Raw Corn Stalk Research Articles

Pelletization property analysis of raw and torrefied corn stalks for industrial application to achieve agricultural waste conversion

Agricultural waste conversion is of great concern to achieve modernization and industrial development and thus leads to a greener route for a sustainable and circular economy. The treatment of corn stalk for pellet production to realize industrial application is implemented, which is conducive to upgrading fuel properties with better storage and transportation characteristics. The obtained results indicate that torrefaction operation is helpful for pellet density enhancement, with a value of up to larger than 0.74 g cm−3. However, the wear strength and hardness are not good enough compared to raw corn stalk, with values of 4.5–7.5 % and 88 kN–92 kN, respectively. A longer compression duration contributes to a greater work condition and higher relative HHV, which is conducive to energy efficiency improvement. To further evaluate the hygroscopicity and moisture resistance capacity of pelletized corn stalk for fuel properties evaluation, the equilibrium moisture content and contact angle reflect that the enhancement of pressure and compression duration are beneficial for moisture resistance capacity improvement, with the values of less than 3.5 % and higher than 130°. When considering the fuel properties and pelletization cost, compromising on operation conditions should be adopted for optimal operation.

Effect of Torrefaction on the Physiochemical Characteristics and Pyrolysis of the Corn Stalk.

Torrefaction of biomass is one of the most promising pretreatment methods for deriving biofuels from biomass via thermochemical conversion processes. In this work, the changes in physicochemical properties and morphology features of the torrefied corn stalk, the changes in physicochemical properties and morphology features of the torrefied corn stalk were investigated. The results of this study showed that the elemental content and proximate analysis of the torrefied corn stalk significantly changed compared with those of the raw corn stalk. In particular, at 300 °C, the volatile content decreased to 41.79%, while the fixed carbon content and higher heating value increased to 42.22% and 21.31 MJ/kg, respectively. The H/C and O/C molar ratios of torrefied corn stalk at the 300 °C were drastically reduced to 0.99 and 0.27, respectively, which are similar to those of conventional coals in China. Numerous cracks and pores were observed in the sample surface of torrefied corn stalk at the torrefaction temperature range of 275 °C-300 °C, which could facilitate the potential application of the sample in the adsorption process and promote the release of gas products in pyrolysis. In the pyrolysis phase, the liquid products of the torrefied corn stalk decreased, but the H2/CO ratio and the lower heating value of the torrefied corn stalk increased compared with those of the raw corn stalk. This work paves a new strategy for the investigation of the effect of torrefaction on the physiochemical characteristics and pyrolysis of the corn stalk, highlighting the application potential in the conversion of biomass.

Co-adsorption and competitive adsorption of sulfamethoxazole by carboxyl-rich functionalized corn stalk cellulose in the presence of heavy metals

Diethylenetriamine pentaacetic acid (DTPA) functionalized modified corn stalk cellulose (DCS) was successfully prepared and applied to the adsorption of sulfamethoxazole (SMZ) wastewater in the presence of copper (Cu). Compared with the raw corn stalk cellulose (RCS), DCS has the characteristics of more hydrophilic groups, larger contact space and lower steric hindrance. The adsorption amount for Cu and SMZ in binary system were 4.41 mg/g and 29.7 mg/g, respectively. Additionally, DCS has good pH buffering capability, resistance to potentially interfering ions (NaCl and HA) and great regeneration performance after 5 cycles. More importantly, the experimental results demonstrated competitive adsorption and complexation synergy occurred between Cu, SMZ and DCS. Cu inhibited the adsorption of SMZ while SMZ promoted the adsorption of Cu, which was attributed to the fact that SMZ provided additional adsorption sites or complexation reduced the surface charge of Cu. Based on this situation, density functional theory (DFT) calculations were carried out for the further explanation of adsorption mechanism. The molecular electrostatic potential maps showed that DCS possessed more SMZ adsorption sites than Cu, and the adsorbed Cu or SMZ on DCS would provide additional adsorption sites. The equilibrium configurations and binding energy indicated that the competitive adsorption, bridge effect adsorption and co-adsorption would occur simultaneously. The total electron density and differential charge confirmed that SMZ was more likely to overlap electron clouds and transfer electrons with DCS, while the adsorption process of Cu was conformed the complexation adsorption dynamic equilibrium. This paper provided a new perspective on the co-adsorption and competitive adsorption processes by multisystem experiments and abundant DFT calculations and indicated the good adsorption performance of DCS on SMZ in the presence of Cu.

