2017 年 1 巻 1 号 p. 27-34
Ouagadougou, the capital city of Burkina Faso, is located in dry savanna and the issue of water scarcity is of particular concern since water shortage affects the local economy. Treated wastewater from treatment plants can be reused for irrigation. Currently, stabilization ponds are widely used in Ouagadougou, however, the effluent could adversely affect crop production due to low water quality, especially during the dry season. Therefore advanced pond systems are required. This study focuses on wastewater management in urban areas, and discusses the application of high-rate algal ponds (HRAPs) to treated wastewater reuse for agricultural irrigation. Compared with conventional stabilization ponds, HRAPs indicated a lower risk of microbial pathogen contaminants in treated water and higher removal efficiency of nutrients from wastewater. When the effluent from stabilization ponds and HRAPs were used as irrigation water, the estimated yields of tomato production were expected to be 10,208 t and 17,488 t, respectively. Since HRAPs have the advantage of a significantly shorter HRT compared to stabilization ponds, evaporation loss is reduced. Thus, when introducing sewage treatment, it is necessary to consider not only the impact of effluent on the environment, but also the value of irrigation water.
