Preparation of activated carbon from sugarcane bagasse by microwave assisted activation for the remediation of semi-aerobic landfill leachate

Preparation of Nitrogen Doped Biochar-Based Iron Catalyst for Enhancing Gasoline-Range Hydrocarbons Production

Developing catalysts to obtain high space time yield (STY) of gasoline-range hydrocarbons via Fischer-Tropsch synthesis (FTS) is a huge challenge due to the restriction of Anderson-Schulz-Flory distribution. Herein, a nitrogen doped biochar-based iron catalyst was synthesized by a one-step method using sugar cane bagasse as carbon precursor, which exhibited an excellent gasoline STY of 8.65 g_C5-12 g_Fe^-1 h^-1, exceeding most reported catalysts. A strong positive relationship between the amount of pyrrolic N and long-chain hydrocarbons selectivity was displayed. The characterization results indicated that pyrrolic N configuration on anchor sites tuned effectively the dispersion of iron species and metal-support interaction as well as CO adsorption, improving the FTS performance.

Kinetics and Equilibrium Studies of the Adsorption of Copper(II) Ions from Industrial Wastewater Using Activated Carbons Derived from Sugarcane Bagasse

The monocomponent adsorption process of Cu(II) ions in synthesized industrial wastewater were investigated using activated carbons (BACs) derived from sugarcane bagasse as the precursor. Batch adsorption studies were done by treating the precursor with H3PO4 (BAC-P) and ZnCl2 (BAC-Zn) in order to observe the effects of experimental variables such as contact time, pH of the solution, and adsorbent dose. The Langmuir isotherm model excellently described the adsorption data for both the derived BACs, indicating monolayer coverage on the BACs with the determination coefficients close to the value of one. Furthermore, the maximum adsorption capacities of 589 and 225 $mg{g}^{-1}$ at 30°C were obtained for BAC-P and BAC-Zn adsorbents, respectively. The modeling of kinetic data of Cu(II) ions adsorption onto BAC-P and BAC-Zn adsorbents illustrated that the Elovich kinetic model fitted well. Here, the adsorption process was film-diffusion controlling, while being principally governed by external mass transport where the slowest step is the diffusion of the particles through the film layer. The mechanism of the adsorption process was proposed taking into cognizance of the ion exchange and surface complexation on active sites between the negatively charged surface of the BACs and the positively charged Cu(II) ions. The BACs were characterized using analytical methods such as SEM, FTIR, EDX, XRD, BET surface area, and zeta potential measurements. Both BACs mainly composed of mesopores and bonds of O-H, C-O, C=O, and C-O-C. The BET surface area of BAC-P and BAC-Zn was 427.5 and 282 m2/g before adsorption, and their isoelectric point (pHIEP) 3.70 and 5.26, respectively.

Biosugarcane-based carbon support for high-performance iron-based Fischer-Tropsch synthesis

Exploiting new carbon supports with adjustable metal-support interaction and low price is of prime importance to realize the maximum active iron efficiency and industrial-scale application of Fe-based catalysts for Fischer-Tropsch synthesis (FTS). Herein, a simple, tunable, and scalable biochar support derived from the sugarcane bagasse was successfully prepared and was first used for FTS. The metal-support interaction was precisely controlled by functional groups of biosugarcane-based carbon material and different iron species sizes. All catalysts synthesized displayed high activities, and the iron-time-yield of Fe₄/C_bio even reached 1,198.9 μmol g_Fe⁻¹ s⁻¹. This performance was due to the unique structure and characteristics of the biosugarcane-based carbon support, which possessed abundant C−O, C=O (η¹(O) and η²(C, O)) functional groups, thus endowing the moderate metal-support interaction, high dispersion of active iron species, more active ε-Fe₂C phase, and, most importantly, a high proportion of Fe_xC/Fe_surf, facilitating the maximum iron efficiency and intrinsic activity of the catalyst.

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A kind of carbon support, derived from the sugarcane bagasse, is prepared

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This biochar catalyst reaches an excellent FTY value in Fischer-Tropsch synthesis

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Functional groups and Fe species sizes regulate metal-support interactions

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Superior performance is due to abundant functional groups and ε-Fe₂C

In situ growth gold nanoparticles in three-dimensional sugarcane membrane for flow catalytical and antibacterial application

In this work, we decorated gold nanoparticles (Au NPs) in the porous, three-dimensional sugarcane membrane for the flow catalytical and antibacterial application. Due to the uniformly distributed Au NPs in sugarcane channels and the porous structure of sugarcane, the interaction between contaminant and catalysis was enhanced as water flowing through the Au NPs/sugarcane membrane. The Au NPs/sugarcane membrane exhibited superior catalytical efficiency for removing methylene blue (MB) with a turn over frequency of 0.27 mol_MB·mol_Au^-1·min^-1 and the water treatment rate reached up to 1.15×10⁵ L/m² h with >98.3 % MB removal efficiency. The Au NPs/sugarcane membrane also exhibited superior bacterial removal efficiency as E. coli suspension flowing through it, due to the superimposition effects of physical barrier in sugarcane and the antibacterial property of Au NPs. The tremendous catalytical and antibacterial performance of Au NPs/sugarcane membrane provides a promising potential for the rational design of flow catalytical membrane reactor to purify the microbial contaminated water.

