Fate, Elimination, and Simulation of Low-Molecular-Weight Micropollutants in Powdered Activated Carbon–Assisted Fertiliser-Drawn Osmotic Membrane Bioreactor

The elimination of low-molecular-weight (low-MW) micropollutants (MPs) remains a challenge in the osmotic membrane bioreactors (OMBRs). This study investigated the fate, elimination, and simulation of low-MW MPs in a powdered activated carbon (PAC)–assisted fertiliser-drawn OMBR. Compared to the conventional OMBR, the water flux and recovery increased by 10% in the PAC-OMBR. Besides, a twice as thin fouling layer was observed on the forward osmosis (FO) membrane surface with 100 mg/g-MLSS of added PAC. This amount of PAC also boosted the richness and diversity (Chao1 and Shannon index increased 1.5 times) in the microbial community, with Proteobacteria , Bacteroidetes , and Acidobacteria being predominant. Low-MW MPs were eliminated effectively in PAC-OMBR, with up to nearly 100% removal efficiency, while only 2–80% was achieved with traditional OMBRs. This reduced the pathway of low-MW MPs into diluted fertiliser from over 47% to less than 1% of the total influent mass. Hydrophilicity (Log Kow) played the crucial role in the rejection of low-MW MPs by the system, in which acetaminophen and nonylphenol behaviours were dissimilar to the others. A neural network model was suitable for the simulation of MP behaviour with high accuracy (R value of 0.98, root mean square error of 4.7%)