Harmful weed to prospective adsorbent: low-temperature-carbonized Ipomoea carnea stem carbon coated with aluminum oxyhydroxide nanoparticles for defluoridation.

Gainful utilization of stems of the pernicious weed, Ipomoea carnea, to prepare good quality carbon and its modification with aluminum oxyhydroxide (AlOOH) nanoparticles for efficient defluoridation from contaminated drinking water is discussed in this paper. Surface functional groups are enhanced by functionalization of the carbons under acid treatment which acted as anchor to the AlOOH nanoparticles. Formation of AlOOH particles over the carbon surface is confirmed from X-ray diffractometry analysis. The AlOOH-carbon nanocomposite showed higher fluoride removal capacity than the neat AlOOH nanoparticles with a maximum removal capacity in the range of 46.55-53.71 mg g-1. Reaction kinetics and isotherm studies showed that fluoride adsorption is quite feasible on the adsorbent surface. The column study showed the possibility of the adsorbent for large-scale applications. The adsorbent can be regenerated by a mild treatment with 0.1 N NaOH solutions. The adsorbent is highly capable for defluoridation from synthetic as well as fluoride-contaminated natural water and, thus, can be used as an alternative for commercial defluoridation adsorbents. The use of Ipomoea carnea for defluoridation can be a way of producing low-cost adsorbent material, and the use for such purposes may also be helpful to control the weed up to a good extent.