Phytoremediation of Oryza sativa with Media Substrates for The Sewage Effluent Treatment in Constructed Wetland

Abstract

The study investigates the phytoremediation capabilities of Oryza sativa in purifying wastewater from a sewage treatment facility through a constructed wetland system. A laboratory scale constructed wetland with various media substrates was employed to treat effluent from the National Water Research Institute of Malaysia (NAHRIM) sewage treatment plant, with the aim of enhancing water quality. The objectives include designing a subsurface flow SSF) constructed wetland based on hydraulic retention time (HRT) and available area, evaluating the pollutant removal efficiency of different media substrates, and determining the phytoremediation capacity of Oryza sativa for sewage effluent treatment. The findings suggest that Oryza sativa, in combination with various media substrates, significantly improved several water quality indicators, such as Biological Oxygen Deman (BOD), ammoniacal nitrogen (AN), total nitrogen (TN), aluminium (Al), nitrite (NO₂), nitrate (NO₃), total coliform, Escherichia coli (E. coli), and faecal coliform. The most significant reduction observed was in faecal coliform, which decreased by 99.7% when Oryza sativa was combined with K1 media. Additional improvements included a 66.7% decrease in BOD with the combination of Oryza sativa and gravel, and lava rock; a 53.3% reduction in aluminium levels with Oryza sativa and gravel; a 23.1% reduction in E.coli with Oryza sativa and gravel; a 21.7% reduction in total coliform with Oryza sativa alone; a 17.7% decrease in nitrate levels with Oryza sativa and K1 media; a 12.5% decrease in nitrite with Oryza sativa and gravel; a 10.5% decrease in AN with Oryza sativa and gravel; and a 6.7% reduction in TN with Oryza sativa alone. These findings suggest that Oryza sativa, when combined with various media substrates, has substantial potential for phytoremediation of sewage effluent.