Fabrication of spherical cellulose/carbon tubes hybrid adsorbent anchored with welan gum polysaccharide and its potential in adsorbing methylene blue

A high performance adsorbent was performed by emulsification of carbon nanotubes (CNTs) entrapped cellulose solution, and followed by grafting welan gum onto the support as tentacle-type polysaccharide ligands. The morphology and mechanical properties of the adsorbent were characterized with optical microscopy, scanning electron microscopy, and flow hydrodynamics. The well-dispersed CNTs throughout the support as nanofillers were proved to effectively enhance both the structure stability and the mechanical strength of support. Moreover, the tentacle-type adsorbent was further investigated carefully for its efficiency in adsorbing methylene blue from water in a batch system. It demonstrated that higher pH and longer adsorption time contributed to larger adsorption capacity since the adsorbent provided more adsorption sites available for the dye adsorption at such conditions. Fitting the isotherm data to Langmuir and Sips models gave the conclusion that the adsorption behavior matched best with Sips model, proving a multilayer adsorption at lower concentration and monolayer adsorption at higher concentration. The equilibrium adsorption capacity onto the adsorbent was determined to be 302.1 mg g−1 at pH 6.0 from Sips model. Combined with the advantages of mechanical strength and adsorption performance, the novel adsorbent would be considered to a top-priority adsorbent for separation field.

► A kind of tentacle-type cellulose-based adsorbent was prepared in the study.
► The entrapped carbon nanotubes endowed the adsorbent with high mechanical strength.
► The welan gum was grafted onto the support for large adsorption capacity.
► The novel adsorbent was evaluated in detail by adsorbing dye molecules in water.