Evaluation of commercial biochar in South Korea for environmental application and carbon sequestration

Abstract

The performance of commercial wood chip (WC) and biosolid (BS) biochars available in bulk from carbonization processes in South Korea was examined via determination of sorption capacity from batch experiments and evaluation of carbon sequestration using biochar-mortar composites according to construction and environmental properties. Compared with rice straw (RS) biochar synthesized in a laboratory, the sorption capacities of WC and BC biochars are determined by the types of contaminants, the properties of the biochar, and sorption mechanisms. BS and WC biochars are competitive as sorbents for nitro explosives and chlorinated phenols. Characterization of biochar-mortar composites showed that 3-5 wt% biochar inclusion did not significantly change the composites' engineering properties, including flowability, compressive strength, and thermal conductivity. As the biochar content increased in the biochar-mortar composites, the benzene and toluene concentrations in air were accordingly reduced, suggesting that biochar inclusion may be favorable to remove volatile toxic contaminants that cause sick building syndrome. The toxicity characteristics leaching procedure (TCLP) and Micotox ® bioassay tests showed that biocharmortar composites were not toxic. These results suggest that BS and WC biochars in South Korea are competitive as sorbents for some organic contaminants and that biochar-mortar composites may be environmentally friendly carbon-sequestering construction materials.

Perspectives of Engineered Biochar for Environmental Applications: A Review

“…563 Biochar in concrete can also be helpful to combat sick building syndrome (SBS) by removing benzene and toluene from the environment, regardless of the type of biochar employed, as shown in a recent work conducted in South Korea. 564 In the conditions of the referred work, the addition of up to 10% of biochar in concrete was able to remove 40% of toluene and benzene from the atmosphere. Additional work also assessed the possible toxicity of concrete−biochar composites by conducting TCLP (toxicity characteristic leaching procedure) tests and showed that there is no risk of harmful effects on living creatures in indoor environments.…”

“…Additional work also assessed the possible toxicity of concrete−biochar composites by conducting TCLP (toxicity characteristic leaching procedure) tests and showed that there is no risk of harmful effects on living creatures in indoor environments. 564 However, further work should assess the performance of lower biochar percentages since, as mentioned earlier, in civil engineering constructions, biochar content is added up to around 3% and seldom up to 5%. 562 The necessity of looking for pathways for C storage in cementitious composites (e.g., concrete) is justified by the necessity of making the cement industry more sustainable from an environmental viewpoint.…”

“…Accordingly, and after measuring the C content in the resulting biochar−mortar composite, Oh et al showed that 1 kg of the composite containing 5% of a specific type of biochar could allow storing up to 34.9 g of CO 2 . 564…”

“…Biochar enables the cementitious composite to hold free water for relatively longer times than formulations without biochar, which helps generate more cement hydration products and improve mechanical properties. , Nevertheless, the workability of the composite can be negatively affected if biochar is added above specific percentages. , Filling cementitious preparations with up to 2–3 mass% biochar has been shown to perform adequately. , Moreover, the thermal and acoustic properties of concrete can be improved by adding biochar (up to 15 mass%) . Biochar in concrete can also be helpful to combat sick building syndrome (SBS) by removing benzene and toluene from the environment, regardless of the type of biochar employed, as shown in a recent work conducted in South Korea . In the conditions of the referred work, the addition of up to 10% of biochar in concrete was able to remove 40% of toluene and benzene from the atmosphere.…”

Changes in surface characteristics and adsorption properties of 2,4,6-trichlorophenol following Fenton-like aging of biochar

“…), abundant microchannels and stable aromatic chemical structure (such as alkaline pH and rich organic functional groups) 4 , biochar has been widely used as an environmentally friendly amendment for the treatment of wastewater and soil pollution 5 . For example, wood chip biochar (3–5%, wt) had a high ability to remove 2,4‐dinitrotoluene (DNT) and 2,4‐dichlorophenol (DCP) from an aqueous solution 6 .…”