Treating anaerobic effluents using forward osmosis for combined water purification and biogas production

Abstract

Forward osmosis (FO) can be used to reclaim nutrients and high-quality water from wastewater streams. This could potentially contribute towards relieving global water scarcity. Here we investigated the feasibility of extracting water from four real and four synthetic anaerobically digested effluents, using FO membranes. The goal of this study was to 1) evaluate FO membrane performance in terms of water flux and nutrient rejection 2) examine the methane yield that can be achieved and 3) analyse FO membrane fouling. Out of the four tested real anaerobically digested effluents, swine manure and potato starch wastewater achieved the highest combined average FO water flux (>3 liter per square meter per hour (LMH) with 0.66 M MgCl as initial draw solution concentration) and methane yield (>300 mL CH per gram of organic waste expressed as volatile solids (VS)). Rejection of total ammonia nitrogen (TAN), total Kjeldahl nitrogen (TKN) and total phosphorous (TP) was high (up to 96.95%, 95.87% and 99.83%, respectively), resulting in low nutrient concentrations in the recovered water. Membrane autopsy revealed presence of organic and biological fouling on the FO membrane. However, no direct correlation between feed properties and methane yield and fouling potential was found, indicating that there is no inherent trade-off between high water flux and high methane production.

Forward Osmosis as Concentration Process: Review of Opportunities and Challenges

“…Thus, technologies focused on concentration and/or nutrient recovery from digestate have been studied recently [ 187 , 188 ]. Digestate from various sources (potato starch WW, swine manure and two types of cattle manure) were comparatively tested for concentration to enhance anaerobic digestion (side stream FO-AnMBR); 1.3-fold CF allows for the significant enhancement of biogas production [ 189 ]. Other studies evaluated the possibility to reject and concentrate organic fraction, N and P from manure digestate using FO.…”

Forward osmosis research trends in desalination and wastewater treatment: A review of research trends over the past decade

“…This categorization was supported by the high occurrence of keywords related to the study of FO performance and application, as in Cluster 1. For instance, extensive publications have shown the potential of the FO process for wastewater treatment [108], nutrient concentration [109,110], resource recovery [111][112][113], food concentration [114], produced water remediation [115], and desalination [116]. All these topics have appeared as keywords in Fig.…”

Complex organic fouling and effect of silver nanoparticles on aquaporin forward osmosis membranes

“…The cleaning of membranes almost completely recovered the characteristics of the membranes after fouling, reaching levels close to those of pristine membranes. Schneider et al [7] investigated the treatment of anaerobic digestion effluents by biomimetic FO membranes. They reported that the initial water flux was 4.3-5.1 l/(m 2 *h) (LMH).…”