Abstract: A method of treating sewage sludge comprises incubating raw sludge at a temperature in the mesophilic range to reduce the pathogen content of the sludge.

Abstract: An aromatic polyethersulphone incorporating sub-unit (1) where A is an electron withdrawing group, the designation "o,p" represents that the bond is at the ortho or para position to the A group, and X is selected from: OH; --O M where M is an organic or inorganic cation (other than hydrogen) and n is at least 1; --NR1R2 where R1 and R2 are the same or different and are selected from hydrogen and alkyl, aryl, aminoalkylene or ammonoalkylene groups; and --OR3 where R3 is an alkyl or aryl group; either as the only sub-units of the polymer or in combination with comonomer units.