RESUMO
To achieve the resource utilization of edible fungi residue and obtain efficient adsorbents for treating dyeing wastewater, biochars were prepared from mushroom residue (MR) with the introduction of alkaline-earth metals (AEMs) and used for methyl orange (MO) wastewater treatment. The thermal behavior of the AEM-treated MR was analyzed using thermogravimetric analysis. The physicochemical properties of the biochars obtained from AEM-treated MR (MRCs) were characterized using Fourier transform infrared spectroscopy, laser particle size analyzer, N2 adsorption/desorption, and scanning electron microscopy. The adsorption performance of MRCs on MO was also investigated. The involvement of AEMs was found to obviously move the main pyrolysis zone of MR to a low temperature region and reduce the temperature corresponding to the maximum weight loss rate and activation energy, which is highly dependent on the concentration of AEMs, the anion and cationic species of the AEMs. Moreover, the addition of AEMs resulted in a decrease in oxygen-containing functional groups (-OH, CO, or C-O), a weakening of surface negative charges, an enhancement in aromatic functional groups, and an increase in specific surface area of the MRCs. The adsorption performance of MO on MRCs was significantly improved with the introduction of AEMs as well. Among them, MR pre-treated with 5 mmol/g MgCl2 (MR-MgCl2-5) shows the lowest temperature corresponding to the maximum weight loss rate and the lowest activation energy of 278.52 °C and 4.28 kJ/mol, respectively. The biochar prepared from MR-MgCl2-5 under 400 °C (MR-MgCl2-5-400C) has the weakest surface negative charge and the highest adsorption capacity for MO. The adsorption isotherms, adsorption kinetics, and thermodynamic analysis results showed that the adsorption of MO on MR-MgCl2-5-400C was a spontaneous, chemically dominant monolayer adsorption, with a theoretical maximum adsorption capacity of 81.30 mg/g. This study suggests that AEMs treatment, especially with 5 mmol/g MgCl2, can readily transform edible fungi residue into a low-cost, high-efficient dyeing wastewater adsorbent.
Assuntos
Agaricales , Compostos Azo , Metacrilatos , Sulfonas , Poluentes Químicos da Água , Adsorção , Águas Residuárias , Metais Alcalinoterrosos , Carvão Vegetal/química , Espectroscopia de Infravermelho com Transformada de Fourier , Redução de Peso , Cinética , Poluentes Químicos da Água/químicaRESUMO
Due to its high carbon content, lignin, particularly for lignin-containing solid waste, is considered an excellent raw material for the preparation of carbon materials like biochar. To produce high-quality lignin-based biochar (LGBCs), lignin extracted from black liquor was employed to prepare biochar at various pyrolysis temperatures (300~600 °C). The physicochemical properties of LGBCs were assessed using scanning electron microscopy, N2 adsorption/desorption, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction. Furthermore, the adsorption capability and potential mechanism of LGBCs in removing Cd(II) were investigated as well. The results indicate that LGBCs produced at higher pyrolysis temperatures exhibit rougher surfaces and more developed pore structures, which facilitate the exposure of numerous active adsorption sites. The adsorption of Cd(II) by LGBCs generally follows the order of LG-300C < LG-400C < LG-500C < LG-600C. According to the Langmuir adsorption isotherm model, the theoretical maximum adsorption capacity of LG-600C for Cd(II) is calculated to be 18.54 mg/g. Adsorption mechanism analysis reveals that the complexation interaction, dependent on the surface functional groups, plays a crucial role in the adsorption of Cd(II) by LGBCs prepared at higher pyrolysis temperatures. This study demonstrates that, by controlling the pyrolysis temperature during biochar preparation, high-quality lignin-based biochar can be readily obtained.
