An Efficient Strategy for Enhancing the Adsorption Capabilities of Biochar via Sequential KMnO4-Promoted Oxidative Pyrolysis and H2O2 Oxidation

Abstract

In this study, sequential KMnO4-promoted oxidative pyrolysis and H2O2 oxidation were employed to upgrade the adsorption capacities of durian shell biochar for methylene blue (MB) and tetracycline (TC) in an aqueous solution. It was found that the KMnO4/H2O2 co-modification was greatly influenced by pyrolysis temperature and the optimal temperature was 300 °C. Moreover, a low concentration of H2O2 enabled the improvement of the adsorption capabilities greatly with the catalysis of pre-impregnated manganese oxides, addressing the shortcoming of single H2O2 modification. The co-modified biochar exhibited high adsorption capabilities for MB and TC, remarkably surpassed KMnO4- and H2O2- modified biochars as well as pristine biochar. The increase of adsorption capabilities could be mainly contributed to the incorporation of MnOx and carboxyl by KMnO4-promoted oxidative decomposition and Mn-catalyzed H2O2 oxidation. This would provide a novel and efficient method for preparing highly adsorptive biochar using sequential KMnO4-promoted oxidative pyrolysis and H2O2 oxidation.

Enhanced Adsorption Capacities of Fungicides Using Peanut Shell Biochar via Successive Chemical Modification with KMnO4 and KOH

“…The surface of PSB is smooth and flat, but PSBOX-A has porous and uneven structures. These results indicate that chemical modification using KMnO4 and KOH might change the surface morphology of the PSB with respect to the adsorption of fungicides [27]. The SEM-EDX results of PSB and PSBOX-A demonstrated the effect of chemical modification with KMnO4 and KOH on the differences in the constituents of PSB and PSBOX-A.…”

“…Considerable quantities (about 30 thousand metric tons) of peanuts shell are used to feed and energy resources each year [16]. The main components of peanut shells have been reported to be fiber (60-70 wt.%), cellulose (34-45 wt.%), and lignin (27)(28)(29)(30)(31)(32)(33) wt.%). The peanut shells have a cellulose-lignin layer that considerably affects the porous structure and the pyrolysis behavior [17].…”

Impact of post‐pyrolysis wash on biochar properties

“…The removal of tars with the surfactant washes from the biochar surfaces reduced the hydrophobic aliphatic groups on the surfaces. The addition of oxidant hydrogen peroxide could have modified some functional groups on the biochar surfaces, [ 105–108 ] improving their interaction with water thereby increasing hydrophilicity, without removing components from the biochar.…”

Enhanced performance and microbial communities of anaerobic digestion with biochar in pilot-scale continuous stirred-tank reactors: effects of substrate concentration and hydraulic retention time

“…4A and D), which could be owing to the excellent properties of coconut shell biochar. 6 In the future, the capacity of corn straw biochar could be improved via chemical activation methods such as KOH and KMnO 4 , 34,35 or thermal oxidation activation methods. 36 In addition, the concentration of ammonia nitrogen positively correlated with the concentration of substrate in AD.…”