Carbon nanotubes and cyclodextrin polymers for removing organic pollutants from water

Abstract

Some organic compounds are major water pollutants. They can be toxic or carcinogenic even at low concentrations. Current technologies, however, fail to remove these contaminants to parts per billion (ppb) levels. Here we report on the removal of organic pollutants from water using cross-linked nanoporous polymers that have been copolymerized with previously functionalized carbon nanotubes. These novel polymers can remove model organic species such as p-nitrophenol by as much as 99% from a 10 mg/L spiked water sample compared to granular activated carbon and native cyclodextrin polymer that removed only 47 and 58%, respectively. These polymers have also demonstrated the ability to remove trichloroethylene (10 mg/L spiked sample) to non-detectable levels (detection limit <0.01 ppb) compared to 55 and 70% for activated carbon and native cyclodextrin polymers, respectively.

Application of Cyclodextrins in Textile Dyeing

“…The polymeric «nanosponge» materials are not durable (usually they are in gel form), so they must be impregnated onto the pore structure of either a ceramic or some other porous surfaces. (Salipira et al, 2007). This technology is very specific for the target pollutant, it is very expensive and the removal of the adsorbed pollutant from the nanosponge is not possible.…”

Polymerization of Cyclodextrin-Ionic Liquid Complexes for the Removal of Organic and Inorganic Contaminants from Water

“…Converting them to water insoluble entities is therefore crucial if CDs are to be utilised in the removal of contaminants from water. To attain this property, CD derivatives have been polymerised with suitable bifunctional linkers in our laboratories to produce water insoluble polymers (Mhlanga et al, 2007;Mamba et al, 2007;Salipira et al, 2007). The presence of the OH groups in the CDs or CD-derivatives allows a reaction in which the monomers react with linkers to produce insoluble polymers.…”

“…The CD polyurethanes have demonstrated a high efficiency for the absorption of organic pollutants in water (Mhlanga et al, 2007;Mamba et al, 2007;Salipira et al, 2007). However, in real water systems organic and inorganic contaminants co-exist; the challenge is to craft a water treatment system that is capable of simultaneously removing these contaminants from water.…”

Application of α, β and γ cyclodextrin polyurethanes in the removal of size specific copper derivatives

“…It was found that these polymers could be recycled at least 18 times while still maintaining their high sorption efficiency [11].…”