Study of the effectiveness of using duckweeds in an oxidation pond to treat municipal wastewater

• Main Authors: Rattanaphan, T.(Prince of Songkla University, Songkhla (Thailand). Faculty of Engineering. Department of Chemical Engineering) E-mail:s4712014@psu.ac.th, Yamsaengsung, R.(Prince of Songkla University, Songkhla (Thailand). Faculty of Engineering. Department of Chemical Engineering), Puetpaiboon, U.(Prince of Songkla University, Songkhla (Thailand). Faculty of Engineering. Department of Civil Engineering)
• Format: Conference Proceeding
• Language: Thai
• Published: Bangkok (Thailand) 2007
• Subjects: Communes; Domestic wastewater; Duckweeds; Efficiency; Lemna; Oxidation pond; Pollutant load; Wastewater treatment; Water quality

Effectiveness of using duckweeds (Lemna perpusilla) for the treatment of domestic wastewater in an oxidation pond at the Prince of Songkla University (PSU) was investigated. The PSU wastewater treatment facility is comprised of 2 stabilization ponds in series, and the second was treated with duckweed to reduce the amount of nutrients present in its effluent before releasing it into the city canal. The objective of this study was to investigate the efficiency and the faecal coliform removal kinetic constants when using duckweeds in a stabilization pond. Wastewater was collected twice a week for a period of 6 months after the duckweeds covered about 90 percent of the water surface. The influent and effluent were monitored for chemical, physical, and bacteriological parameters. Results indicated about a 25-50 percent reduction in BOD5, 30-50 percent drop in TSS, 40-60 percent reduction in TP and 94 percent elimination of faecal coliform bacteria.