Use of Maerua Decumbens as a Natural Coagulant for Water Purification in the Dry Lands of Kenya

Indigenous management and utilization of naturally occurring tree species and shrubs/lianas is not a new culture worldwide. Various communities in the world use their indigenous tree /shrub / liana species to meet their needs for food (human and livestock), shelter and medicine among other diverse wood and non-wood forest products. Introduction of new exotic species has eroded the importance of some of these important indigenous plant species to great extends. It is however, important to consider that while these exotic species have multiple uses, most of them are not well adapted to our arid and semi-arid regions hence the need to promote the management and sustainable use of the indigenous species. Maerua decumbens is a shrub or woody herb species in the Capparaceae family and grows to a height of 0.5 to 3m with a large swollen root. It mostly occurs naturally in the arid and semi-arid areas in Kenya and is used traditionally by rural communities for medicinal and water purification purposes. Members of the Mearua species are indicated as poisonous and probably a health risk and yet some of the communities chew the roots of Mearua decumbens against thirst and also use them for purifying water (Beenje H.1994). The study was done to enhance the use of Maerua decumbens as a natural coagulant for water purification by determining whether the plant used for water purification in Mutha in Kitui County is toxic or not. A reconnaissance survey was done to confirm its use for water purification and toxicity tests were done to determine the safety of the plant for human utilization as a natural coagulant for water purification. The results of the study revealed that M.decumbens is completely safe for human consumption and does not have any heavy metals that pose a risk to human health.