Adsorption Characteristics and Mechanisms of Fe-Mn Oxide Modified Biochar for Pb(II) in Wastewater

Abstract

This study prepared iron-manganese oxide-modified biochar (FM-BC) by impregnating rice straw biochar (BC) with a mixed solution of ferric nitrate and potassium permanganate. The effects of pH, FM-BC dosage, interference of coexisting ions, adsorption time, incipient Pb(II) concentration, and temperature on the adsorption of Pb(II) by FM-BC were investigated. Moreover, the Pb(II) adsorption mechanism of FM-BC was analyzed using a series of characterization techniques. The results showed that the Fe-Mn oxide composite modification significantly promoted the physical and chemical functions of the biochar surface and the adsorption capacity of Pb(II). The specific surface area of FM-BC was 18.20 times larger than that of BC, and the maximum Pb(II) adsorption capacity reached 165.88 mg/g. Adsorption kinetic tests showed that the adsorption of Pb(II) by FM-BC was based on the pseudo-second-order kinetic model, which indicated that the adsorption process was mainly governed by chemical adsorption. The isothermal adsorption of Pb(II) by FM-BC conformed to the Langmuir model, indicating that the adsorption process was spontaneous and endothermic. Characterization analyses (Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy) showed that the adsorption mechanism of Pb(II) by FM-BC was mainly via electrostatic adsorption, chemical precipitation, complexation, ion exchange, and the transformation of Mn2O3 into MnO2. Therefore, FM-BC is a promising adsorbent for Pb(II) removal from wastewater.

Preparation and Performance Study of Fe2O3/Geopolymer Porous Ceramics

“…The spin orbit splitting energy difference of these two peaks is about 13.2 eV, and two satellite peak locates at 719.9 eV and 733.01 eV, indicating that the iron oxide loaded on the surface of samples is mainly Fe 2 O 3 [22,23]. And the peaks with binding energies of 716.35 eV belong to Fe (III) [24].The position of the Fe2p 3/2 peak did not change while the Fe2p 1/2 peak shifted towards a higher binding energy after the adsorption of Pb(Ⅱ), indicating that the occurrence of charge transfer from Fe during the adsorption process.…”

Adsorption of anionic and cationic heavy metals by Zn-Mn-Fe oxide-loaded biochar: Performance and mechanism

“…6b. At 557 cm -1 , the characteristic peak of M-O (M is Mn, Zn and Fe) appeared in the FTIR spectrum of ZMFBC, indicating that BC was successfully loaded Zn-Mn-Fe oxide (Tang et al 2022). The peak at 3420 cm -1 was attributed to the O-H bond stretching vibration.…”

Preparation of Adsorbent from Mechanochemical Reaction-Based Waste Seashell with Sodium Oxalate and Its Application in Pb Ion Adsorption

“…Wang et al (2021) reported that the amount of Pb 2+ adsorbed was in the range of 1.9 × 10 −4 -3.0 × 10 −4 mol/g in pH 5.5-6.5 using calcined mussel shell-based adsorbent [20]. Tang et al (2022) reported that the maximum amount of Pb 2+ adsorbed was 8.0 × 10 −4 mol/g using Fe-Mn oxide-modified biochar [38]. Ariffin et al (2017) prepared hydroxyapatite from bulk shells for lead ion adsorption and reported that the adsorption equilibrium relationship followed the Langmuirtype and the saturated adsorption capacity was 74.63 mg/g (3.6 × 10 −4 mol/g) [39].…”