Raw Pine Cone Research Articles

Kinetic study of the pyrolysis of pine cone shell through non-isothermal thermogravimetry: Effect of heavy metals incorporated by biosorption

The study concerns the pyrolysis kinetics of exhausted pine cone shell after its use as biosorbent of copper and lead from aqueous solutions in a fixed bed column. First, breakthrough curves of biosorption process were obtained. Main dynamic biosorption parameters were determined and analyzed. Then, non-isothermal thermogravimetric experiments were carried out with raw and metal-loaded biomass in a thermobalance under nitrogen atmosphere at different heating rates. A comparative study was performed. The activation energy dependent on the conversion rate was estimated by Flynn–Wall–Ozawa (a free integral or iso-conventional method) and a mechanistic model (an integral or model-fitting method that considers three independent parallel reactions). The fluctuation of activation energy in Flynn-Wall Ozawa model can be considered the result of thermal degradation reactions of different pseudo-components of the lignocellulosic material (hemicellulose, cellulose and lignin). For raw pine cone shell and metal-loaded-pine cone shell, best fit parameters were determined according to a three independent parallel reactions scheme. The copper and lead present in metal-loaded samples did not modify values of determined parameters which describe the pyrolysis process. Finally, chemical analysis of the chars indicated that about 95% and 99% of copper and lead presented on original waste was recovered in generated chars.

Application of raw and modified pine biomass material for cesium removal from aqueous solution

The growing investment in nuclear power has led to increasing concentrations of radionuclides in the ecosystem near nuclear facilities, therefore cheap and efficient filter materials for removal of these radionuclides needs to be designed to handle effluent waters from these facilities. The study investigates the use of hexacyanoferrate complex immobilized on chemically treated pine cone (TPC) biomass as an effective adsorbent. Raw pine cone (RPC) was treated with toluene–ethanol mixture to extract plant components and modified with hexacyanoferrate complex (HPC).Properties of RPC, TPC and HPC such as pHPZC, bulk density and surface area, and types of functional groups on the sorbent surface were determined. The batch kinetic uptake of cesium ions onto RPC, TPC and HPC were modelled using the Elovich and pseudo-nth order model kinetic models. Equilibrium modelling was also performed using the Langmuir, Freundlich and Sips isotherm. The results revealed that the adsorption is monolayer for all biosorbents with the modified adsorbent having the highest capacity of 8.74mg/g which was also confined by the Sips isotherm. The Cs+ adsorption data for TPC and HPC were better fitted to the pseud-nth order model suggesting ion exchange mechanism while the RPC was better fitted to the Elovich model. Desorption analysis was also used to confirm ion-exchange mechanism.

Arsenic(III) removal from aqueous solution by raw and zinc-loaded pine cone biochar: equilibrium, kinetics, and thermodynamics studies

The potential of raw pine cone (PC) biochar and its modified form (Zn-loaded biochar) was evaluated for the removal of trivalent arsenic [As(III)] from the aqueous solution. The influence of treatment of PC biochar with Zn(NO3)2 on the physico-chemical properties of biochar was examined using elemental analyzer, surface area analyzer, thermo-gravimetric analyzer, Fourier transform infrared spectroscopy, and scanning electron microscopy. Experimental results revealed that the removal of As(III) was almost consistent (66.08 ± 3.94 and 87.62 ± 3.88 % on raw and Zn-loaded biochar, respectively) over an acidic pH range of 2–4 as a consequence of high affinity between the positively charged biochar surface and the predominant arsenic species (H3AsO3 and H2AsO4 −), followed by a decrease with increase in pH in the range of 4–12. Langmuir isotherm model was well fitted to the experimental equilibrium data (R 2 = 0.93) rendering the maximum adsorption capacity of 5.7 and 7.0 μg g−1 on raw and Zn-loaded PC biochar, respectively. The adsorption of As(III) was well represented by pseudo-second order with reaction rate constant (k 2) of 0.040 and 0.282 mg g−1 min on raw and zinc-loaded PC biochar, respectively, and was mainly controlled by boundary layer diffusion followed by some extent of intra-particle diffusion. The adsorption process was spontaneous with Gibb’s free energy (ΔG°, −4.42 ± 0.72 and −11.86 ± 1.78 kJ mol−1) and exothermic in nature with enthalpy (ΔH°, 13.25 and 31.10 kJ mol−1) and entropy (ΔS°, 0.058 and 0.141 kJ mol−1 K−1) for raw and zinc-loaded adsorbent, respectively.

