Peanut Shell Biochar Research Articles

Effect of biochar on permeability of compacted soil and its microscopic mechanism

Biochar has attracted much attention in the field of geo-environmental engineering as a carbon-neutral alternative for soil amendment. In this study, the effects of biochar dosage, type, and particle size on the permeability and physical properties of compacted silty clay were investigated. And the prediction model of permeability coefficient of biochar-amended soil (BAS) was established. Based on the microscopy test results, the influence mechanism of biochar on the permeability of compacted soil was analyzed. Results revealed that adding different biochar types affected the consistency limits, specific gravity, and compaction curves of soil obviously. As the biochar content increased, the permeability coefficient of compacted BAS initially decreased before increasing. The permeability coefficient of compacted BAS with peanut-shell biochar was much higher than with other biochar types. Additionally, reducing the particle size of biochar can effectively decrease the permeability coefficient of BAS due to the pore-filling effect. Microscopy test results show that the permeability coefficient of BAS is affected by both the most probable pore size and the main-peak area of the pore-size distribution curve. Results suggest that controlling the biochar content at 5% and reducing the particle size of biochar are more beneficial to improve the impermeability of compacted BAS.

Transport and retention of microplastics in saturated porous media with peanut shell biochar (PSB) and MgO-PSB amendment: Co-effects of cations and humic acid

Biochar particles are extensively used in soil remediation and interact with microplastics (MPs), especially metal oxide-modified biochar may have stronger interactions with MPs. The mechanism of interactions between humic acid (HA) and different valence cations is different and the co-effect on the transport of MPs is not clear. In this study, the co-effects of HA and cations (Na+, Ca2+) on the transport and retention of MPs in saturated porous media with peanut shell biochar (PSB) and MgO-modified PSB (MgO-PSB) were systematically investigated. Breakthrough curves (BTCs) of MPs were fitted by the two-site kinetic retention model for analysis. In the absence of HA, the addition of PSB and MgO-PSB significantly hindered the transport of MPs in saturated porous media, and the retention of MPs increased from 34.2% to 59.1% and 75.5%, respectively. In Na+ solutions, the HA concentration played a dominant role in controlling MPs transport, compared to the minor role of Na+. The transport capacity of MPs always increased gradually with the increase of HA concentration. Whereas, in Ca2+ solutions, Ca2+ concentrations had a stronger effect than HA. The transport ability of MPs was instead greater than that in Na+ solutions as the HA concentration increased at low ionic strength (1 mM). However, the transport capacity of MPs was significantly reduced with increasing HA concentrations at higher ionic strength (10, 100 mM). The two-site kinetic retention model indicated that chemical attachment and physical straining are the main mechanisms of MPs retention in the saturated porous media.

Annealed peanut shell biochar as potential reinforcement for aloe vera fiber-epoxy biocomposite: mechanical, thermal conductivity, and dielectric properties

Annealed peanut shell biochar as potential reinforcement for aloe vera fiber-epoxy biocomposite: mechanical, thermal conductivity, and dielectric properties

Over two years study: Peanut biochar promoted potassium availability by mediating the relationship between bacterial community and soil properties

In acidic soil, potassium (K) deficiency is a main limiting factor that restricts the growth of fruit trees. Biochar has been used as a soil amendment to increase pH and nutrients. However, studies on the effect of biochar on the bacterial community and soil properties in potted experiments are limited. Therefore, we used peanut shell biochar to investigate the effect of biochar on the structure and function of bacterial communities by high-throughput sequencing, soil enzymes (urease, dehydrogenase, and extracellular enzymes), and gene function prediction in response to K deficiency in acidic soil. The results indicated that soil pH, enzyme activity, and available nutrients were improved by biochar. In particular, biochar still had a beneficial effect on improving soil and plant K levels after thirty months of application. In addition, biochar promoted the growth of K-dissolving bacteria and relative abundance of bacteria (p_actinomycetes, p_chloroflexi, p_proteobacteria, p_acidobacteriota, and p_firmicutes). Based on the above results, we assumed that biochar application can effectively improve soil K levels and bacterial functions. Such as: K-dissolving, soil organic matter decomposition and the conversion of nutrients. Our findings encourage and support the use of biochar as an amendment in acidic soil.

