Constructed Wetlands (CW) are engineered systems mimicking the process of natural wetlands: use of soil and plants to treat wastewater. In the CW, the plants are usually grass due to their resistance to harsh wastewater conditions, while the soil media or substrates used are gravel and sand for effective filtration and adsorption of the pollutants. Other pollutants and nutrients can be taken up by the plants for further treatment of the wastewater, while its deep and extensive root systems provide the environment for microorganisms, which can also remove other organic matter in the wastewater. Aside from this, CW provides ecological benefits such as promoting biodiversity conservation, aesthetics for tourism and even as a source of livelihood.
A framework to guide CW and its implementation will improve its replicability. Such guide should include suitability mapping, design, construction, operation and maintenance, social acceptance, and economic evaluation. A CW treating 540 m3/d of septic tank effluent being operated in Bayawan City, Philippines, since 2006 is used as a case study to establish the above-mentioned framework.
The guide complements a video, offering visuals of the positive impacts created by the CW in Bayawan City (where the local government unit has created a manual of their CW system) and instil confidence to replicate CWs across the country with precision and appropriateness.
Video Link: https://youtu.be/De2V-JMZT_o