Table 7.
Hybrid MF/UF membrane with chemical/physical processes after conventional secondary treatment for water reuse applications.
| Membrane Process (Scale and Operation Duration) |
Feed Wastewater | Operating Conditions | Feed Characteristics | Permeate Quality/Removal Rate | Application for Reuse | Standard Basis | References |
|---|---|---|---|---|---|---|---|
| GAC+MF (submerged) (lab scale,140 d) |
Secondary treated water of the sewage treatment plant in Sung- kyunkwan University | MF: 0.22 μm Flux: 98 L·m−2·h−1 TMP: 0–0.4 bar |
pH: 7.62–8.02 Turbidity: 2.2–10.3 NTU TSS: 4–20 mg·L−1 UV260: 0.28–0.32 cm−1 DOC: 6–8 mg·L−1 COD: 10–30 mg·L−1 TN: 30–50 mg·L−1 TP: 15–30 mg·L−1 |
Turbidity: 0.1–0.4 NTU, 100% TSS: 100% UV260: 0.26–0.3 cm−1, 60% DOC: 2–4 mg·L−1, 40–46% COD: 8–25 mg·L−1, 53% TN: 20–40 mg·L−1 15% TP: 10–20 mg·L−1, 13% |
Not mentioned | WHO guidelines | [100] |
| Submerged MF–GAC (Semi-batch, 60 d) |
Biologically treated sewage effluent | MF: 0.14 μm, flat sheet NF: 700 Da, flat sheet TMP: ≤ 4 bar Flux: 2.5 L·m−2·h−1 GAC: 10% daily replacement |
pH: 6.8–7.6 EC: 520–1120 μS·cm−1 DOC: 3.6–7.7 mg·L−1 |
DOC: 2.4 ± 0.2 mg·L−1, 53 ± 5% PPCPs: < 5 ng·L−1 (for each) |
Not mentioned | Australian and New Zealand Guidelines for Fresh and Marine Water Quality | [88] |
| Coagulation +MF (lab scale, 5 months) |
Secondary effluent from WWTP | Coagulant: 10–50 mg·L−1 alumina MF: 0.1, 0.22 μm; TMP: 0.34 bar |
Turbidity: 19.7 ± 87.9 NTU TOC: 7.2 ± 6.5 mg·L−1 pH: 7.0 ± 0.2 UV254: 0.040–0.058 cm−1 Alkalinity: 202.8 ± 12.2 mg·L−1 as CaCO3 TSS: 14.4 ± 25.8 mg·L−1 |
Turbidity: 0.11–0.13 NTU, >93%; TOC: 1.30–1.56 mg·L−1, 23.5–35.5% UV254: 0.019–0.02 cm−1, 52.5–54.5% |
Not mentioned | Not mentioned | [99] |
| Coagulation + PAC + UF (lab scale) | Secondary effluent from WWTP | UF: 50 kDa TMP: 1 bar Coagulant: FeCl3 |
pH: 7.4 Turbidity: 18 NTU TSS: 35 mg·L−1 BOD5: 30 mg·L−1 COD: 77 mg·L−1 EC: 1350 μS·cm−1 Zeta potential: 4.118 mV |
COD: 13.33–21 mg·L−1 Turbidity: 0.5–0.8 NTU Zeta potential: −0.332–0.166 mV |
Not mentioned | Not mentioned | [106] |
| PAC+UF (lab scale, ~1 h) |
Secondary effluent from domestic WWTP | UF: 100 kDa TMP: 1 bar |
pH: 7.1–7.6 Turbidity: 0.9–1.5 NTU TOC: 3.3–5.2 mg·L−1 UV254: 0.09–0.12 cm−1 COD: 25–32 mg·L−1 Color: 18–24 CU Coliforms: 300–700 mL−1 |
DOC: 22.2–28.8% UV254: 33.7–38.3% |
urban reuse, agricultural, landscape and industrial reuse | Not mentioned | [107] |
| MF+UF | Secondary effluent from urban WWTP | MF: 0.2 μm, hollow fiber, 0.2–0.8 bar (TMP) UF: 0.05 μm, flat sheet, 0.2–0.6 bar (TMP) |
Turbidity: 4–20 NTU TSS: 11–87 mg·L−1 T-UV253.7: 11–41% Nematode eggs: 0–200 Un·L−1 E. coli: 104–106 CFU·100 mL−1 Fecal coliforms: 104–106 CFU·100 mL−1 Coliphages: 103–104 PFU·100 mL−1 |
Turbidity: 0–0.9 NTU TSS: 1–7 mg·L−1 T-UV253.7(%): 0 Nematode eggs: 0 E. coli: 0 CFU·100 mL−1 Fecal coliforms: 0–9 CFU·100 mL−1 Coliphages: 0–1 PFU·100 mL−1 |
Not mentioned | Water reuse guidelines of US EPA | [108,109] |
CFU: colony forming unit; EC: electrical conductivity; PPCPs: pharmaceuticals and personal care products; SAC: spectral absorption coefficient.