Amount Of Biochar Research Articles

Efficient adsorption capability of banana and cassava biochar for malachite green: Removal process and mechanism exploration

In this study, banana biochar (BB) and cassava biochar (CB) were roasted in a tube furnace at 400℃ for 2 h, and their adsorption effects on malachite green (MG) were studied. The removal of MG with respect to the solution concentration and reaction time was also investigated. The results show that the optimal amount of biochar is 2 g/L. Studies of the adsorption kinetics and adsorption isotherms show that the pseudo-second-order kinetics can most accurately reflect the adsorption process. Freundlich model fits the experimental data well. The theoretical saturated adsorption capacities of BB and CB are 1,092.80 mg/g and 261.42 mg/g, respectively. SEM-EDS, TGA, BET, FTIR, XRD, element analysis and other characterization techniques were used to explore the adsorption mechanism. Based on the characterization results, it is speculated that the adsorption of BB and CB for MG mainly includes chemical adsorption and physical adsorption.

A comprehensive study on the transition metal–catalysed pyrolysis kinetics, thermodynamics and mechanisms of bamboo powder

Effects of Co(II), Ni(II) and Fe(III) impregnations on the pyrolysis behaviours of bamboo were investigated by using thermogravimetry and fixed-bed pyrolyser. Results reveal that the impregnated metals have significant effect on biomass devolatilization. Nickel impregnation increases the organic phase yield and relative amounts of tar in liquid phase. Cobalt impregnation drops cellulose degradation temperature and increases aqueous phase and non-condensable gas yields. Similarly, iron-impregnated biomass produces the highest amounts of biochar. Impregnated metals act as catalysts during pyrolysis and change degradation mechanism by lowering apparent activation energies and by changing thermodynamic parameters. Mean activation energies determined by three different isoconversional methods for normal and Co(II)-, Ni(II)- and F(III)-impregnated biomass are around 240, 197, 183 and 180 kJ.mol−1 respectively and similar to the values calculated by combined kinetic model (CK model). However, Kissinger method–based activation energy of Co(II)-impregnated biomass (295.9 kJ.mol−1) is quite high compared to the values predicted by isoconversional methods (~197 kJ.mol−1) and the CK model (197.7 kJ.mol−1). The observed results can be related to the complex degradation behaviour of Co(II)-impregnated biomass and the limitations on the uses of the Kissinger method in such a complex process. The CK model–based single-step pyrolysis mechanisms of normal and Co(II)-, Ni(II)- and Fe(III)-impregnated biomass are f(α) = (1-α)1.118.α−1.828, f(α) = (1-α)1.286.α−1.033, f(α) = (1-α)0.8895.α−1.898.[−ln(1-α)0.360] and f(α) = (1-α)0.8898.α−1.670.[−ln(1-α)0.060] respectively. The single-step CK model poorly explains biomass devolatilization behaviour. However, the same model can explain metal-impregnated biomass pyrolysis quite satisfactorily. Additionally, thermo-kinetic results obtained from various methods adequately explain the results obtained from thermogravimetric and fixed-bed pyrolysis experiments.

Study on the new dynamics and driving factors of soil pH in the red soil, hilly region of South China.

Soil acidification has always been a substantial eco-environmental problem restricting agricultural development in the red soil region of southern China. It is necessary to determine the dynamic change in soil pH in this area to formulate regional agricultural and environmental management measures. Yujiang County, a typical county with red soil acidification in southern China, was selected as the study area. Based on soil data from 1982, 2007, and 2018, the spatiotemporal variation characteristics and the latest changes in soil pH in the county were analyzed. The results show that the soil pH in Yujiang County decreased from 5.66 to 4.74 and then increased to 4.96 from 1982 to 2018, showing a trend of first decreasing and then increasing. According to the spatial distribution characteristics of soil pH, the low soil pH values in the three periods were mainly distributed in the northern mountainous areas with more forestland and dry land area and some southern hilly areas, while the paddy soil pH values in the middle low hilly areas were relatively higher. The soil pH decreased rapidly from 1982 to 2007, showing a large area of acidification. In 2007, the proportions of acidic (4.5 < pH < 5.5) and strongly acidic (pH < 4.5) soils increased by 67.37% and 10.6%, respectively, compared with that in 1982. However, from 2007 to 2018, the soil pH of the whole county increased, and the acidification trend was alleviated, which is of great significance to the regional red soil ecological environment. Through the analysis of the main factors affecting the change in soil pH, it was found that the sharp decline in soil pH in Yujiang County during 1982-2007 was mainly caused by acid rain and excessive nitrogen application. From 2007 to 2018, no significant reduction in nitrogen fertilizer in this area occurred, and although the increase in soil organic matter contributed to alleviating soil acidification, the analysis showed that the decrease in acid rain was the main reason for the rise in soil pH in Yujiang County. At the same time, notably, there is a large area of soil in the area that is still acidic, and effective control of soil acidification is still an important ecological and environmental issue in this area. In order to further improve the pH value of soil in red soil region, it is suggested that on the basis of continuous improvement of acid rain, in addition to increasing soil organic matter by returning straw to field and other measures, appropriate amount of lime or alkaline biochar can be applied to better improve the soil ecological environment in red soil hilly region.

