Choosing Aquatic Plant Species for High Wastewater Treatment Efficiency through Small Wetland

The research was aimed to choose the most appropriate aquatic plant in high capacity as grown in small wetland for community wastewater treatment, they were Typha angustifolia Linn., Cyperus corymbosus Rottb., and Canna indica Linn. The small wetland, sometimes called vertical flow constructed wetland (VFCW), has been designated on 100-m long, 5-m wide and 0.75-m deep in size in which four-hole pipes were laid down at the bottom for releasing some treated wastewater as effluent through the outlet to the storage reservoir. There must be paved the gravel on the bottom up to the level of 5-cm height and overtopping with sand about 15 cm that be followed by 30-cm mixed soil (soil: sand equivalent to 3:1). All selected aquatic plant species were planted in small wetland before flowing community wastewater until soil at saturated level for first week and about 30 cm during second week up to the maximum age of plants. The choosing aquatic plant species were only depended on the high efficiency of wastewater treatment. The most probable aquatic plant was selected on Typha as the first priority for high wastewater treatment efficiency, Canna the second, and more or less efficiency for the others. Fortunately, Typha has been grown well in everywhere, particularly flat wetland in central, west, east and down north of Thailand.