Corn Stalk Pith Research Articles

The top-down construction of cornstalk-based columns as self-adaptive bio-adsorbents for selective dye adsorption from wastewater

High chemical stability, biological toxicity, and chromaticity of synthetic dyes lead to the problems such as excessive oxidant dosage, microbial anaerobic retardation, and difficult photocatalytic degradation during their wastewater treatment. The technology of selective adsorption makes it possible to recycle or reuse dyes for the purpose of achieving low energy-consumptive and eco-benign strategy in dye effluent purification. Based on the inherent structure of corn stalk pith (CSP), we prepared carbohydrate columns (CSPC) and dimethyldiallylammonium chloride-CSPC (D-CSPC) via in-situ delignification followed by surface cationization. Our study illustrates that these adsorbents retain the original anisotropic three-dimensional structure of CSP, providing highly-developed channels and pores for efficient mass transfer. In cationic/anionic dye binary system, D-CSPC shows controllable selective adsorption capacity by changing its surface N+(CH3)2 density. The selectivity factor of D-CSPC for MO (methyl orange) and AR (alizarin red) increased from 0.13 to 6.17 and 0.17 to 4.73, respectively, as the cationization degree of CSPC was elevated. Both adsorbents have been also confirmed to be effectively recycled, while maintaining over 80% of the dye adsorption capability after five cycles. Moreover, the adsorbent demonstrated significant potential for practical industrial applications, as evidenced by its successful performance to treat the high ionic strength solution and simulated textile wastewater. The approach of current study provides a new, facile, and green-synthesis route toward the exploration of natural and biodegradable agricultural waste integrated into a simple process for the production of cheap, selective, and recyclable adsorbent.

Sustainable water sterilization by nano-ZnO using anisotropic polysaccharide columns derived from agro-waste stalk

The escalating demand for clean water and proliferation of microbial contamination in water have challenged ecosystems and human health safety. ZnO NPs are widely used as environmental restoration agents, but their efficacy in water decontamination is hindered by low biological toxicity. In order to enhance its sterilization efficiency, we propose a top-down strategy utilizing the unique maze structure of corn stalk pith (CSP) as a germ trapper for ZnO. The in-situ delignified CSP offers abundant active sites for the adsorption of Zn2+, exhibiting the typical behaviors of monolayer, physisorption, endothermicity, spontaneity, and randomness. This adsorption behavior exerts an influence on microscopic morphology of the composite column, consequently resulting in alterations to antibacterial properties. The results show that the hybrid column fabricated under the Zn2+ initial dosage of 1.00 mol/L at 30 h for 40 °C, possesses such optimal features as stacked grain-shaped ZnO NPs of 669.3 mg/g loading amount with adhesion coefficients of 0.73 ∼ 0.86 for bacterial microparticles. Consequently, the assembled bio-filter can eliminate E. coli and S. aureus as high as 99.7 % and 96.5 % respectively, attributed to CSPP labyrinth structure to enhance pathogen capture from water and facilitate ZnO-mediated inactivation. The collective findings emphasize the viability of agro-waste stalks as bio-filters for water purification.

Upcycling of Agro-waste: Biobased Piezoresistive Sensor by Exploiting the Natural Porous Structure of Cornstalk Pith for Detecting Pressure Signals

Upcycling of Agro-waste: Biobased Piezoresistive Sensor by Exploiting the Natural Porous Structure of Cornstalk Pith for Detecting Pressure Signals

Corn stalk pith-based hydrophobic aerogel for efficient oil sorption

Bio-based aerogel has become an attractive sorbent for spilled oil and organic pollutants because of its light weight, high porosity and strong sorption capacity. However, the current fabrication process is mainly "bottom-up" technology, which is cost-expensive, time-consuming, and energy-intensive. Herein, we report a top-down, green, efficient and selective sorbent prepared from corn stalk pith (CSP) using the deep eutectic solvent (DES) treatment, followed by TEMPO/NaClO/NaClO2 oxidization and microfibrillation, and then hexamethyldisilazane coating. Such chemical treatments selectively removed lignin and hemicellulose, broke the thin cell walls of natural CSP, forming an aligned porous structure with capillary channels. The resultant aerogels had a density of 29.3 mg/g, a porosity of 98.13%, and a water contact angle of 130.5◦, exhibiting excellent oil/organic solvents sorption performance, with a high sorption capacity in the range of 25.4–36.5 g/g, approximately 5–16-fold higher than CSP, and with fast absorption speed and good reusability.