Adsorption of Copper by Raw Pinecone

Adsorption of Copper by Raw Pinecone

Removal of cationic dye methylene blue (MB) from aqueous solution by ground raw and base modified pine cone powder

The adsorption capacity of raw and sodium hydroxide-treated pine cone powder in the removal of methylene blue (MB) from aqueous solution was investigated in a batch system. It was found that the base modified pine cone exhibits large adsorption capacity compared with raw pine cone. The extent of adsorption capacity was increased with the increase in NaOH concentration. Overall, the extent of MB dye adsorption increased with increase in initial dye concentration, contact time, and solution pH but decreased with increase in salt concentration and temperature for both the systems. Surface characteristics of pine cone and base modified pine cone were investigated using Fourier transform infrared spectrophotometer and scanning electron microscope. Equilibrium data were best described by both Langmuir isotherm and Freundlich adsorption isotherm. The maximum monolayer adsorption capacity was found to be 129.87 mg g−1 at solution pH of 9.02 for an initial dye concentration of 10 ppm by raw pine cone. The base modified pine cone showed the higher monolayer adsorption capacity of 142.25 mg g−1 compared with raw pine cone biomass. The value of separation factor, R L, from Langmuir equation and Freundlich constant, n, both give an indication of favourable adsorption. The various kinetic models, such as pseudo-first-order model, pseudo-second-order model, intraparticle diffusion model, double-exponential model, and liquid film diffusion model, were used to describe the kinetic and mechanism of adsorption process. Overall, kinetic studies showed that the dye adsorption process followed pseudo-second-order kinetics based on other models. The different kinetic parameters, including rate constant, half-adsorption time and diffusion coefficient, were determined at different physicochemical conditions. A single-stage bath adsorber design for the MB adsorption onto pine cone and modified pine cone has been presented based on the Langmuir isotherm model equation. Thermodynamic parameters, such as standard Gibbs free energy (ΔG 0), standard enthalpy (ΔH 0) and standard entropy (ΔS 0), were also calculated.

Use of Forestry Wastes for Biosorption of Dyes and Cr (VI)

The pine cone and oak cups pulp were used as low‐cost adsorbents for the removal of basic (Basic Red 18) and acidic (Acid Red 111) dyes and Cr (VI) from aqueous solutions. The adsorbents were modified by HNO3 to improve their biosorption capacity. The adsorbents were characterized using scanning electron microscopy and FTIR spectroscopy. The zeta potential was determined as a function of the pH, in order to explain the effect of pH on electrostatic adsorption ability of biosorbent. Modification of adsorbents with nitric acid led to an increase in accessibility of some functional groups on the surface or a decrease in negativity of surface charge. The modification of pine cone increased its adsorption capacity for the basic dye, whereas the modification of oak cups pulp decreased the adsorption ability for basic dye to some extent. The adsorption isotherms fitted the Langmuir model. The adsorption capacities were found to be 142.85, 158.73, and 156.20 mg g‐1 for modified and raw pine cone and oak cups pulp, respectively. The acidic dye and Cr (VI) adsorptions were much lower compared to basic dye on all tested adsorbents. The results indicated that the forest wastes (pine cone and oak cups pulp) were an attractive candidate for basic dyes from aqueous solution.

The grafting of acrylic acid onto biosorbents: Effect of plant components and initiator concentration

Acrylic acid was grafted onto raw and Fenton's reagent treated pine cone using KMnO4 as initiator to determine the effect of plant organic components on grafting process. Concentration of the KMnO4 was varied between 0.0005 and 0.0200mol/dm3 and progress of the initiation process monitored using ORP and change in hydrogen ion concentration (ΔH+).The optimum ratio for Fenton's modification was Fe2+/H2O2=1/50 which corresponds to the highest leaching of plant components and having the least bulk density, ORP and ΔH+. It was observed that increasing KMnO4 concentration, reduced the MnO2 deposited on the pine surface, increased Mn3+ production in bulk solution while reducing grafting efficiency but increasing homopolymer formation. Radical formation on the raw pine cone was found to be lower as seen from the lower ORP and ΔH+ values observed at similar grafting conditions.Plant organic components was observed to affect the grafting efficiency and monomer conversion as observed from the weight increase, surface charge and FTIR analysis of the acrylic acid grafted Fenton's reagent treated pine and the raw pine.Optimum dye removal did not correspond to highest grafting efficiency.

Removal of anionic dye Congo red from aqueous solution by raw pine and acid-treated pine cone powder as adsorbent: Equilibrium, thermodynamic, kinetics, mechanism and process design

