Adsorbent Pollutant Adsorption capacity Reference Significant findings SnO2 -CNT As (III) 106.95 mg/g [29 ] (i) 86% removal efficiency after 5 regeneration cycles Oxidized multiwalled carbon nanotubes with different oxygen contents Tetracycline Adsorption capacity of CNTs- [44 ] Ciprofloxacin (CPX) [46 ] qm/SSA continued to increase with increasing oxygen content SWCNT, acidified ammonium persulfate treated SWCNT (t-SWCNT) Bisphenol A (BPA), 17β -estradiol (E2) BPA: 19.4 mg/g and 8 mg/g, respectively, for SWCNT and t-SWCNT; E2: 27.2 mg/g [48 ] MWCNTs with 15nm, 30nm, 50nm and SWCNTs (hydroxyl functionalized, carboxy functionalized, and pure) Ofloxacin (OFL) and norfloxacin (NOR) [47 ] The structural and hydrophobic characteristics of OFL and NOR influenced their adsorption SWCNTs and MWCNTs Ibuprofen (IBU) and triclosan (TCS) For SWCNT, IBU at pH 7: 232 mg/g; TCS at pH 7: 558 mg/g [49 ] SWCNT adsorbed more IBU and TCS than MWCNT; IBU adsorption was higher at pH 4, but TCS adsorption was higher at pH 7; CNT surface oxidation decreased adsorption MWCNTs Ciprofloxacin (CPX) 150 mg/g [50 ] CNT absorbed more CPX than activated carbon and carbon xerogel; however, oxidation and heat treatment had little effect on CNT adsorption SWCNTs and MWCNTs Perchlorate (ClO4 − ) 3.55 mg/g [51 ] DWCNTs adsorbed better than SWCNTs and MWCNTs; the presence of additional ClO4 oxygen-containing functional groups increased adsorption SWCNTs in the presence of natural organic matter (NOM) Bisphenol A (BPA) and 17β -estradiol (E2) [52 ] The adsorption of BPA and E2 varied from 7.3 to 95% depending on the solution pH and the presence or absence of NOM and SWCNTs MWCNT carboxyl functionalization Mixture of four linear alkyl benzene sulfonates 168 mg/g [53 ] The adsorption was made possible through hydrophobic contact and the creation of hydrogen bonds