Combined use of lime, bentonite, and biochar for immobilization of Cd and mobilization of Se in paddy soil.

Remediation of soil contaminated with cadmium (Cd) that can produce rice enriched with selenium (Se) is highly significant for improving the public health in China. A key issue needing resolution in this regard is the simultaneous immobilization of Cd and mobilization of Se. To explore a potential promising method to remediate median-high Se soil that is contaminated by Cd, a potted experiment was conducted, and seven combined amendments (0.03-0.12% lime, 0.03-0.18% bentonite, and 0.3-1.2% biochar of the dry soil weight) were used to immobilize Cd in three paddy soils, in which the concentrations of Cd and Se are 0.46 and 0.45 mg/kg, 1.12 and 0.33 mg/kg, and 2.96 and 0.31 mg/kg, respectively. The soil pH increased by 1.5-2 units after the application of the amendments, and the soil organic carbon (SOC) concentration increased notably with the addition of large quantities of biochar. As the pH and SOC concentration increased, the concentrations of the available Cd in the soil decreased by 35-50%, and the FTIR spectrum showed that O-containing groups and Si-O facilitated the Cd immobilization. The concentration of Cd in brown rice decreased with a decrease in the available Cd. There was no apparent correlation between the Se concentration in the brown rice and the concentration of the available Se in the soil, although the available Se increased by 40-80% after the application of amendments. The accumulation of Se in rice grains was regulated by interactions among the lime, bentonite, biochar, and the soil. An SEM-EDS analysis showed that the biochar particles were covered with bentonite and other soil minerals that could postpone biochar aging and contribute to the longevity of the combined amendments in the soil.

Prediction of batch sorption of barium and strontium from saline water

Celestite and barite formation results in contamination of barium and strontium ions hinder oilfield water purification. Conversion of bio-waste sorbent products deals with a viable, sustainable and clean remediation approach for removing contaminants. Biochar sorbent produced from rice straw was used to remove barium and strontium ions of saline water from petroleum industries. The removal efficiency depends on biochar amount, pH, contact time, temperature, and Ba/Sr concentration ratio. The interactions and effects of these parameters with removal efficiency are multifaceted and nonlinear. We used an artificial neural network (ANN) model to explore the correlation between process variables and sorption responses. The ANN model is more accurate than that of existing kinetic and isotherm equations in assessing barium and strontium removal with adj. R2 values of 0.994 and 0.991, respectively. We developed a standalone user interface to estimate the barium and strontium removal as a function of sorption process parameters. Sensitivity analysis and quantitative estimation were carried out to study individual process variables’ impact on removal efficiency.

Experimental and Numerical Study of Biochar Fixed Bed Column for the Adsorption of Arsenic from Aqueous Solutions

Two laboratory tests were carried out to verify the suitability of an Italian commercial biochar as an adsorbing material. The chosen contaminant, considered dissolved in groundwater, was As. The circular economic concept demands the use of such waste material. Its use has been studied in recent years on several contaminants. The possibility of using an efficient material at low cost could help the use of low-impact technologies like permeable reactive barriers (PRBs). A numerical model was used to derive the kinetic constant for two of the most used isotherms. The results are aligned with others derived from the literature, but they also indicate that the use of a large amount of biochar does not improve the efficiency of the removal. The particular origin of the biochar, together with its grain size, causes a decrease in contact time required for the adsorption. Furthermore, it is possible that a strong local decrease in the hydraulic conductibility does not allow for a correct dispersion of the flow, thereby limiting its efficiency.

