Membranes Based on Cellulose Nanofibers and Activated Carbon for Removal of Escherichia coli Bacteria from Water

Abstract

Cellulosic nanomaterials are potential candidates in different areas, especially in water treatment. In the current work, palm fruit stalks cellulose nanofibers (CNF), TEMPO-oxidized CNF (OCNF), and activated carbon (AC) were used to make thin film membranes for removal of E. coli bacteria from water. Two types of layered membranes were produced: a single layer setup of crosslinked CNF and a two-layer setup of AC/OCNF (bottom) and crosslinked CNF (up) on hardened filter paper. The prepared membranes were evaluated regarding their microstructure and layers thickness using scanning electron microscopy (SEM). Water flux and rejection of E. coli bacteria was tested using dead end stirred cells at 1 MPa pressure. Thickness of the cosslinked CNF layer in both types of membranes was about 0.75 micron. The results showed that exchanging water by isopropyl alcohol before drying increased porosity of membranes, and thus resulted in increasing pure water flux and flux of bacteria suspension. The two-layer AC/OCNF/CNF membrane had much higher water flux than the single layer CNF due to higher porosity seen on the surface of the former. Both types of membranes showed high capability of removing E. coli bacteria (rejection~96-99%) with slightly higher efficiency for the AC/OCNF/CNF membrane than CNF membrane. AC/OCNF/CNF membrane also showed resistance against growth of E. coli and S. aureus bacteria on the upper CNF surface while the single layer CNF membrane did not show resistance against growth of the aforementioned bacteria.

Novel cellulose nanofibers/barium titanate nanoparticles nanocomposites and their electrical properties

“…The prepared TEMPO‐oxidized CNFs isolated from bagasse showed very homogeneous thin width of about 5 nm and length of several microns (Figure ); these dimensions are similar to those obtained from other agricultural residues such as rice straw and palm fruits stalks . The carboxylic groups' content of the nanofibers due to oxidation was about 0.64 mmole/g.…”

“…S is a factor that depends on temperature and doping content, which gives information of suitable mechanism involved for ac‐electric conductivity. Moreover, the ac‐universality law has found to decrease the ac response of large number of different types of materials, such as ion conducting glasses, amorphous semiconductors, conducting polymers, and polymer matrix‐conductivity filler composites . The values of s were calculated from the slope of the straight lines of data in Figure and are tabulated in Table .…”

Highly efficient bacterial removal and disinfection by magnetic barium phosphate nanoflakes with embedded iron oxide nanoparticles

“…There is a need to develop novel biocides, since conventional biocides can become less and less efficient and effective due to the emergence of antibiotic-resistant strains. 4 Recently, a number of new materials or methods have been proposed to remove bacteria from water, for example, polyoxometalate supported ionic liquid phases, 5 single cell imprinting on Ag-ZnO bimetallic nanoparticle modified graphene oxide sheets, 6 silvermodified zeolite, 7 cellulose nanofibers and activated carbon membranes, 8 pompon-like ZnO-PANI heterostructures, 9 electrocoagulation and electro-Fenton. 10 These materials showed removal and/or bactericidal properties.…”

Metallo-Terpyridine-Modified Cellulose Nanofiber Membranes for Papermaking Wastewater Purification

“…TEMPO-oxidized CNF was isolated from bleached pulp as described in the literature [14]. Bleached pulp (3 g) was dispersed in distilled water (400 ml) with TEMPO (0.048 g, 0.3 mmol) and sodium bromide (0.48 g, 4.8 mmol).…”