Treatment of wastewater with modified constructed wetland system as a tertiary treatment unit

Incorporation of constructed wetlands into the sewage treatment process is done in order to mimic processes found in the natural ecosystems where wetland plants and their associated microorganisms remove pollutants from wastewater. Vegetation in a wetland provides a substrate upon which microorganisms can grow, and break down organic materials. These organisms and natural chemical processes are responsible for approximately 90% of pollutant removal and waste breakdown in nature. This research work has been undertaken with a view to integrating the natural ecosystem into the existing treatment plant on a large scale, which will be instrumental in minimising the use of machineries and reducing high investment and operating cost as well as energy consumption. The greywater can be reused for purification but the currently adopted process to obtain a secondary water source is complicated and expensive. The conventional process constructed wetlands can be used as a tertiary treatment unit of sewage treatment process.