Design Approach for Sub-surface Flow Constructed Wetlands

Constructed Wetlands are an engineered wastewater treatment system that tries to mimic the natural biological, physical and chemical processes to treat wastewater. It is emerging as a cost-effective decentralized wastewater treatment solution in the communities where there is availability of inexpensive lands and lack of skilled operators. Different design approaches have been followed and design parameters based on different literatures have been chosen to design a Sub-surface Flow Constructed Wetlands. A simplified design approach well suited to climatic needs to be developed to maintain the cost effectiveness of the system. The kinetic parameters involved in the treatment should be selected properly in order to get the effective design of the system. he developing countries are focusing on cost effective decentralized approach for the sanitation solutions. In recent years, Constructed Wetland (CW) systems have emerged as cost effective options to wastewater (WW) treatment. In Nepal, CWs are becoming a popular method of wastewater treatment in decentralized WW treatment plants, as these systems are well suited for small communities where land is inexpensive and skilled operators are hard to find. Constructed wetland treatment plants in Nepal have shown good performances like asabove 85% of removal fororganic load, 58% for total nitrogen, 75% for phosphorous (as orthophosphate-phosphorous), above 95% for total suspended solids (TSS), 62% for