Characterization of ball-milled bamboo-based activated carbon treated with KMnO4 and KOH as activating agents

Abstract

Bamboo-based activated carbon was made using the activating agents KOH and KMnO4 at high temperature. This study examined the ability of unmilled and ball-milled bamboo activated using KOH or KMnO4 to fulfil the activated carbon standard parameters. Chemical activation was done using KOH and KMnO4 at 2.5% and 5% concentration, heated at 800 °C, and steamed for 1 hour. Sample size was reduced to 500 nm using high energy ball-milling at 500 rpm for 80, 150, or 180 min. Analysis included the yield, water content, ash content, volatile matter content, burn-off weight percentage, morphology analysis, functional groups (Fourier transform infrared spectroscopy, FTIR), crystallinity analysis (X-ray diffraction, XRD), and Brunauer, Emmett, and Teller (BET) analysis. Ball-milling treatment for 150 min produced activated carbon of 449 nm in size and a particle distribution index (PDI) score of 0.66. Ball milled activated carbon from the experiment had a pore radius ranging from 1.18 to 2.49 nm. The activated carbon that met the criteria of ANSI/AWWA B604-12 (2012) standard for moisture content, iodine number, and JIS K 1474 (1967) standard for methylene blue adsorption level and surface area were milled activated carbon with activator KMnO4 2.5%.

Synthesis and characterization of ground biochar (GB) reinforced composites for removal of heavy metal from palm oil mill effluent (POME)

“…5(b) shows more pronounced particles' deformation at 30 h of milling times, changing the sample morphology due to the shear force applied by the metallic balls on the surface of biochar particles in the mono planetary stainless-steel jar. This result followed other researchers who showed significant particle size reduction after periods of ball milling (Phanthong et al 2018;Lyu et al 2018;Qanytah et al 2020). However, the particle size remained constant after 30 h of milling, as no further changes were observed.…”

“…The result was similar to findings by Shan et al (2016), who reported that coconut shell-based activated carbon particle size remained the same even after increasing the milling time. Qanytah et al (2020) added that a longer milling process reduces the sample crystallinity, producing an amorphous sample, as displayed in Fig. 5.…”

“…This may initiate agglomeration of biochar to form large particulates. Despite the disadvantage of a longer milling time, this approach can increase the adsorption capabilities of biochar by creating numerous pores on its surface (Hu et al 2019), leading to an increase in reactivity as the volume ratio of the sample increases (Qanytah et al 2020). Besides, it also increases the contact surface area and leaves numerous vacant pores (Qanytah et al 2020;Abbas et al 2021).…”

A systematic literature review on the effects of synthesis conditions to the physicochemical properties of activated carbons and their performance in methylene blue adsorption

“…Next, 93 full-text articles were reviewed, out of which 44 studies were eligible for the qualitative analysis according to the established inclusion criteria. The 44 papers were composed of articles containing the physicochemical and adsorption properties of ACs from the three selected biomass sources with the respective distributions: coconut shell [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], bamboo [16,[23][24][25][26][27][28][29][30][31][32][33][34] and rice husk [35][36][37][38][39][40][41][42][43][44][45][46][47][48]. The analyses were divided into two categories: (a) synthesis conditions affecting the differences in physicochemical properties of ACs and (b) effects of physicochemical properties onto MB adsorption performance.…”