Chlorine attack on reverse osmosis membranes: Mechanisms and mitigation strategies

Gohil, Jaydevsinh M.; Suresh, Akkihebbal K.

doi:10.1016/j.memsci.2017.06.092

Cited by 150 publications

(73 citation statements)

References 171 publications

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“…We have further studied the effect of GO coating on the chlorine tolerance of RO membranes. The degradation mechanism of the fully aromatic polyamide membrane by chlorine has been extensively studied . The most widely accepted mechanism of RO membrane degradation is N‐chlorination and concomitant ring chlorination reactions along with the altered physiochemical characteristic in polyamide matrix, leading to the decline in the RO performance .…”

Section: Resultsmentioning

confidence: 99%

“…Depending on the chlorine conditions, i. e ., the product of chlorine concentration ( c ) and exposure time ( t ), ( ct HOCl ), the membranes exhibited different physiochemical and structural properties resulted from the different extent of membrane damage upon chlorine attack, typically changing water flux and salt rejection at different trend. As a general rule of thumb, the membrane failure is identified when the normalized salt rejection decreased about 10% below the base line …”

Section: Resultsmentioning

confidence: 99%

“…As shown in Figure , the water flux decreases significantly to ∼20% for all the membranes. The decline in water flux is generally attributed to the increased hydrophobicity of polyamide layer as a result of chlorine addition ,. In contrast, a more pronounced effect of GO coating can be observed for the rejection behavior in response to chlorine.…”

Section: Resultsmentioning

confidence: 99%

“…[38][39][40][41] The most widely accepted mechanism of RO membrane degradation is N-chlorination and concomitant ring chlorination reactions along with the altered physiochemical characteristic in polyamide matrix, leading to the decline in the RO performance. [38] Depending on the chlorine conditions, i. e., the product of chlorine concentration (c) and exposure time (t), (ct HOCl ), the membranes exhibited different physiochemical and structural properties resulted from the different extent of membrane damage upon chlorine attack, typically changing water flux and salt rejection at different trend. As a general rule of thumb, the membrane failure is identified when the normalized salt rejection decreased about 10% below the base line.…”

Section: Membrane Chlorine Resistancementioning

confidence: 99%

“…As a general rule of thumb, the membrane failure is identified when the normalized salt rejection decreased about 10% below the base line. [38] In this study, the chlorine resistance of RO and GO coated RO membrane has been evaluated by comparing the normalized water flux and salt rejection before and after soaking membranes in a NaClO solution with 6000 ppm free chlorine for 1 h at pH = 7. As shown in Figure 6, the water flux decreases significantly to ∼ 20% for all the membranes.…”

Section: Membrane Chlorine Resistancementioning

confidence: 99%

See 4 more Smart Citations

Facile Fabrication of Unimpeded and Stable Graphene Oxide Coating on Reverse Osmosis Membrane for Dual‐Functional Protection

Wang

Liu

et al. 2018

ChemistrySelect

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Membrane fouling and chlorination have remained the greatest threats to durable reverse osmosis (RO) membrane applications. Here, we report a facile technique of high pressure assisted deposition (HPSD) to physically anchor stable graphene oxide (GO) coatings on RO membranes for simultaneous dual‐functional protection against fouling and chlorination without sacrifice of water flux. Thick coatings were directly prepared by HPSD, and a subsequent “skin‐removing” method was used to obtain GO thin coatings with stronger adhesion. The measurement of GO coating thickness was achieved by a “removing‐transferring” method, demonstrating a thickness of 200 and 50 nm for GO thick and thin coatings, respectively. Benefiting from our coating deposition technique of HPSD, 100% of coverage by GO was achieved for both GO coated membranes. The filtration test showed that GO coating was highly permeable to water resulted from the optimized small size of GO sheets (∼200 nm) and the unique water transport properties through GO laminates. The GO thin coating could effectively alleviate the membrane fouling by rendering membrane surface more hydrophilic and smoother, while the thick coating reversely aggravated the fouling due to the more hydrophobic surface. In addition, GO coating could dramatically improve the chlorine stability of RO membrane by impeding the diffusion of reactive chlorine, with a high level of salt rejection after chlorination for GO coated membranes.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Membrane Chlorine Resistancementioning

confidence: 99%

Section: Membrane Chlorine Resistancementioning

confidence: 99%

See 3 more Smart Citations

Facile Fabrication of Unimpeded and Stable Graphene Oxide Coating on Reverse Osmosis Membrane for Dual‐Functional Protection

Wang

Liu

et al. 2018

ChemistrySelect

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Membrane Degradation

2023

Reverse Osmosis 3rd Edition

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Self‐doped sulfonated polyaniline ultrafiltration membranes with enhanced chlorine resistance and antifouling properties

Alhweij

Amura

Wenk

et al. 2021

J of Applied Polymer Sci

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Membranes heavily rely on chlorination to diminish (bio)fouling, but chlorination can also lead to membrane degradation. We developed sulfonated polyaniline (S‐PANI) ultrafiltration (UF) membranes with improved chlorine resistance and intrinsic antifouling properties. The S‐PANI membranes were synthesized through Non‐solvent Induced Phase Separation (NIPS). Membrane performance was evaluated under harsh chlorine conditions (250 ppm sodium hypochlorite for 3 days under different pH conditions). The S‐PANI membranes showed improved chlorine resistance including a stable performance without changes in model foulant BSA rejection. In contrast, PANI membranes suffered critical structural damage with complete leakage and commercial PES membranes showed a 76% increase in pure water flux and a noticeable change in BSA rejection. Small changes in S‐PANI membrane performance could be linked to membrane structural changes with pH, as confirmed by SEM, IR spectroscopy, and contact angle measurements. Additionally, the S‐PANI membranes showed better antifouling properties with a high flux recovery ratio in comparison to PANI membranes using alginic acid, humic acid, and BSA model foulants. Chemical cleaning by sodium hypochlorite re‐instated the transport properties to its initial condition. Overall, the developed S‐PANI membranes have a high chlorine tolerance and enhanced antifouling properties making them promising for a range of UF membrane applications.

show abstract

Chlorine attack on reverse osmosis membranes: Mechanisms and mitigation strategies

Cited by 150 publications

References 171 publications

Facile Fabrication of Unimpeded and Stable Graphene Oxide Coating on Reverse Osmosis Membrane for Dual‐Functional Protection

Facile Fabrication of Unimpeded and Stable Graphene Oxide Coating on Reverse Osmosis Membrane for Dual‐Functional Protection

Membrane Degradation

Self‐doped sulfonated polyaniline ultrafiltration membranes with enhanced chlorine resistance and antifouling properties

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