Operation results from a treatment plant for highly loaded dump leachate

As well as a high salt content, the leachate of a special dump which has been closed since 1984 contains up to 250 mg/l iron and high trace amounts of volatile and non volatile hydrocarbons, e.g. dichloromethane, hexachlorocyclohexane (HCH), chlorophenols, aromatic compounds, BTX-compounds and PCB's. At this time the average characteristic concentrations of COD and AOX are 10000 mg/l and 80 mg/l respectively. The leachate is treated in the following steps: - oil separation; - precipitation, flocculation, sedimentation; - rectification; - activated carbon filtration; -neutralization. After having been treated, the water can be discharged into a suitably sized sewage treatment plant, as all poisons and disturbing substances have been eliminated in the course of this treatment (e.G. AOX < 1 mg/l, chlorinated hydrocarbons < 0,1 mg/l). Summing up, it may be said that in an operation lasting more than two years the plant proved to be a success. (orig.)