Evaluation of pervious concrete performance with pulverized biochar as cement replacement

Manufacturing cement in the industry is responsible for most of carbon dioxide (CO2) emissions to the atmosphere, while producing biochar (BC) reduces CO2 emissions to the atmosphere. Replacing a portion of cement with BC will be a win-win alternative to curtail CO2 emissions and simultaneously lock up BC. However, the mechanical performance and properties of concrete with BC as a cement replacement, especially pervious concrete, have not been well understood. In this study, we comprehensively study the porosity, water permeability, water absorption, evaporation, compressive strength, splitting tensile strength, solar reflectance, and microstructure morphology of pervious concrete samples that are prepared by replacing a portion of cement with pulverized BC. The replacement ratio, in weight, is set as 0%, 0.65%, 3.2%, 6.5%, 9.5%, and 13.5%, respectively. It is found that the BC content has little and/or no impact on the porosity and water permeability of the BC pervious concrete samples considered here, and that the water absorption increases with BC contents. BC pervious concrete samples show both the greater compressive strength and splitting tensile strength than conventional ones when the BC content is 0–6.5%, above which these strengths are compromised. The reason is that a small amount of BC will promote cement hydration, so hydration products generated in a higher amount respect to those without BC contribute to the development of the strength of pervious concrete. It is also found that 6.5% BC in the cement paste can decrease an albedo of 0.05, this decrease, however, can be compensated by the water absorption increment and strength improvement. Based on our findings, it is speculated that producing pervious concrete by replacing up to 6.5%, in weight, of cement by pulverized BC is feasible to curtail CO2 emissions and lock up BC.

Evaluating the Effects of Biochar with Farmyard Manure under Optimal Mineral Fertilizing on Tomato Growth, Soil Organic C and Biochemical Quality in a Low Fertility Soil

Biochar amendments are widely recognized to improve crop productivity and soil biogeochemical quality, however, their effects on vegetable crops are less studied. This pot study investigated the effects of cotton stick, corncob and rice straw biochars alone and with farmyard manure (FYM) on tomato growth, soil physico–chemical and biological characteristics, soil organic carbon (SOC) content and amount of soil nutrients under recommended mineral fertilizer conditions in a nutrient-depleted alkaline soil. Biochars were applied at 0, 1.5 and 3% (w/w, basis) rates and FYM was added at 0 and 30 t ha−1 rates. Biochars were developed at 450 °C pyrolysis temperature and varied in total organic C, nitrogen (N), phosphorus (P) and potassium (K) contents. The results showed that biochars, their amounts and FYM significantly improved tomato growth which varied strongly among the biochar types, amounts and FYM. With FYM, the addition of 3% corncob biochar resulted in the highest total chlorophyll contents (9.55 ug g−1), shoot (76.1 cm) and root lengths (44.7 cm), and biomass production. Biochars with and without FYM significantly increased soil pH, electrical conductivity (EC) and cation exchange capacity (CEC). The soil basal respiration increased with biochar for all biochars but not consistently after FYM addition. The water-extractable organic C (WEOC) and soil organic C (SOC) contents increased significantly with biochar amount and FYM, with the highest SOC found in the soil that received 3% corncob biochar with FYM. Microbial biomass C (MBC), N (MBN) and P (MBP) were the highest in corncob biochar treated soils followed by cotton stick and rice straw biochars. The addition of 3% biochars along with FYM also showed significant positive effects on soil mineral N, P and K contents. The addition of 3% corncob biochar with and without FYM always resulted in higher soil N, P and K contents at the 3% rate. The results further revealed that the positive effects of biochars on above-ground plant responses were primarily due to the improvements in below-ground soil properties, nutrients’ availability and SOC; however, these effects varied strongly between biochar types. Our study concludes that various biochars can enhance tomato production, soil biochemical quality and SOC in nutrient poor soil under greenhouse conditions. However, we emphasize that these findings need further investigations using long-term studies before adopting biochar for sustainable vegetable production systems.

