Freeze–Thaw Cycle Events Enable the Deep Disintegration of Biochar: Release of Dissolved Black Carbon and Its Structural-Dependent Carbon Sequestration Capacity

Citations Over TimeTop 10% of 2024 papers

Abstract

Biochar is widely regarded as a recalcitrant carbon pool. However, the impact of freeze-thaw cycle events on its storage capacity, particularly on the release of dissolved black carbon (DBC), has remained poorly investigated. This study investigated the release behavior of DBC from biochar pyrolyzed at 300-700 °C during freeze-thaw cycles and their retention capacity in soil. Freeze-thaw cycles dramatically promoted DBC release (33.08-230.74 mg C L-1), exhibiting an order of magnitude higher than those without freeze-thaw process. The release kinetics of freeze-thaw-induced DBC varied depending on the pyrolysis temperature of biochar due to the different disintegration mechanisms. Interestingly, the retention capacity of freeze-thaw-induced DBC in soil showed a reduction ranging from 7.7 to 29.5% compared to DBC without the freeze-thaw process. This reduction can be attributed to numerous hydrophilic low-molecular-weight compounds (16.97-75.31%) in freeze-thaw-induced DBC, as evidenced by the results of size exclusion chromatography, fluorescence excitation/emission matrix, Fourier transform infrared spectroscopy, and nuclear magnetic resonance. These compounds tend to concentrate in the aqueous phase rather than being retained in the soil, potentially exacerbating the outflow of dissolved organic carbon. These findings clarify the release behavior of DBC during freeze-thaw cycles and reveal their contribution to the attenuation of carbon pools in cold regions.

Related Papers

• Biochar-Soil Interactions in Four Agricultural Soils(2015)
• → Role of Plant‐Based Biochar in Pollutant Removal: An Overview(2017)4 cited
• 05 포스터 발표 : 대기 환경 분야(PA) ; PA-01 : 브로콜리 재배시 대나무 biochar 시용량에 따른 온실가스 배출특성 평가(2014)
• 포스터 발표 : 토양 환경 분야(PS) ; 전기 Biochar 제조장치에서 제조된 과수전정지 Biochar의 화학적 특성(2013)
• → Επίδραση εισροών βιοεξανθρακωμάτων (biochar) στη δέσμευση του άνθρακα και σε φυσικές ιδιότητες δύο εδαφών διαφορετικής υφής(2024)