Carbon from Bagasse Activated with Water Vapor and Its Adsorption Performance for Methylene Blue

This research work reports on the potential of bagasse, a solid waste from sugar factories, to produce activated-carbon (AC) as an adsorbent. The activation was conducted under 500, 600, and 700 °C using steam as the activation agent to produce AC500, AC600, and AC700, respectively. The prepared-materials were characterized to understand their elemental content, surface morphology, thermal properties, functional groups identification, surface area, and pore size. AC700 provided the highest surface area of 592.36 m2/g and indicated the contribution of mesopores distributes along 1.5–8.0 nm of pore size. Therefore, an adsorption test was conducted with AC700 as adsorbent. The results show that methylene blue (MB) adsorption reached equilibrium after 30 min of adsorption time. The adsorption isotherm applied to a monolayer Langmuir isotherm was fitted by linearization, resulting in a constant R2 of 0.999. The MB adsorption to AC700 favorably occurred, as proven by the Freundlich parameter 1/n of 0.881, which is less than 1. The Dubinin-Radushkevich isotherm confirmed that the adsorption proceeded through physical interaction with adsorption energy of 3.536 kJ/mol.

Adsorption of cationic dye from water using an iron oxide/activated carbon magnetic composites prepared from sugarcane bagasse by microwave method

In this work, using an agricultural waste of sugarcane bagasse, new biomass of magnetic sugarcane bagasse activated carbon (MSBAC) has been successfully prepared by a simple microwave method. The composition and structure of MSBAC were characterised by SEM, XRD, BET, and FT-IR. It was found that MSBAC was a mesoporous material with a loose structure and rough surface, and it had a high specific surface area. The pH_PZC was 4.1, and MSBAC presented a greater amount of acid functional groups than basic groups, making it efficient for adsorption of cationic dye. To study the adsorption ability of MSBAC, methylene blue (MB) was selected as sample pollutant. Effects of pH, MSBAC dosage, initial MB concentration, temperature, time on the adsorption of MB, and the possibility of regeneration of MSBAC were investigated. The adsorption results showed that the maximum adsorption capacity was 36.14 mg·g^-1, and the pH had no significant effect on the MB adsorption in the range of 2-10. The equilibrium data fitted Langmuir isotherm, and the adsorption kinetic data obeyed pseudo-second-order kinetic model. The adsorption process involving the surface diffusion and film diffusion. The positive value of ΔH revealed the adsorption behaviour was an endothermic process. The salt concentration had a negative effect on MB removal. MSBAC had a good magnetic separation performance. The used MSBAC could be regenerated by a simple calcination method under the temperature of 300℃ for 30 min.

Adsorption and sugarcane-bagasse-derived activated carbon-based mitigation of 1-[2-(2-chloroethoxy)phenyl]sulfonyl-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl) urea-contaminated soils

Burgeoning pesticide usage in agriculture sector required to be evaluated by assessing the adsorption rate in soils. The herbicide triasulfuron was used in this research to analyze its sorption behavior in seven distinct soils using batch equilibrium methodology. The adsorption coefficient (Kd) values ranged from the 3.32 to 29.7 µg/mL. Peshawar soil displayed the highest Kd value because of the distinct physiochemical properties when compared with the other six samples. Gibbs free energy exhibited negative values displaying less contact between soil particles and pesticides, showing the exothermic nature of the phenomena. A negative association was observed between the pH of the soil samples and Kd (R2 = −0.71) but a direct relation with the organic content (R2 = 0.74). Triasulfuron mitigation was performed by the economical remediation of soils using acid-activated charcoal prepped from Saccharum officinarum husk. Activated carbon derived from biomass displayed the great potential for triasulfuron removal from soils.

