A Review On Sub-Surface Flow Constructed Wetlands In Tropical And Sub-Tropical Countries

Abstract

Water pollution is mostly caused by direct disposal of waste to the ground or river without prior treatment. Several methods had been proposed to overcome the pollution, e.g. by treating the waste prior disposal or by applying artificial wetland systems (constructed wetlands) to treat domestic wastewater. Artificial wetland systems (constructed wetlands) resembles water treatment processes in natural wetlands, that utilizes hydrophytes to symbiose with the microorganisms in the media around the rhizosphere of the plants. A good example of the plant is Cyperus alternifolius, a plant that grows rapidly in wet environments. This plant has a triangular stem, with adult stem height ranged between 0.5-1.5 m. Organic materials contained in the wastewater will be cleaved by the microorganisms into simpler compounds and will be consumed by the plants as a nutrient, while the root system of aquatic plants will produce oxygen that can be used as a source of energy or catalyst for a series of metabolic processes for heterotropic aerobic microorganism. In general, horizontal flow SSF-Constructed Wetlands (hSSF-CW) is being used continuously and applied in many tropical countries. SSF-CW is a good choice for wastewater treatment due to its low maintenance costs and simple operational.