RESUMO
Co-pyrolysis is considered a very promising technology for the treatment of solid wastes as it can rapidly realize the volume reduction of raw materials and obtain high value-added products. To realize the resource utilization of newly emerging solid wastes in relation to edible fungi residue and waste plastics, mushroom residue (MR), a representative of edible fungi residue, was co-pyrolyzed with waste plastic bags (PE), waste plastic lunch boxes (PP), and waste plastic bottles (PET). The thermal behavior and pyrolysis kinetics of the mixtures were investigated. It was found that the softening of the plastics in the mixtures led to an increase in the initial pyrolysis temperature of MR by 2-27 °C, while the pyrolytic intermediates of MR could greatly promote the decomposition of the plastics, resulting in a decrease in the initial pyrolysis temperatures of PE, PP, and PET in the mixtures by 25, 8, and 16 °C, respectively. The mixture of MR and PE (MR/PE) under different mixture ratios showed good synergies, causing the pyrolysis peaks attributed to MR and PE to both move towards the lower temperature region relative to those of individual samples. The increase in heating rate led to enhanced thermal hysteresis of the reaction between MR and PE. The strength of the interaction between plastics and MR based on mass variation was subject to the order PE > PP > PET. The pyrolysis activation energies of MR, PE, PP, and PET calculated from kinetic analysis were 6.18, 119.05, 84.30, and 74.38 kJ/mol, respectively. The activation energies assigned to MR and plastics were both reduced as plastics were introduced to co-pyrolyze with MR, indicating that MR and plastics have a good interaction in the co-pyrolysis process. This study provides theoretical and experimental guidance for the resource utilization of agricultural solid wastes via thermochemical conversion.
RESUMO
To explore the influence of mineral components in bio-sorbent on its adsorption capability towards heavy metal ions, the physicochemical properties of original mushroom residue (UMR) and that treated by an acid solution to remove its minerals (AMR) were comparatively analyzed using inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and fourier transform infrared spectrometer (FT-IR). Then, the adsorption performance of UMR and AMR for Cd(II) as well as the potential adsorption mechanism were investigated. Results show that UMR contains abundant K, Na, Ca and Mg, with the contents of 245.35, 50.18, 1390.63 and 29.84 mmol kg-1, respectively. Acid treatment (AMR) results in the removal of most of the mineral components, exposing more pore structures and increasing the specific surface area by about 7 times to 20.45 m2 g-1. The adsorption performance of UMR is significantly better than that of AMR when they are employed to purify a Cd(II)-contained aqueous solution. The theoretical maximum adsorption capacity of UMR calculated by Langmuir model is 75.74 mg g-1, which is about 22 times of that of AMR. Moreover, the adsorption of Cd(II) on UMR reaches an equilibrium at about 0.5 h, while the adsorption equilibrium of AMR takes more than 2 h. The mechanism analysis shows that 86.41% of the adsorption of Cd(II) on UMR can be attributed to ion exchange and precipitation caused by mineral components (especially for K, Na, Ca and Mg). The adsorption of Cd(II) on AMR mainly depends on the interactions between Cd(II) and surface functional groups, electrostatic interaction and pore-filling. The study indicates that those bio-solid wastes with abundant mineral components can be potentially developed as low-cost and high-efficient adsorbents for the removal of heavy metal ions from aqueous solution.
Assuntos
Agaricales , Metais Pesados , Poluentes Químicos da Água , Cádmio/análise , Adsorção , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise , Metais Pesados/química , Minerais , Água , Cinética , Concentração de Íons de HidrogênioRESUMO
With the continuous development of society, the output of kitchen waste (KW) is fast increasing. De-oiled kitchen water (DKW) and kitchen waste treatment residue (KWTR), two main by-products of the KW treatment industry, are produced accordingly on a large scale. The need to develop an effective technique for the utilization of DKW and KWTR is attracting wide attention. In the present study, black soldier fly larvae (BSFL) were employed as a biological treatment method to treat KWTR with the addition of DKW. The influence of DKW (0-140 mL) on the efficiency of BSFL treatment evaluated by the growth and development of BSFL, the body composition of BSFL, the nutrient content of bioconversion residue (BR), and the bioconversion efficiency of KWTR, was investigated. The results showed that the growth and development of BSFL, the body composition of BSFL, and the conversion rate of KWTR were initially promoted and then inhibited with the addition of DKW. Notably, the amount of DKW added in the T110 group was the most suitable for the growth of BSFL and the accumulation of body composition. Compared with the blank comparison group, the content of crude protein (CP), crude ash (CA), salinity, total phosphorus (TP), and dry matter (DM) of BSFL in the T110 group increased by 3.54%, 6.85%, 0.98%, 0.07% and 2.98%, respectively. However, the addition of DKW could steadily increase the nutrient content of BR, with the highest amount at 140 mL DKW. Following DKW addition, the contents of CP, ether extract (EE), crude fiber (CF), organic matter (OM), total nitrogen (TN), TP, and total potassium (TK) were increased by 4.56%, 3.63%, 10.53%, 5.14%, 0.73%, 0.75%, and 0.52%, respectively, compared with those of the blank comparison group. The study showed that DKW could be used as a nutrient additive in the bioconversion process of KWTR by BSFL, which provided a new method for the resource utilization of DKW.