Co-pyrolysis characteristics of raw/torrefied corn stalk and oil shale

Biomass torrefaction followed by co-pyrolysis with oil shale is of great potential in further upgrading of bio-oil. Therefore, a comparative analysis of oil shale co-pyrolysis with raw/torrefied corn stalk was carried out. During co-pyrolysis, oil shale played a key role in the significant promoting effect on oil yield, but only occurred after corn stalk torrefaction. The promotion on oil shale decomposition by raw corn stalk was reflected in the increment of long-chain aliphatic hydrocarbons content in oil, which also led to a larger proportion of heavy oil. While after torrefaction, short-chain aromatic hydrocarbons content in oil increased during co-pyrolysis, and thus led to larger light oil proportion. Considering the distribution of pyrolysis products, 50% was the best blending ratio of oil shale for both raw and torrefied corn stalk.

Synthesis of nitrogen-enriched hydrochar via co-hydrothermal reaction of liquid digestate and corn stalk.

Synthesis of carbon material from low-cost and sustainable precursors has been intensively explored in recent years. In this study, a nitrogen (N)-enriched hydrochar was developed via a facile one-step hydrothermal carbonization (HTC) of corn stalk (CS) with liquid digestate (LD) of food waste. The LD substituted water and functioned as the N precursor during HTC. The physicochemical properties of hydrochar derived at different HTC temperatures (180-300 °C) were examined and the reaction mechanism was investigated. Intermolecular dehydration and condensation were the primary reactions in the HTC process of CS without LD. The CS-chars maintained the original structure and morphology of the raw corn stalk. The ammonia and inorganic salts in LD promoted the lignin removal, and accelerated the cleavage of the glycosidic linkages of the polysaccharide and hydrogen bonds of cellulose. Benefited from the ammonia and metals in the LD, the recalcitrance structure of the corn stalk was disrupted during the co-HTC even at a low temperature of 220 °C. Moreover, carbon spheres were observed in the LDCS-chars, indicating the LDCS-chars were resulted from sequential hydrolysis, dehydration and condensation during co-HTC reactions. Reactions between N compounds in the LD and derivatives from CS contributed to N doping. The N content of LDCS-chars achieved 4.95% at 260 °C and 83.94% of the N was presented as pyridinic-N. Co-hydrothermal treatment of CS and LD not only enhanced the characteristics of hydrochar, but also recovered two-thirds of ammoniacal N from the digestate to reduce greenhouse gas emission.

Modification of Corn stalk for high-performance adsorption of Coomassie Brilliant blue dye in simulated polluted water: Kinetic study

<p>In the present work, corn stalk was used as a low cost adsorbent for removal of anionic dye (" CBB"). Corn stalk was treated with two methods to inform Modified corn stalk with magnetic particles (MMCS) and Modified corn stalk with sulfuric acid (SMCS). Comparison between raw and treated corn stalk in dye removal was done. The effect of various parameters as dye concentration (5 to 25 mg/L), particle size (4 mm-125 µm), adsorbent dose (1 to 10 g/L), shaking rate (100 to 250 rpm) , Temperature (15 to 45̊ C) and pH (3 to 11) was investigated versus time interval. The results summarize that the highest % removal of dye 85 % by using raw corn stalk followed by SMCS about 80% and 50% for MMCS. Different kinetic models were applied, the results suggested that adsorption of CBB dye for raw and treated corn stalk follows the pseudo second order model</p>

