First-order Reaction Kinetic Model Research Articles

Synthesis of KBiO3/Nano-Ag3PO4 Composite Photocatalyst and its Application for Degradation of Organic Pollutant under visible light

In this work, a novel composite photocatalyst, KBiO3/nano-Ag3PO4 (K/Ag catalyst), was synthesized, and efficiently degraded methylene blue (MB) under visible light. The various properties of photocatalyst were measured by modern analytical techniques, such as XRD, FT-IR, SEM, XPS, and UV-Vis. We also utilized Density functional theory calculation (DFT) to investigate the photocatalytic degradation mechanism in this reaction process. The multiple characterization findings demonstrated that K/Ag composite catalyst was successfully synthesized using Ag3PO4 and KBiO3, and it displayed excellent absorption for visible light. The photocatalytic results confirmed that K/Ag catalyst greatly promoted the degradation of MB under visible light. The first-order reaction kinetics model could satisfactorily describe the apparent photocatalytic degradation process in this system. In addition, adding electron capture agents to the photocatalytic system highly decreased the degradation efficiencies of target pollutant. Moreover, K/Ag composite catalyst exhibited perfect photocatalyst stability after recycling three times. Through calculating the band structure, Density of States (DOS) and work function, KBiO3 and Ag3PO4 could be considered as n type and p type semiconductor material, respectively. When the composite catalyst was exposed to light, the light-excited electrons would be appeared in both the conduction bands. Furthermore, the transfer trend of electrons and holes made photogenerated electrons concentrate on the conduction band of n type KBiO3, and photogenerated holes concentrate on the valence band of p type Ag3PO4, and thereby greatly improve the photocatalytic efficiency.

Degradation of Tryptophan by UV Irradiation: Influencing Parameters and Mechanisms

The chlorination of dissolved amino acids can generate disinfection by-products (DBPs). To prevent the formation of DBPs, we examined the UV-induced degradation of tryptophan (Trp). In order to further understand the impact of UV disinfection on Trp, the effects of initial concentrations of Trp, pH, temperature, concentrations of NO3−, HCO3− and Cl− on Trp removal were investigated, and a degradation mechanism was also proposed. The results demonstrated that degradation fitted a pseudo first-order reaction kinetic model. The degradation of Trp was mainly caused by direct UV degradation. The apparent rate constant kobs decreased with the increase in initial Trp concentration and increased with increases in pH and temperature. The thermal degradation activation energy was 19.65 kJ/mol. Anions in water also had a significant influence on the degradation of Trp. HCO3− and NO3− contributed to the kobs of Trp, but Cl− inhibited the degradation rate. By electron paramagnetic resonance (EPR) spectroscopy, ·OH was proven to be formed during the degradation of Trp by UV. Based on the intermediate products of C11H15NO3, C10H15N and C9H13N detected by LC-MS-MS, the degradation pathway of Trp was speculated.

Effect of Hot-Air Convective Drying on Activity Retention of Amylase and Invertase in Dried Mango of Varieties Sindri, SB Chaunsa, and Tommy Atkins

Recently, fruit-drying industries are showing great interest in producing dry fruits that preserve a high enzyme content. Therefore, this study aimed to investigate the effect of hot-air convective drying on activity retention of amylase and invertase in dried mango of varieties Sindri, Samar Bahisht (SB) Chaunsa, and Tommy Atkins. Convection drying was conducted under over-flow mode at five temperatures (40, 50, 60, 70, and 80 °C), two air velocities (1.0 and 1.4 m s−1), and constant specific humidity of 10 g kg−1 dry air. The enzymatic degradation data were fitted to the first-order reaction kinetics model, in which the temperature dependence of the rate constant is modelled by the Arrhenius-type relationship. Results showed that the maximum amylase and invertase activity for dried mango of all three varieties was best preserved in samples dried at a temperature of 80 °C and an air velocity of 1.4 m s−1. In contrast, a lower drying temperature and an air velocity of 1.0 m s−1 contributed to a significant decrease (p < 0.05). Exploration of different temperatures and air velocities to save amylase and invertase in dried mango is useful from an industrial point of view, as mango can be a natural dietary source of digestive enzymes to improve digestion.

