Tertiary Treatment of Municipal wastewater from Lagoons: Use of Constructed Wetlands and UV irradiation
Water is less available on the African continent than any other yet it is almost common knowledge that there is a significant lack of proper wastewater treatment in most of the continent’s countries thereby exposing the scarce water resource to pollution.The inadequacy in treatment stems from a number of reasons that include lack of tertiary systems for extended treatment. Often the reason is ﬁnancial, but it is also due to an ignorance of low-cost wastewater treatment processes and of the economic beneﬁts of treated wastewater reuse.Since most African countries belong to the low income category, the choice of interventions against sustainability is a key issue. With this in mind, processes that use relatively more land and are lower in energy consumption are therefore more attractive. Again, the tropical climate enjoyed by most African countries is salubrious enough to support a number of low-cost biological wastewater treatment technologies for extended treatment. Constructed wetlands exhibit characteristic properties like utilization of natural processes, simple construction, simple operation and maintenance and cost effectiveness and are well suited for tropical climates.