Effect of active alkali and alkaline earth metals on physicochemical properties and gasification reactivity of co-pyrolysis char from coal blended with corn stalks

During co-pyrolysis, active alkali and alkaline earth metals (AAEMs) can influence the synergistic effect of coal and biomass. For exploring the influence of active AAEMs on the co-pyrolysis process, this paper studied the physicochemical properties and gasification reactivity of co-pyrolysis char of four blends: raw coal and raw corn stalks (RC&RCS), pickling coal and raw corn stalks (HC&RCS), raw coal and pickling corn stalks (RC&HCS), and pickling coal and pickling corn stalks (HC&HCS). The results show that the synergistic effects on char yields are within 3%. During co-pyrolysis, the presence of corn stalks is beneficial to the generation of spherical particles from coal char, and the promotion effect of pickling corn stalks is greater than that of the raw corn stalks. The active AAEMs have an inhibitory effect on the decomposition of aliphatic C–H, CO and –CH3 in Shenmu coal, and also on the decomposition of O–H, aliphatic C–H and C–O in the corn stalks. The experimental values of gasification residual carbon of RC&RCS/HC&RCS co-pyrolysis char are 24–77% of the calculated values, while that of RC&HCS/HC&HCS co-pyrolysis char are 86–103% of the calculated values. The interaction between the blends promotes the reactivity of co-pyrolysis char.

Effects of process parameters on the physicochemical properties of corn stalk hydrochar and the removal of alkali and alkaline earth metals

The advantages of the direct combustion of agricultural biomass for power generation are restricted due to the drawbacks of this biomass and the deep peak shaving trend. Hydrothermal carbonization can improve the physical and thermochemical properties of raw materials. Corn stalk samples were selected as the research object in this study. Corn stalk hydrochars were prepared with reaction pressures of 0–3 MPa, reaction temperatures of 160–240 °C, and residence times of 1–10 h. The effects of the process parameters on the physicochemical properties of hydrochar and on the removal of alkali and alkaline earth metals (AAEMs) were studied by measuring the hydrochar mass, energy yield, product composition, morphology, as well as the removal efficiency of AAEMs. The results indicated that the corn stalk hydrochar had higher mass and energy yields than the raw corn stalk. X-ray diffraction showed that the carbon content in the hydrochar was greater than that in raw corn stalk. Scanning electron microscopy showed that the reaction temperature played a more significant role in the hydrothermal carbonization process than the reaction pressure and residence time.

Characterization of Cornstalk and Bituminous Coal Based on Kinetic and Thermodynamic Parameter for Co-pyrolysis

The pyrolysis characteristic of bituminous coal (BC) and raw cornstalk (RC) were investigated through thermogravimetric analysis from environment temperature to 900 °C with 5, 15 and 25 °C/min. The distributed activation energy model (DAEM) was applied to estimate the kinetic parameters of samples. The average activation energy (E a) of BC, RC and the blended sample (mBC/mRC=6/4) were 304.56, 207.77 and 226.26 kJ/mol, respectively. The heat energies of the experiment to be needed was lower than that of calculation during co-pyrolysis, comparing with the theoretical calculation E a. To further researcher the thermal behavior during co-pyrolysis, the closeness of change in Enthalpy (ΔH) values vs. E a values for the blend indicated that activated complex formation may be favored because of lower potential energy barrier. Moreover, Gibbs free energy (ΔG) for the blend varied from 108.40 to 275.93 kJ/mol, the pyrolysis process was converted to disordered-state from ordered-state, considering the changes of Entropies (ΔS) loss.

High Acid Biochar-Based Solid Acid Catalyst from Corn Stalk for Lignin Hydrothermal Degradation.