Assuntos
Dípteros , Animais , Larva , Nutrientes , ÁguaRESUMO
Carbon nanomaterials, such as carbon nanoonions (CNOs), possess promising applications in various fields. There are urgent demands to synthesize carbon nanomaterials from a green and renewable carbon source. In this study, solid CNOs with relatively uniform size distribution (with diameters of about 30-50 nm), abundant structure defects and oxygen-containing surface functional groups (such as -OH and -COOH) are developed from co-pyrolysis of lignin (LG) and polyethylene (PE) in the presence of Ni-based catalysts. The type of catalyst, the concentration of catalyst and catalytic co-pyrolysis temperature play important roles in the morphologies and properties of CNOs as confirmed by TEM and SEM. Furthermore, the produced CNOs can act as a low-cost and highly-efficient adsorbent to remove Cu(ii) from aqueous solution according to a homogeneous monolayer, chemical action-dominated, endothermic and spontaneous process. The theoretical maximum adsorption capacity of CNOs calculated from the Langmuir model is 100.00 mg g-1. Surface deposition, complexation, π electron-cation interaction and electrostatic interaction are responsible for the adsorption of Cu(ii) using the prepared CNOs.
RESUMO
In order to seek the value-added utilization method of sewage sludge and develop low-cost and high-efficient adsorbents, a hydrochar was prepared by the co-hydrothermal carbonization of sewage sludge and citric acid and then characterized. The differences in Pb(II) adsorption performance between the citric acid-sewage sludge hydrochars (AHC) and the hydrochar prepared solely from sewage sludge (SSHC) were also investigated. When citric acid dose ratio (mass ratio of citric acid to dry sewage sludge) is 0.1, the obtained hydrohcar (AHC0.1) has the highest specific surface area (59.95 m2·g-1), the most abundant oxygen-containing functional groups, the lowest pHpzc (5.43), and the highest equilibrium adsorption capacity for Pb(II). The maximum adsorption capacity of AHC0.1 for Pb(II) is 60.88 mg·g-1 (298 K), which is approximately 1.3 times that of SSHC. The potential mechanisms can be electrostatic attraction, co-precipitation, complexation, and cation-π interaction. It was demonstrated that by incorporating citric acid into the hydrothermal carbonization, resource utilization of sewage sludge can be accomplished effectively.
RESUMO
In the present study, the coked catalysts derived from catalytic reforming of the pyrolysis volatiles of polyethylene (PE), lignin (LG) and their mixture were developed as low-cost and environmentally-friendly carbon materials-containing composites to remove heavy metal ions from aqueous solution. The composites were thoroughly characterized by SEM, TEM, XRD, TGA and FT-IR and then their adsorption capability towards Pb(ii) was investigated. It is found that curved cone-shape carbon nanotubes (CNTs) with abundant structural defects and O-containing surface functional groups, such as C-O, C[double bond, length as m-dash]O and -OH, can be obtained from the catalytic reforming of the mixture of PE and LG. The CNT-containing catalyst composite presents a superior adsorption capability towards Pb(ii) when it is employed in Pb(ii) removal. Adsorption isotherm and adsorption kinetics studies show that the adsorption process can be well simulated by the Langmuir isotherm and pseudo-second-order model, demonstrating that the adsorption is subjected to a homogeneous and chemical process. The calculated maximum adsorption capacity is as high as 146.08 mg g-1, which is much higher than most of the adsorbents reported. Moreover, thermodynamic analysis reveals that the adsorption is spontaneous and endothermic. Accordingly, the used catalyst from the catalytic reforming can be developed as a low-cost and highly-efficient adsorbent.
