Macrophytes Potentials of Indigenous Plant Species for Faecal Sludge Constructed Wetland Treatment System

A Case in the Sudano-Sahelian Context

Abstract

Constructed Wetland technology has positive potentials for the management of faecal sludge in developing countries of Sub-Saharan Africa. However, identification of indigenous plant species that can survive the high levels of faecal sludge toxicity is a major challenge to its application. Preliminary study highlighted a high complexity of potential macrophytes species identification within the Sahelian context. This study is a preliminary stage of acclimatising four indigenous plant species Setaria verticillata (SV), Cymbopogon nardus (CN), Bambusa vulgaris (BV) and Typha latifolia L. (TL) to wastewater contamination in pot experiment. Macrophytes were subjected to wastewater irrigation from maturation basin of the 2iE Ouagadougou campus wastewater treatment plant. Macrophytes growth was monitored weekly by three growth parameters (No. of Plants per pot, Plant Height and No. of Leaves per pot).  Initial plant height of 46.6, 75.7 and 61.7cm for SV, BV and TL, increased to 98, 103.1 and 93.5 cm after 13, 11 and 8 weeks of planting respectively. After 11 weeks of planting the average height of CN, reduced from 66.3 to 42 cm. Number of plants averagely increased from 25 to 130, 4 to15, 4 to 10 and 4 to 8 respectively for SV, CN, BV and TL. Average leaves per pot increased from 95 to 839, 19 to 67, 368 to 508 and 4 to 49 for SV, CN, BV and TL respectively. Variations of average growth rate among species were statistically insignificant. The results thus indicate satisfactory reed potentials with wastewater acclimatisation.