Effective removal of Pb(II) by low-cost fibrous silica KCC-1 synthesized from silica-rich rice husk ash

[Display omitted] •Rice husk ash (RHA) acts as an alternative sodium silicate for KCC-1.•KCC-1(RHA) has comparable physicochemical properties with commercial KCC-1.•KCC-1(RHA) has an excellent performance in the Pb(II) removal.•Optimum conditions of Pb(II) adsorption onto KCC-1(RHA) were determined using RSM.•Optimum conditions: Co = 322.06 mg/L, m = 2.4 g/L, t = 117 min; Pb(II) removal = 75%. Rice husk ash was utilized as a low-cost silica precursor in preparing KCC-1(RHA) for Pb(II) removal. The characterization results revealed the comparable properties of KCC-1(RHA) with the conventional KCC-1. The optimum adsorption conditions were achieved at initial concentration of 322.06 mg/L, adsorbent dosage of 2.4 g/L, and time of 117 min, with Pb(II) removal of 75%. The experimental results followed the pseudo-second-order kinetic model (R2 ≥ 0.9950) and Langmuir isotherm model (R2 = 0.9934). The KCC-1(RHA) showed good performance during five cycles of adsorption-desorption, thus, affirmed great potential of RHA as silica precursor in synthesizing KCC-1(RHA) for excellent Pb(II) removal.