Development of composite filters from biochars for wastewater treatment

ABSTRACT The aim of this research is to develop a bio-nanocomposite filter from locally sourced agro-wastes to treat waste and effluent water. The filters were formulated from coconut and peanut shell biochars, with kaolin as the binding agent and rice husk as the pore-creating agent within nanometric size range using planetary balling milling. The batch composition of the filters was carried out in 10 groups and labelled F1 to F10. The parameters for comparison include linear shrinkage, apparent porosity, water absorption, hardness test, bulk density, and modulus of rupture. The results indicate that the filter F7 showed more resistance to indention with a hardness value of 29.4 than the control with a hardness value of 26.6 and also the flow rate in F7 was noted to be 23.07 ml/h, whereas F9 recorded the least flow rate of 1.03 ml/h. It was also observed that filter F8 had a higher bulk density value of 2.587 g cm-3 due to its high degree of compaction, while the control had a lesser bulk density value of 1.9990 g cm-3. However, the control proved to have a higher apparent porosity of 50%, which was slightly higher than filter F10 with 49.46% apparent porosity.

Soil organic carbon characteristics affected by peanut shell biochar in saline-sodic paddy field

Biochar exhibits a profound impact on soil organic carbon (SOC) turnover and dynamics, but the underlying mechanism under field conditions is still unclear. A three-year field experiment was performed to evaluate the impact of peanut shell biochar applied at rates of 0, 33.75, 67.5, and 101.25 t/ha (referred to as B0, B1, B2, and B3, respectively) on SOC content and chemical composition in a saline-sodic paddy field using stable carbon isotope composition and <sup>13</sup>C nuclear magnetic resonance technology. With increasing rates of biochar, SOC and aromatic carbon contents and alkyl carbon/oxygen-alkyl carbon and hydrophobic carbon/hydrophilic carbon ratios increased, while alkyl carbon and oxygen-alkyl carbon contents and aliphatic carbon/aromatic carbon ratio decreased. The new carbon from biochar and rice residues accounted for 26.5% of SOC under B0 and increased to above 80.0% under B2 and B3. The decay rate of old carbon was faster in biochar-amended than in unamended soil. SOC content was positively correlated with alkyl carbon/oxygen-alkyl carbon and hydrophobic carbon/hydrophilic carbon ratios but negatively correlated with aliphatic carbon/aromatic carbon ratio. The results suggest that biochar can increase SOC content by increasing its humification, aromaticity, and hydrophobicity. However, negative priming is not the main mechanism for SOC accumulation during the short-term period.

Simultaneous reduce NO/CO2/CO emissions by modified peanut shell biochars in Ca-L/CARBONOx process

A composite of biochar (BC) derived from peanut shells—with high ash contents—blended with CaO was used in the Ca-L/CARBONOx process. BC was subjected to acid pickling (BC-A), direct nitrogen doping (BC-N), and acid pickling with nitrogen doping (BC-A-N). The efficacy of modified biochar for simultaneous reduce NO/CO2/CO emissions was investigated in this study. The results show that simultaneous NO/CO2 removal was realized in the Ca-L/CARBONOx process using peanut-shell-biochar/CaO. However, higher CO emission was also generated during the process, which increased significantly as the temperature, biochar addition, and oxygen concentration increased. CO2 produced by the oxidation of biochar accelerates CaO consumption and decreases its catalytic effect on NO reduction. The simultaneous NO/CO2 removal ratio declined with the cycle number due to CaO sintering. Acid pickling and nitrogen-doping of biochar significantly decreased the CO and CO2 emissions, whereas sintering of CaO at higher cycle numbers had little effect on NO reduction by BC-A-N.

Biochar mitigation of soil acidification and carbon sequestration is influenced by materials and temperature

