The effects of media size on the performance of biological aerated filters.

Biological aerated filters (BAFs) are an attractive process option, particularly when low land usage is required. They can combine BOD, solids and ammoniacal nitrogen removal and can be utilised at both secondary and tertiary stages of wastewater treatment. Media selection is critical in the design and operation of BAFs to achieve effluent quality requirements.

Biopolymers in wastewater treatment.

Studies investigating the formation and manipulation of biopolymers produced by the heterogeneous microbial cultures found in wastewater treatment are not advancing at a fast rate, reflecting the inherent complexity of the systems involved. Adjustment of the nutrients present within the treatment process currently appears to offer more potential than bioaugmentation with genetically modified organisms for improving certain aspects, such as sludge settling properties and chlorinated organic pollutant removal. An area likely to be of increasing importance in the future is the role of the microbial biopolymer in retaining water within the sludge matrix.