RESUMO
Osteoarthritis (OA) is a degenerative disease that has received increasing attention among the elderly. Its clinical manifestation is primarily long-term joint pain. Evidence for the pharmacological effects of geraniol in various diseases is accumulating. However, whether geraniol has a therapeutic effect against OA remains to be determined. In this study, we discussed the anti-inflammatory effects of geraniol in IL-1ß-induced chondrocytes and the anti-cartilage degradation effects in a mouse model of destabilization of the medial meniscus (DMM). In cell experiments, we found that the treatment of geraniol inhibited the expression of IL-1ß-induced PGE2, NO, COX-2, iNOS, TNF-α and IL-6 by western blot, qRT-PCR and immunofluorescence staining. Besides, geraniol inhibited the expression of MMP-9 and ADAMTS-5, and reversed the degradation of aggrecan and type II collagen. Mechanistically, we revealed that geraniol suppressed IL-1ß-stimulated PI3K/Akt/NF-κB and MAPK activation. Importantly, we have found in animal experiments that oral treatment of geraniol was beneficial in protecting articular cartilage from degradation. Overall, these data indicated that geraniol may have the potential to be developed as an effective treatment for OA.
Assuntos
Monoterpenos Acíclicos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Subunidade p50 de NF-kappa B/metabolismo , Osteoartrite/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Monoterpenos Acíclicos/uso terapêutico , Agrecanas/metabolismo , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Células Cultivadas , Condrócitos/efeitos dos fármacos , Colágeno Tipo II/metabolismo , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Modelos Animais de Doenças , Matriz Extracelular/efeitos dos fármacos , Interleucina-1beta/toxicidade , Interleucina-6/genética , Interleucina-6/metabolismo , Masculino , Meniscos Tibiais/patologia , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Osteoartrite/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Osteoarthritis (OA) is a degenerative disease found in middle-aged and elderly people, which seriously affects their quality of life. The anti-inflammatory and anti-apoptosis pharmacological effects of salvianolic acid A (SAA) have been shown in many studies. In this study, we intended to explore the anti-inflammatory and anti-apoptotic effects of SAA in OA. We evaluated the expression of pro-inflammatory mediators and cartilage matrix catabolic enzymes in chondrocytes by ELISA, Griess reaction, immunofluorescence, and Western blot, which includes nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), MMPs (MMP-3, MMP-13), and ADAMTS-5. Bax, Bcl-2, and cleaved caspase-3 were also measured by Western blot methods. The results of this experiment in vitro showed that SAA not only inhibited the production of inflammatory mediators induced by IL-1ß and the loss of cartilage matrix but also reduced the apoptosis of mouse chondrocytes induced by IL-1ß. According to the results of immunofluorescence and Western blot, SAA inhibited the activation of the NF-κB pathway and MAPK pathway. The results of these in vitro experiments revealed for the first time that SAA down-regulated the production of inflammatory mediators and inhibited the apoptosis of mouse chondrocytes and the degradation of extracellular matrix (ECM), which may be attributed to the inhibition of the activation of NF-κB and MAPK signaling pathways. In the in vivo experiments, 45 mice were randomly divided among three groups (the sham group, OA group, and OA + SAA group). The results of animal experiments showed that SAA treatment for eight consecutive weeks inhibited further deterioration of OA. These results demonstrate that SAA plays an active therapeutic role in the development of OA.
