Constructed wetlands are considered as a promising wastewater treatment option. Though extensively studied, most field experiments reflect the performance of these systems in temperate and cold climates and in relatively controlled flow conditions. This study aims at evaluating the performance of a horizontal subsurface flow constructed wetland using indigenous macrophytes in a tropical climate (i.e., in East Africa, Ethiopia) under suboptimal conditions of flow. Two selected plant species, i.e., Cyperus papyrus (papyrus) and Scirpus validus (bulrush) were tested using the wastewater from a dormitory at Jimma University Campus in Ethiopia. The experimental period consisted of two (rather) well controlled phases with two non-controlled and non-sampled phases and one intentional disturbance phase in between. BOD5 removal was 81% in papyrus, 76% in bulrush and 48% in Control. TSS removal was 76% and 75% in papyrus and bulrush compared to 54% in the control. COD removal showed 65% and 62% in the planted beds and 32% in the control. TSS removal demands more controlled operations than other parameters. It was concluded that CWs can function well under irregular flow conditions and can be the technology of choice in low income countries particularly in tropical climates.

人工湿地被认为是有前途的废水处理选择。尽管进行了广泛的研究，但大多数现场实验都反映了这些系统在温带和寒冷气候以及相对受控的流动条件下的性能。这项研究的目的是评估在热带地区（即东非，埃塞俄比亚）的次最佳流动条件下，使用本土大型植物对水平地下流动人工湿地的性能。使用来自埃塞俄比亚吉马大学校园内一间宿舍的废水，对两种选定的植物物种，即莎草纸莎草纸（莎草纸）和Scirpus Validus纸莎草（纸莎草）进行了测试。实验阶段包括两个（完全）控制良好的阶段，两个非控制和非采样阶段以及一个故意扰动阶段。纸莎草中BOD5的去除率为81％，芦苇占76％，对照占48％。纸莎草纸和芦苇中TSS的去除率分别为76％和75％，而对照组为54％。种植床中的COD去除率分别为65％和62％，对照为32％。除去TSS所需的操作要比其他参数更多。得出的结论是，化学武器在不规则流量条件下可以很好地发挥作用，并且可以成为低收入国家，特别是在热带气候中的首选技术。