A separation module that includes a porous membrane, where the porous membrane includes a poly(phenylene ether) copolymer containing 10 to 40 mole percent repeat units derived from 2-methyl-6-phenylphenol and 60 to 90 mole percent repeat units derived from 2,6-dimethylphenol; and a block copolymer containing backbone or pendant blocks of poly(C2-4 alkylene oxide). The separation module can be used in devices for wastewater treatment, water purification, desalination, separating water-insoluble oil from oil-containing wastewater, membrane distillation, sugar purification, protein concentration, enzyme recovery, dialysis, liver dialysis, or blood oxygenation.