The main objective of the present work is to treat tannery effluent with a total dissolved content of 150 g/L using solar energy by humidification and dehumidification process using a roof even type greenhouse evaporator. This system not only helps to effectively treat the tannery effluent by increasing its total dissolved solids content to 350 g/L but also helps to generate potable water from tannery effluent by using solar energy. In this study, the performance of the effluent was tested in six different modes. It was found that the tannery effluent total dissolved solids content increased to 350 g/L in just 2.5 days when the greenhouse evaporator was operated in Mode 6 which is the shortest duration when compared to other modes of operation. The specific fuel consumption of the roof even type greenhouse system to treat tannery effluent is 22.55 kW h/ m(3) which is 8.3 % of the energy consumed by the zero liquid discharge plant. Meanwhile, the land area required to dehydrate 1 m(3) of tannery effluent got decreased by 43 % when the roof even type greenhouse evaporator was used. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.