Removal of pollutants from wastewater using tropical constructed wetland

Abstract

A constructed wetland is considered as a cheap and sustainable alternative for wastewater treatment. The aim of this study is to find the most suitable plants or combination of plants along with the substrate for a horizontal sub-surface flow constructed wetland in Brunei Darussalam. The plants performance regarding removal efficiency of E. coli (EC), Total Coliform (TC), Total Nitrogen (TN), Total Oil and Grease (TOG) and Total Petroleum Hydrocarbon (TPH) were determined during this study. Twelve units of cell A (A1, A3, and A4) made of pixel glass and four units of cell B made of concrete are filled with 0.4 m depth of substrate. Each of cell of A1, A3 and A4 is planted with any of these local plants such as Pandan (Pandanus amaryllifolius)/Nipah (Nypa fruticans) or Lalang (Imperata Cylindrica). The cells in B are planted with all three plants but with different ratio of plant density. Each cell's performance was analysed based on removal efficiency of EC and TC, TN, TOG and TPH. The study concluded that using sand as substrate was found to be most efficient for removing EC and TC consistently and effectively when planted with Nipah, Pandan and Lalang at a ratio of 1:1:1.