A review of the application of adsorbents for landfill leachate treatment: Focus on magnetic adsorption

Landfill leachate is a significant environmental threat due to the complexity and variety of its pollutants. There are various physical, chemical, and biological treatment methods proposed for leachate treatment. Adsorption with conventional adsorbents such as activated carbon is a process which has been widely employed with relative success. Magnetic adsorbents are a special type of adsorbents with favorable stability, high adsorption capacities, and excellent recycling and reuse capabilities when compared to conventional sorbents. Research regarding the synthesis and use of magnetic adsorbents has been growing at a rapid pace, exhibiting >8-fold increase in publications in the decade of 2010 to 2020. In the current study, both conventional and magnetic adsorbents for landfill leachate treatment have been comprehensively reviewed and discussed. The application of magnetic adsorbents for landfill leachate treatment is relatively new, with numerous avenues of research open to study. Although the production of magnetic adsorbents is significantly more expensive than conventional adsorbents, when taking into consideration all life cycle costs, they are much more competitive than it initially appears. If environmental impacts are of concern, research should shift towards the use of greener chemicals and processes for magnetic adsorbent synthesis, because preliminary analysis of the current synthesis processes shows a much higher environmental impact compared to conventional adsorbents, in particular in terms of global warming potential and energy use.

Sustainable Activated Carbon Production via Microwave for Wastewater Treatment: A Comparative Review

This is an era where the application of adsorption and usage of activated carbons (AC) are considered as mainstream water treatments. The upgrade of these materials may only be through its preparation methods, where most researchers have transitioned from using the conventional furnace methods to using microwave ovens. Derived from various precursors, ACs can be the key in developing numerous environmental applications. This paper reviews the development of production processes of AC from various precursors in the past decades by microwave heating. The importance of the applied methodology and how activating conditions play an influential role, such as carbonisation temperature, activation time, and impregnation ratio are also outlined in this review. From the review of AC production processes, ACs produced from various precursors by chemical method with microwave heating have shown to be the significant factor in developing ACs with relatively higher surface area compared to conventional heating ACs.

Microwave-assisted production of CO2-activated biochar from sugarcane bagasse for electrochemical desalination

A high-performance carbon electrode is desirable for promoting electrochemical desalination efficiency in the membrane capacitive deionization (MCDI). Sugarcane bagasse (food waste) was employed in this study to prepare hierarchically porous biochars by microwave-assisted carbonization and activation with potassium hydroxide in N₂ or CO₂ atmosphere under varying flow rates (100-600 cm³ min^-1). The sugarcane bagasse-derived biochars activated under CO₂ flow of 300 cm³ min^-1 (denoted as SBB-CO₂-300) possessed the ratio of mesopores to total pore volume (V_meso/V_total) of 56.7% with a specific surface area of 1019 m² g^-1. The electrochemical behavior of SBB-CO₂-300 was demonstrated by a surpassing specific capacitance of 208 F g^-1 at 5 mV s^-1 by means of cyclic voltammetry. The desalination tests using a batch-mode MCDI at 1.2 V in a 5 mM NaCl solution indicated that the SBB-CO₂-300 electrode exhibited an excellent electrosorption capacity of 28.9 mg g^-1. The improvement in the electrochemical deionization performance of SBB-CO₂-300 was attributed to the superior V_meso/V_total ratio, high surface area, excellent capacitance behavior, and hierarchical pore structure. The biowaste-derived biochars prepared via facile microwave-assisted carbonization and CO₂ activation route can provide a sustainable and high-efficiency carbon electrode for electrochemical deionization of brackish water.

Potential of agro-waste sugarcane bagasse ash for the removal of ammoniacal nitrogen from landfill leachate

Ammoniacal nitrogen is considered as one of the major pollutants of the leachate generated from the landfill site and has the potential to deteriorate the environment as well as health. Considering this, locally available agricultural waste, i.e., sugarcane bagasse ash, was employed as an adsorbent for the removal of ammoniacal nitrogen from landfill leachate. Batch-mode experiments were conducted to see the effect of dose (2-60 g L^-1), pH (2-12), and temperature (20-60 °C) on ammoniacal nitrogen adsorption. Application of sugarcane bagasse ash showed 60% removal of ammoniacal nitrogen (50 mg L^-1 strength) at an optimum dose of 20 g L^-1 and 180 min of contact time with an adsorption capacity of 0.31 mg g^-1. The Langmuir adsorption model was found to be best fit at 40 °C with R² = 0.944, depicting a monolayer coverage of ammoniacal nitrogen onto sugarcane bagasse ash. According to the result, solute uptake rate could be well described by the pseudo-second-order model (R² = 0.928), whereas the intraparticle diffusion model and Boyd plot indicated that the overall adsorption rate is governed by the external mass transfer. Thermodynamic studies revealed that adsorption is feasible, spontaneous, and endothermic in nature. Hence, the study shows that sugarcane bagasse ash could turn out to be a cost-effective adsorbent for the removal of ammoniacal nitrogen from leachate.