Magnetically attracted iron scrap anode based electrocoagulation for phosphate removal.

This study shows the effectiveness of a novel electrocoagulation process using magnetically attracted iron scrap anodes for phosphate removal from aqueous solution. The effect of contact time, reaction temperature, dose of iron scrap, initial phosphate concentration, applied voltage, pH, magnetic force, and the species of competing anions on the efficiency of phosphate removal and the reaction products has been investigated. The techniques of XRD, XPS, and VSM were used to characterize the elemental composition and the types of the reaction products in order to clarify the interaction between novel anode and phosphate ions. The removal of phosphate was fitted by a pseudo first-order reaction kinetic model. The results showed that magnetically attracted iron scrap anodes were electrodissoluted under an applied potential and reacted with phosphate into Fe-hydroxo-phosphate complexes. The work suggested that electrocoagulation using magnetically attracted iron scrap anodes had the potential to become a promising technique for phosphate precipitation.

A novel low temperature aerobic technology with electrochemistry for treating pesticide wastewater: Compliance rate, mathematical models, economic and environmental benefit analysis

In this study, a novel combination system of the tapered variable diameter biological fluidized bed (TVDBFB) with electrochemistry (EC) has been developed and its performances are investigated at different seasons. The results showed that the COD removal efficiency of TVDBFB increased from 61% to 67% and compliance rate increased from 84% to 88% when the carrier packing rate increased from 15% to 30% and temperature was 12 ℃. However, COD removal efficiency and compliance rate increased to 87% and 100% when EC was a post treatment unit. The mathematical models could fit well with the attached biomass, which can be applied to reflect and predict the biomass per unit carrier under different conditions, and the EC removal of COD follow the first-order reaction kinetic model. The economic and environmental benefit analysis indicated that TVDBFB and EC were feasible for treating pesticide wastewater.

The fate of sulfonamides in the process of phytoremediation in hydroponics

Phytoremediation has been proven to be an alternative in-situ treatment technique for sulfonamide polluted wastewater. However, the fate of sulfonamides in the phytoremediation process of multiple sulfonamides coexistence is unclear. Therefore, the possibility and mechanism of phytoremediation of ten sulfonamides by different wetland plants through hydroponics were investigated in this study. The phytoremediation rates of Σsulfonamides by different wetland plants were from 44.5% to 56.9%. Mass balance analysis showed that rhizosphere biodegradation (90.2% − 92.2%) dominated the phytoremediation of Σsulfonamides, while hydrolysis (7.63% − 8.95%) and plant uptake (0.05% − 0.17%) accounted for a small proportion. It is worth mentioning that the dissipation of the target sulfonamides in the hydroponic system followed the first-order reaction kinetic model, with half-lives of 13.3 d to 53.3 d, which are close to or even lower than that of aerobic biodegradation in river water, sediment, and piggery wastewater. Six of the ten spiked sulfonamides were detected in plant samples demonstrated that the selective uptake of plants under the coexistence of multiple sulfonamides. The distribution of sulfonamides (concentrations and uptake amounts) in plant tissues followed the sequence of root > stem > leaf in this study, but the distribution in stems and leaves needs further study. The uptake and rhizosphere biodegradation of Cyperus papyrus to sulfonamides are optimally resulting that its phytoremediation rate is significantly higher than other plants (p < 0.05), which indicates that plant species is one of the key factors affecting the phytoremediation efficiency of sulfonamides. These findings verify the feasibility of phytoremediation of sulfonamides, and provide new insights into the fate of sulfonamides in the process of phytoremediation.

