A new approach to scale inhibitor detection: Application and analysis of a novel modified membrane enrichment method

• Published in: Desalination 2024-10, Vol.586, p.117818, Article 117818
• Main Authors: Luo, Yanru, Gao, Fei, Cheng, Zhiyang, Wang, Liangjie, Jia, Hui, Wang, Jie
• Format: Article
• Language: English
• Subjects: Enrichment detection; Membrane modification; Reverse osmosis; Scale inhibitor
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2024.117818

Scaling of reverse osmosis (RO) is an important factor affecting its permeability. Various types of scale inhibitors are widely used to reduce scale formation on membrane surfaces. In particular, polyaspartic acid (PASP) is increasingly used due to its environmental benefits. However, efficient detection of PASP during application remains a challenge. Here, we report method for enrichment and determination of PASP using dodecyl dimethyl benzyl ammonium chloride (DDBAC)-modified membranes. The DDBAC-PES membrane detection method improved detection accuracy by 45 % compared to the conventional method. This is due to DDBAC binding to PASP, causing small molecules to combine into larger ones. Additionally, DDBAC reduced the electronegativity of the PES membrane surface, resulting in a PASP retention rate increase from 90 % to 97 %. The experimental result was explained and demonstrated in DFT calculations. The binding energy of DDBAC to PASP was calculated to be −2.774 eV. In addition，the DDBAC-PES membrane maintained good stability of the PASP assay after two months of storage. It also demonstrated the validity and practicality of detection using the new module. Theoretical calculations also give the same results as the experimental ones. [Display omitted] •Development of a DDBAC-PES modified membrane for PASP detection.•A novel modified membrane enrichment method for PASP detection is proposed.•The properties of DDBAC-PES membranes comparing conventional methods were explored.