Activated carbon from pyrolysed sugarcane bagasse: Silver nanoparticle modification and ecotoxicity assessment

Activated carbon from pyrolysed sugarcane bagasse (ACPB) presented pore size ranges from 1.0 to 3.5nm, and surface area between 1200 and 1400m(2)g(-1) that is higher than commonly observed to commercial activated carbon. The ACPB material was successfully loaded with of silver nanoparticles with diameter around 35nm (0.81wt.%). X-ray photoelectron spectroscopy (XPS) analyses showed that the material surface contains metallic/Ag(0) (93.60wt.%) and ionic/Ag(+) states (6.40wt.%). The adsorption capacity of organic model molecules (i.e. methylene blue and phenol) was very efficient to ACPB and ACPB loaded with silver nanoparticles (ACPB-AgNP), indicating that the material modification with silver nanoparticles has not altered its adsorption capacity. ACPB-AgNP inhibited bacteria growth (Escherichia coli), it is a promising advantage for the use of these materials in wastewater treatment and water purification processes. However, ACPB-AgNP showed environmental risks, with toxic effect to the aquatic organism Hydra attenuata (i.e. LC50 value of 1.94mgL(-1)), and it suppressed root development of Lycopersicum esculentum plant (tomato). Finally, this work draw attention for the environmental implications of activated carbon materials modified with silver nanoparticles.

Self-powered denitration of landfill leachate through ammonia/nitrate coupled redox fuel cell reactor

In order to explore the feasibility of energy-free denitrifying N-rich wastewater, a self-powered device was uniquely assembled, in which ammonia/nitrate coupled redox fuel cell (CRFC) reactor was served as removing nitrogen and harvesting electric energy simultaneously. Ammonia is oxidized at anodic compartment and nitrate is reduced at cathodic compartment spontaneously by electrocatalysis. In 7.14 mM ammonia+0.2M KOH anolyte and 4.29 mM KNO3+0.1M H2SO4 catholyte, the nitrate removal efficiency was 46.9% after 18 h. Meanwhile, a maximum power density of 170 mW m(-2) was achieved when applying Pd/C cathode. When NH4Cl/nitrate and ammonia/nitrite CRFCs were tested, 26.2% N-NH4Cl and 91.4% N-NO2(-) were removed respectively. Nitrogen removal efficiency for real leachate at the same initial NH3-N concentration is 22.9% and nitrification of ammonia in leachate can be used as nitrate source. This work demonstrated a new way for N-rich wastewater remediation with electricity generation.

Reaction Behavior of Cellulose in the Homogeneous Esterification of Bagasse Modified with Phthalic Anhydride in Ionic Liquid 1-Allyl-3-methylimidazium Chloride

In order to elucidate the reaction behavior of cellulose component in bagasse, the homogeneous phthalation of bagasse was investigated comparatively with the isolated cellulose in 1-allyl-3-methylimidazium chloride (AmimCl) with phthalic anhydride (PA) at the dosage of 10–50 mmol/g. The phthalation degrees of bagasse and the isolated cellulose were in the range of 5.66% to 22.71% and 11.61% to 44.11%, respectively. A phthalation degree increase of cellulose was proportional to phthalic anhydride dosage due to its regular macromolecular structure and followed the equationyPDI=0.004x-0.02. FT-IR and 2D HSQC NMR analyses confirmed the attachment of phthaloyl group. The phthalation reactivity of the three hydroxyls in the isolated cellulose followed the order of C-6 > C-2 > C-3, and the more selective phthalation to C-6 position was found in the cellulose component in bagasse. These results provide detailed understanding of the homogenous modification mechanism of lignocellulose.

Novel synthesis of a versatile magnetic adsorbent derived from corncob for dye removal

Corncob, an agricultural waste, was successfully converted into a novel magnetic adsorbent by a low-temperature hydrothermal method (453K), including carbonization under saline conditions and magnetization using iron (III) salt. The resultant magnetic carbonaceous adsorbent (MCA) exhibited a porous structure with a higher specific surface area and more oxygen-containing functional groups than its carbonaceous precursor (CP), which can be attributed to the catalytic effect of Fe (III). The adsorption behaviors of both MCA and CP could be described well by Langmuir isotherm and pseudo-second-order model. The adsorption capacity for Methylene blue (MB) revealed by adsorption isotherms were 163.93mg/g on MCA and 103.09mg/g on CP, respectively. Moreover, MCA was demonstrated as a versatile adsorbent for removal of both anionic and cationic dyes, and it showed good reusability in regeneration studies. This work provides an alternative approach for effective conversion of biomass waste and application of them in pollutant removal.

Aerobic granular sludge-derived activated carbon: mineral acid modification and superior dye adsorption capacity

A novel aerobic granular sludge-derived activated carbon (AC) was prepared by a zinc chloride activation method and further modified by mineral acid (nitric acid (NA) and sulfuric acid (SA)).