Exhaust Air and Condensate Treatment

This chapter describes the kind, the features and the quantity of volatile organic and of inorganic gas components being transferred to exhaust air during belt drying of sludge. Also, the factors influencing VOC- and odor-load are mentioned. The dust issue is also treated. The different kinds of scrubbers are described and links for proper operation are given. Tables describing ingredients of wastewater periodically flushed off from the scrubbers are presented. Trickling bed reactors and bio scrubbers are discussed additionally. Bio filters and activated carbon filters are descrbied. In case of higher loads of exhaust air with VOC and odor units the exhaust treatment unit has to be boosted to get sufficient reduction. Upgrading with UV-C-radiation or regenerative thermal oxidation are discussed in detail. The composition of condensate is discussed and processes to remove COD- and ammonia load are described.