Study on the infiltration mechanism of molten urea and biochar for a novel fertilizer preparation

Xiang, Aihua; Qi, Riying; Wang, Mingfeng; Zhang, Ke; Jiang, Enchen; Ren, Yuping; Hu, Ziwan

doi:10.1016/j.indcrop.2020.112558

Cited by 29 publications

(17 citation statements)

References 26 publications

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“…The binding energy between the biochar and pollutant depends on the chemical nature of both compounds. The adsorption capacity of biochar and the affinity for pollutants can be strongly affected by incorporating organic functional groups on the surface and/or inside the pores [14][15][16]. Therefore, it is very important to explore the mechanisms by which environmentally relevant pollutants such as metal ions and organic compounds are removed by biochar.…”

Section: Introductionmentioning

confidence: 99%

Surface characterization of maize-straw-derived biochar and their sorption mechanism for Pb2+ and methylene blue

et al. 2020

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Biochar derived from straw is a potential low-cost adsorbent for metal ions and organic pollutants, but its practical application is still limited by the adsorption capacity. In this study, the correlation between the biochar's properties and pyrolysis temperature was explored. The adsorption mechanism was studied by monitoring the changes of biochar properties before and after adsorption using BET, SEM, XPS and FT-IR spectroscopy. The adsorption mechanism was revealed following the adsorption kinetics and the changes in biochar's properties before and after adsorption. The methylene blue (MB) and Pb 2+ adsorption removal efficiency reached 95% at the initial concentration of 125 and 500 mg/L, respectively. Physisorption, chemisorption, and pore filling mechanisms determined the adsorption process of MB and Pb 2+ on biochar. The Pb 2+ adsorption process was highly affected by chemical co-precipitation at higher pyrolysis temperatures. The appearance of tar particles increased the adsorption rate of Pb 2+. The biochar obtained at the pyrolysis temperature at 500, 800 and 900˚C proved to be applicable for Pb 2+ removal. Chemisorption and porosity dominated the MB adsorption, and biochars produced at pyrolysis temperatures of 200, 800 and 900˚C are potential materials for MB removal. This study provides optimal pyrolysis conditions for transforming maize straw into valuable, low-cost materials for the removal of different pollutants.

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Section: Introductionmentioning

confidence: 99%

Surface characterization of maize-straw-derived biochar and their sorption mechanism for Pb2+ and methylene blue

et al. 2020

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“…However, in the absence of a SOM management strategy, loss can predominate (Zhang et al 2015). The efficiency of mineral N fertilizers is limited both by gaseous losses of N 2 , N 2 O and NH 3 and by leaching losses, predominantly as NO 3 − (Xiang et al 2020). Biochar-induced reductions in N 2 O losses can result from a higher proportion of NO 3 − being converted to N 2 as compared to N 2 O (Harter et al 2013;Weldon et al 2019), meaning that reductions in N 2 O emission do not necessarily indicate a reduction in gaseous N loss.…”

Section: The Theory Of N-efficient Bcfsmentioning

confidence: 99%

“…A slow-release effect can be obtained either with fertilizer products of limited solubility (ISO. 2015) or through coating with a protective layer that requires hydrolysis and/or biodegradation before the fertilizer is released (ISO 2015; Xiang et al 2020). Biochar has been tested as an ingredient in coating material for urea, showing promise for improving the slow-release effect, especially when using high-temperature biochars with high surface area (Jia et al 2020).…”

Section: The Theory Of N-efficient Bcfsmentioning

confidence: 99%

“…Such a 'mole sieve' effect of biochar, excluding denitrifiers, is one of many explanations for the reduction of N 2 O emissions observed when biochar is applied to soil (Borchard et al 2019;Kammann et al 2012;Kammann et al 2015). High macroporosity might also be key for adding specific products in concentrated BCFs, such as those based on infiltration of molten urea in biochar particles (Wang et al 2021;Xiang et al 2020).…”