An Eco-friendly and Economical Approach for Removal of Remazol Blue, Malachite Green and Rhodamine B Dyes from Wastewater using Bio-char Derived from Chlorella Vulgaris Biomass

Background::Rapid urbanization and industrialization has led to depletion of water resource and generation of enormous amount of wastewater. One among them is textile industry which discharge huge amount of dye wastewater into aquatic environment.Methods::This study deals with adsorption of Remazol blue, Malachite green and Rhodamine B dyes into bio-char derived from Chlorella vulgaris biomass cultivated from municipal wastewater. Column studies were performed to depict the industrial usage of bio-char for treatment of large quantity of wastewater. Effect of temperature, time, pH, dye concentration and adsorbent dosage on dye removal was studied in batch process.Results::The best batch adsorption conditions are temperature (25⁰C), time (60min), pH (7), dye concentration (100ppm) and adsorbent dosage (1g) with ± 5% for all three dyes. Dye removal percentage of bio-char increased with increased in adsorbent dosage to 94.5%, 88.2% and 90.1% for Remazol blue, Malachite green and Rhodamine B dyes at 1g/L adsorbent dosage. Freundlich isotherm exhibited correlation coefficient (R2) values of 0.99, 0.98 and 0.99 for Remazol blue, Malachite green and Rhodamine B dyes respectively. Kinetic studies revealed that all three dyes followed pseudo first order model. Increase in column bed height resulted in increased dye removal percentage since increase in bed height resulted in increase in bio-char quantity with more number of surface area.Conclusion::From the study, it can be concluded that Bio-char was the economical and eco-friendly alternative adsorbent for wastewater treatment process. Bio-char reusability study revealed that it could be used for 3-4 consecutive cycles.

The residual impact of straw mulch and biochar amendments on soil physiochemical properties and yield of maize under rainfed system

AbstractGlobal warming and climate alterations have adversely affected agricultural production systems. The application of biochar can help mitigate climate change impacts and enhance the production and quality of agriculture. The field experiments were conducted during 2018 and 2019 to evaluate the effects of straw mulch (0 and 8 tons ha−1) and biochar (0, 4, 12, and 36 tons ha−1) on soil temperature, soil pH, bulk density, electric conductivity, cation exchange capacity, soil organic carbon, soil nutrient status (available P, K, NO3−, and NH4+) at various soil depth (10, 20, and 30 cm), and yield and yield‐related traits of rainfed maize (Zea mays L.). The results showed that addition of biochar regulated the soil temperature, pH, electrical conductivity, cation exchange capacity, and increased the soil organic carbon, soil nutrient status (available P, K, NO3−, and NH4+) compared to non‐biochar‐treated soils. In contrast, the higher amount of biochar (36 tons ha−1) application decreased the soil bulk density compared to control. However, the combined application of straw mulch and biochar improved the grain yield and yield contributing traits of maize. In conclusion, either straw mulch and biochar or combined straw mulch + biochar‐based soil management techniques regulate the temperature and physiochemical properties of soil. These improvements in soil properties increased the grain yield of rainfed maize and help to mitigate global warming.

Virtuous utilization of biochar and carbon dioxide in the thermochemical process of dairy cattle manure

The huge generation of livestock manures has been raised due to the dramatically increasing protein demand. In this study, dairy cattle manure (DCM) was valorized through a pyrolysis platform using CO2 as a co-feedstock, suggesting the conversion of manure to value-added chemicals in a sustainable and renewable way. This work demonstrated that biocrude derived from DCM involves high contents of N-containing hetero-hydrocarbons and aromatic compounds. Because they are not desirable chemicals to be used as fuels due to the challenges during combustion processes, they were further transformed into syngas. CO2 and DCM-derived biochar signified the conversion of biocrude into syngas at ≤ 600 °C, where no gasification reaction works. The gas phase reactions of CO2 with gas phase biocrude led to enhanced CO formation. In addition, alkaline metal(oxide)s in biochar promoted gas phase reactions and chemical bond scissions of biocrude, resulting in more than 5 times higher H2 and CO formations with 3 g DCM biochar than non-catalytic pyrolysis. To evaluate the performance of DCM biochar, pyrolysis of DCM was done with Ni and Co catalysts. The promotion effect of DCM biochar for syngas formation was better than that of equivalent amount of Co catalyst. The performance of DCM biochar was higher than Ni when the additional amount of biochar was used. Considering that DCM is emitted as an agricultural waste material, it is inferred that the waste derived biochar has more economic viability than metal catalysts. Therefore, this study provides that the CO2-driven pyrolysis with DCM biochar could be an environmentally benign means for syngas generation with an economic benefit.

