Application of nano TiO2 modified hollow fiber membranes in algal membrane bioreactors for high-density algae cultivation and wastewater polishing. (October 2015)

• Record Type: Journal Article
• Authors: Hu, Weiming; Yin, Jun; Deng, Baolin; Hu, Zhiqiang
• Is Part Of: Bioresource technology. Volume 193(2015)
• Page Start: 135
• Page End: 141
• Publication Date: 2015-10
• Subjects: Nano TiO2 -- Membrane fabrication -- Membrane bioreactor -- High-density algae cultivation -- Wastewater polishing; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2015.06.070
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Polyvinylidene fluoride (PVDF) membranes containing nano-TiO2 were fabricated. PVDF/TiO2 membranes had a better antifouling property than PVDF membranes. Mineral precipitation due to photosynthesis caused irreversible membrane resistance. Algae production rate was 6.5 ± 0.1 g/m 2 /d in lab-scale algal MBRs (A-MBRs). The A-MBRs removed 78% of phosphorus and 34% of nitrogen at the SRT of 25 d. Abstract: Polyvinylidene fluoride (PVDF) hollow fiber membranes with nano-TiO2 (5% of PVDF by mass, average size = 25 nm) additives were fabricated and applied for high-density algae ( Chlorella vulgaris ) cultivation. At the average light intensity of 121 μmol/m 2 /s, the algal membrane bioreactors (A-MBR) operated at a hydraulic retention time of 0.5 d and an average solids retention time of 25 d had an average algae biomass concentration of 2350 ± 74 mg/L (in COD units) and algal biomass production rate of 6.5 ± 0.1 g/m 2 /d. The A-MBRs removed an average of 78% of phosphorus from the wastewater at the initial total phosphorus concentrations ranging from 3.5 to 8.6 mg/L. The nano TiO2 -embedded membranes had improved surface hydrophilicity with its total resistance about 50% lower than that of the control. This study demonstrated that PVDF/TiO2 nanocomposite membranes had a better antifouling property for high-density algae cultivation and wastewater polishing.