With traditional sandstone oil reservoirs coming to the end of their useful lives, there is interest in extracting oil and gas from shale and carbonate rocks. Recovered samples often contain hydrocarbon material, sometimes in a fairly mobile form, sometimes in a tarry form. There is also an interest in studying forms of porous carbon, such as biochar, both for their soil-remedial properties, and for carbon sequestration. Biochars, depending on heat-treatment temperature and duration, also frequently contain resid- trains to quantify the measurements. This study also applies NMR cryoporometry, to measure structure: pore-size distribution and pore volumes of the rock, and of the stable carbon skeleton. It has the significant advantage of being usable even when there are liquids and volatile components already in the pores. In porous rocks, combining mobility and structural information will provide a measure of the difficulty of removing the tar/oil from the rock.In biochar, combining the mobility of the labile components with the structural information for the stable biochar skeleton will inform calculations of lifetime of the labile components within the biochar. The NMRC data will also inform estimates of the lifetime of the biochar carbon skeleton.

Abstract:The presence of biochar in soils through natural processes (forest fires, bush burning) or through application to soil (agriculture, carbon storage, remediation, waste management) has received a significant amount of scientific and regulatory attention. Biochar alters soil properties, encourages microbial activity and enhances sorption of inorganic and organic compounds, but this strongly depends on the feedstock and production process of biochar. This review considers biochar sources, the production process and result of pyrolysis, interactions of biochar with soil, and associated biota. Furthermore, the paper focuses on the interactions between biochar and common anthropogenic organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), pesticides, and dioxins, which are often deposited in the soil environment. It then considers the feasibility of applying biochar in remediation technologies in addition to other perspective areas yet to be explored.

No abstract

This study investigated the impact of two different wood biochars (BioC1 and BioC2) on the extractability and biodegradation of 14 C-naphthalene in soil. Both biochars had contrasting properties due to difference in feedstocks and pyrolytic conditions (450-500 o C and 900-1000 o C, designated as BioC1 and BioC2, respectively). This study investigated effects of biochar on the relationship between 14 C-naphthalene mineralisation and calcium chloride (CaCl 2), hydroxypropyl-β-cyclodextrin (HPCD) or methanol extraction in soil amended with 0%, 0.1%, 0.5% and 1% BioC1 and BioC2 after 1, 18, 36 and 72 d contact times. Total extents of 14 C-naphthalene mineralisation and extraction were reduced with increasing concentrations of biochar; however, BioC2 showed greater sorptive capacity. Good linear correlation existed between total extents of 14 Cnaphthalene mineralisation and HPCD extractions in BioC1 (slope = 0.86, r 2 = 0.92) and BioC2 (slope = 0.86, r 2 = 0.94) amended soils. However CaCl 2 and methanol extractions underestimated and overestimated extents of mineralisation, respectively. These results indicate that biochar can reduce the bioaccessibility of PAHs and the corresponding risk of exposure to biota, whilst HPCD extraction estimated the bioaccessible fraction of PAHs in soil. Bioaccessibility assessment is vital in evaluation of biodegradation potential and suitability of bioremediation as a remediation option.