Nutrients Enrichment and Process Repercussions in Hybrid Microfiltration Osmotic Membrane Bioreactor: A Guideline for Forward Osmosis Development Based on Lab-Scale Experience

Water

Mads Koustrup Jørgensen¹  Morten Lykkegaard Christensen¹  Khum Gurung²  Mika Sillanpää³  Mohamed Chaker Ncibi⁴ 

[1] Center for Membrane Technology, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg Øst, Denmark;Department of Separation Science, School of Engineering Science, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland;Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam;International Water Research Institute, Mohammed VI Polytechnic University, Green City Ben Guerir 43150, Morocco;

关键词: membrane bioreactor;    nutrients enrichment;    reverse salt flux;    salinity;    fouling;    simulation;   

DOI  :  10.3390/w12041098

来源: DOAJ

【 摘 要 】

The effects of reverse salt diffusion through a forward osmosis membrane were studied in a microfiltration osmotic membrane bioreactor. The reactor was used to treat and simultaneously concentrate nutrients from wastewater. The system was operated at different draw solution concentrations, leading to varying salinity conditions. A relatively low, yet stable forward osmosis flux was observed regardless of increasing draw solution conductivities from 10 to 50 mS cm⁻¹. A substantial increase in sludge conductivity from 5.7 to 19.8 mS cm⁻¹ was observed during the operation. Batch transmembrane pressure-step experiments showed a decline in sludge filtration properties with increasing salinity buildup in sludge due to increasing deflocculation and associated release of protein and carbohydrate fractions of extracellular polymeric substances. Mathematical simulations showed that accumulation of total dissolved solids could mainly be attributed to reverse flux of salts from the draw solution rather than by the enrichment of incoming nutrients when forward osmosis membrane’s salt permeability was high and water permeability low. Ideally, salt permeability below 0.010 L m⁻² h⁻¹ and effective water permeability above 0.13 L m⁻² h⁻¹ bar⁻¹ are crucial to ensure enhanced nutrient enrichment and reduce sludge osmotic pressure, microbial inactivation, sludge deflocculation and membrane fouling.

【 授权许可】

Unknown