Application of Native Plants in Domestic Wastewater Treatment using Overland Flow System

Abstract

This study investigated the wastewater treatment efficiencies of the overland flow models planted with 4 different native plants found in the northern part of Thailand, Blumeopsis flava (DC.) Gagnep., Imperata cylindrica Beauv., Ageratum conyzoides Linn. and Paederia linearis Hook. F. The synthetic domestic wastewater controlled organic loading rate in the range of 1.6-2.4 gCOD/m².d was used. It was found that the reactor planted with Paederia linearis Hook. F. showed the highest tolerance to the wastewater. This plant produced new shoot from 30 shoot/m² to 56 shoot/m². The plant growth was related to the high TKN and Otho-P removal efficiencies which were 28% and 85%, respectively. It was found that the nitrogen accumulation in Paederia linearis Hook. F. tissue was increased 22.7 mgN/g in 9 weeks of the experiment.  Paederia linearis Hook. F.  had grew covering most of the reactor surface area helping increased filtration mechanism.
The organic removal efficiencies of reactor planted with Paederiapilifera Hook. F. were 67% and 72% of COD and BOD, respectively. However, it was slightly low compared to Imperata cylindrical Beauv. with COD and BOD removal at 82% and 73%, respectively.