RESUMO
Pathological changes, such as articular cartilage degeneration, destruction, and hyperosteogeny, are regarded as the main features of osteoarthritis (OA). Sinomenine (SIN) is a monomeric component purified from the plant Sinomenium acutum which has been found to have anti-inflammatory effects, however, the mechanism of action of SIN on OA is not clear. In this study, we evaluated whether SIN could regulate the inflammatory response induced by interleukin (IL)-1ß and improve outcomes in the instability model of OA (medial meniscus mice (DMM)) by acting on the Nrf2/HO-1 and NF-κ B signaling pathways in chondrocytes. From our experiments, which include Griess reaction, ELISA, Western blot, and immunofluorescence, we found that SIN not only down-regulated the expression of pro-inflammatory factors induced by IL-1ß, including; inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nitricoxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), but also decreased the production of IL-1ß-induced cartilage matrix catabolic enzymes including; ADAMTS-5 and MMPs, in mouse chondrocytes. In addition, the degradation of aggrecan and type II collagen protein in the extracellular matrix (ECM) stimulated by IL-1ß was reversed. Most importantly, we have revealed for the first time that in OA, SIN inhibited the inflammatory response and ECM degradation by activating the Nrf2/HO-1 signaling pathways and inhibiting NF-κB activity in mouse-cartilage cells. In in vivo experiments, SIN treatment helped to improve the cartilage destruction in OA model mice. In conclusion, this study has demonstrated that SIN inhibits the IL-1ß-induced inflammatory response and cartilage destruction by activating the Nrf2/HO-1 signaling pathway and inhibiting the NF-κB signaling pathway in mouse chondrocytes, suggesting a new use for SIN in the treatment of OA.
Assuntos
Anti-Inflamatórios/farmacologia , Condrócitos/efeitos dos fármacos , Heme Oxigenase-1/imunologia , Proteínas de Membrana/imunologia , Morfinanos/farmacologia , Fator 2 Relacionado a NF-E2/imunologia , NF-kappa B/imunologia , Osteoartrite/imunologia , Animais , Anti-Inflamatórios/uso terapêutico , Cartilagem Articular/citologia , Células Cultivadas , Condrócitos/imunologia , Articulação do Joelho/efeitos dos fármacos , Articulação do Joelho/patologia , Masculino , Camundongos Endogâmicos C57BL , Morfinanos/uso terapêutico , Fator 2 Relacionado a NF-E2/genética , Osteoartrite/tratamento farmacológico , Osteoartrite/patologia , Transdução de Sinais/efeitos dos fármacosRESUMO
OBJECTIVES: Defects in the human GLI-similar 3 (GLIS3) gene are reported to be a rare cause of congenital hypothyroidism (CH) and neonatal diabetes. The aim of this study was to examine the prevalence of GLIS3 mutation among CH patients in the Guangxi Zhuang Autonomous Region of China and to define the relationships between GLIS3 genotypes and clinical phenotypes. METHODS: Blood samples were collected from 592 patients with CH in Guangxi Zhuang Autonomous Region, China, and genomic DNA was extracted from peripheral blood leukocytes. All exons of the GLIS3 gene with their exon-intron boundaries were screened by next-generation sequencing (NGS) and CNVplex®. Chromosomal microarray analysis (CMA) was performed to detect the existence of the adjacent gene deletion. RESULTS: NGS and CNVplex® analysis of GLIS3 in 592 CH patients revealed two different variations in two individuals (2/592, 0.3%). Patient 1 was the paternal allele of 9p24.3p23 heterozygous deletion including the whole GLIS3 gene, and patient 2 was heterozygous for c.2159G>A (p.R720Q) GLIS3 variant combined with compound heterozygous DUOX2 mutations (p.R683L/p.L1343F). CONCLUSIONS: Our study indicated that the prevalence of GLIS3 variations was 0.3% among studied Chinese CH patients. Multiple variations in one or more CH associated genes can be found in one patient. We found a novel GLIS3 variation c.2159G>A (p.R720Q), thereby expanding the variation spectrum of the gene.