The alleviation effects on soil acidification by different raw materials and pyrolysis temperatures can broaden the utilization of biochar. In this study, nine types of biochar produced from three raw materials, namely fruit tree branch, peanut shell, and cow dung, at three pyrolysis temperatures (300, 450, and 600 °C) were used to amend acidified brown soil; the rape growth, physiology character, soil chemical and microbial, along with soil organic carbon mineralization were also investigated. The results showed that application of biochar increased soil pH by 8.48–79.25% and reduced exchangeable acidity, exchangeable Al, and exchangeable H by 56.94–94.95%, 34.38–95.66%, and 58.72–93.27%, respectively. Biochar alleviated oxidative stress in plants, reduced malondialdehyde and glutathione content in leaves, promoted rape growth, and increased microbial community diversity and the relative abundances of Acidobacteria and Olpidiomycota in the acidic soil. Moreover, biochar reduced the mineralization rate of organic carbon and the proportion of mineral-bonded organic carbon. Overall, biochar application is an effective strategy to ameliorate soil acidification and enhance rape production and carbon sequestration. The mitigation effect of branch biochar and cow dung biochar on soil acidification was superior to that of peanut shell biochar. The effects of biochar depended on the pyrolysis temperature; the positive effects of biochar samples pyrolyzed at 450 and 600 ℃ were stronger than those pyrolyzed at 300 ℃. In this study, the optimum biochar materials and carbonization temperature for acidified soil improvement, as well as the effects of biochar application on soil microbial and carbon mineralization were clarified, which provides a new potential strategy for acidified soil improvement and expand the application range of biochar.

Mechanism Insight of Simultaneous Removal of P-Nitrophenol and Cr(Vi) from Groundwater by Green Synthetic Peanut Shell Biochar Supported Nano Zero Valent Iron/Copper

Mechanism Insight of Simultaneous Removal of P-Nitrophenol and Cr(Vi) from Groundwater by Green Synthetic Peanut Shell Biochar Supported Nano Zero Valent Iron/Copper

Ni(II), Cr(VI), Cu(II) and nitrate removal by the co-system of Pseudomonas hibiscicola strain L1 immobilized on peanut shell biochar

At present, the improvement of nitrate and mixed heavy metals removal in wastewater by microorganism are urgently needed. Previous studies have shown that Pseudomonas hibiscicola strain L1 exhibited Ni(II) removal ability under aerobic denitrification. In this study, the characteristics of the free strain L1, peanut shell biochar (PBC) and further the co-system of strain L1 immobilized on PBC were investigated for the removal of Ni(II), Cr(VI), Cu(II) and nitrate in mix-wastewater. The results illustrated that strain L1 could remove 15.51% - 32.55% of Ni(II) (20–100 mg·L−1), and removal ratios by co-system were ranked as Ni(II) (81.17%) > Cu(II) (45.84%) > Cr(VI) (38.21%). Scanning Electron Microscope (SEM), X-ray Diffractometer (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) images indicated that the strain L1 immobilized well on PBC and had vigorous biological activity; the crystals of Ni(OH)2, Cu(OH)2 and CrO(OH) etc. were formed on surface of co-system with various functional groups participated in. In Sequential Batch Reactor (SBR), the pollutant removal ratios by co-system were higher than that by free strain L1. This study illustrated that the co-system of strain L1 immobilized on PBC was qualified to be applied for practical scenarios of effective heavy metal removal of electroplating mix-wastewater.

Activation of peroxymonosulfate by magnetic Fe3S4/biochar composites for the efficient degradation of 2,4,6-trichlorophenol: Synergistic effect and mechanism

The synergistic catalytic degradation of metal carbon-based composites is a feasible strategy to improve the efficiency of advanced oxidation processes (AOPs) by means of green chemistry. In this work, Fe3S4 nanoparticles were anchored on the surface of peanut shell biochar to prepare magnetic Fe3S4/biochar (Fe3S4/BC) composites, which were applied to activate peroxymonosulfate (PMS) to degrade 2,4,6-trichlorophenol (2,4,6-TCP). The addition of biochar not only reduced the aggregation of Fe3S4 nanoparticles, but also accelerated the electron transfer rate, and the constructed C-O-Fe bridges accelerated the regeneration of Fe(Ⅱ), which made Fe3S4/BC have better catalytic performance than pure Fe3S4 even though the use of metal sulfides was reduced. Fe on the surface of Fe3S4/BC was the catalytic reaction center. The dominant role of sulfate radical (SO4·-) and hydroxyl radical (HO·) on the degradation of 2,4,6-TCP was verified by electron paramagnetic resonance (EPR) and free radical quenching experiments. The mechanism of C-O-Fe bridges was verified by density functional theory (DFT) calculation. The mechanism of PMS activation by Fe3S4/BC was elucidated by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). Based on the detection results of intermediate products, the possible degradation pathways to 2,4,6-TCP were proposed. This work provides new insights into the synergistic catalytic mechanism of metal carbon-based sulfides and promotes the development of environmentally friendly and efficient metal carbon-based catalysts.