Pine cone a natural, low-cost agricultural by-product in Australia has been studied for its potential application as an adsorbent in its raw and hydrochloric acid modified form. Surface study of pine cone and treated pine cone was investigated using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The modification process leads to increases in the specific surface area and decreases mean particle sizes of acid-treated pine cone when compared to raw pine cone biomass. Batch adsorption experiments were performed to remove anionic dye Congo red from aqueous solution. It was found that the extent of Congo red adsorption by both raw pine cone biomass and acid-treated biomass increased with initial dye concentration, contact time, temperature but decreased with increasing solution pH and amount of adsorbent of the system. Overall, kinetic studies showed that the dye adsorption process followed pseudo-second-order kinetics based on pseudo-first-order and intra-particle diffusion models. The different kinetic parameters including rate constant, half-adsorption time, and diffusion coefficient were determined at different physico-chemical conditions. Equilibrium data were best represented by Freundlich isotherm model among Langmuir and Freundlich adsorption isotherm models. It was observed that the adsorption was pH dependent and the maximum adsorption of 32.65mg/g occurred at pH of 3.55 for an initial dye concentration of 20ppm by raw pine cone, whereas for acid-treated pine cone the maximum adsorption of 40.19mg/g for the same experimental conditions. Freundlich constant ‘n’ also indicated favourable adsorption. Thermodynamic parameters such as ∆G0, ∆H0, and ∆S0 were calculated. A single-stage batch absorber design for the Congo red adsorption onto pine cone biomass also presented based on the Freundlich isotherm model equation.

Biosorption of copper from aqueous solution by chemically activated pine cone: A kinetic study

The effect of different chemical activating agents (NaOH, KOH and Ca(OH) 2) on external and internal diffusion of copper(II) onto pine cone has been studied. Base treatment favored the formation of new pores with mesopore predominating in the order of raw < Ca(OH) 2 < KOH < NaOH treatment. The approach to equilibrium was enhanced by base treatment, while surface area and surface negative charge were found to influence the external mass transfer, boundary layer thickness and intraparticle diffusion to varying degrees. Initial solution pH affected the Cu(II) removal to a greater extent for the base treated samples than for the raw pine cone. The pseudo-first order rate constant calculated using the intrinsic adsorption rate, k a , had a linear relationship with initial concentration, hence it is proposed that diffusion of copper(II) ions across the liquid film at the surface of the absorbent particle control the adsorption process at the initial stage. The values of mass transfer parameters, K D 1 were higher than K D 2 indicating that the adsorption differences within the samples are due to mass transfer in the fast step. External mass transfer was favored by increased magnitude of pore volume of the sample.

Equilibrium, Kinetics and Mechanism of Removal of Methylene Blue from Aqueous Solution by Adsorption onto Pine Cone Biomass of Pinus radiata

The kinetics and mechanism of methylene blue adsorption onto raw pine cone biomass (Pinus radiata) was investigated under various physicochemical parameters. The extent of the methylene blue dye adsorption increased with increases in initial dye concentration, contact time and solution pH but decreases with the amount of adsorbent, salt concentration and temperature of the system. Overall the kinetic studies showed that the methylene blue adsorption process followed pseudo-second-order kinetics among various kinetic models tested. The different kinetic parameters including rate constant, half-adsorption time and diffusion coefficient are determined at different physicochemical conditions. Equilibrium data were best represented by Langmuir isotherm among Langmuir and Freundlich adsorption isotherm. The maximum monolayer adsorption capacity of pine cone biomass was 109.89 mg/g at 30°C. The value of separation factor, R L, from Langmuir equation and Freundlich constant, n, both give an indication of favourable adsorption. Thermodynamic parameters such as standard Gibbs free energy (∆G 0), standard enthalpy (∆H 0), standard entropy (∆S 0) and the activation energy (A) were calculated. A single-stage batch absorber design for the methylene blue adsorption onto pine cone biomass has been presented based on the Langmuir isotherm model equation.

Surface modification of pine cone powder and its application for removal of Cu(II) from wastewater

Pine cone powder is an agricultural waste material from the wood industry. In this investigation, chemical modification of pine cone powder using NaOH solution of different concentrations (0.01, 0.05, 0.10, and 0.15 mol dm−3) was carried out. The changes in surface properties produced by modification and the ability of the modified products to remove copper(II) from aqueous solution was examined. Chemical characterization of the adsorbent surface by FTIR and Bohem titration showed that an increase in NaOH concentration in the wash solution was found to reduce the amounts of carboxyl and phenolic groups and increase the iodine number. The pHPZC of the raw pine cone powder reduced with NaOH concentration in the wash solution from 7.49 to 2.55. Optimum NaOH concetration for pine cone powder surface modification was 0.15 mol dm−3, while the optimum solution pH, contact time and biosorbent dose for copper(II) removal were pH 5.0, 5 min and 4.0 g dm−3 for all samples. Copper(II) removal capacity was higher for samples washed with higher concentrations of NaOH solution (PCP 6.8 mg g−1, PCP 0.1 13.01 mg g−1, PCP 0.05 15.03 mg g−1, PCP 0.10 16.38 mg g−1 and PCP 0.15 17.22 mg g−1). The equilibrium solution pH at the end of the biosorption experiments were higher than the initial solution pH when modified samples were used for biosorption but lower than the initial pH when the raw pine cone powder was applied. This may suggest a different mechanism of copper(II) uptake by raw pine cone powder as compared with the modified samples. The paseudo-second order kinetics for copper(II) biosorption gave the best fit with the experimental data for both the raw and NaOH modified pine cone powder.