Bh. Boyden et al., TREATMENT OF BLEACHERY EFFLUENTS FROM KRAFT MILLS PULPING MATURE EUCALYPTS, Water science and technology, 29(5-6), 1994, pp. 247-258
Citations number
40
Categorie Soggetti
Water Resources","Environmental Sciences","Engineering, Civil
This study concentrated on the biological treatment and post-ozonation
of mature eucalypt kraft bleachery effluents. The objectives were to
optimise reduction of priority pollutants such as AOX, chlorate, high
molecular weight chromophores and toxicity while maintaining high COD/
BOD removals. Biological treatment was adequately modelled with Monod
kinetics, using biodegradable COD. Sludge yields were of the order 0.7
6 g biomass/g BCOD. Treatment was most effective (70% total COD reduct
ion and 95% BOD5 reduction) with sludge ages over 20 days and F/M rati
os 0.2-0.3. Biological treatment did not reduce total AOX nor colour b
ut reduced chlorate by 63% in preliminary trials. A fungal isolate, As
pergillus.p2 reduced colour by 54% when supplemented with glucose. Ozo
nation as a tertiary treatment reduced AOX by 60% and colour decrease
followed first-order kinetics with respect to ozone consumption.