Industrial wastewater treatment using constructed wetland, vegetated with Pista Statiotes (removal of cod nitrates-nitrogen)

摘要

River pollution has been an environmental problem since the 1980 in which the major source came from the industrial area build near the waterways. While the country is heading well towards achieving Vision 2020 as an industrialized nation, the industries are facing with the loads of waste that needs treatment before it can be discharge into main waterways. The high cost of some conventional treatment processes has produced economic pressures. Thus, these have caused the search for alternatives which are cost-effective and environmental-friendly. This lab-scale study was investigating the efficiency of Surface-Flow Constructed Wetland (SFCW) to treat industrial pollutant. The treatment system was vegetated with Pistia stratiotes (water lettuce). There were two designs of experiments conducted to determine the highest percentage removal of pollutants in 15 days of treatment; varying number of Pistia stratiotes and varying dilution factor of wastewater. The parameters studied were Nitrates-Nitrogen and Chemical Oxygen Demand (COD) which are analyzed by using the Hach method. Results from both designated treatment system indicate that the optimal pollutant removal efficiency were the 15 Pistias and dilution factor of 15. System vegetated with 15 Pistia stratiotes shows COD removal of 92.5% and Nitrate-Nitrogen removal of 91.9%, while system using dilution factor of 15 shows COD removal of 84.9% and Nitrate-Nitrogen removal of 97.7%. Besides, the water quality of treated wastewater in this study complies with the standards of industrial effluents discharge. Thus, the study was a success in treating the industrial wastewater by using the SFCW system vegetated with Pistia stratiotes.