Extraction of Novel Effective Nanocomposite Photocatalyst from Corn Stalk for Water Photo Splitting under Visible Light Radiation

Novel (Ca, Mg)CO3&SiO2 NPs-decorated multilayer graphene sheets could be successfully prepared from corn stalk pith using a simple alkaline hydrothermal treatment process followed by calcination in an inert atmosphere. The produced nanocomposite was characterized by SEM, EDX, TEM, FTIR, and XRD analytical techniques, which confirm the formation of multilayer graphene sheets decorated by inorganic nanoparticles. The nanocomposite shows efficient activity as a photocatalyst for water-splitting reactions under visible light. The influence of preparation parameter variations, including the alkaline solution concentration, hydrothermal temperature, reaction time, and calcination temperature, on the hydrogen evolution rate was investigated by preparing many samples at different conditions. The experimental work indicated that treatment of the corn stalk pith hydrothermally by 1.0 M KOH solution at 170 °C for 3 h and calcinating the obtained solid at 600 °C results in the maximum hydrogen production rate. A value of 43.35 mmol H2/gcat.min has been obtained associated with the energy-to-hydrogen conversion efficiency of 9%. Overall, this study opens a new avenue for extracting valuable nanocatalysts from biomass wastes to be exploited in hot applications such as hydrogen generation from water photo-splitting under visible light radiation.

Adsorption behavior of three-dimensional bio-adsorbent from maize stalk pith for methylene blue

To realize the comprehensive and convenient utilization of the whole biopolymers and the natural biological structure of agro-residual stalks during the dye-wastewater treatment, we reported a simple and effective strategy to directly convert corn stalk pith (CSP) into a three-dimensional bio-adsorption material (DCSP) by degreasing treatment for purification of methylene blue (MB) wastewater by filtration. The unique anisotropic structure of DCSP provided well-developed channels and pores for mass transfer; Removal of lipids from parenchyma and vessel cells of CSP led to a larger specific surface area, promoting the exposure of adsorption sites. Due to these structural advantages, the DCSP column with 3 cm length could adsorb MB from water as high as 99.1% under the batch condition of 9 mL/min filtration rate, 5 mg/L MB solution with initial pH 6.5 at 35 ℃. As demonstrated by adsorption kinetics, isotherms and thermodynamics, this adsorption process was chemisorbed, multilayer, endothermic, spontaneous and random. According to breakthrough investigation, the prominent features like volume of MB solution at the breakthrough point, adsorbent exhaustion rate and column capacity were 3000 mL, 0.70 g/L and 7.33 mg/g, respectively, when the biofilter height was 45 cm. Its performances of adsorption capacity (7.0809 mg/g) and MB removal efficiency (0.1811 g/mg/min) during continuous process were superior to other biomass-based adsorbents previously reported. This approach provides an agricultural-waster stalks as efficient filters for dye remediation. • The defatted corn stalk pith (DCSP) acted as an excellent three-dimensional filter. • Porous structure with rich biopolymer promoted DCSP to adsorb methylene blue (MB). • The filter removed MB more than 99.0% in the batch adsorption system. • Filter had a low adsorbent exhaustion rate (0.70 g/L) via breakthrough analysis. • The adsorption rate constants of MB by DCSP was up to 0.1811 g/mg/min.

A green pretreatment approach of corn stalk wastes for obtaining micro/nano-cellulose fibers, monosaccharides and lignin fractions

Efficient separation of carbohydrates and lignin from lignocellulosic biomass, and further high-value conversion are still the main challenge of biorefinery. Oxygen-enhanced alkali treatment as a green method for separating polysaccharides and lignin from gramineous materials with environmental, economic and low energy consumption. Herein, oxygen-enhanced alkali technology was used to pretreatment corn stalk pith, and then realize high-value transformation. The results showed that oxygen-enhanced alkali treatment combined with acid precipitation, ethanol precipitation, enzymatic hydrolysis or ultrasonic can achieve clean, efficient separation and subsequent high-value transformation of various components of corn pith. The enzymatic efficiencies of solid and liquid polysaccharides were 75.42% and 50.52% respectively, and the structure of micro/nano-cellulose fiber is mostly flaky and granular. In addition, the separated lignin contains many small molecular compounds, which has the potential value of further utilization. In this study, oxygen-enhanced alkali treatment can achieve clean, efficient separation and subsequent high-value transformation of various components in corn stalk or lignocellulosic biomass, which has important practical significance.

