Preparation and characterization of polyvinyl chloride (PVC) nanocomposite membranes including modified carbon nanotubes (CNT) for using in water treatment

Masoumi Khosroshahi, Sepideh (2018) Preparation and characterization of polyvinyl chloride (PVC) nanocomposite membranes including modified carbon nanotubes (CNT) for using in water treatment. Masters thesis, University of Mohaghegh Ardabili.

Preview

Text (ساخت و ارزیابی غشاهای نانوکامپوزیتی پلی‌وینیل کلراید محتوی نانولوله‌های‌کربنی اصلاح‌شده جهت استفاده در تصفیه آب) Sepideh Masoumi Khosroshahi.pdf Download (446kB) | Preview

Abstract

Due to growth of industrial and population as well as water resources shortage, wastewater treatment with a focous on water reuse is one of the ways to water resources development. Nowadayes, one of the most suitable and cost-effective ways to water treatment is membrane technology. In this work, polyvinyl chloride (PVC) membranes containing pristine and modified multiwall carbon nanotubes (MWCNTs) were prepared and characterized. MWCNTs were carboxylated in order to achieve an efficient dispersion within the membranes. To evaluate functionalization accuracy of MWCNTs, Fourier transform infrared (FTIR) was applied. Structural and characterization analyses such as, Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), Pore size distribution, contact angle measurement, porosity, water content, mechanical properties, abrasion test, pure water flux, and also filtration of humic acid (HA) solution to evaluate fouling behavior and rejection performance were carried out. The FTIR spectra analysis revealed that COOH groups were formed on the surface of MWCNTs. FESEM images indicated that the amount of surface pores increased at the presence of pristine and modified MWCNTs and pore size distribution curves shifted towards smaller pores. The fabricated nanocomposite membranes have more hydrophilic surface and water contact angle has decreased from 88.6 for PVC membrane to 70.20 and 70.08 for the ones with 0.3 wt% MWCNTs. Pure water flux increased continuously with MWCNTs addition because of higher surface hydrophilicity and more porosity. By adding MWCNTs the pore size distribution of membranes shifted toward smaller pores and consequentially HA rejection reached a peak of 96.88% in PVC/MWCNTs-COOH (0.3 wt. %) nanocomposite membrane. In addition, tensile strength and abrasion resistance of the nanocomposite membranes were improved. It was found that antifouling properties of membranes increases with increasing nanoparticles content, specially carboxylated MWCNTs. However, higher nanofillers content more than 0.3 wt.%, caused a nanoparticle aggregation resulting in a decline in the performance of the composite membranes.The results of classic fouling modeling (Hermia) of membranes showed that cake formation model is the dominant mechanism for all the membranes. Furethermore, the analysis of fouling mechanisms by combined models showed that cake fltration-complete blockage model was in good agreement with the experimental data for the nanocomposite membranes. At last, The PVC/MWCNT-COOH nanocomposite membranes may have potential application in water and wastewater treatment pbased on their low price, enhanced mechanical strength, high permeability, high removal efficiency, and good antifouling performance.

Actions (login required)

View Item