Biochar Promotes Nitrogen Transformation and Tomato Yield by Regulating Nitrogen-Related Microorganisms in Tomato Cultivation Soil

Nitrogen (N) transformation in soil directly determines the effectiveness of N for plant growth. Biochar has received evermore attention because of its significant ability to improve soil. However, the effects of biochar on N-related microorganisms (Lycopersicon esculentum Mill.) in tomato cultivation soil, N transformation, utilisation of water and N fertiliser, and tomato yield remain unclear. The objective of this study was to investigate the responses of N-related microorganisms to biochar and N fertilisation in soil, along with the implications of biochar for altering N transformation, N uptake by tomatoes, and utilisation of water and N fertiliser. A two-year greenhouse experiment containing six biochar levels under drip irrigation (0, 10, 30, 50, 70, and 90 t ha−1) and two N fertiliser application rates (190 and 250 kg ha−1) was conducted in the northwest of China. The results showed that adding biochar significantly promoted urease activity, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and the number of amoA-type nitrifiers in the soil. The MBC:N ratio and the number of nirS-type denitrifiers were significantly inhibited when the added amount of biochar was greater than or equal to 30 t ha−1. Moreover, biochar can increase the water content in the soil and can reduce the N lost to leaching. The inorganic N (NO3− and NH4+) in the soil could be better maintained in the rootzone and better absorbed by tomato plants when adding 30, 50, and 70 t ha−1 of biochar. The amount of N fertiliser could be reduced by 24% without a significant loss of tomato yield when the amount of biochar added was over 30 t ha−1. It was indicated that the yield of tomatoes and the net profits were quadratically related to the application rate of biochar. In the test area, 53 t ha−1 of biochar with 190 kg ha−1 of N and 44.6 t ha−1 of biochar with 190 kg ha−1 of N were calculated to be the best amounts from the perspectives of tomato yield and net profit, respectively. Thus, biochar promotes N transformation by regulating N-related microorganisms; hence, it increases the inorganic N in the roots of the plants, reduces N lost to leaching, and significantly promotes the N absorption of tomatoes. The results in this research are of great significance for the development of management strategies for tomato maintenance, environmental protection, and resource conservation.

Cadmium, lead, and zinc immobilization in soil using rice husk biochar in the presence of citric acid

The interaction between biochar and heavy metals in the presence of low molecular weight organic acids is largely unknown, but it is important to understand biochar’s influence on heavy metals immobilizing in the rhizosphere. The impacts of different amounts of biochar (5%) and citric acid, coupled with combinations of biochar and citric acid on the redistribution of cadmium, lead, and zinc among their different geochemical forms, including their bioavailability in metal contaminated soil, were investigated in an incubation experiment. Adding biochar, low concentration of citric acid (2 mmol kg−1 soil), and biochar with a low level of citric acid markedly reduced the acid-soluble and available (CaCl2-extractable) cadmium, lead, and zinc compared to control in which biochar plus low concentration of citric acid proved to be the most effective treatment. These trends were reversed in the case of high concentrations of citric acid (> 5–20 mmol kg−1 soil) and the combined biochar plus high levels of citric acid treatments. With incubation time, biochar in combination with a low concentration of citric acid transformed the largest amounts of acid-soluble and reducible cadmium, lead, and zinc into oxidizable and residual fractions. These results suggested that a low level of citric acid enhanced metals’ immobilization, while higher concentration of citric acid increased their mobilization. The study concluded that biochar with this low level of citric acid did in fact emerge as the best treatment, and can serve as an amendment for metals’ immobilization/redistribution in contaminated soils.

Impact of biochar on nutrient supply, crop yield and microbial respiration on sandy soils of northern Germany

AbstractThe application of biochar to agricultural soils to increase nutrient availability, crop production and carbon sequestration has gained increasing interest but data from field experiments on temperate, marginal soils are still under‐represented. In the current study, biochar, produced from organic residues (digestates) from a biogas plant, was applied with and without digestates at low (3.4 t ha−1) and intermediate (17.1 t ha−1) rates to two acidic and sandy soils in northern Germany that are used for corn (Zea mays L.) production. Soil nutrient availability, crop yields, microbial biomass and carbon dioxide (CO2) emissions from heterotrophic respiration were measured over two consecutive years. The effects of biochar application depended on the intrinsic properties of the two tested soils and the biochar application rates. Although the soils at the fallow site, with initially low nutrient concentrations, showed a significant increase in pH, soil nutrients and crop yield after low biochar application rates, a similar response was found at the cornfield site only after application of substantially larger amounts of biochar. The effect of a single dose of biochar at the beginning of the experiment diminished over time but was still detectable after 2 years. Whereas plant available nutrient concentrations increased after biochar application, the availability of potentially phytotoxic trace elements (Zn, Pb, Cd, Cr) decreased significantly, and although slight increases in microbial biomass carbon and heterotrophic CO2 fluxes were observed after biochar application, they were mostly not significant. The results indicate that the application of relatively small amounts of biochar could have positive effects on plant available nutrients and crop yields of marginal arable soils and may decrease the need for mineral fertilizers while simultaneously increasing the sequestration of soil organic carbon.Highlights A low rate of biochar increased plant available nutrients and crop yield on marginal soils. Biochar application reduced the availability of potentially harmful trace elements. Heterotrophic respiration showed no clear response to biochar application. Biochar application may reduce fertilizer need and increase carbon sequestration on marginal soils.