Modification of Peanut Shell Biochar and Its Adsorption Performance

In order to improve the efficient recovery and utilization of agricultural waste, biochar was prepared from peanut shells through oxygen-limited pyrolysis at 240 °C in this work, and biochar was modified with sodium hydroxide solution to explore the adsorption performance of Pb2+ on biochar before and after modification. The specific surface area, pore structure, surface functional groups, microscopic morphology, surface element distribution of the peanut shell biochar before and after modification were analyzed by Brunauer-Emmett-Teller (BET), Fourier transform infrared Spectroscopy (FTIR), and Scanning Electron Microscopy-Energy Dispersive Spectrometer (SEM-EDS). The Pb2+ adsorption experiments on biochar before and after modification were carried out under different conditions, it was found that the suitable solution pH for biochar to adsorb Pb2+ were both 5.5~6.5, the suitable solid-liquid ratio of unmodified biochar was 2.5 g·L−1, the suitable solid-liquid ratio of modified biochar was 2.0 g·L−1, and equilibrium adsorption time of modified biochar was shortened. The adsorption behaviors of the two kinds of biochar conformed to Pseudo-second-order kinetic model and Langmuir isothermal model, thermodynamic parameters were ΔG < 0, |ΔG| < 40 kJ·mol−1, ΔH > 0, ΔS > 0. These adsorption processes were spontaneous endothermic processes including both physical and chemical adsorption.

Characteristics of Phosphorus Adsorption in Aqueous Solution by Si-modified Peanut Shell Biochar

In this work, a novel sodium silicate-modified peanut shell biochar(Si-PSB) was synthesized and used as phosphorus adsorbents. Compared with unmodified biochar(PSB), the adsorption capacity of Si-PSBs increased significantly. The adsorption capacity of 8% sodium silicate solution modified biochar(8%Si-PSB) was 3.9 times higher than that of PSB. The biochar was characterized using scanning electron microscopy(SEM), Fourier transformed infrared(FTIR), and X-ray diffraction(XRD), which confirmed that silica was present on the surface of 8%Si-PSB. The introduction of silica improved the reaction activity of biochar's own metal ions by affecting the morphology of calcium carbonate. The 8%Si-PSB had a good adsorption effect on phosphorus in both acid and alkali environments. Phosphorus adsorption by 8%Si-PSB and PSB was described well by the pseudo-second-order model, and the adsorption capacity after equilibrium fluctuated between 2.79 mg·g-1 and 0.71 mg·g-1, respectively. Further, the isothermal adsorption experimental data fitted well to the Langmuir model. The presence of humic acid in the solution inhibited the adsorption of phosphorus by the 8%Si-PSB and PSB. The 8%Si-PSB, as a new low-cost phosphorus removal material, can improve the utilization of metal ions in peanut shell itself.

Sediment metals adhering to biochar enhanced phosphorus adsorption in sediment capping

Abstract Metal ions in sediment are inherent Ca and Fe sources for biochar modification. In this work, the effect of Ca2+ and Fe2+ released from sediment on biochar for phosphorus adsorption was evaluated. Results showed that raw peanut shell biochar (PSB) was poor in phosphorus adsorption (0.48 mg/g); sediment-triggered biochar (S-PSB) exhibited a P adsorption capacity of 1.32 mg/g in capping reactor and maximum adsorption capacity of 10.72 mg/g in the Langmuir model. Sediment released Ca2+ of 2.2–4.1 mg/L and Fe2+/Fe3+ of 0.2–9.0 mg/L. The metals loaded onto the biochar surface in the forms of Ca-O and Fe-O, with Ca and Fe content of 1.47 and 0.29%, respectively. Sediment metals made point of zero charge (pHpzc) of biochar shifted from 5.39 to 6.46. The mechanisms of enhanced P adsorption by S-PSB were surface complexation of CaHPO4 followed by precipitation of Ca3(PO4)2 and Ca5(PO4)3(OH). Sediment metals induced the modification of biochar and improvement of P adsorption, which was feasible to overcome the shortcomings of biochar on phosphorus control in sediment capping.

