Author(s): Syafiq Shaharuddin; Nor Azazi Zakaria; Aminuddin Ab. Ghani; Chun Kiat Chang
Keywords: Constructed wetland; Water quality; Biodiversity; Stormwater runoff
Abstract: The aim of the present study is to investigate the performance of constructed wetland in BIOECODS system for water quality treatment from stormwater runoff as well as the performance from species and biodiversity composition. There were 17 sampling stations, starting from Inlet Wetland (InletWet), and Macrophyte zone, which consist of 7 sampling stations, Micropool zone, consist of 9 sampling station and end up at Outlet Wetland (Outwet). The wetland was divided into several sections due to each section possesses different composition, different area and different composition of wetland plant species. Weekly physico-chemical parameters were analysed during the one year period starting from December 2010 and finish at December 2011. The parameters studied were temperature, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), conductivity, total suspended solids (TSS), nitrite, nitrate, ammoniacal-nitrogen (AN-NH3), and orthophosphate. The biological sample covered from phytoplankton, zooplankton and fish. The species composition and diversity for each trophic level species was analysis and relate to the water quality performance. Based on the result obtained, improvement of water quality was obtained as the concentration of nitrate, nitrite, ammoniacal-nitrogen, orthophosphate, TSS, BOD and COD decreased after the water pass through the macrophyte zone and micropool zone before it discharge to outlet wetland. The concentration of nitrite reduce from 0. 035 mg/l to 0. 007, remove 80% ; nitrate reduce from 2. 94 mg/l to 1. 13mg/l remove 61. 56% , ammoniacal-nitrogen reduce from 0. 303 mg/l to 0. 147 mg/l, remove 51. 49 % , orthophosphate reduce from 0. 41mg/l to 0. 16 mg/l, remove 60. 98% , TSS reduce from 28 mg/l to 9 mg/l, remove 67. 86 % , BOD reduce from 2. 78mg/l to 2. 01mg/l, remove 27. 7% and COD reduce from 28mg/l to 15mg/l, remove 46. 43% . The decrease of concentration showed that the improvement of water quality was done in the wetland. Most of the concentrations fall in Class IIA and IIB based on National Water Quality Standards for Malaysia and Department of Environment (DOE) Water Quality Index Classification. Biological measurement showed high diversity of species. Based on the result obtained, W1 and W2 area in the macrophyte zone showed high number of species and percentage distribution of phytoplankton and zooplankton, while Oreochromis niloticus was the dominant species found in the constructed wetland. The improvement of water quality gave positive benefit to sustain and maintain biodiversity at each trophic level.