A bio-based elastomer from cornstalk pith scaffold and natural rubber complexing with ferric ions: Preparation and mechanical properties

Commercial cushioning foam and adhesive tape are commonly produced from petrochemicals, leading to disadvantages like lack of/slow degradation and unsustainability. Herein we designed a polymer composite made from cornstalk pith (a cellulose-based porous scaffold) and a natural rubber as substitution for commercial cushioning foam. Cornstalk pith was firstly pre-treated with FeCl3 to remove lignin and form micro-porous structure and then, interpenetrated with a natural rubber to generate a strengthened construct. The metal ions acted as junctions for combining the two components and resulting the generation of dynamically reversible bonds. When loading was added to the material, these bonds would break and dissipate the added loading, and then after the loading was removed, they would spontaneously reconstruct. The elasticity of the cornstalk was enhanced by the filling and entanglement of the rubber, while the revisable bonds giving by ferric ions and the rubber with good elasticity works synergistically to form a bio-based elastomer with good mechanical properties. The anti-fatigue performance of all samples was investigated through a 100 times cyclic compression tests, displaying a 95% height recovery, which is better than commercial cushioning foam samples. The good cushioning performance, sustainability, ease preparation process, environmentally friendliness, low cost of the prepared bio-based elastomer shows great potential for industrialization and replacing current petrochemical-based products.

Enzymatic preparation of hydrophobic biomass with one-pot synthesis and the oil removal performance

Oil pollution is causing deleterious damage to aquatic ecosystems and human health. The utilization of agricultural waste such as corn stalk (CS) to produce biosorbents has been considered an ecofriendly and efficient approach for removing oil. However, most previous studies focused on the modification of the whole CS, which is inefficient due to the heterogeneity of CS. In this study, corn stalk pith (CP), which has excellent amphipathic characteristics, was selected to prepare a high-efficiency oil sorbent by grafting dodecyl gallate (DG, a long-chain alkyl) onto CP surface lignin via laccase mediation. The modified biomass (DGCP) shows high hydrophobicity (water contact angle = 140.2°) and superoleophilicity (oil contact angle = 0°) and exhibits a high oil sorption capacity (46.43 g/g). In addition, DGCP has good stability and reusability for adsorbing oil from the aqueous phase. Kinetic and isotherm models and two-dimensional correlation spectroscopy integrated with FTIR analyses revealed that the main sorption mechanism involves the H-bond effect, hydrophobic effect and van der Waals force. This work provides an ecofriendly method to prepare oil sorbents and new insights into the mechanisms underlying the removal of spilled oil from wastewater.

Chitin/corn stalk pith sponge stimulated hemostasis with erythrocyte absorption, platelet activation, and Ca2+-binding capabilities

Chitin (CT) is widely used as a hemostatic material in surgical sponges, although its efficacy needs improvement to promote the clotting process. In this study, another green biomass, corn stalk pith (CSP), was incorporated into CT through ball milling to fabricate CT-CSP composite hemostatic sponges to enhance erythrocyte absorption, platelet activation, and clotting factor accumulation (Ca2+). In vitro hemostatic analysis indicated that CSP incorporation greatly promoted the coagulation process, with a much lower blood clot index and higher blood clot stability. In addition, the composite sponge promoted more platelet adhesion and activation, and the composite sponge demonstrated a greater ability to bind clotting factors (Ca2+). Consistently, it achieved complete hemostasis with less blood loss and a shorter hemostatic time in a rat liver injury-model. This composite hemostatic sponge is sustainable, cost-efficient, and biocompatible, which highlight the excellent translational potential in clinical settings.

Laccase-modified cornstalk pith for cleanup of spilled diesel oil

Laccase-modified cornstalk pith for cleanup of spilled diesel oil

Synthesis, characterization and water-absorption behavior of tartaric acid-modified cellulose gel fromcorn stalk pith

The eco-benign water-absorbent gel was obtained by modification of tartaric acid (TA) onto parenchyma cellulose from corn stalk pith (CSP) in N, N-dimethylacetamide (DMAc)/LiCl system. The water affinity of the gel was aided with TA as both grafting agent and cross-linker via esterification. The degree of swelling was strongly influenced by TA amount, reaction temperature and duration, and the absorbency of TA-esterified product reached up to about 417 g H2O/g dry gel. The three-dimensional macro-porous structures of the bio-absorbent led to fast penetration and diffusion of water into gel. Studies of absorption behavior in deionized water showed that the initial water uptake followed the non-Fickian mechanism, the Schott second-order equation governed the swelling kinetics, and the later part of swelling was relaxation of polymer chains. FTIR and X-ray diffraction analyses confirmed successful modification of TA molecules onto cellulose chains through the formation of ester bonds and transition of crystalline forms from cellulose Ⅰ to cellulose Ⅱ. Moreover, thermogravimetric outcomes illustrated the thermal resistance of the TA-esterified gel with a loose structure was lower than SCP cellulose. This work designed a green water-absorbent that could be potentially utilized as favorable water retention material in agriculture and horticulture.