Solid acid catalysts generally show the disadvantage of low acid amount and low recycling rate. To solve these problems, corn stalk-based solid acid catalysts were synthesized through carbonization and sulfonation processes in this work. The results showed that besides the rod-like structure inherited from raw corn stalk, the catalysts contained some small broken pieces on the surface, and the specific surface area varied from 1120 to 1640 m2/g. The functional groups (-SO3H) were successfully introduced onto the surface of the obtained solid acid catalysts. The acid amount varied between 1.2 and 2.4 mmol/g, which was higher than most of solid acid catalysts. The catalyst produced at 800 °C for 6 h in carbonation and then at 150 °C for 8 h in sulfonation had larger specific surface area and more sulfonate groups. In the degradation of lignin, the use of catalyst led to the generation of more aromatic compounds (65.6 wt. %) compared to that without using the catalyst (40.5 wt. %). In addition, a stable yield of reaction (85%) was obtained after four reuses. Therefore, corn stalk is suitable for high-value utilization to prepare high-acid amount biochar-based catalyst.

Nutritional impact of partial or complete replacement of clover hay by untreated or biologically treated rice straw and corn stalks on: 1. growth performance and economic evaluation of growing New Zealand (NZW) White rabbits

BackgroundAgriculture by-products are considered a great potential value for utilization by ruminants as well as rabbits. They usually can be the maintenance and part of the production requirements. However, in developing countries, as well as in Egypt, animals suffer from shortage of feeds that are continuously increasing in costs. In general, biological treatments were shown to be the most effective and improved chemical composition of rice straw or corn stalks.MethodThis work aimed to investigate the possible ways of utilizing rice straws or corn stalks in rabbit feeding. The field work is designed to study the effect of biological treatment of Pleurotus ostreatus cultivated on rice straws and Trichoderma reesei cultivated on corn stalks and replacing clover hay by rice straws and corn stalks at levels of 0, 33, 66, and 100% either without or with microbes adding. Seventy-eight New Zealand White (NZW) rabbits aged 4–5 weeks (565 ± 13.57 g) were randomly divided into thirteen equal experimental groups.ResultsUntreated rice straws or biologically treated with Pleurotus ostreatus increased their contents of crude protein (CP) by 178.75 and 224.5% and nitrogen-free extract (NFE) by 6.30 and 24.53, respectively. Meanwhile, crude fiber (CF) content was reduced by 31.32 and 56.75%, and organic matter content was decreased by 2.81 and 5.51%, respectively, in comparison with the raw rice straws. Also, biological treatment of rice straws caused a decrease in values of neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and hemicellulose contents in comparison with either raw or treated rice straws. Furthermore, biological treatment with Trichoderma reesei realized a decrease in organic matter (OM), CF, NDF, and ADF and increased CP and ash contents in corn stalks. NFE content of corn stalks was decreased as a result of treatment without or with Trichoderma reesei experimental rations by 11.95% and 3.82% compared to raw corn stalks (CS). Biological treatments with fungi significantly (P < 0.05) improved average daily gain (ADG) and feed conversion. ADG and feed conversion were significantly (P < 0.05) improved when rabbits were fed diets containing rice straw (RS) compared to that fed CS. Rabbits fed diets replaced clover hay (CH) with 33% or 66% of RS or CS significantly increased ADG compared to control and that replaced 100% of both RS and CS containing rations. Levels of replacing had no significant effect on their dry matter intake (DMI) values. The highest improvement in feed conversion was recorded with rabbits that received diets replaced 33% of berseem hay (BH) by RS or CS, followed by that replaced 66% of BH by RS or CS. There were significantly interactions between biological treatments (T), roughage source (S), and replacement levels (L) (T × S × L) only on ADG. The best fed conversion was realized by rabbits fed diet replaced BH with 33% of RS that are treated by Pleurotus ostreatus (4.05 g DMI/g gain). Rabbits fed 33% biologically treated rice straw with Pleurotus ostreatus showed the highest economic efficiency (179%) followed by rabbits that received 33% of both rice straws treated without Pleurotus ostreatus and rabbits that received corn stalks biologically treated with Trichoderma reesei (161%).ConclusionBiological treatments of rice straws by Pleurotus ostreatus or corn stalks by Trichoderma reesei were safe, and it improves their chemical analysis and improved both daily gain and feed conversion, decreasing the costing of diet formulation which consequently decreased the price of 1-kg live body weight.

