Aerobic treatment of digested sludge for the removal of regulated and emerging organic micro-pollutants

 

Sludge is currently disposed of through composting and landfills for the Odense Vandselskab waste water treatment plants. This disposal is costly, due to the amount of sludge and the organic micro-pollutants contained in it, making the farmers potentially less interested in using sludge or sludge-compost on their land as fertiliser.

To decrease the amount of sludge (dry solids basis) an aerobic treatment of sludge is being discussed. Within this project it will be studied, whether this treatment is also effective to bring down concentrations of regulated organic micro-pollutants. To increase the understanding of the processes it is suggested to add some emerging compounds to the list of analysed parameters.

 

 

Miljøstyrelsen (2000) reported a number of measures to reduce the concentratons of LAS, Nonylphenol, PAHs and DEHP. Among those sludge mineralisation (reed bed treatment), composting and post treatment aeration are reported amongst the most successful ones. All these treatments were reported to be most successful on LAS (elimination 95-100%), while Nonylphenols (75-95%), DEHP (30-82%), and PAHs (30-72%) were more critical.