Valorization of peanut shell biochar for soil amendment

Biochar is one of the best and economical soil amendments as it helps in carbon sequestration, retains soil nutrients, increases water retention capacity of the soil, attracts more beneficial microbes and thus improves the crop yield. Peanut shell (PNB) biochar is produced by slow pyrolysis at 300 °C, 400 °C, 500 °C and 600 °C. PNB produced at these various temperatures were characterized (pH, electrical conductivity, ash and moisture content, bulk density, FTIR, SEM, XRD, SBET and elemental analyses). Pot study was carried out with soil amended with PNB obtained at various temperatures and PNB in combination with N (Nitrogen) fertilizer on sorghum crops over 30 days. It is found that Biochar increased soil water retention capacity and N fertilizer utilization efficiency by the plants. PNB, in combination with urea, had a synergistic effect that enhanced sorghum crop growth (fresh and dry weight, height of the plant, stem diameter, leaf length, leaf area). PNB showed no significant effect on seed germination. Thus, PNB, in combination with urea, can be used as an effective soil amendment technique. Highlights Biochar amendment increased the soil water holding capacity Peanut shell biochar in combination with urea has a synergistic effect Increased N fertilizer utilization efficiency by the plants when biochar and N fertilizer applied together Enhanced sorghum crop growth due to biochar amendment Application of Peanut shell biochar showed no significant effect on seed germination

Micro-particle biochar for soil carbon pool management: Application and mechanism

In this study, the possibility of using biochar for soil carbon pool regulation owing to its unique physical and chemical properties was tested. Specifically, to investigate the effects of different biochar particle sizes (500–2000, 250–500, 20–250, and < 20 μm) on the soil carbon pool structure as well as the associated mechanism, pot culture experiments were performed using peanut shell biochar. The results obtained showed that the chemical properties of the biochar remained unchanged; however, the different particle sizes influenced the porosity properties of the biochar. Smaller-sized biochar particles showed specific surface area (32.91 m2/g), pore volume (0.043 m3/g), and pore size (4.56 nm) that were larger than those corresponding to their larger-sized counterparts. Further, biochar application enhanced the organic carbon content of the treated soil by up to 46.85 % compared with conventional fertilisation. Biochar with particle size < 20 μm improved the mean weight diameter of soil water-stable aggregates by 2.5–12.5 %. Furthermore, the easily oxidisable carbon content of the biochar-treated soil reached 2.22 g/kg, increasing by 80.31–89.58 % compared with that achieved via conventional fertilisation. The average soil dissolved organic carbon content was 356.64 mg/kg, which is 78.86 % higher than that achieved via conventional fertilisation. Additionally, biochar with a particle size < 20 μm also significantly improved the soil carbon pool management index by 186.17 %. Therefore, the results of this study provide a theoretical basis for the scientific application of biochar based on particle size given that micro-particle biochar, in particular, can significantly improve the soil carbon pool management index.

Enhanced Adsorption Capacities of Fungicides Using Peanut Shell Biochar via Successive Chemical Modification with KMnO4 and KOH

This study explored the effects of peanut shell biochar (PSB) on the adsorption capacities of fungicides with and without successive chemical modifications, using KMnO4 and KOH (PSBOX-A), in order to provide a valuable understanding of their adsorption mechanisms and behaviors. To this end, the physicochemical properties of PSB and PSBOX-A were examined by using the Brunauer–Emmett–Teller method, Fourier transform infrared spectroscopy, and scanning electron microscopy with an energy dispersive X-ray spectrometer. The effects of temperature, ionic strength, and humic acids on the adsorption of fungicides, using PSB and PSBOX-A, were estimated through batch experiments. Furthermore, adsorption kinetics, isotherms, and thermodynamics were studied. The maximum adsorption capacities of fungicides by PSBOX-A were estimated to be more notable (Qmax of carbendazim = 531.2 μmol g−1, Qmax of pyrimethanil = 467.7 μmol g−1, and Qmax of tebuconazole = 495.1 μmol g−1) than PSB (Qmax of carbendazim = 92.6 μmol g−1, Qmax of pyrimethanil = 61.7 μmol g−1, and Qmax of tebuconazole = 66.7 μmol g−1). These findings suggest that successive chemical modification using KMnO4 and KOH could potentially be used to effectively fabricate PSB to remove fungicides in water-treatment processes.

