Research Paper Effects of Moringa oleifera seeds on the physicochemical properties and microbiological quality of borehole water from Botswana Tiroyamodimo Semanka, Eyassu Seifu* and Bonno Sekwati-Monang Department of Food Science and Technology, Botswana University of Agriculture and Natural Resources, Private Bag 0027, Gaborone, Botswana *Corresponding author. E-mail: eseifu@buan.ac.bw; eyassu.b@gmail.com ABSTRACT This study was conducted to determine the effects of Moringa oleifera seeds on the physicochemical properties and microbiological quality of borehole water collected from Thamaga village in Botswana. Borehole water samples were subjected to two different Moringa seed treat- ment methods: M. oleifera crushed seed powder and Moringa seed extract. Five treatment levels (0, 10, 20, 30, 40 g or mL extract) were used for each treatment method. Borehole water treated with Moringa seed extract had significantly lower ( p , 0.05) total dissolved solids and conductivity as compared with water treated with crushed Moringa seed powder. However, borehole water treated with Moringa seed extract had significantly higher ( p , 0.05) pH and total suspended solids as compared with water treated with crushed Moringa seed powder. Escherichia coli and total coliforms were completely inhibited by Moringa seed extract after 2 h of treatment at a concentration level of 40 mL extract. It was observed that Moringa seed extract at a concentration level of 40 mL was the most effective in treating borehole water compared with Moringa crushed seed powder. In conclusion, Moringa seed extract can be used as an alternative and affordable source of borehole water treatment in rural Botswana. Key words: antibacterial property, Moringa oleifera seed, Thamaga village, water treatment HIGHLIGHTS • Moringa seed extract resulted in complete elimination of Escherichia coli and total coliforms from borehole water. • Moringa seed extract improved the physical properties of borehole water. • Moringa seed extract was most effective in improving the quality of borehole water at a concentration level of 40 mL. • Moringa seed extract can be used as an alternative source of borehole water treatment. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/). © 2022 The Authors Journal of Water, Sanitation and Hygiene for Development Vol 00 No 0, 1 doi: 10.2166/washdev.2022.100 corrected Proof Downloaded from http://iwaponline.com/washdev/article-pdf/doi/10.2166/washdev.2022.100/1109430/washdev2022100.pdf by guest on 25 September 2022