Platinum-supported aluminum oxide on activated carbon filter media for removal of formaldehyde in the indoor condition

Formaldehyde is one of the hazardous indoor air pollutants which have harmful effects on humans, domestic animals, and environmental health. The goal of this study was to synthesize a Pt/Al2O3 coated on granular activated carbon (GAC), which is easily recoverable and can be used as an absorbent for formaldehyde removal from polluted indoor air. Moreover, the Pt/Al2O3 catalyst could achieve complete and stable HCHO oxidation at ambient temperature. The characteristic properties of the Pt/Al2O3/GAC sample were analyzed using scanning electron microscopy, energy-dispersive spectrometer, Fourier-transform infrared spectroscopy, and Brunauer–Emmett–Teller techniques. The Pt/Al2O3/GAC catalyst was investigated to determine the catalytic performance with regard to formaldehyde (HCHO) oxidation under different face velocity and initial formaldehyde concentration applicable to a building environment. It was revealed that the removal capacity of Pt/Al2O3 catalyst reached a maximum of 2.23 mg g−1 during 0.1 m s−1 face velocity and 0.75 ppm HCHO inlet concentration. Among zero-, first- and second-order reaction kinetic model, the correlation coefficient of the first-order reaction kinetic model (0.7948 < R2 < 0.9249) and second-order reaction kinetic model (0.6056 < R2 < 0.8146) is lower than zero-order reaction kinetic model (0.9352 < R2 < 0.9921) of Pt/Al2O3 catalyst. The oxidation kinetic of HCHO was well fitted with the zero-order reaction for Pt/Al2O3 catalyst. This study provides some instructions for the design and manufacture of environmentally harmless and cost-effective catalysts with excellent catalytic oxidation properties to remove HCHO at room temperature.

The defluorination of perfluorooctanoic acid by different vacuum ultraviolet systems in the solution.

Perfluorooctanoic acid (PFOA) is one kind of persistent organic pollutants that is often detected in water. In recent years, the effective degradation technologies of PFOA have attracted widespread attentions. Thus, in this study, the defluorination efficiency of PFOA in different systems (i.e., ultraviolet (UV), vacuum ultraviolet (VUV), vacuum ultraviolet/persulfate (VUV/PS) and vacuum ultraviolet/residual chlorine (VUV/RC)) was evaluated. Moreover, the different impact factors (i.e., the initial concentrations of persulfate and PFOA, temperature, anions, and initial pH values) on PFOA degradation by VUV/PS system were investigated. The results showed that VUV system was more effective than UV system for PFOA defluorination. VUV system combined with persulfate would further enhance the defluorination efficiency while residual chlorine would decrease it. In VUV/PS system, the defluorination efficiency of PFOA was the best as the molar ratio of PFOA and persulfate at 1:60. Moreover, higher temperature, lower initial PFOA concentration, and acid condition were favorable for the defluorination of PFOA. Under the different influence factors, the defluorination efficiency of PFOA fitted well to the first-order reaction kinetic model. When the temperature was range from 20°C to 40°C, the value of activation energy was 8.73kJ/mol. Besides, the inhibition effect of three kinds of anions on PFOA defluorination followed the order: >Cl- > . PRACTITIONER POINTS: The defluorination efficiency of perfluorooctanoic acid (PFOA) in water by different VUV systems was compared. VUV system is more effective than UV system for PFOA defluorination. Persulfate will enhance the defluorination efficiency by VUV system. Hypochlorite will decrease the defluorination efficiency by VUV system.

Pyrolysis of oil extracted safflower seeds: Product evaluation, kinetic and thermodynamic studies

In this study, pyrolysis kinetics and thermodynamic parameters of Safflower residues (SR) obtained from oil extraction were investigated by using TG/DSC-FTIR and py-GC/MS. Thermal analysis was performed from ambient temperature to 750 °C under a nitrogen atmosphere. The first-order reaction kinetics model was applied to thermal analysis data to determine apparent kinetic parameters. Activation energy and pre-exponential factor were calculated as 76.60 kJ.mol−1 and 1.89x106 min−1, respectively. The thermodynamic parameters such as the change in Gibb’s free energy, the difference in enthalpy and the entropy change were calculated to be 201.36 kJ mol−1, 71.79 kJ mol−1, and −0.196 kJ mol−1, respectively. TG/FTIR analysis revealed that CO2, C6H5OH, and CC functional group as the main pyrolysis gas products. According to Py-GC/MS results of SR, the presence of high energy-containing compounds among the pyrolysis products was proved. All these results show that SR is suitable for pyrolysis to produce biofuel and/or chemicals.

