Designing the vertical flow constructed wetland based on targeted limiting pollutant

[Display omitted] •Novel approach to optimize Constructed wetland (CW) area calculation suggested.•Calculation of areal rate coefficient (K) using reverse Kikuth approach.•Reported rate coefficient values for BOD, NH4-N, TN and TP show large deviations.•Better data fit was observed with Plug flow model as compared to CSTR model.•Data classification based on loading, temperature, depth decreased RSDM in K to 10% The requirement of large land area limits the adoption of constructed wetlands (CWs) in urban settings with limited land availability. The area calculations for CW design are commonly carried out following Kikuth approach where the removal rate constant (K) is derived from literature. Investigation of secondary data of 82 vertical flow CWs, performed in this study, yielded wide variations (0.0003 – 0.822 md−1) in the calculated K values for different pollutants under different environmental and operational conditions indicating that it is important to incorporate the desired levels of pollutant removal to arrive at customized design of CWs. The results indicated that the relative standard deviation of K values could be narrowed by classifying the datasets based on design parameters like depth, hydraulic loading rates and substrate loading rates. These calculations can help arrive at more scientific design of CW to achieve the prevailing standards for the discharge or reuse of sewage.