Adsorption of Lead Ion from Wastewater Using Non-Crystal Hydrated Calcium Silicate Gel

Abstract

In order to obtain low-cost and excellent adsorption materials, this paper used calcium acetate and water glass as raw materials to synthesis hydrated calcium silicate gel by precipitation method. The performance and structure of hydrated calcium silicate gel were systematically studied by X-ray photoelectron spectroscopy, fourier transform infrared spectroscopy, specific surface area analyzer and scanning electron microscope. Studies have shown that, non-crystal hydrated calcium silicate gel (CSH) were successfully prepared, and the removal rate of lead ion using CSH reached more than 90%. The adsorption process is consistent with the pseudo-second-order kinetic model and Langmuir adsorption isotherm model, and the limit adsorption capacity reaches 263.17 mg·g−1. The acid treatment experiment proved that the adsorption capacity of lead ion using CSH was satisfactory, and the adsorption rate remained at >60% after 5 cycles. The research may provide a low-cost, high-efficiency and high stability adsorbent.

Mixed-Phase Ion-Exchangers from Waste Amber Container Glass

“…In general, the batch uptakes of Pb 2+ and Cd 2+ by AN-150, AF-150 and AH-150 and their associated equilibrium times fall within the ranges reported for other low-cost and waste-derived inorganic materials [3,[30][31][32][33][34][35][36][37][38][39][40]. The batch uptakes of Pb 2+ and Cd 2+ by AN-150, AF-150 and AH-150 are compared with those of other low-cost and waste-derived inorganic sorbents in Table 5 [3,[30][31][32][33][34][35][36][37][38][39][40].…”

“…In general, the batch uptakes of Pb 2+ and Cd 2+ by AN-150, AF-150 and AH-150 and their associated equilibrium times fall within the ranges reported for other low-cost and waste-derived inorganic materials [3,[30][31][32][33][34][35][36][37][38][39][40]. The batch uptakes of Pb 2+ and Cd 2+ by AN-150, AF-150 and AH-150 are compared with those of other low-cost and waste-derived inorganic sorbents in Table 5 [3,[30][31][32][33][34][35][36][37][38][39][40]. The Pb 2+ removal capacities and equilibrium times of the amber glass-derived mixed-phase sorbents were superior to those reported for waste concretes [31,32] and inferior to those of fly ash-derived zeolite Na-X [33] and hydrated calcium silicate gel [35].…”

“…In general, the batch uptakes of Pb 2+ and Cd 2+ by AN-150, AF-150 and AH-150 and their associated equilibrium times fall within the ranges reported for other low-cost and waste-derived inorganic materials [3,[30][31][32][33][34][35][36][37][38][39][40]. 1 C i = initial metal concentration in solution.…”

“…Increases in supernatant Cd 2+ solution pH from an initial value of 5.4 to 7.3 for AH-150, and to 8.6 for both AN-150 and AF-150 were noted, although the trends did not correlate directly with the observed extents of Cd 2+ -removal. The batch uptakes of Pb 2+ and Cd 2+ by AN-150, AF-150 and AH-150 are compared with those of other low-cost and waste-derived inorganic sorbents in Table 5 [3,[30][31][32][33][34][35][36][37][38][39][40]. The Pb 2+ removal capacities and equilibrium times of the amber glass-derived mixedphase sorbents were superior to those reported for waste concretes [31,32] and inferior to those of fly ash-derived zeolite Na-X [33] and hydrated calcium silicate gel [35].…”

“…The batch uptakes of Pb 2+ and Cd 2+ by AN-150, AF-150 and AH-150 are compared with those of other low-cost and waste-derived inorganic sorbents in Table 5 [3,[30][31][32][33][34][35][36][37][38][39][40]. The Pb 2+ removal capacities and equilibrium times of the amber glass-derived mixed-phase sorbents were superior to those reported for waste concretes [31,32] and inferior to those of fly ash-derived zeolite Na-X [33] and hydrated calcium silicate gel [35]. Maximum Pb 2+ uptake of glass-derived tobermorite [3] was approximately 3.5 times higher than that of the glass-derived mixed-phase sorbents, although the reported tobermorite sample failed to achieve equilibrium within 24 h. Similarly, the Cd 2+ removal capacity of waste-derived tobermorite [30] was greater than that of AN-150, AF-150 and AH-150 with a significantly longer equilibrium time of greater than 6 days.…”