TY - JOUR
T1 - Comparison of different cleaning strategies on fouling mitigation in hollow fiber nanofiltration membranes for river water treatment
AU - Lee, Jaewon
AU - Zhan, Min
AU - Kim, Youngjin
AU - Hong, Seungkwan
N1 - Funding Information:
A novel HFNF membrane module was supplied by Synopex Corporation, South Korea. The HFNF membrane and scanning electron microscopic (SEM) images of the cross-section and active layer are shown in Fig. 1a–c. The chemical structure of the HFNF membrane was analyzed by fourier transform infrared spectroscopy (ATR-FTIR, Jasco, FT-IR 4600, USA). In Fig. S1, an intense band peak at 1630 cm−1 represents the primary amide bond (amide I band) from the polyamide (PA) active layer, and the band peaks at 1451 and 2243 cm−1 represent peaks of CH2 and nitrile groups (C≡N) from the polyacrylonitrile (PAN) support (Dalwani et al., 2011). A schematic illustration of the chemical structure of the novel HFNF membrane was represented in Fig. 1d. Further detailed membrane information and performance of the HFNF membrane are listed in Table 1. The analysis methods used for membrane properties are provided in the Supplementary information.This research was supported by the Korea Environment Industry & Technology Institute (KEITI) grant funded by the Korean Ministry of Environment (MOE) as “Global Top Project (2016002100007)”, and by the Korea Ministry of Environment (MOE) through Human Resource Development Program for Carbon Neutrality. Also, Y. Kim acknowledges the support from Korea Environment Industry & Technology Institute (KEITI) through the Project to develop eco-friendly new materials and processing technology derived from wildlife, funded by Korea Ministry of Environment (MOE) (2021003270007).
Funding Information:
This research was supported by the Korea Environment Industry & Technology Institute (KEITI) grant funded by the Korean Ministry of Environment (MOE) as “Global Top Project ( 2016002100007 )”, and by the Korea Ministry of Environment (MOE) through Human Resource Development Program for Carbon Neutrality. Also, Y. Kim acknowledges the support from Korea Environment Industry & Technology Institute (KEITI) through the Project to develop eco-friendly new materials and processing technology derived from wildlife, funded by Korea Ministry of Environment (MOE) ( 2021003270007 ).
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/12/20
Y1 - 2022/12/20
N2 - In this study, a novel hollow fiber nanofiltration (HFNF) was investigated for treating real Cijengkol river water in Indonesia. Ultrafiltration (UF) pretreatment was performed to evaluate the effect of UF on the HFNF performance. The water quality of the raw water and permeate of the UF, HFNF, and UF-HFNF hybrid was first characterized. UF could remove only solids, while both nanofiltration (NF) and the UF-NF hybrid achieved a high removal efficiency for impurities in river water, meeting the standards for drinking water quality. However, severe organic fouling occurred in the HFNF membranes. To effectively control organic fouling, various cleaning methods were investigated, and then the analyses of gel permeation chromatography (GPC) and fluorescence excitation emission matrix (FEEM) were conducted on backwashing wastewater to identify the cleaning mechanism. First, hydraulic flushing and backwashing were evaluated, and both methods achieved higher than 90% efficiency particularly for high-molecular-weight organic foulants (>1000 Da). However, the cleaning efficiency decreased during long-term operation because of the low removal efficiency of low-molecular-weight (LMW) organics. Hence, chemically enhanced backwashing (CEBW) (i.e., 5 ppm and 10 ppm NaOCl) was employed to enhance the cleaning efficiency. The results showed that membrane fouling was easily controlled by CEBW with 95% removal efficiency. To reduce the usage of chemicals, CO2 scouring, and CO2 nucleation backwashing were also examined. CO2 nucleation backwashing exhibited a better efficiency than CO2 scouring because of the additional effect of CO2 nucleation on the HFNF membrane surface. Interestingly, a relatively high removal efficiency for fulvic acid-like organic fouling was observed in both CEBW and CO2 nucleation backwashing, whereas tryptophan and tyrosine-like proteins, soluble microbial products (SMPs), and humic-like organics were hardly removed by acidic condition (pH < 6.5) or high shear force, leading to a low cleaning efficiency of CO2 nucleation backwashing.
AB - In this study, a novel hollow fiber nanofiltration (HFNF) was investigated for treating real Cijengkol river water in Indonesia. Ultrafiltration (UF) pretreatment was performed to evaluate the effect of UF on the HFNF performance. The water quality of the raw water and permeate of the UF, HFNF, and UF-HFNF hybrid was first characterized. UF could remove only solids, while both nanofiltration (NF) and the UF-NF hybrid achieved a high removal efficiency for impurities in river water, meeting the standards for drinking water quality. However, severe organic fouling occurred in the HFNF membranes. To effectively control organic fouling, various cleaning methods were investigated, and then the analyses of gel permeation chromatography (GPC) and fluorescence excitation emission matrix (FEEM) were conducted on backwashing wastewater to identify the cleaning mechanism. First, hydraulic flushing and backwashing were evaluated, and both methods achieved higher than 90% efficiency particularly for high-molecular-weight organic foulants (>1000 Da). However, the cleaning efficiency decreased during long-term operation because of the low removal efficiency of low-molecular-weight (LMW) organics. Hence, chemically enhanced backwashing (CEBW) (i.e., 5 ppm and 10 ppm NaOCl) was employed to enhance the cleaning efficiency. The results showed that membrane fouling was easily controlled by CEBW with 95% removal efficiency. To reduce the usage of chemicals, CO2 scouring, and CO2 nucleation backwashing were also examined. CO2 nucleation backwashing exhibited a better efficiency than CO2 scouring because of the additional effect of CO2 nucleation on the HFNF membrane surface. Interestingly, a relatively high removal efficiency for fulvic acid-like organic fouling was observed in both CEBW and CO2 nucleation backwashing, whereas tryptophan and tyrosine-like proteins, soluble microbial products (SMPs), and humic-like organics were hardly removed by acidic condition (pH < 6.5) or high shear force, leading to a low cleaning efficiency of CO2 nucleation backwashing.
KW - CO backwashing
KW - Chemically enhanced backwashing
KW - Hollow fiber nanofiltration
KW - Hydraulic backwashing
KW - Indonesia river Water
UR - http://www.scopus.com/inward/record.url?scp=85140988106&partnerID=8YFLogxK
U2 - 10.1016/j.jclepro.2022.134764
DO - 10.1016/j.jclepro.2022.134764
M3 - Article
AN - SCOPUS:85140988106
SN - 0959-6526
VL - 380
JO - Journal of Cleaner Production
JF - Journal of Cleaner Production
M1 - 134764
ER -