Natural Cornstalk Pith as an Effective Energy Absorbing Cellular Material

Natural Cornstalk Pith as an Effective Energy Absorbing Cellular Material

High-rate supercapacitor based on 3D hierarchical N-doped porous carbon derived from sustainable spongy cornstalk pith

Carbon-based supercapacitors have been widely applicated in the energy storage fields due to superior physicochemical stability and large specific power. However, there is still an urgent need for improvement of specific energy which can be attributed to low mesoporosity, poor conductivity and narrow working voltage. This paper has introduced spongy and porous cornstalk pith aerogel as carbon precursor and one-step facile carbonation treat to prepare the 3D hierarchical N-doped porous carbon as supercapacitor electrode materials. The obtained cornstalk porous carbon exhibits high mesoporous volume ratio (90.7%) and large specific surface area of 2155 m2 g-1 to the benefit of fast electrolyte ions diffusion and forming large double layer interface. And the N doping of 3.96 at% from cornstalk pith biological component and NH3 enhance the electron conductivity, a certain amount of capacitive performance and surface wettability of carbon materials with electrolyte ions. The electrochemical measurements have demonstrated that the sample shows a high specific capacitance of 381 F g-1 at 0.2 A g-1 with prominent rate performance (82% retention at 80 A g-1) and 97.6% capacitance retention after 50,000 cycles. Furthermore, to extend working voltage using an organic electrolyte (MeEt3NBF4/acetonitrile solutions), the cornstalk porous carbon electrode presents high specific energy of 47.5 W h kg-1 (1.50 kW kg-1) and an ultra-large specific power of 113 kW kg-1 (36 W h kg-1).

A Comparative Study on Sorption Characteristics by Corn Stalk Pith Using Green Modification with Different Polycarboxylic Acids

In this study, an efficient and economical modification with low chemical concentration process was used for preparing biosorbent. Corn stalk pith (CP) was esterified with different polycarboxylic (tartaric, citric, and malic) acids, and then the resultant modified products were applied as sorbents to remove methylene blue (MB) via sorption. Compared with the raw materials, the esterification led to some variation in the specific surface area, pore volume and structure, which thereby affected the sorption efficacy of MB. The pseudo-second-order kinetic model and the Langmuir model well described the MB sorption for all modified CPs. Following modification, sorption capacity increased by 290.1 % for tartaric acid modified-CP, 759.0 % for citric acid modified-CP and 658.2 % for malic acid modified-CP, and the maximum MB sorption were 208.3, 458.7 and 404.9 mg/g, respectively. The mechanisms of MB sorption via modified CP involve electrostatic interaction, π-π interaction, and hydrogen bonds interaction. The substantial enhancement on MB sorption by the CP esterified with polycarboxylic acids provides a novel means for dyes removal from wastewater.

Effective multi-functional biosorbent derived from corn stalk pith for dyes and oils removal

In this study, malic acid-modified corn stalk pith (MA-CSP) was prepared as an environmentally friendly multi-functional bio-sorbent for adsorbing of dyes and oils. The sorption capacity of the MA-CSP for single and binary dyes is 328.46 mg/g - 566.27 mg/g. In addition, the MA-CSP also had good sorption for lubricating oil, soybean oil, diesel oil, and isopropyl alcohol, which were 37.2 g/g, 44.1 g/g, 33.8 g/g, and 29.3 g/g, respectively. Physical and statistical models were used to analyze the adsorption behavior of methylene blue (MB) and crystal violet (CV). And its sorption behavior for dyes was also affected by the co-existing salts in water. The sorption mechanism of the dye was mainly electrostatic attraction and hydrogen bonding action. The sorption of oil was primarily via the role of van der Waals force and hydrophobic interaction. The MA-CSP, as an eco-friendly, economical and efficient multi-functional sorbent, holds promise for effective dyes and oil removal from contaminated water, and its application in other fields is also highly anticipated.

Composited Gels from Nature Growing Scaffold: Synthesis, Properties, and Application.

