Enhanced adsorption performance of tetracycline in aqueous solutions by KOH-modified peanut shell-derived biochar

Abstract

Modification of biochar is essential to improve its properties and then promote its adsorption effect. In this study, modified biochar derived from peanut shell was prepared by KOH treatment. Adsorption behavior and mechanisms toward tetracycline (TC) by biochar were investigated. The results showed that KOH modification significantly changed the surface morphology, pore structure, elemental composition, functional groups, minerals, and carbon defects of biochar. The content of C, H, N, and S of biochar decreased as well as the content of O and ash increased after KOH modification. Surface area and pore volume of KBC were 1271.97 m 2 •g −1 and 0.653 cm 3 •g −1 , which was 5.8 and 5.4 folds than that of BC, respectively. KOH modification also changed the Ca, Si minerals components in biochar. Moreover, the functional groups in biochar also significantly changed after modification, especially O-and N-containing groups. More carbon defects occurred in KBC due to the KOH reactions. Pseudo-second-order model and Langmuir model can better describe the adsorption processes of TC on biochars. The maximum adsorption capacity of TC on KBC reached 356.19 mg•g −1 at 318.15 K. KBC has a stable removal effect to TC in a wide pH range and under the interference of co-existing ions. Pore filling and π-π interaction were the main adsorption mechanisms for TC removal by KBC. Therefore, KOH-modified peanut shell-derived biochar has a potential to act as an adsorbent to remove TC from aqueous solutions or immobilization in soils.

Honeycomb-like MnO2/Biochar Catalyst Fabricated by High-Energy Electron Beam Irradiation for Degradation of Antibiotics in Swine Urine

“…After treating the BC with aqueous KOH solution for 1 h, the prepared MBC particles became smaller (10–200 μm) ( Figure 1 A(d)), the fragments were removed, and the initially clogged pores were opened ( Figure 1 A(e)). The modification mechanism might be that KOH reacted with SiO 2 in BC to form silicate (2KOH + SiO 2 = K 2 SiO 3 + H 2 O) [ 19 , 20 ] and tended to be washed away by water. As seen from the EDX spectra, the relative peak intensities of Si and O in MBC were significantly lower than those in BC ( Figure 1 A(j,k)).…”

Preparation of Biochar with Developed Mesoporous Structure from Poplar Leaf Activated by KHCO3 and Its Efficient Adsorption of Oxytetracycline Hydrochloride

“…In order to optimize the adsorption performance of biochar, activating agents are usually added during the synthesizing process. The most commonly used activators, such as KOH [ 31 ], H 3 PO 4 [ 32 ], ZnCl 2 [ 33 ], and FeCl 3 [ 34 ], can effectively create pores in biochar, but they are strongly corrosive and cause serious pollution to the environment. Furthermore, the biochar synthesized with the above activators possesses a relatively large specific surface area, but lacks a mesoporous structure, which is not conducive to the improvement of adsorption rate or the adsorption of antibiotics with relatively large molecular sizes [ 35 , 36 , 37 ].…”

The effect of various thermochemical methods on the production of biochar and removal of 2‐naphthol orange from wastewater

“…The main product at the end of the process is pyrolyzed solid biomass. In terms of materials, biochar produced from waste biomass has been found to exhibit great adsorbent potential, as also it enables waste recycling 3‐10 . Therefore, organic fertilizers, sewage sludge and agricultural wastes can be used as feedstocks for biochar production.…”

“…In terms of materials, biochar produced from waste biomass has been found to exhibit great adsorbent potential, as also it enables waste recycling. [3][4][5][6][7][8][9][10] Therefore, organic fertilizers, sewage sludge and agricultural wastes can be used as feedstocks for biochar production. The adsorption capacity of biochar is greatly affected by the raw material used 11 owing to the varying elemental composition of materials.…”