Assuntos
Hipotireoidismo Congênito/genética , Fatores de Transcrição/genética , Pré-Escolar , China , Estudos de Coortes , Hipotireoidismo Congênito/sangue , Hipotireoidismo Congênito/diagnóstico , Proteínas de Ligação a DNA , Humanos , Lactente , Recém-Nascido , Mutação , Proteínas Repressoras , Transativadores , Fatores de Transcrição/sangueRESUMO
Earthworm manure, the by-product obtained from the disposing of biowastes by earthworm breeding, is largely produced and employed as a feedstock for biochar preparation through pyrolysis. For repairing acidic soil or acidic electroplating effluent, biochar physicochemical properties would suffer from some changes like an acidic washing process, which hence affected its application functions. Pristine biochar (UBC) from pyrolysis of earthworm manure at 700°C and biochar treated by HCl (WBC) were comparatively investigated regarding their physicochemical properties, adsorption capability and adsorption mechanism of Cu2+ and Cd2+ from aqueous solution to explore the immobilization characteristics of biochar in acidic environment. After HCl treatment, the soluble ash content and phenolic-OH in the WBC sample was notably decreased against the increase of the carboxyl CO, aromatic CC and Si-O-Si, compared to that of UBC. All adsorption processes can be well described by Langmuir isotherm model. The calculated maximum adsorption capacity of Cu2+ and Cd2+ adsorption on UBC were 36.56 and 29.31mg/g, respectively, which were higher than that of WBC (8.64 and 12.81mg/g, respectively), indicating that HCl treatment significantly decreased biochar adsorption ability. Mechanism analysis revealed that alkali and alkaline earth metallic, salts (carbonates, phosphates and silicates), and surface functional groups were responsible for UBC adsorption, corresponding to ion exchange, precipitation and complexation, respectively. However, ion exchange made little contributions to WBC adsorption due to the great loss of soluble ash content. WBC adsorption was mainly attributed to the abundant exposure of silicates and surface functional groups (carboxyl CO and aromatic CC).
Assuntos
Cádmio/química , Carvão Vegetal/química , Cobre/química , Recuperação e Remediação Ambiental , Concentração de Íons de Hidrogênio , Modelos QuímicosRESUMO
To attain a low-cost and high-efficient phosphate adsorbent, lanthanum (La) loaded biochar (La-BC) prepared by a chemical precipitation method was developed. La-BC and its pristine biochar (CK-BC) were comparatively characterized using zeta potential, BET surface area, scanning electron microscopy/energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The adsorption ability and the mechanisms during adsorption process for the La-BC samples were also investigated. La loaded on the surface of biochar can be termed as La-composites (such as LaOOH, LaONO3 and La(OH)3), leading to the decrease of negative charge and surface area of biochar. La-BC exhibited the high adsorption capacity to phosphate compared to CK-BC. Adsorption isotherm and adsorption kinetic studies showed that the Langmuir isotherm and second order model could well describe the adsorption process of La-BC, indicating that the adsorption was dominated by a homogeneous and chemical process. The calculated maximum adsorption capacity was as high as 46.37 mg g(-1) (computed in P). Thermodynamic analysis revealed that the adsorption was spontaneous and endothermic. SEM, XRD, XPS and FT-IR analysis suggested that the multi-adsorption mechanisms including precipitation, ligand exchange and complexation interactions can be evidenced during the phosphate adsorption process by La-composites in La-BC.
Assuntos
Carvão Vegetal/química , Lantânio/química , Fosfatos/química , Adsorção , Cinética , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Difração de Raios XRESUMO
The potential phytotoxicity of water extractable toxicants in a typical corn stover biochar, the product of fast pyrolysis, was investigated using an aqueous biochar extract on a soil-less bioassay with tomato plants. The biochar dosage of 0.0-16.0 g beaker(-1) resulted in an inverted U-shaped dose-response relationship between biochar doasage and seed germination/seedling growth. This indicated that tomato growth was slightly stimulated by low dosages of biochar and inhibited with higher dosages of biochar. Additionally, antioxidant enzyme activities in the roots and leaves were enhanced at lower dosages, but rapidly decreased with higher dosages of biochar. With the increased dosages of biochar, the malondialdehyde content in the roots and leaves increased, in addition with the observed morphology of necrotic root cells, suggesting that serious damage to tomato seedlings occurred. EC50 of root length inhibition occurred with biochar dosages of 9.2 g beaker(-1) (3.5th day) and 16.7 g beaker(-1) (11th day) (equivalent to 82.8 and 150.3 t ha(-1), respectively), which implied that toxicity to the early growth of tomato can potentially be alleviated as the plant grows.