As a nature ultralight, well-aligned porous and anisotropy feedstock, cornstalk pith (CSP) has not been exploited for material design. Herein, we use CSP as substrate to prepare multifunctional elastic composite gels. First, CSP is pretreated by ferric chloride then immersed in an unsaturated monomer solution, following by a polymerization to form enhanced networks. The ferric ions act as junction sites for the combination between the polymer chains and the CSP matrix, therefore, dynamically reversible bonds are constructed. The bonds dissipate the compression force by breaking the dynamic bonds and reconstruct when the loading is removed. The reconstructed dynamic bonds endow an antifatigue performance of the prepared gels, in the cyclic compression test conducting 100 times with a 50% strain, and the gel holds a 94% elastic recovery. Furtherly, oil/water separation, cushioning system and biobased sensor are developed on the basis of what the matrix endows and what the reversible bonds exhibit. The preparation method in this study enriches a simply and high value-added method to utilize biobased material.

Biosorbent with superhydrophobicity and superoleophilicity for spilled oil removal

The development of efficient and sustainable sorbents for emergent oil cleanup has attracted tremendous attention. In this study, the feasibility of enzymatic grafting of octadecylamine (ODA) on corn stalk pith (CSP) by laccase-TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) treatment for enhanced oil–water separation was investigated. The dynamic contact angle tests suggest that the modified CSP (LCSP) had higher hydrophobicity (WCA, 157.2˚) and lipophilicity (OCA, 0˚) than the CSP did. In addition, the introduction of ODA onto the surface of modified CSP was verified by a variety of characterization techniques including SEM, FT-IR, and XPS. Compared with the control, laccase-TEMPO treatment of CSP coupled with octadecylamine grafting greatly improved the oil sorption capacity from 13.24 g/g to 44.25 g/g, while substantially reduced the water sorption capacity from 15.52 g/g to 2.76 g/g. LCSP has fast kinetic (sorption equilibrium reached before 60 min) and high fits to the pseudo-second-order kinetic model. The results obtained in this study reveal the feasibility of using Laccase-TEMPO treatment to graft the ODA onto the surface of CSP, thereby enhancing the rate and capacity of oil separation from oily water. The method and sorbent developed in this study hold promise for green, simple and cost-effective oil cleanup during oil spillage emergency events.

Impact of reinforcing additives on the structure and performance of composite films based on regenerated cellulose from corn stalk pith

Cellulose was extracted from corn stalk pith (CSP) and used for fabricating hybrid composite films with acceptable physical properties. As reinforced additives, low contents of graphene oxide (GO) and black phosphorene (BP), both ranging from 0.05 to 0.15 wt%, were separately incorporated into the cellulose matrix in a ZnCl2 aqueous system. A series of the composites were prepared via a regeneration process. The as-prepared composites showed various properties depending largely on the additive content, manner of processing, and the type of additive used. GO and BP nanosheets were homogeneously dispersed in the regenerated cellulose (RC), smoothly forming the dense films. Crystalline structures of RC-based films were revealed to be cellulose-II, and in addition to GO-crosslinked RC samples (RC-GO), an increase in the additive dosage led to a decrement in the crystallinity index of blended films (RC/GO and RC/BP). At 0.15 wt% additive amount, the RC-GO possessed superior thermal stability, tensile strength, and Young’s modulus, increasing 7.8%, 190.2%, and 79.0%, respectively, while the RC/BP exhibited a 3.5 times improvement in the elongation at break.

Continuous photo-fermentative hydrogen production in a tubular photobioreactor using corn stalk pith hydrolysate with a consortium

Corn stalk pith, a low-cost organic material, was first utilized to produce hydrogen by photo-fermentation in a long tubular photobioreactor (PBR) with continuous mode. The effect of hydraulic retention time (HRT: 12, 18, 24, 30 and 36 h) on hydrogen production and light conversion in the tubular PBR was evaluated. The distributions of cell optical density, pH, sugar and soluble metabolites products (SMPs) along the tubular PBR (0 cm, 25 cm, 50 cm, 75 cm, and 100 cm from the inlet) were also assessed under different HRTs. The HRT of 24 h was found to be the optimum condition with the highest hydrogen production (2670 mL), yield (211.9 mL/L-medium), hydrogen production rate (38.4 mL/L/h), and light conversion efficiency (0.42%). In addition, statistical analysis revealed that cell optical density, pH value, sugar concentration and SMPs varied with different locations of the tubular PBR. Moreover, HRT of 24 h and 36 h accounted for 2.6–1.3% and 4.0–11.8% of the total SMPs in the effluent, respectively. Besides, acetic acid and butyric acid were the main SMPs in the effluent.