Section: The Importance Of Surface Area and Porositymentioning

confidence: 99%

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Enhancing plant N uptake with biochar-based fertilizers: limitation of sorption and prospects

et al. 2022

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Background Biochar-based fertilizer products (BCF) have been reported to increase both crop yield and N-use efficiency. Such positive effects are often assumed to result from the slow-release of N adsorbed on BCF structures. However, a careful review of the literature suggests that actual mechanisms remain uncertain, which hampers the development of efficient BCF products. Scope Here, we aim at reviewing BCF mechanisms responsible for enhanced N uptake by plants, and evaluate the potential for further improvement. We review the capacity of biochar structures to adsorb and release N forms, the biochar properties supporting this effect, and the methods that have been proposed to enhance this effect. Conclusions Current biochar products show insufficient sorption capacity for the retention of N forms to support the production of slow-release BCFs of high enough N concentration. Substantial slow-release effects appear to require conventional coating technology. Sorption capacity can be improved through activation and additives, but currently not to the extent needed for concentrated BCFs. Positive effects of commercial BCFs containing small amount of biochar appear to result from pyrolysis-derived biostimulants. Our review highlights three prospects for improving N retention: 1) sorption of NH3 gas on specifically activated biochar, 2) synergies between biochar and clay porosities, which might provide economical sorption enhancement, and 3) physical loading of solid N forms within biochar. Beyond proof of concept, quantitative nutrient studies are needed to ascertain that potential future BCFs deliver expected effects on both slow-release and N use efficiency.

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“…Further, the exploitation of elds can eventually deplete them from some essential nutrients reducing the crop yields in the future. Sustainable approaches that avoid chemical fertilizer use may be ecologically more advantageous (Xiang et al 2020). Cost-effective sustainable approaches have a high current priority in agricultural research (Lee et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Characteristics and agrarian properties of biochar derived from pyrolysis and co-pyrolysis of rubberwood sawdust and sewage sludge for further application to soil improvement

Ali

Palamanit

Techato

et al. 2021

Preprint

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This study investigated the characteristics of biochars derived from pyrolysis of rubberwood sawdust and sewage sludge, and co-pyrolysis of these feedstocks at the ratios of 50:50 and 75:25. All feedstocks were pyrolyzed at 550°C in slow pyrolysis with a moving bed pyrolysis reactor. Then, the investigated characteristics of biochar samples were determined and are reported. The rubberwood sawdust biochar (RWSB) had a higher in carbon content (86.70 wt%) and was lower in oxygen content (7.89 wt%), while sewage sludge biochar (SSB) had a higher ash content (65.61 w%) and a low carbon content (24.27 wt%). The weight losses of biochars were observed in TGA while the DTG graphs show degradation rate of biochar produced in pyrolysis specific conditions. RWSB had a lower content of Si, Fe, K, Na and P than SSB as observed by XRF. The pH of RWSB, SSB and the blends (50:50, 75:25) of biochars was in the range 8.41–10.02. High carbon content of the biochar confirms potential for its use in carbon sequestration. The large pore volumes and specific surface areas of biochars were found by SEM and BET. The available functional groups in biochars were C–O, C = C, and C–H as confirmed by FTIR. Water holding capacity (WHC) and water releasing ability (WRA) of RWSB, SSB, and the blends (50:50 and 75:25) of biochars were 1.01–3.08 (mL/g) and 1.19–52.42 (wt%), respectively. In this study, our results show that blending woody and non-woody based biochars can help address nonpoint source contaminants in environment. So, these all findings should develop as tune to parameters of thermal degradation of biomass and bio-biowaste with sustain and eco-friendly biochar production.

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Study on the infiltration mechanism of molten urea and biochar for a novel fertilizer preparation

Cited by 29 publications

References 26 publications

Surface characterization of maize-straw-derived biochar and their sorption mechanism for Pb2+ and methylene blue

Surface characterization of maize-straw-derived biochar and their sorption mechanism for Pb2+ and methylene blue

Enhancing plant N uptake with biochar-based fertilizers: limitation of sorption and prospects

Characteristics and agrarian properties of biochar derived from pyrolysis and co-pyrolysis of rubberwood sawdust and sewage sludge for further application to soil improvement

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