Removal of CR(VI) with various adsorbents prepared using waste cigarette filters and cellulose acetate

Wastewater consists of sources from domestic wastewater industrial wastewater and agricultural activities. Wastewater contains harmful pollutants for humans, other living beings and ecosystems. Since Cr(VI) is one of the toxic heavy metal pollutants in water environments, it must be removed from wastewater. In this study, waste cigarette filters were used as adsorbents to remove Cr(VI) from aqueous solutions. The main component of waste cigarette filters is cellulose acetate, and it was preferred because it is easily accessible and cost-free. The Cr(VI) adsorption capacities of the waste filters were determined both in their raw form and by modifying them with nickel-iron layered double hydroxides (Ni-Fe-LDH) and multi-walled carbon nanotubes (MWCNT). Also, the same processes were carried out using cellulose acetate to compare the adsorption capacities. Prepared 6 different adsorbents (AF, AF-LDH, AF-LDH-MB, AF-LDH-MB-MWCNT, CA-LDH-MB, CA-LDH-MB-MWCNT) used for removal of Cr(VI) and the effects of various parameters such as pH, contact time, initial concentration and temperature were investigated. In addition to this, adsorption kinetics, isotherm and thermodynamics studies were carried out. The maximum adsorption capacities of AF and AF-LDH adsorbents were found to be 2.68 and 2.70 mg/g, respectively. Moreover, the reuse of used adsorbents was tested. Various characterization techniques such as FTIR, XRD, TGA, SEM, TEM, BET and zeta potential were used to determine the structural, morphological, thermal and compositional properties of the adsorbents.