Recycling of aged RO membranes as NF/UF membranes: Biosafety evaluation and aging process

Zheng, Xiang; Chen, Yi‐Chen; Zheng, Liping; Cheng, Rong; Hao, Hua

doi:10.1016/j.desal.2022.115845

Cited by 11 publications

(7 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The micrograph of the recycled RO membrane in Figure 7 shows the removal of the polyamide layer and large pore sizes. After 10 h of exposure with sodium hypochlorite solution, the PA layer has been removed, similar to the membrane morphology presented in a study [ 31 ].…”

Section: Resultsmentioning

confidence: 97%

“…For conversion, an active system (AS) followed in which, at the start, alkaline cleaning was performed using 0.1% of sodium hydroxide (NaOH) in pellet form purchased from Sigma Aldrich (Burlington, MA, United States) dissolved in 14 L of distilled water and stirred for 5 min [ 31 ]. The exposure time was 2 h, at 2 bar pressure, and the CIP pump was used for the alkaline cleaning process, and 5–10 min relaxation time was given after one hour.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Performance Evaluation of UF Membranes Derived from Recycled RO Membrane, a Step towards Circular Economy in Desalination

et al. 2023

View full text Add to dashboard Cite

Reverse osmosis (RO) spiral wound membrane generation reached 93.5% in 2020, resulting in 14,000 tons of used RO membranes being discarded annually into landfills, which is unprecedented. The current study aims to chemically convert the end-of-life RO membrane, followed by its performance evaluation and microbial removal efficiency on three different sources of water, i.e., tap water (TW), integrated constructed wetland permeate (ICW-P), and membrane bio-rector permeate (MBR-P), respectively. This was accomplished by selecting 6 years of spent Filmtech (LC-LE-4040) thin film composite type brackish water reverse osmosis (BWRO) membrane, followed by alkaline and acidic cleaning for 2 h. Finally, the conversion was carried out by 6% sodium hypochlorite (NaOCl) with 300,000 ppm/h exposure by active system (AS) using the clean in place CIP pump at 2 bars for 10 h duration. The membrane demonstrated 67% water recovery and 1% saltwater rejection, which means RO membrane now converted into recycled RO (R-RO) or (UF) by removal of the polyamide (PA) layer. Water recovery was 67% for TW, 68% for ICW-P, and 74% for MBR-P, respectively, with the consistent saltwater rejection rate of 1% being observed, while R-RO exhibited an effective COD removal of 65.79%, 62.96%, and 67.72% in TW, ICW-P, and MBR-P, respectively. The highest turbidity removal of 96% in the ICW-P was also recorded for R-RO. For morphological properties, SEM analysis of the R-RO membrane revealed a likewise appearance as a UF membrane, while pore size is also comparable with the UF membrane. The most probable number (MPN) also showed complete removal of total coliforms after passing through the R-RO membrane. These features made the R-RO membrane an excellent choice for drinking water treatment and wastewater treatment polishing steps. This solution can help developing nations to be efficient in resource recovery and contribute to the circular economy.

show abstract

Section: Resultsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 99%

Performance Evaluation of UF Membranes Derived from Recycled RO Membrane, a Step towards Circular Economy in Desalination

et al. 2023

View full text Add to dashboard Cite

show abstract

“…At this stage, actions need to be taken with respect to disposal or recycling of the EoL modules. − Additional risks are related to the possible accumulation of hazardous substances that had been retained in the modules. The main challenge today is the lack of guidelines and standards for EoL membrane disposal, resulting in the urgency and necessity for establishing a membrane life cycle management.…”

Section: End-of-life Membranes: Challenges and Opportunitiesmentioning

confidence: 99%

Membrane Life Cycle Management: An Exciting Opportunity for Advancing the Sustainability Features of Membrane Separations

Ulbricht

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

Membrane science and technology is growing rapidly worldwide and continues to play an increasingly important role in diverse fields by offering high separation efficiency with low energy consumption. Membranes have also shown great promise for "green" separation. A majority of the investigations in the field are devoted to the membrane fabrication and modification with the ultimate goals of enhancing the properties and separation performance of membranes. However, less attention has been paid to membrane life cycle management, particularly at the end of service. This is becoming very important, especially taking into account the trends toward sustainable development and carbon neutrality. On the contrary, this can be a great opportunity considering the large variety of membrane processes, especially in terms of the size and capacity of plants in operation. This work aims to highlight the prominent aspects that govern membrane life cycle management with special attention to life cycle assessment (LCA). While fabrication, application, and recycling are the three key aspects of LCA, we focus here on membrane (module) recycling at the end of life by elucidating the relevant aspects, potential criteria, and strategies that effectively contribute to the achievement of green development and sustainability goals.

show abstract

“…UV irradiation has the advantage of faster treatment time, precision, and can increase the efficiency of membrane treatment [97]. In addition, UV irradiation does not damage the supporting layer and the membrane substrate, so it does not cause secondary disturbances in the membrane [62]. A breakthrough in the technique of removing the active PA layer on the surface of the RO membrane was made by Khoo et al [48], who used ultrasonics to save PA decay time.…”

Section: Eol Ro On Other Applicationsmentioning

confidence: 99%

A Review: End Of Life Reverse Osmosis Membrane Conversion And Its Prospects In The Study Of Conversion To Reconditioned Membrane

Putri,

Widiasa,

Susanto

2023

E3S Web Conf.

View full text Add to dashboard Cite

Reverse Osmosis (RO) is the most widely applied water purification technology worldwide. However, RO membranes have a short service life before they become waste (End of Life RO/EoL RO), so they must be incinerated or disposed of in landfills. Several sustainability solutions have been proposed and studied in recent years. Therefore, a comprehensive review of the emerging trends in the reuse of EoL RO membranes is presented in this paper. Recycling EoL RO membranes is the most preferred option to solve this waste problem either as direct reuse or after conversion into other types of membranes. Direct reuse of EoL RO membranes can be divided into three categories, such as rejuvenation of EoL RO membranes, use at lower rates of treatment, and use for new applications. Rejuvenation of EoL RO can be done by cleaning treatment, use at a lower level can be done by converting it into NF, UF or MF membranes and EoL RO can be made into recycled products by utilizing parts of the EoL RO membrane module. A review of prospects and challenges faced in the conversion process into reconditioned membranes is also presented in this paper.

show abstract

Recycling of aged RO membranes as NF/UF membranes: Biosafety evaluation and aging process

Cited by 11 publications

References 49 publications

Performance Evaluation of UF Membranes Derived from Recycled RO Membrane, a Step towards Circular Economy in Desalination

Performance Evaluation of UF Membranes Derived from Recycled RO Membrane, a Step towards Circular Economy in Desalination

Membrane Life Cycle Management: An Exciting Opportunity for Advancing the Sustainability Features of Membrane Separations

A Review: End Of Life Reverse Osmosis Membrane Conversion And Its Prospects In The Study Of Conversion To Reconditioned Membrane

Contact Info

Product

Resources

About