Feasibility of using constructed wetland treatment for molasses wastewater treatment

The surface flow constructed wetland (SFCW) with Cyperus involucratus, Typha augustifolia and Thalia dealbata J. Fraser was applied to treat anaerobic treated-molasses wastewater (An-MWW) under the organic loading rates (OLRs) of 612, 696, 806, 929 and 1213 kg BOD5 ha−1 day−1. The results showed that both removal efficiency and plant growth rate were increased with the decrease of organic loading rate (OLR). All tested-plant species could not grow under OLR of higher than 696 kg BOD5 mg l−1 (p > 0.05). Also, the plant-biomass of the systems was reduced by 10.4%, 26.5%, and 64.7% of initial plant-biomass under the OLR of 806, 929 and 1213 kg BOD5 ha−1 day−1, respectively. However, all tested-plant species showed the same pattern on the plant-biomass production yield and removal efficiency. The highest SS, BOD, COD, total phosphorus, NH4+, NO3- and molasses pigments (MP) removal efficiencies of 90–93%, 88–89%, 67%, 70–76%, 77–82%, 94–95% and 72–77%, respectively were detected under the OLR of 612 kg BOD5 ha−1 day.