Optimization of biochar and nitrogen fertilizer in rice cultivation

To optimize the biochar and nitrogen fertilizer, an experiment was conducted based on CCD. The high and low levels of biochar were 0 and 40 t.ha−1 and 0 and 300 kg.ha−1 of nitrogen fertilizer, respectively. Grain yield, nitrogen losses, and NUE were measured as the dependent variables. The optimal amount of biochar and nitrogen fertilizer was calculated based on three economic, environmental, and economic-environmental scenarios. In site 1, the highest grain yield was obtained at 40 t.ha−1 of biochar and 300 kg.ha−1 of the nitrogen fertilizer. In site 2, it was obtained at 20 t.ha−1 of biochar and 300 kg.ha−1 of the nitrogen fertilizer. The lowest nitrogen losses were obtained in 40 t.ha−1 of biochar and 0 kg.ha−1 of the nitrogen fertilizer in the two sites. In both sites, the highest NUE was obtained in 20 t.ha−1 of biochar and 150 kg.ha−1 of the nitrogen fertilizer. In site 1, the optimum amount of independent variables in the economic scenario was 29.49 t.ha−1 of biochar and 239.39 kg.ha−1 of the nitrogen fertilizer. In the environmental scenario, the optimum amount of biochar and nitrogen fertilizer equaled 40 t.ha−1 and 55 kg.ha−1, respectively. The optimum amount of these in the economic-environmental scenarios was 20 t.ha−1 of biochar and 97 kg.ha−1 of the nitrogen fertilizer. In site 2, the optimum amount of biochar and nitrogen fertilizer in economic, environmental, and economic-environmental scenarios equaled 23.8 t.ha−1 of biochar and 263.6 kg.ha−1 of the nitrogen fertilizer, 40 t.ha−1 of biochar and 97 kg.ha−1 of the nitrogen fertilizer, and 19.4 t.ha−1 of biochar and 133.3 kg.ha−1 of the nitrogen fertilizer, respectively.

Bio‐Based Poly(3-hydroxybutyrate)/Thermoplastic Starch Composites as a Host Matrix for Biochar Fillers

Biochar is an excellent, but less-used candidate to serve as an alternative filler in poly(3-hydroxybutyrate) (PHB)-based composites. Increasing amounts of biochar between 20 and 50 wt% were incorporated in PHB/char and PHB/thermoplastic starch (TPS)/char composites and its effects on the microstructure, crystallization and thermal properties were investigated. PHB shows a significant reduction in molecular weight after processing and the increasing amounts of biochar decreases this even stronger. From thermogravimetric analysis, it was clear that the onset degradation temperature of the PHB/char composites (255 °C) is only slightly influenced by the biochar particles up to 40 wt%. Contrastingly, this temperature reduces to 245 °C when 50 wt% of biochar is added. Additional data confirm that morphology and crystallization kinetics are enhanced up to 40 wt% of biochar, while even higher percentages of filler clearly have an opposite effect. Finally, this work reveals the ability of TPS to work as an excellent intermediator between biochar and PHB at biochar concentrations up to 20 wt%, where degradation and resulting reduction in molecular weight remains limited as compared to that of the PHB/char sample. Furthermore, like biochar, TPS acts as a nucleation agent in the composites and removes the influence of the biochar on the thermal stability of the composites.

