Biochar particle aggregation in soil pore water: the influence of ionic strength and interactions with pyrene

Castan, Stephanie; Sigmund, Gabriel; Hüffer, Thorsten; Hofmann, Thilo

doi:10.1039/c9em00277d

Cited by 12 publications

(6 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mid-infrared spectra at wavelengths from 4000-400 cm −1 were recorded (average of 64 scans per sample at 4 cm −1 resolution) by using diffuse reflectance infrared Fouriertransformed (DRIFT) spectroscopy (TENSOR 27 spectrophotometer,Bruker,Fällanden,Switzerland). Figure 1 shows the differences in the spectra of oxidized and fresh PyOM for the three PyOM batches, indicating an overall increase in O-and H-containing functional groups after the PyOM oxidation (increases in absorbance at A, C, E and G; Chatterjee et al, 2012;Keiluweit et al, 2010;Wood, 1988), loss of aliphatic compounds (decrease in absorbance at B and H; Chatterjee et al, 2012;Keiluweit et al, 2010), a shift in aromaticity (increase at C and decrease at D) and decarbonation (decreases at D and H; Rechberger et al, 2017); see Fig. S2 in the Supplement for all spectra.…”

Section: C Labeled Pyrogenic Organic Mattermentioning

confidence: 99%

Vertical mobility of pyrogenic organic matter in soils: a column experiment

et al. 2020

Self Cite

View full text Add to dashboard Cite

Abstract. Pyrogenic organic matter (PyOM) is a major and persistent component of soil organic matter, but its mobility and cycling in soils is largely unknown. We conducted a column experiment with a topsoil and subsoil of a sand and a sandy loam to study the mobility of highly 13C labeled ryegrass PyOM (>2.8 at. %), applied as a layer on a 7 cm long soil column, under saturated conditions. Further, we used fresh and oxidized PyOM (accelerated aging with H2O2) to identify changes in its migration through the soil with aging and associated surface oxidation. Due to the isotopic signature, we were able to trace the PyOM carbon (PyOM-C) in the soil columns, including density fractions, its effect on native soil organic carbon (nSOC) and its total export in percolates sequentially sampled after 1000–18 000 L m−2. In total, 4 %–11 % of the added PyOM-C was mobilized and <1 % leached from the columns. The majority of PyOM-C was mobilized with the first flush of 1000 L m−2 (51 %–84 % of exported PyOM-C), but its export was ongoing for the sandy soil and the loamy subsoil. Oxidized PyOM showed a 2–7 times higher mobility than fresh PyOM. In addition, 2-fold higher quantities of oxidized PyOM-C were leached from the sandy soil compared to the loamy soil. Besides the higher mobility of oxidized PyOM, its retention in both soils increased due to an increased reactivity of the oxidized PyOM surfaces and enhanced the interaction with the soil mineral phase. Density fractionation of the upper 0–2.3 cm, below the PyOM application layer, revealed that up to 40 % of the migrated PyOM was associated with the mineral phase in the loamy soil, highlighting the importance of mineral interaction for the long-term fate of PyOM in soils. The nSOC export from the sandy soil significantly increased by 48 %–270 % with addition of PyOM compared to the control, while no effect was found for the loamy soil after the whole percolation. Due to its high sorption affinity towards the soil mineral phase, PyOM can mobilize mineral-associated soil organic matter in coarse-textured soils, where organo-mineral interactions are limited, while finer-textured soils have the ability to re-adsorb the mobilized soil organic matter. Our results show that the vertical mobility of PyOM in soils is limited to a small fraction. Aging (oxidation) increases this fraction but also increases the PyOM surface reactivity and thus its long-term retention in soils. Moreover, the migration of PyOM affects the cycling of nSOC in coarse soils and thus influences the carbon cycle of fire-affected soils.

