"More than water scarcity, diseases and civil wars, Africa is also the least wealthy continent, in terms of economic and financial resources. These combined and tightly linked problems have led to a restricted range of choices, affordable for African countries, to deal particularly with the water issue, as a major topic. Polluted water treatment before use has been their almost unique solution to deal with a growing water scarcity. The treatment of water and elimination of pollutants, mainly pathogenic organisms, xenobiotics and heavy metals, although itself presents significant challenges, is crucial for human health and environmental considerations. However, most regions in developing countries cannot afford the costs of advanced and specialized systems.Numerous water cleaning methods are based in natural, plants or micro-organisms, biochemical processes. Biotechnology is a useful tool that is delivering improved products and process for environmental sustainability, and promises a range of benefits to manage the industrial WW economically and effectively around the world. Some biotechnological techniques are quite sophisticated but others are simple, cost effective and adapted to local conditions and resources of developing countries.These natural biological treatment systems include lagooning, land treatment, phytodepuration, or constructed wetlands systems. They can be applied as secondary or tertiary purification treatment, allowing the removal of pathogenic microorganisms and the degradation of the organic pollutants, so that waste water can be recycled for irrigation and domestic use and hence reduce the pressure on the hydric resources. Other biotechnological techniques to be taken into account within this proposal are biofiltration, membrane bioreactors and algae and other aquatic crops’ application for wastewater purification."