Assuntos
Carvão Vegetal/toxicidade , Germinação/efeitos dos fármacos , Células Vegetais/efeitos dos fármacos , Sementes/efeitos dos fármacos , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/crescimento & desenvolvimento , Zea mays/química , Antioxidantes/metabolismo , Hidroponia , Incineração , Malondialdeído/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimentoRESUMO
A series of biochars were prepared by pyrolyzing oak sawdust with/without LaCl3 involvement at temperature of 300-600 °C, and approximate and ultimate analyses were carried out to check their basic characteristics. Meanwhile, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars and the adsorption of NH4(+), NO3(-) and PO4(3-) by biochars were investigated. Results indicated that the involvement of LaCl3 in pyrolysis could advance the temperature of maximum mass loss by 10 °C compared with oak sawdust (CK), and potentially promoted biochar yield. Overall, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars were negatively related to pyrolysis temperature, and the releases were greatly weakened by La-biochars. Additionally, the adsorption to NH4(+) can be promoted by the biochars produced at low temperature. On the contrary, the NO3(-) adsorption can be improved by increasing pyrolysis temperature. The highest PO4(3-) adsorption was achieved by the biochars produced at 500 °C. According to the results of adsorption isotherms, the maximum adsorption capacity of NH4(+), NO3(-) and PO4(3-) can be significantly promoted by 1.9, 11.2, and 4.5 folds using La-biochars. Based on the observations of FT-IR, SEM-EDS, and surface functional groups, the improvement of NH4(+) adsorption was potentially associated with the existing acidic function groups (phenolic-OH and carboxyl C=O). The increased basic functional groups on La-biochars were beneficial to improve NO3(-) and PO4(3-) adsorption. Besides, PO4(3-) adsorption was also potentially related to the formed La2O3.
Assuntos
Carvão Vegetal/química , Temperatura Alta , Lantânio/química , Quercus/química , Madeira/química , Adsorção , Compostos de Amônio/metabolismo , Microscopia Eletrônica de Varredura , Modelos Químicos , Nitratos/metabolismo , Fosfatos/metabolismo , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , TermogravimetriaRESUMO
In order to seek a high-efficient pretreatment path for converting lignocellulosic feedstocks to fermentable sugars by enzymatic hydrolysis, the concentrated H3PO4 plus H2O2 (PHP) was attempted to pretreat different lignocellulosic biomass for evaluating the pretreatment flexibility on feedstocks. Meanwhile, the responses of pretreatment to particle sizes were also evaluated. When the PHP-pretreatment was employed (final H2O2 and H3PO4 concentration of 1.77% and 80.0%), 71-96% lignin and more than 95% hemicellulose in various feedstocks (agricultural residues, hardwood, softwood, bamboo, and their mixture, and garden wastes mixture) can be removed. Consequently, more than 90% glucose conversion was uniformly achieved indicating PHP greatly improved the pretreatment flexibility to different feedstocks. Moreover, when wheat straw and oak chips were PHP-pretreated with different sizes, the average glucose conversion reached 94.9% and 100% with lower coefficient of variation (7.9% and 0.0%), which implied PHP-pretreatment can significantly weaken the negative effects of feedstock sizes on subsequent conversion.
Assuntos
Biocombustíveis , Peróxido de Hidrogênio/química , Lignina/química , Ácidos Fosfóricos/química , Biomassa , Cromatografia Líquida de Alta Pressão , Conservação de Recursos Energéticos/métodos , Glucose/análise , Glucose/química , Hidrólise , Tamanho da Partícula , Xilose/análise , Xilose/químicaRESUMO
Although lignocellulosic biomass has been extensively regarded as the most important resource for bioethanol, the wide application was seriously restricted by the high transportation cost of biomass. Currently, biomass densification is regarded as an acceptable solution to this issue. Herein, briquettes, pellets and their corresponding undensified biomass were pretreated by diluted-NaOH and hydrothermal method to investigate the responses of biomass densification to these typical water-involved pretreatments and subsequent enzymatic hydrolysis. The densified biomass auto-swelling was initially investigated before pretreatment. Results indicated pellets could be totally auto-swollen in an hour, while it took about 24 h for briquettes. When diluted-NaOH pretreatment was performed, biomass briquetting and pelleting improved sugar conversion rate by 20.1% and 5.5% comparing with their corresponding undensified biomass. Pelleting improved sugar conversion rate by 7.0% after hydrothermal pretreatment comparing with the undensified biomass. However, briquetting disturbed hydrothermal pretreatment resulting in the decrease of sugar conversion rate by 15.0%.