Air drying kinetics and quality characteristics of osmodehydrated-candied pumpkins using alternative sweeteners

In order to obtain nutritious, low calorie candied pumpkins, of superior quality, air drying kinetics of pretreated pumpkin slices were investigated using three different drying temperatures (40, 60 & 80 °C). Before drying, pumpkins were osmotically treated using different osmotic agents, namely sucrose, oligofructose and their mixture (1:1) in a solution of a constant concentration (70°Brix), at three temperature (75, 85 & 95 °C) for 150 min. Changes in texture (hardness and compression work) were determined during drying and sensory characteristics of the final products were evaluated by trained panelists. A first-order reaction kinetic model was used to predict the drying rate and hardness, in which the rate constant was a function of the process temperature. The results showed that as the drying temperature is increased, the drying constant also increases whereas the equilibrium moisture content of the dehydrated products decreases. The hardness of candied pumpkins was mostly affected by the air drying temperature regardless the osmotic dehydration conditions. Sensory evaluation of the final candied pumpkins, showed a preference for the products osmotically treated by oligofructose.

Electrocatalytic Oxidation of Sulfadiazine with Ni-Doped Sb-SnO2 Ceramic Ring Particle Electrode

The excessive use and abuse of antibiotics has brought about serious threats to water environmental safety and human health. It is necessary to develop efficient, cheap, and environmentally friendly treatment technologies for antibiotics. In this work, a Ni-doped Sb-SnO2 microporous ceramic ring particle electrode was prepared by the dipping method and characterized by scanning electron microscopy, energy dispersion spectroscopy, and X-ray diffraction. The electrocatalytic oxidation ability and kinetic characteristics of sulfadiazine (SDZ) were studied using the prepared electrode, and the degradation pathways of SDZ were analyzed preliminarily. The results showed that Ni and Sb-SnO2 crystals were loaded on the particle electrode surface, which is beneficial for electron transfer and SDZ adsorption and improvement of electrocatalytic oxidation efficiency. Under the conditions of 0.02 mol·L-1 NaCl solution (pH 8), 15 mA·cm-2 of current density, and 15 g particle electrode, 50 mg·L-1 SDZ could be completely removed on the three-dimensional electrode within 15 min. The removal efficiency of TOC in the reaction solution reached 80.8% for 3 h degradation and was 17.6% higher than that with two-dimensional electrode. The kinetic process of the electrocatalytic oxidation could be well described by the first-order reaction kinetic model, and the rate constant was 0.329 min-1. The degradation products of SDZ were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the possible pathways of electrocatalytic degradation mainly include the fractures of S-N bond on sulfamido and C-N bond on pyrimidine ring, desulfonation, deamination, and·OH oxidation.

Non-isothermal pyrolysis kinetics characteristics of ZhaoTong lignite using thermogravimetric analysis

ABSTRACTIn this study, the effects of heating rate and ash content on the pyrolysis kinetic characteristics of ZhaoTong lignite were investigated by using thermogravimetric analysis (TGA) method. The non-isothermal pyrolysis process of lignite was strongly affected by the heating rate and ash content. Raw lignite was treated by demineralization method, indicating that with increasing the demineralizing time, carboxyl groups content of lignite increased, while hydroxyl content and minerals content of lignite decreased, respectively. The pyrolysis kinetics characteristics of lignite such as the activation energy (E) and frequency factor (A) were discussed by Coats–Redfern method. The first-order reaction kinetics model had the higher linear fitting correlation on the non-isothermal pyrolysis reaction of lignite. The activation energy of lignite pyrolysis increased with increasing heating rate, but decreased with increasing ash content. The study can provide the theoretical foundation for large-scale pyrolysis of lignite.

