Removal of iron–cyanide complexes from wastewaters by combined UV–ozone and modified zeolite treatment

摘要: Abstract A treatment system was developed to remove iron-complexed cyanide from wastewaters discharged by small surface finishing workshops. Alkaline chlorination, a widely used method, does not iron–cyanide complexes and produces chlorine secondary pollution effects. In this work, the effectiveness of bench scale with UV–ozone step, followed fixed bed made manganese-modified natural zeolite studied potassium hexacyanoferrate(II) K 4 [Fe(CN) 6 ]. The operated on semi-continuous basis processing up 7.2 l batches synthetic wastewater. optimal residence time established feeding free iron solution using distribution (RTD) model. With employed experimental conditions, 66% removal observed at stage. retained 55% total fed an additional 5% precipitated. Cyanide slightly increased 68%. This method achieved significant complexes. results were analysed RTD model mechanism for processes occurred proposed. Technical economical scaling conditions must be in future works assess feasibility treating electroplating