Sulfurized biochar prepared by simplified technic with superior adsorption property towards aqueous Hg(II) and adsorption mechanisms

The biomass-based sulfurized biochar (CSS) that was prepared by co-heating sublimed sulfur and raw corn stalk in relatively low temperature (450 °C) and heating duration (15 min) showed an excellent adsorption property towards aqueous Hg(II) and was evaluated for its Hg(II) adsorption behavior and mechanism. Meanwhile, biochar-based sulfurized biochar (BCS) produced by co-heating sublimed sulfur and corn stalk biochar would be used for comparison. The results showed that the sulfur content of CSS and BCS was 7.4 and 2.2 wt% and the maximum Hg(II) adsorption capacity of CSS and BCS were 268.5 and 117.7 mg g−1. The Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy data suggested that the species of functional groups for Hg(II) adsorption on sulfurized biochar might be hydroxy, C=S and sulfoxide groups, etc. The X-ray photoelectron spectroscopy (XPS) results showed that the dominant existing forms of sulfur on sulfurized biochar were alkyl sulphides and sulphone groups along with thiophene and inorganic sulfur. The XPS data also verified the complexation between Hg(II) and CSS by forming irreversible Hg–S and Hg–O bond. Our research suggested that CSS processed more sulfur-containing groups with greater affinity to Hg(II) than BCS, and Hg(II) was stable adsorbed via complexation with hydroxy, C=S and sulfoxide groups in CSS by forming Hg–S and Hg–O bond.

Microwave-assisted hydrothermal carbonization of corn stalk for solid biofuel production: Optimization of process parameters and characterization of hydrochar

The optimization of microwave-assisted hydrothermal carbonization for corn stalk was conducted to study the effects of reaction temperature (122.7–257.3 °C), residence time (4.8–55.2 min), and biomass loading (0.98–6.02 g/50 mL H2O) using the response surface methodology. The hydrochars produced from hydrothermal carbonization of cork stalk under different reaction conditions were characterized to understand their physical, chemical, and structural properties. Statistical analysis shows that the carbonization temperature is the dominant parameter determining the product yield as well as heating value and quality of hydrochar. Due to the interactive effects amongst the process parameters, hydrochar mass yield and heating value cannot be maximized simultaneously. The highest energy yield under the predicted optimum conditions of 181.9 °C, 39.7 min and 3.8 g/50 mL H2O reached 80.55%. The higher heating value of 22.82 MJ/kg was observed at 230 °C, 45 min and 2 g/50 mL H2O, which is 41% higher than that of the raw corn stalk. The characterization results reveal that the microwave-assisted hydrothermal carbonization is a viable process for producing hydrochar, which can be used as a direct solid fuel or auxiliary fuel.

Optimization of photo fermentation in corn stalk through phosphate additive

Phosphorus is an essential nutrient for microbial growth which effectively influences the bio‑hydrogen production process. In the present study, the effect of phosphate concentration on simultaneous saccharification fermentation (SSF) hydrogen production by phototrophic microbial consortium has been investigated at various initial pH conditions (6, 7 and 8). The experimental results show that the hydrogen yield has been improved through the addition of phosphate, depending on initial pH and phosphate concentration. The maximum hydrogen yield of 63.09 ± 0.38 mL/g TS and highest energy conversion efficiency of 4.14 ± 0.02% from raw corn stalk were achieved at the phosphate concentration of 4 mmol/L with initial pH value of 6. We have shown that hydrogen yield for raw corn stalk can be enhanced by selecting appropriate amount of the additive. These results may help in optimization of the hydrogen production yield at industrial scale.

