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Physical and chemical characterizations of biochars derived from different agricultural residues

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  • Wangeningen University

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Biochar has received large attention as a strategy to tackle against carbon emission. Not only carbon fixation has been carried out but also other merits for agricultural application due to unique physical and chemical character such as absorption of contaminated compounds in soil, trapping ammonia and methane emission from compost, and enhancement of fertilizer quality. In our study, different local waste feed stocks (rice husk, rice straw, wood chips of apple tree (Malus Pumila) and oak tree (Quercus serrata)), in Aomori, Japan, were utilized for creating biochar with different temperature (400–800 °C). Concerning to the biochar production, the pyrolysis of lower temperature had more biochar yield than higher temperature pyrolysis process. On the contrary, surface areas and adsorption characters have been increased as increasing temperature. The proportions of carbon content in the biochars also increased together with increased temperatures. Infrared-Fourier spectra (FT-IR) and 13C-NMR were used to understand carbon chemical compositions in our biochars, and it was observed that the numbers of the shoulders representing aromatic groups, considered as stable carbon structure appeared as the temperature came closer to 600 °C, as well as in FT-IR. In rice materials, the peak assigned to SiO2, was observed in all biochars (400–800 °C) in FT-IR. We suppose that the pyrolysis at 600 °C creates the most recalcitrant character for carbon sequestration, meanwhile the pyrolysis at 400 °C produces the superior properties as a fertilizer by retaining volatile and easily labile compounds which promotes soil microbial activities.
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... To provide a better solution to the aforementioned issues, several studies have been carried out in the last couple of decades adopting eco-friendly and sustainable techniques [22][23][24][25][26][27]. These practices involve the usage of rice straw on a small and large scale for composting [28][29][30], paper production [31][32][33], feed for ruminants [34][35][36], pellet production [37][38][39], silica extraction [24,40], power generation [8,41,42], bio-fuels [43][44][45][46], mushroom production [47][48][49], direct combustion [50,51], gasification and pyrolysis [52][53][54][55], biochar production [56][57][58], construction sector [59][60][61] and adsorption of toxic compounds [26,62,63]. ...
... On the ground level, it is used in the agricultural fields as a conditioner for the soil that helps to increase crop production, water retention capacity of soil and lowers the emission of GHGs [331,336,337]. Previous studies have suggested that the biochar produced from rice straw possesses high surface alkalinity and micronutrients such as phosphorus and potassium that indicates the possibility of the usage of biochar as a soil conditioner/enhancer [56,338,339]. The biochar produced at different elevated temperatures has more carbon, leading to a significant effect on the soil property in terms of carbon sequestration [19,331,340]. ...
Article
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... In the present study such bonds were identifiable in both the rice husk and their products. Silicon is a major component in chemical structure of rice material, and is typical of its recalcitrant property (Jindo et al., 2014). ...
... These characteristics are generally enhanced after biochar amendment but the extent depends, in part, on the biochar production characteristics. Notably, high pyrolysis temperatures result in the decomposition of organic compounds, higher pH, and an increase in concentrations of oxides and carbonates of Na, K, Mg, and Ca on the surface of the biochar (Jindo et al., 2014). These base cations can be readily exchanged with Al 31 and H 1 on the negatively charged surface sites of soil, with the overall impact of increasing soil pH (Shetty & Prakash, 2020). ...
Chapter
The physical and geochemical modifications to soils following biochar amendment are intimately linked, especially in coarse-textured acidic soils, where biochars’ inherent soil water retention abilities effectively hold nutrients and trace elements in pore spaces. The magnitude of these effects is biochar type and dose specific but can be long-lasting. As a result, adding biochars to some degraded soils can increase soil moisture holding, nutrients, and trace element retention such that they can be utilized as a part of plant-based remediation efforts. Here we present and discuss data and review evidence of linkages between soil water retention and nutrient and trace element geochemistry in soils amended with biochars.
... Biochars generally have low anion exchange capacities (AEC) compared to cation exchange capacities (CEC); as such, in fertilised soils, NO 3 − is generally more mobile where biochar is added than NH 4 + (Laird et al., 2010). In the case of phosphorous (P), studies have shown biochar dose and type-dependent effects in agricultural soils (Glaser and Lehr, 2019), whilst, for potassium (K), the large surface areas of biochars and negatively charged surfaces generally favour the retention of K in soils (Jindo et al., 2014). In this context, experimentation with co-produced biochar-compost or biochar-manure blends has been initiated to attempt to match biochars' nutrient retention characteristics to the contrasting nutrient leaching traits of some manures and composts. ...
Article
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... The band at 1470 − 1430 cm -1 is ascribed to C-H bending vibrations in CH 3 groups [35]. C = O vibrations at 1100 − 1000 cm -1 are produced by the stretching vibration of the oxygen-containing functional group C = O bond [37]. There is a weak vibration band between 765 − 530 cm -1 , which is judged as an aromatic structure. ...
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Application of Engineering and Technology in Bridging Technology and Community
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