Baloïtcha Gbètingan Marien Patern, Mayabi Alfred O, Home Patrick G
Department of Civil Engineering, Pan African University Institute for Basic Sciences, Technology and Innovation (PAUSTI), P.O. Box 62000-00200 Nairobi, Kenya.
Department of Civil, Construction and Environmental Engineering, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000-00200 Nairobi, Kenya.
Heliyon. 2022 Mar 19;8(3):e09141. doi: 10.1016/j.heliyon.2022.e09141. eCollection 2022 Mar.
Drinking water quality describes the conditions for water to be accepted as suitable for human consumption. The water quality index is characterized by including, in the assessment process, water quality parameters such as physical, chemical and micro-biological. The availability of adequate management strategies to maintain good quality water has always been a challenge for water utilities. To proffer a solution to ths problem, a simple and effective tool that can be used to easily assess the quality of water is required. Water Quality Index (WQI) and Water Stability Index (WSI) are the most reliable tools for assessing water quality and aggressiveness. This study, therefore assessed the water quality, potential scaling and corrosion of the water supply in the Juja water distribution network by using WQI and WSI based on Langelier Saturation Index (LSI). Five sampling locations including the treatment plant outlet and consumption points were selected for physical, chemical and bacteriological water quality analysis and determination of WQI and WSI. It was found that 100 % of the collected water samples had Calcium concentrations within the World Health Organization (WHO) and Kenya Bureau of Standards (KEBS) acceptable ranges. Additionally, all the collected water samples had TDS concentrations within the WHO and KEBS acceptable ranges. However, water quality parameters such as Residual Chlorine, E. coli, Alkalinity, and Turbidity deviated from the WHO and KEBS standards. The pH values ranged from 6.29 to 8.06 and were generally within acceptable limits. The WSI ranged between - 3.04 to - 0.99, indicating that the water is generally corrosive and may pose a risk to water quality and shorten the lifespan of the network facilities. Generally, the water from the Treatment Plant was of good quality, while at consumption points, JKUAT Main Gate, JKUAT Campus, High Point, and Juja Stage had fair water quality based on the calculated WQI. Also, low concentrations of residual chlorine and E. coli slightly dropped the water quality at all the stations. Overall, the water quality deteriorated in the distribution network and was corrosive throughout the system right from the Treatment Plant based on the WQI and WSI. The water company needs to improve on the water quality chemically by adjusting the Calcium and Alkalinity concentration up to 40 mg/L CaCO3 as recommended for stable water and relook at management strategies of the network to provide better services to consumers.
饮用水质量描述了水被认为适合人类饮用的条件。水质指标的特点是在评估过程中纳入物理、化学和微生物等水质参数。采用适当的管理策略来维持优质水的供应，一直是供水企业面临的一项挑战。为了解决这个问题，需要一种简单有效的工具，用于轻松评估水质。水质指数（WQI）和水稳定性指数（WSI）是评估水质和侵蚀性最可靠的工具。因此，本研究基于朗格利尔饱和指数（LSI），利用WQI和WSI评估了朱贾供水网络的水质、潜在结垢和腐蚀情况。选择了包括处理厂出水口和消费点在内的五个采样地点，进行物理、化学和细菌学水质分析以及WQI和WSI的测定。结果发现，100%采集的水样中钙浓度在世界卫生组织（WHO）和肯尼亚标准局（KEBS）可接受范围内。此外，所有采集的水样中总溶解固体（TDS）浓度也在WHO和KEBS可接受范围内。然而，余氯、大肠杆菌、碱度和浊度等水质参数偏离了WHO和KEBS标准。pH值范围为6.29至8.06，总体在可接受限度内。WSI在-3.04至-0.99之间，表明水总体具有腐蚀性，可能对水质构成风险，并缩短管网设施的使用寿命。总体而言，处理厂的水质量良好，而根据计算出的WQI，在消费点朱贾农业技术大学主大门、朱贾农业技术大学校园、高点和朱贾阶段的水质一般。此外，低浓度的余氯和大肠杆菌在所有站点都略微降低了水质。总体而言，根据WQI和WSI，整个配水网络的水质恶化，并且从处理厂开始整个系统都具有腐蚀性。自来水公司需要按照稳定水质建议将钙和碱度浓度调整至40mg/L碳酸钙，以化学方式改善水质，并重新审视管网管理策略，以便为消费者提供更好的服务。