Pyrolysis biochar has negligible effects on soil greenhouse gas production, microbial communities, plant germination, and initial seedling growth

Biochar has been promoted as a soil amendment that enhances soil quality and agronomic productivity and reduces greenhouse gas production. However, these benefits are not always realized. A major hurdle to the beneficial use of biochar is our limited knowledge regarding the mechanisms directing its effects on soil systems. This project aimed to eliminate some of this uncertainty by examining the biological responses (plant productivity, greenhouse gas production, soil microbial community structure) of a suite of soils (10) to the addition of biochars produced by different processes (pyrolysis, gasification, burning) from a range of feedstocks (corn stalks, hardwood, grass). Results indicated that these three responses were not significantly impacted by the addition of pyrolysis biochars from different feedstocks at 1 and 5% (w/w) addition levels. On the other hand, both an open-air burned corn stalk (5%) and raw corn stalks (1 and 5%) additions did alter the measured soil functionality. For example, the 5% burnt corn stalks addition reduced total above ground plant biomass (∼30%), increased observed N2O production by an order of magnitude, and altered soil bacterial community structure. The bacterial groups that increased in relative abundance in the burnt corn stalks-amended soils included families associated with cellulose decomposition (Chitinophagaceae), plant pathogens (Xanthomonadaceae), and biochar/charcoal-amended media (Gemmatimonadetes). In contrast, the abundance of these bacterial groups was not impacted by the pyrolysis biochars. Therefore, this research suggests that pyrolysis biochar represents a stabilized form of carbon that is resistant to microbial mineralization and has negligible effects on soil biological responses.

Understanding the mechanism of cornstalk liquefaction in water/ethanol mixtures through Py-GC/MS analysis of the solid residues

Few investigations have been made to apply thermal analysis methods on solid residue analysis to understand biomass liquefaction mechanistic information. To investigate the mechanism of cornstalk liquefaction in water/ethanol mixtures, the solid residues remaining after the liquefaction process were characterized by thermogravimetric analysis (TGA) and analytical pyrolysis (Py-GC/MS). Pyrolysis temperature and liquefaction temperature have synergetic effects on the distributions and yields of various chemical groups during the pyrolysis process. The thermal stabilities of the solid residues remaining after the cornstalk liquefaction process increased with the increase of liquefaction temperature. Compared with raw cornstalk pyrolysis, the proportions of total phenol compounds from solid residue pyrolysis at 400 °C, 500 °C and 600 °C were reduced. The volatilized compounds identified by Py-GC/MS analysis of solid residues and cornstalks displayed significant variability in the peak area and composition distribution. These changes reflect different mechanistic information during the biomass liquefaction process. These results indicate that analytical pyrolysis of the solid residues remaining after biomass liquefaction in water/ethanol mixtures could provide new information about the mechanism of the liquefaction process.

Superior Au-adsorption performance of aminothiourea-modified waste cellulosic biomass

Waste cellulosic biomass obtains various applications due to low-cost and eco-benign characteristics. A general strategy is proposed for waste cellulosic biomass to be modified with dialdehyde functional groups as intermediates through periodate partial oxidation. Finally, aminothiourea-modified waste cellulosic biomass can be prepared through Schiff reaction. Waste corn stalk, cotton and paper as typical precursors, were used to prepare cellulosic biomass, abbreviated as AT-S, AT-C and AT-P, respectively, and their adsorption behaviors of Au(III) from the hydrochloric acid medium were investigated. The pseudo-second kinetics equation as well as the Langmuir isotherm equation can be used to depict the adsorption process, and the maximum adsorption capacities of Au(III) are 21.4, 19.0 and 3.28 mol/kg for AT-S, AT-C and AT-P at 298 K, respectively. The adsorption capacities of Au(III) on aminothiourea modified corn stalk (AT-S) is almost 357 times greater than that of raw corn stalk. To the best of our knowledge, AT-S has the highest adsorption capacity towards Au(III). AT-S also displays a superior separation selectivity towards Au(III) in the presence of Cu(II), Ni(II), Co(II), Pt(VI), Pd(II) and Rh(III). Furthermore, the characterization analysis of XRD, TG, SEM, TEM and FTIR confirms that AuCl4– has been reduced to elemental Au nanoparticles and deposit onto the surface of the biomass. It shows a prospect for waste corn stalk to be used to adsorb Au(III) from liquid phase and the possible fabrication of gold nanoparticles by a general adsorption process without any reductant.

