Dynamic Membranes for Enhancing Resources Recovery from Municipal Wastewater

Abstract

This paper studied the feasibility of using dynamic membranes (DMs) to treat municipal wastewater (MWW). Effluent from the primary settler of a full-scale wastewater treatment plant was treated using a flat 1 µm pore size open monofilament polyamide woven mesh as supporting material. Two supporting material layers were required to self-form a DM in the short-term (17 days of operation). Different strategies (increasing the filtration flux, increasing the concentration of operating solids and coagulant dosing) were used to enhance the required forming time and pollutant capture efficiency. Higher permeate flux and increased solids were shown to be ineffective while coagulant dosing showed improvements in both the required DM forming time and permeate quality. When coagulant was dosed (10 mg L−1) a DM forming time of 7 days and a permeate quality of total suspended solids, chemical oxygen demand, total nitrogen, total phosphorous and turbidity of 24 mg L−1, 58 mg L−1, 38.1 mg L−1, 1.2 mg L−1 and 22 NTU, respectively, was achieved. Preliminary energy and economic balances determined that energy recoveries from 0.032 to 0.121 kWh per m3 of treated water at a cost between €0.002 to €0.003 per m3 of treated water can be obtained from the particulate material recovered in the DM.

Keywords

• direct membrane filtration
• dynamic membranes
• resource recovery
• municipal wastewater treatment