Adsorption and recovery of cadmium and copper ions in mono and bicomponent systems using peanut shells biochar as a sustainable source: model development

This study evaluates the adsorption efficiency of Cd2+ and Cu2+ by peanut shell biochar (BPS) in monocomponent and bicomponent systems. The characterization indicated that BPS was mesoporous and amorphous, with presence of hydroxyl and carboxylic functional groups, with a pHPZC of 7.9. The effects of pH, stirring speed and adsorbent dosage were investigated, and the best results were obtained at pH 5.9, 200 rpm and 2 g·L−1. In monocomponent systems, the Elovich and BET models had the best adjustment, obtaining maximum adsorption capacity of 0.39 mmol·g−1 for Cd2+ and 0.48 mmol·g−1 for Cu2+, and the adsorption process was spontaneous and endothermic. With regard to bicomponent systems, a model was developed in order to predict the evolution and equilibrium of kinetics. BPS had regeneration potential after desorption. These results demonstrate the viability of the use of BPS for the adsorption of Cd2+ and Cu2+ in both systems.

Impact of N-fertilization and peanut shell biochar on soil microbial community structure and enzyme activities in a Typic Haplustoll under different management practices

The application of biochar with N-fertilizer is one of the most attractive practices for increasing soil quality and fertility. However, few studies have examined the combined effects of peanut biochar and urea on soil microbial community structure and function. Phospholipid fatty acid (PLFA) analysis and various enzyme activities were used to monitor microbial community structure and function in a 20-week incubation experiment. Different rates of biochar (0, 1, and 3% dry wt. soil) and N-fertilizers (with or without urea addition at 0.2 g kg−1) were applied to a Typic Haplustoll under conventional (CV) and conservation (CS) land management practices. A pristine forest soil (CK) was also included as control. Overall, the lowest microbial activity and abundance of microbial PLFA bioindicators were recorded under CV, confirming that conservation management may improve soil quality. Our study also indicated that the effect of biochar and management practices on the microbial community structure was more significant than that of urea. Particularly under both CS and CK, biochar tended to increase glucosidase, glucuronidase, and phosphomonoesterase activities, being on average 65%, 43%, and 85% significantly higher in biochar 3% than in the control treatment, respectively. Thus, we found a strong correlation between soil macronutrients and enzymes such as glucosidase and urease. Although total PLFA content was poorly affected, biochar addition increased some individual PLFA biomarkers, suggesting that both the biochar rates (1% and 3%) may increase Gram-negative bacteria and fungal populations. Regardless of biochar addition, urea application significantly increased urease activity. We also found a positive correlation between fungal PLFAs (VAM and total fungi) and urease activity, indicating that biochar tended to increase fungal biomass. The combined application of biochar and urea to soil under appropriate management may thus be a feasible and effective strategy for improving soil microbial quality.

Changes in surface characteristics and adsorption properties of 2,4,6-trichlorophenol following Fenton-like aging of biochar

Fenton-like system formed in a natural soil environment deemed to be significant in the aging process of biochar. Aged biochars have distinct physico-chemical and surface properties compared to non-aged biochar. The aged biochar proved to be useful soil amendment due to its improved elements contents and surface properties. The biochar aging process resulted in increased surface area and pore volume, as well as carbon and oxygen-containing functional groups (such as C=O, –COOH, O–C=O etc.) on its surface, which were also associated with the adsorption behavior of 2,4,6-trichlorophenol (2,4,6-TCP). The biochar aging increased the adsorption capacity of 2,4,6-TCP, which was maximum at pH 3.0. The 2,4,6-TCP adsorption capacity of aged-bush biochar (ABB) and aged-peanut shell biochar (APB) was increased by 1.0–11.0% and 7.4–38.8%, respectively compared with bush biochar (BB) and peanut shell biochar (PB) at the same initial concentration of 2,4,6-TCP. All biochars had similar 2,4,6-TCP desorption rates ranging from 33.2 to 73.3% at different sorption temperatures and times. The desorbed components were mainly 2,4,6-TCP and other degraded components, which were low in concentration with small molecule substance. The results indicated that the aged-biochar could be effective for the long-term remediation of naturally organic polluted soils.