Biotechnological sulphide removal from effluents.

A new system for sulphide removal is reported in which sulphide is converted to elemental sulphur using colourless sulphur bacteria. A 4 m 3 biorotor reactor has been tested using sulphide-containing anaerobically treated papermill wastewater. Sulphide removal efficiencies well above 90% were achieved at a hydraulic retention time of 19 minutes, using Pall rings of 2.5 cm or Bio-Net 200 as carrier materials. It was also found that reticulated polyurethane is not suitable as carrier material for the sulphide removal process in the presence of fatty acids.