Dewatering stabilized solids (high P) Minimal Pretreatment (grit removal, screens) Influent Effluent Anaerobic MBR methane O2O2 sludge (8-10% P) stabilized sludge AnoxicAnaerobic Two-stage MBR First stage: convert organics into methane Objectives: recover more energy from the organics, use less O 2 produce less sludge, first stage generates carbon needed for N and P removal, avoid chemicals for disinfection. Second stage: remove nutrients membranes

First stage converts organics into methane Second stage removes nutrients Laboratory setup

Dept. Civil & Environmental Engineering, Stanford University Chok Hang Joanne Yeung SU, PhD student Daniel Yeh Univ. S. Florida, Asst Prof Craig Criddle SU, Assoc. Prof Bob Hickey Ecovation, VP MBR Project Team Charles Hardy SU, MS student (graduated) Bob Brown SU Exp Lab Young Lee SU, Postdoc Philip Wong SU, PhD student George Wells SU, PhD student Alicia Ng SU, undergrad