Physical-Chemical Characterization of Different Carbon-Based Sorbents for Environmental Applications

Abstract

Biochar has been used in various applications, e.g., as a soil conditioner and in remediation of contaminated water, wastewater, and gaseous emissions. In the latter application, biochar was shown to be a suitable alternative to activated carbon, providing high treatment efficiency. Since biochar is a by-product of waste pyrolysis, its use allows for compliance with circular economics. Thus, this research aims to obtain a detailed characterization of three carbonaceous materials: an activated carbon (CARBOSORB NC 1240®) and two biochars (RE-CHAR® and AMBIOTON®). In particular, the objective of this work is to compare the properties of three carbonaceous materials to evaluate whether the application of the two biochars is the same as that of activated carbon. The characterization included, among others, particle size distribution, elemental analysis, pH, scanning electron microscope, pore volume, specific surface area, and ionic exchange capacity. The results showed that CARBOSORB NC 1240® presented a higher specific surface (1126.64 m2/g) than AMBIOTON® (256.23 m2/g) and RE-CHAR® (280.25 m2/g). Both biochar and activated carbon belong to the category of mesoporous media, showing a pore size between 2 and 50 nm (20–500 Å). Moreover, the chemical composition analysis shows similar C, H, and N composition in the three carbonaceous materials while a higher O composition in RE-CHAR® (9.9%) than in CARBOSORB NC 1240 ® (2.67%) and AMBIOTON® (1.10%). Differences in physical and chemical properties are determined by the feedstock and pyrolysis or gasification temperature. The results obtained allowed to compare the selected materials among each other and with other carbonaceous adsorbents.

Revealing the Adverse Impact of Additive Carbon Material on Microorganisms and Its Implications for Biogas Yields: A Critical Review

“…The amount of the elements contained in a material is usually determined as percentage content of total hydrogen, nitrogen, carbon, oxygen, and sulfur using elemental analyzers [179,180].…”

Treatment of Wastewater from Soil Washing with Soluble Humic Substances Using Biochars and Activated Carbon

“…The adsorbent dosage (12.5; 25; 50; and 100 g/L): in this experiment, 20 mL of SWW was shaken at different adsorbent dosages for 24 h at 90 rpm; then samples were centrifuged at 8000 rpm for 10 min and filtered through a 0.45 µm filter; -Adsorption time (30,60,120,180, and 1440 min): this experiment was performed with an adsorbent dosage of 100 g/L; the samples were prepared in the same way as in the previous experiments.…”

“…Based on the micropore volume and total pore volume, the proportion of micropores in the total pore volume decreased in this order: BW (76%) < ACN (24%) < BPB (9%) < BCH (4%). The average pore diameter of BW and ACN was characteristic of mesoporous materials (2-50 nm) [30], while the average pore diameter of BPB and BCH was typical for macroporous materials (>50 nm). Surface area and porosity are the most important physical properties affecting the metal sorption capacity of biochar [21].…”

“…In general, the surface area of biochar can vary over a wide range, from less than 1.0 to about 500 m 2 /g [35]. Some commercial activated carbons have a high surface area of nearly 1000 m 2 /g, a total pore volume of 0.5 cm 3 /g, and an average pore diameter of 2-3 nm [30,32]. The content of volatiles in the tested adsorbents ranged from 13.7% (ACN) to 35.1% (BCH).…”

Activated Biochar Is an Effective Technique for Arsenic Removal from Contaminated Drinking Water in Pakistan

“…Biochar is a carbon-rich solid material produced through the burning of organic matter in a closed container with little or no air [31,34,35]. The physio-chemical properties of biochar, such as its three-dimensional reticulated and porous structure [36], might serve as a long-term carbon storage solution, while also adsorbing and decomposing contaminants [37]. Biochar may be made from a range of carbonaceous feedstocks, the majority of which are considered organic wastes; hence, it indirectly supports waste management [38].…”