Wastewater treatment from tannery industry by subsurface wetlands using Zantedeschia Aethiopica

Abstract

Subsuperficial flux wetlands at bench scale were evaluated for tannery wastewater treatment. Plastic containers of 51 cm of length, 35 cm of width and 30 cm of height were used together with a substrate of gravel between 9 and 12.5 mm. One of the wetlands was planted with Zantedeschia Aethiopica, the other one was no planted and used as a control. Measurement of physical and chemical parameters as pH, turbidity, COD and total chromium were made. The operation of the wetlands was made with different dilution of the wastewater, initiating with a diluted water and finishing with pure wastewater in order to prepare the wetlands. The wastewater was recirculated for both wetlands and a period of time of 26 days was used for this study. A large improvement of the evaluated parameters was found for both wetlands. Nevertheless, a big difference between the planted and control wetland was not found. Accumulation of chromium in the plants was founded in roots, stems, leafs and flowers, making this plant ideal for phytostabilization and phytoremediation process.