Evaluation of Forward Osmosis and Low-Pressure Reverse Osmosis with a Tubular Membrane for the Concentration of Municipal Wastewater and the Production of Biogas

Mónica Salamanca; Laura Palacio; Antonio Hernandez; Mar Peña; Pedro Prádanos

doi:10.3390/membranes13030266

Evaluation of Forward Osmosis and Low-Pressure Reverse Osmosis with a Tubular Membrane for the Concentration of Municipal Wastewater and the Production of Biogas

Membranes (Basel). 2023 Feb 23;13(3):266. doi: 10.3390/membranes13030266.

Authors

Mónica Salamanca^{1

2

3}, Laura Palacio^{1

2}, Antonio Hernandez^{1

2}, Mar Peña^{1

3}, Pedro Prádanos^{1

2}

Affiliations

¹ Institute of Sustainable Processes (ISP), University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain.
² Department of Applied Physics, Faculty of Sciences, University of Valladolid, Paseo Belén 7, 47011 Valladolid, Spain.
³ Department of Chemical Engineering and Environmental Technology, University of Valladolid, Paseo Prado de la Magdalena 3-5, 47011 Valladolid, Spain.

Abstract

Currently, freshwater scarcity is one of the main issues that the world population has to face. To address this issue, new wastewater treatment technologies have been developed such as membrane processes. Among them, due to the energy disadvantages of pressure-driven membrane processes, Forward Osmosis (FO) and Low-Pressure Reverse Osmosis (LPRO) have been introduced as promising alternatives. In this study, the behavior of a 2.3 m² tubular membrane TFO-D90 when working with municipal wastewater has been studied. Its performances have been evaluated and compared in two operating modes such as FO and LPRO. Parameters such as fouling, flow rates, water flux, draw solution concentration, organic matter concentration, as well as its recovery have been studied. In addition, the biogas production capacity has been evaluated with the concentrated municipal wastewater obtained from each process. The results of this study indicate that the membrane can work in both processes (FO and LPRO) but, from the energy and productivity point of view, FO is considered more appropriate mainly due to its lower fouling level. This research may offer a new point of view on low-energy and energy recovery wastewater treatment and the applicability of FO and LPRO for wastewater concentration.

Keywords: biogas production; forward osmosis (FO); low-pressure reverse osmosis (LPRO); municipal wastewater; tubular membrane.

Grants and funding

This research was funded by the Regional Government of Castilla y León and the EU-FEDER (CLU 2017-09, CL-EI-2021-07, VA088G19, and UIC 082 and UIC 334) and by the Ministry of Science and Innovation through the research project PID2019-109403RB-C21/AEI/10.13039/501100011033.