Green and low-temperature synthesis of the magnetic modified biochar under the air atmosphere for the adsorptive removal of heavy metal ions from wastewater: CCD-RSM experimental design with isotherm, kinetic, and thermodynamic studies

Modified coconut shell biochars (MCSBCs): Fabrication and their adsorptions for Pb(II)

“…Presently, two-parameter kinetic models are primarily included Lagergren first-order (1st-O) and second-order (2nd-O) kinetic equations [ [24] , [25] , [26] ], intra-particle diffusion (Ip-D) model [ 27 , 28 ], Elovich model [ 29 , 30 ], diffusion-chemisorption (Di-Ch) model [ 31 , 32 ], and Avrami fractional-order model [ 33 , 34 ]. Unfortunately, three-parameter kinetic model is unavailable so far.…”

“…For probing the effect of Pb(II) adsorption whether from exterior functional groups or from the pores of CSBC, Pb(II) adsorption on UCSBC, Zn-modified and Mn-modified MCSBCs was analyzed by Ip-D model [ 27 , 28 ]. Its expression can be given in Eq.…”