Restudy on torrefaction of corn stalk from the point of view of deoxygenation and decarbonization

In this study, the torrefaction of corn stalk was performed at 200–290 °C for 30 min. The solid products (torrefied corn stalk), liquid products (water and tar), and gaseous products were collected and analyzed, and the migration of oxygen and carbon during torrefaction was discussed. Results showed that as the torrefaction temperature increased from 200 °C to 290 °C, the relative content of aromatic/aliphatic carbon (CC, CC, and CH) in the torrefied corn stalk increased from 55.66% to 69.90%, while the content of ether or hydroxyl/phenol groups (COR) obviously decreased from 21.96% to 8.79%. This result was also confirmed by ultimate analysis, indicating that increasing in the torrefaction temperature resulted in a sharp decrease of the oxygen content and a gradual increase of carbon content of corn stalk. During the torrefaction process, oxygen of corn stalk was released in the form of CO2 and CO in the gaseous products, and H2O and oxygen-containing compounds like acids and phenols in the liquid products. In the temperature range of torrefaction experiments, 7.05%-57.25% of oxygen in raw corn stalk migrated into the liquid and gaseous products in the form of H2O, followed by CO2 and CO. Along with the deoxygenation process, a small amount of the carbon (3.31%–27.26%) from raw corn stalk was transferred into the gaseous products, followed by tar. These results indicated that the dehydration reactions and gas formation dominated the deoxygenation and decarbonization of corn stalk torrefaction, respectively.

Research on Green Remediation Technology of Oil Spill By Biosorbent

Oil spillage is a serious problem all over the world. Usage of agricultural byproducts for raw materials in biosorbents applications is a promising way to solve this problem. In this paper, a green biotechnological procedure has been developed using Phanerochaete chrysosporium to produce an oil-sorbent from corn stalk and corn cob. Without fungal modification, the maximum sorption of oil by raw corn stalk and corn cob was 6.95 g/g and 4.14 g/g, whereas the treatment with Phanerochaete chrysosporium increased up to 9.03 g/g and 7.69 g/g, respectively. SEM and XRD were applied to characterization of treated and untreated materials, which showed the changes in the surface morphology and crystallinity of all biosorbents. The agricultural by-products can be utilized as biosorbent for efficient oil removal, and fungal treatment can serve as a mild and green method to increase the sorption capacity.

Adsorption isotherms, kinetics and thermodynamics of nitrate and phosphate in binary systems on a novel adsorbent derived from corn stalks

Novel adsorbents from raw corn stalks (RCS) were synthesised after cellulose isolation followed by modification with epichlorohydrin, N,N-dimethylformamide, pyridine and diethylamine. The MCCS (modified cellulose from corn stalks) products were characterised by thermogravimetric analysis, elemental analysis, scanning electron microscopy–energy dispersive spectrometry (SEM-EDS) and Fourier transform infrared spectroscopy (FT-IR); moreover, the adsorption characteristics of nitrate and phosphate on MCCS were investigated in binary systems using batch adsorption procedures. The mass loss of RCS and MCCS may be divided into three stages and the modification reaction increased the stability of samples. The surface of MCCS was rougher than that of RCS and amine groups were successfully loaded onto MCCS, as shown by elemental analysis results and FT-IR spectra. The pseudo-second order kinetics equation and Langmuir isotherm could well describe the adsorption process, and the maximum adsorption capacities (298 K) of nitrate and phosphate on MCCS as calculated from the Langmuir isotherm were 13.6054 and 22.8833 mg/g, respectively. The obtained thermodynamic parameters indicated the spontaneous and exothermic nature of adsorption.