Selectors in pulp and paper mill-activated sludge operations: do they work? Successful aerated selectors have an F/M between 0.5 and 4.4

This paper reviews the Performance and evaluates the success of selectors i n use at seven pulp and paper systems. Three of four aerated selectors and two of three nonaerated selectors examined were successful at filament cont rol. Successful selectors varied significantly in design. Selector hydrauli c detention times ranging from 30 minutes to two hours were successful. The successful aerated selectors had a selector F/M in the range 0.5 to 4.4. T he nonaerated selectors had a selector F/M in the range 10-14. Selectors we re successful at several types of pulp and paper mills including a groundwo od and sulphite mill, a groundwood SCMP mill, and several deinking mills an d TMP mills.