Production and Characterization of Crop Residues Derived Biochars for Soil Amendment and Carbon Sequestration

This study focused on the production and characterization of biochars from three types of crop residues comprising cotton stems, corn cobs and sorghum stems. The reactor used was a local cone kiln made from a 200-liter drum. The production parameters measured included the duration of pyrolysis, the amount of biochar produced and the production yield. The chemical characteristics of the biochars were determined using the usual analytical methods used for organic amendment analyses. According to the study, pyrolysis time, biochar quantities and production yields depended on the type of crop residues. The three types of biochar obtained showed high C/N values indicating that their use as soil amendment must be combined with mineral fertilizers to ensure good plant development and crop yield. The heavy metal contents of the three biochar types complied with the international standards recommended for biochars by the International Biochar Initiative (IBI) and by the European Biochar Certificate (EBC). The production and the use of Biochar from crop residues is an interesting alternative for sustainable soil fertility management in the Sahelian countries.

Does biochar application improve soil aggregation? A meta-analysis

Biochar as a potential soil amendment has been widely used in agricultural soils for improving soil physical properties. However, the effects of biochar addition on soil aggregation are inconsistent in many individual studies. Therefore, we conducted a meta-analysis of 641 comparisons from 119 published studies to assess the combined effects of biochar application on soil aggregation through biochar attributes, initial soil properties, and experimental conditions. Overall, our results indicate that biochar application significantly improved soil aggregation by 16.4 ± 2.5 %, regardless of biochar/experimental/soil conditions. The response ratio (lnR) of biochar-induced soil aggregation had significant variability across different studies. In the context of biochar attributes, there was a higher favorable influence of wood biochar with higher pyrolysis temperature (> 600 °C). With the amount of biochar increased, the effects of biochar on soil aggregation significantly improved (P < 0.001). Considering experimental conditions, the advancement of soil aggregation was more significant over a longer period of time (> 3 years). In particular, the wet sieving method (18.2 %) is better than the dry sieving method (4.05 %) for assessing soil aggregation. Moreover, soil aggregation intensified in neutral and acidic soil, while alkaline soil was not significantly changed. Also, biochar amendment strengthened soil aggregation in the loam-textured (19.9 %) soils relative to sandy soils (13.4 %). Our meta-analysis demonstrates that biochar as a soil amendment can improve soil aggregation through the combination of experimental conditions with specific biochar, and soil properties.

Short‐term biochar effects on greenhouse gas emissions and phosphorus availability for maize

Short‐term biochar effects on greenhouse gas emissions and phosphorus availability for maize

Biochar Alters Soil Physical Characteristics, Arbuscular Mycorrhizal Fungi Colonization, and Glomalin Production

Soil enhancements such as biochar (BC) are gaining attention as tools to mitigate climate change and also to promote crop growth. However, biochar use can disrupt soil ecosystems by changing the soil’s physical, chemical, and biological properties. The study aimed to determine how biochar influences soil physical changes such as specific surface area (SSA) and water vapor sorption, and how these conditions affect arbuscular mycorrhizal fungal (AMF) hyphae growth and glomalin production. The study analyzed these factors at different plant phenological phases (i.e., flowering, development of fruit, and ripening of fruit and seed) to better understand the changes within the system while varying biochar amounts. The study also investigated the effect of different soil physical and chemical parameters on mycorrhizal hyphae growth and glomalin production. Four treatments were investigated: 0, 0.5%, 2.5%, and 5.0% (w/w) biochar amended silt loam soil planted with pepper. Soil samples were taken at the beginning and weeks 6, 10, and 12 of the study. The amount of adsorbed water vapor increased with an increasing amount of biochar added to the soils. Compared to control, SSA was significantly higher in all biochar amended treatments based on adsorption data, and only in the highest biochar amended soils for the desorption data at the end of the experiment. The presence of AMF in the roots appeared at week 6 of the experiment and the intensity of AMF root colonization increased with the age of plants. The AMF colonization parameters were significantly lower in BC2.5 compared to all other biochar amended soils. The abundance of intraradical AMF structures was highly correlated with several physicochemical soil parameters, such as SSA, the geometric mean diameter of soil aggregate, soil aggregate sizes, or pH. Glomalin production was negatively correlated with SSA, water vapor adsorption, aggregate stability, aggregate size, total nitrogen, potassium, and organic carbon content of the soil, while positive correlation was observed with bulk density. Increased biochar amount resulted in a significant decrease in glomalin production, concurrent with the age of the plants. Our results highlight the great complexity of interactions between soil physicochemical and biological parameters, and the importance of the time of sampling when biochar is used in soil, as the effects of biochar additions on the plant, soil physical characteristics, and soil microsymbionts vary over time.