critical evaluation of data presented indicated that pH generally ranged from 7.02-7.30; turbidity varied from 0.34-2.79 NTU; conductivity fluctuated from 359-374 microS/cm; and TDS values were found to be ranging between 180-187 mg/l. Station # 7 was found to be most contaminated. The value of total chlorine was found to be 0.86 to1.7 mg/l at Station # 3 and 6, respectively. Highest standard plate count was 62 CFU/ml at Station # 7. Total coliforms were less than 1.1 MPN/100 ml at almost most of the stations except at Station # 3 where it was found to be greater than 23.0 MPN /100 ml. Overall aim of this study is to create awareness about contamination of drinking water in the water distribution networks and to make recommendations to provincial agencies such as EPA, CDA and WASA that regular monitoring should be carried out to ensure that the chlorine residual is available at consumer end.
本研究旨在通过从八个不同地点采集样本，检测拉瓦尔品第拉瓦尔处理厂及其配水管网的饮用水质量。目的是确定配水管网中微生物的存在与余氯之间的潜在关系。对余氯、浊度、标准平板计数（SPC）、粪大肠菌群和总大肠菌群进行了最可能数（MPN）定量分析。在每个采样站测量了三种不同形式的氯，即游离氯、余氯、氯胺和总余氯。对所呈现数据的批判性评估表明，pH值一般在7.02 - 7.30之间；浊度在0.34 - 2.79 NTU之间变化；电导率在359 - 374微西门子/厘米之间波动；总溶解固体（TDS）值在180 - 187毫克/升之间。发现7号站污染最严重。3号站和6号站的总氯值分别为0.86至1.7毫克/升。7号站的最高标准平板计数为62 CFU/毫升。除3号站总大肠菌群大于23.0 MPN /100毫升外，几乎所有站点的总大肠菌群均小于1.1 MPN/100毫升。本研究的总体目标是提高人们对配水管网中饮用水污染问题的认识，并向省级机构如环境保护局（EPA）、首都发展管理局（CDA）和水与卫生管理局（WASA）提出建议，即应进行定期监测，以确保消费者端有余氯。