show abstract

Section: C Labeled Pyrogenic Organic Mattermentioning

confidence: 99%

Vertical mobility of pyrogenic organic matter in soils: a column experiment

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Almost all the BMBC was retained in the quartz columns at 10 mM of Mg 2+ . The different mechanism of Mg 2+ and Na + on the mobility of BMBC was mainly attributed to the bridging effect of Mg 2+ [ 51 , 52 ]. On the other hand, the critical coagulation concentrations (CCCs) of biochar colloids in divalent cation solutions (Ca 2+ , 38 mM) were much lower than those in monovalent cation solutions (Na + , 183 mM) [ 32 ].…”

Section: Resultsmentioning

confidence: 99%

Systematic Research on the Transport of Ball-Milled Biochar in Saturated Porous Media: Effect of Humic Acid, Ionic Strength, and Cation Types

Cao

Qiao

et al. 2022

Nanomaterials

View full text Add to dashboard Cite

Ball-milled biochar (BMBC) is a typical engineering material that has promising application prospects in remediating contaminated soil and water. It is fundamental to rate the transport behaviors of BMBC in the underground environment before extensive use. In this study, the effects of the ubiquitous cations (Na+, Mg2+, and Al3+) and model organic matter (humic acid) on the transport of BMBC were investigated using laboratory column experiments. The results demonstrated the facilitated effect of HA on the transport of BMBC due to the negatively charged surface and steric effect under neutral conditions. HA and ionic strength manifested an antagonistic effect on the transport of BMBC, where the presence of one could weaken the effect from the other. We also found the charge reversal of the BMBC surface in the presence of Mg2+, thus enhancing the deposition of BMBC onto the medium surface. On the other hand, the charge reversal from Al3+-coupled acid conditions led to the restabilization and transport of BMBC in porous media. Therefore, the rational usage of BMBC is indispensable and more attention should be paid to the composition and change in underground water that might facilitate the transport of BMBC and thus lead to negative environmental implications.

show abstract

“…The elemental composition (C, H, N, S and O) and ash content of the biochars were used to calculate the molar element ratios H/C, C/N, and O/C. The amount of oxygen in the samples was calculated from the subtraction of total percentage carbon, hydrogen, nitrogen, and sulphur and ash content from 100 (Castan et al, 2019).…”

Section: Characterization Of Biocharsmentioning

confidence: 99%

Physico-chemical properties of waste derived biochar from community scale faecal sludge treatment plants

et al. 2022

View full text Add to dashboard Cite

Background: The dumping of untreated faecal sludge from non-sewered onsite sanitation facilities causes environmental pollution and exacerbates poor public health outcomes across developing nations. Long-term mechanisms to treat faecal sludge generated from these facilities are needed to resolve the global sanitation crisis and realize the Sustainable Development Goal (SDG) 6 “ensure availability and sustainable management of water and sanitation for all” by 2030. Pyrolysis of faecal sludge removes pathogens and generates biochar, which can be used as a soil enhancer. Methods: The properties of faecal sludge biochars from three full-scale treatment plants in India were determined via Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive x-ray (EDX) spectroscopy, crystal x-ray diffraction (XRD), proximate analyses, and BET surface area porosimetry. Results: Results showed that all three biochars had low specific surface area, high alkaline pH values, high ash content, and negative surface charge. Fourier transform infrared spectra showed the same surface functional groups present in each biochar. X-ray diffraction analysis showed the mineral composition of each biochar differed slightly. Scanning electron microscopy analysis indicated a porous structure of each biochar with ash particles evident. Conclusions: Slight differences in the ash content, surface area, pH and mineral content was observed between the three biochars.

show abstract

Biochar particle aggregation in soil pore water: the influence of ionic strength and interactions with pyrene

Abstract: Adsorption of pyrene to biochar surfaces in a solution with low CaCl2 concentrations results in charge neutralization and promotes biochar aggregation.

Cited by 12 publications

References 40 publications

Vertical mobility of pyrogenic organic matter in soils: a column experiment

Vertical mobility of pyrogenic organic matter in soils: a column experiment

Systematic Research on the Transport of Ball-Milled Biochar in Saturated Porous Media: Effect of Humic Acid, Ionic Strength, and Cation Types

Physico-chemical properties of waste derived biochar from community scale faecal sludge treatment plants

Contact Info

Product

Resources

About