CONSTRUCTED WETLAND FOR DOMESTIC WASTEWATER TREATMENT USING SIDA ACUTA AND SYNEDRELLA NODIFLORA: A CASE STUDY OF ZAGYURI IN THE NORTHERN REGION OF GHANA

Abstract

Constructed wetlands provide sustainable alternative for wastewater treatment with the advantages of pollutants removal efficacy, economical, simple to setup, operate and maintain. Macrophytes have tremendous contribution in wastewater treatment. Their functions include gas transport, a large surface area for the attachment of microbial growth, oxygen release via roots, nutrients and heavy metals absorption and influence on soil hydraulic conductivity. The purpose of this study was to assess the effectiveness of constructed wetlands for the treatment of domestic wastewater using Sida acuta and Synedrella nodiflora as macrophytes. Eight vertical flow mesocosms with dimensions 30 cm (L) X 24cm (W) x 40cm (D) were constructed using sand and gravels amended with biochar and planted with Sida acuta and Synedrella nodiflora. Domestic wastewater was run through the mesocosms with 1.2 × 10-7m3/sec average flow rate and hydraulic retention time of 3 days (72hrs). Efficiency of the treatment was compared between the unplanted (control) and planted beds. The results revealed Sida acuta as a better plant in enduring and tolerating wastewater. However, Synedrella nodiflora was highly effective in the reduction of parameters such as Phosphate, Sulphate, and Nitrate. The difference between the combined treatments and the single treatments in enhancing the wastewater quality was not significant. The study also showed that biochar amended treatments was much better as compared to the sand treatments. It is recommended that further research should be conducted to discover more endemic plants which are capable of reducing nutrients and heavy metals in our domestic wastewater.