Evaluating the effect of different draw solutes in a baffled osmotic membrane bioreactor-microfiltration using optical coherence tomography with real wastewater

Abstract

This study investigated the performance of an integrated osmotic and microfiltration membrane bioreactor for real sewage employing baffles in the reactor. To study the biofouling development on forward osmosis membranes optical coherence tomography (OCT) technique was employed. On-line monitoring of biofilm growth on a flat sheet cellulose triacetate forward osmosis (CTA-FO) membrane was conducted for 21 days. Further, the process performance was evaluated in terms of water flux, organic and nutrient removal, microbial activity in terms of soluble microbial products (SMP) and extracellular polymeric substance (EPS), and floc size. The measured biofouling layer thickness was in the order sodium chloride (NaCl) > ammonium sulfate (SOA) > potassium dihydrogen phosphate (KHPO). Very high organic removal (96.9 ± 0.8%) and reasonably good nutrient removal efficiency (85.2 ± 1.6% TN) was achieved. The sludge characteristics and biofouling layer thickness suggest that less EPS and higher floc size were the governing factors for less fouling.

Evaluation of membrane fouling mitigation strategies in an algal membrane photobioreactor (AMPBR) treating secondary wastewater effluent

“…A similar trend was observed for the biomass roughness, with the highest value for APMBRRLX (0.58), followed by the APMBRBW (0.43) and APMPBRCT (0.27). The behavior of the biomass formed with no control strategy (APMPBRCT) is in agreement with results reported in previous studies on membrane performance without applying physical cleaning showing a decrease in roughness and a tendency towards more compact and dense morphology at early stages (Pathak et al, 2018;Wang et al, 2017). A different trend was found for the APMBRBW and APMBRRLX, showing a constant and higher value in relative roughness during the whole period of observation.…”

Management of table olive processing wastewater by an osmotic membrane bioreactor process

“…Proteins and carbohydrates are the main components found inherently in SMP and EPS [29]. SMP and eEPS content play also an important role in the membrane fouling [44]. Fig.…”

Membrane processes

“…Improved characteristics of mixed liquor in terms of sludge filterability, particle size, and biomass growth along with the degradation of soluble microbial products (SMP) were found in the organic draw solution. Pathak, Fortunato, et al (2018) evaluated the performance of different draw solutes in an integrated baffled osmotic and MF MBR for real sewage employing baffles in the reactor, by employing optical coherence tomography technique, to study the biofouling development on FO membrane. Online monitoring of biofilm growth on a flat sheet cellulose triacetate FO (CTA FO) membrane was conducted for 21 days, and the process performance was evaluated in terms of water flux, organic and nutrient removal, microbial activity in terms of SMP and EPS and floc size.…”