Removal of nitrobenzene from wastewater by vertical flow constructed wetland and optimizing substrate composition using Hydrus-1D: optimizing substrate composition of vertical flow constructed wetland for removing nitrobenzene from wastewater

Nitrobenzene is a toxic chemical that is mainly used in industries to produce aniline and many other products, and eventually it is excessively present in industrial wastewaters. In this study, NB removal efficiency data were obtained by experimental scale vertical flow constructed wetlands. Four columns with same size and diameter named as A, B, C and D were used for the experiment and filled with the substrate in three layers having different soil compositions. Synthetic wastewater was prepared in the laboratory and fed to all the wetland columns. The Hydrus-1D model was used to mimic the removal and transport of nitrobenzene by these data with the same boundary conditions. The values of NB removal and the influence of water content and hydraulic conductivity were compared with all the columns, and best composition of substrate was selected on the basis of maximum removal of nitrobenzene. 76.2% was the maximum removal efficiency of NB exhibited by column D, while column A, B and C were having 50.2%, 55.8% and 65.9%, respectively.