Treatment of industrial wastewater using constructed wetland : removal of orthophosphate and ammonia nitrogen

Industrial wastewater is one of the major concerns of the environment problems. As the wastewater is found to be highly contaminated, it could not be discharged directly into the environment. Therefore, wastewater treatment is essential to minimize the effect of the contaminants to nature. Based on previous studies, constructed wetland system (CWS) was proved to have high efficiency in treating industrial wastewater with low operating and maintenance cost. The industrial wastewater studied was Palm Oil Mill Effluent (POME) which was taken from Lepar Hilir Palm Oil Mill. In this research, lab scale of free water surface constructed wetlands was designed with the water lettuce (Pistia Stratiotes) as the wetland plant. The parameter studied including ammonia nitrogen (NH 3-N) and orthophosphate (Po \n4 3- \n). In order to investigate the effectiveness of the systems, three variables were studied which were the number of plant used (5, 10, 15), the wastewater concentration (87.5%, 75%, 62.5%) and the physical appearance of the plants during the treatment. The results showed that NH3-N was removed at high removal efficiency meanwhile Po \n4 3- \nremoval appeared at low removal efficiency. Both NH 3-N and Po \n \n4 3- \nremoval showed better results in the CWS with 15 plants. In term of the different POME concentration variable, the CWS with 87.5% showed the highest removal efficiency for NH \n-N and 75% POME concentration showed the highest removal efficiency for Po \n3 \n4 3- \n. For plant growth observation, at the end of the treatment, many of the water lettuces were wilted. As conclusion, this study showed that constructed wetland can remove contaminant in POME.