Ozonolysis Post-Treatment of Anaerobically Digested Distillery Wastewater Effluent

ABSTRACTIn this study, the ozonolysis of real anaerobically digested distillery wastewater (DWW) was carried out. The effect of operating parameters, such as pH, initial concentration, and ozone dosage, on the efficiency of ozone utilization, color removal, and sludge solubilization was studied. The highest ozone utilization of 99% was observed at the highest initial concentration (COD of 3000 mg/L) and lowest ozone flowrate (22.5 mg O3/L/min), but with a very low color reduction of 20%, after 60 minutes of ozonolysis. To achieve a higher color reduction >80% and at ozone utilization >95%, the DWW had to be diluted twice (COD 1500 mg/L), and the flowrate doubled to 45 mg O3/L/min. The reduction in color signified the oxidation of the color causing biorecalcitrant aromatic melanoidin compounds. This was confirmed by the 47% reduction in ultraviolet absorbance at 254 nm indicating the breakdown of the complex aromatic compounds into low molecular weight organics. Moreover, increases in average oxidation state from −0.6 to −0.2 suggested a decline in aromaticity and formation of easily biodegradable aliphatic compounds. The ozonolysis process was found to follow the first-order reaction kinetic model with the highest rate constant of 0.0326 min−1 obtained. A reduction in suspended COD by 88% indicated solubilization of the sludge contained in the effluent.

Photocatalytic degradation kinetics of unsymmetrical dimethylhydrazine in aqueous solution by Fe3+ doped Bi2O3

The Fe3+ doped Bi2O3 photocatalyst was prepared by sol-gel method. The photocatalytic degradation experiment was carried out using unsymmetrical dimethylhydrazine (UDMH) simulated wastewater as the target pollutant. The results showed that Fe3+ doping significantly improved the degradation efficiency of UDMH with an optimum doping concentration of 2.0%. The reaction kinetics study indicated that the reaction was heterogeneously catalyzed and the kinetic fitting results were consistent with pseudo first-order reaction kinetics model. According to the results of linear fitting, the kinetic reaction rate constant of Fe3+ doped Bi2O3 (2.0%) was the largest, about 1.9 times as much as that of undoped Bi2O3. Finally, a possible mechanism was proposed to explain the enhanced photocatalytic activity.

Degradation of α-HCH in Soil Washing Solutions with nZVI and CaO2

Nano zerovalent iron (nZVI) and CaO2 were used to construct a heterogeneous Fenton-like system to degrade α-hexachlorocyclohexane (α-HCH) in soil solution, and the degradation efficiency and mechanism were investigated. The results showed that nZVI/CaO2 can degrade α-HCH in an extensive pH range. When the dosage of nZVI and CaO2 was 1 g·L-1 and pH was 5, the degradation rate of α-HCH reached 93.23%. The degradation process of nZVI, CaO2, and nZVI/CaO2 treatments accorded with the first-order reaction kinetics model. The reaction rate constant of nZVI/CaO2 was greater than the sum of individual treatments, showing that nZVI/CaO2 has a synergistic effect on the degradation of α-HCH. Through quenching free radical experiments, the contribution rate of superoxide radicals was shown to be greater than that of hydroxyl radicals. Intermediates, including trichlorobenzene and chlorobenzene, were detected. The content of trichlorobenzene showed a sharp increase initially, and then decreased quickly. The chlorobenzene content was low and showed little change. The α-HCH in the soil washing solution was first reduced to trichlorobenzene, which was further reduced to chlorobenzene or mineralized into CO2 and water directly.

Enhanced Degradation of Aniline by PS Oxidation in the Presence of UV and Ferric Oxalate

Oxidative degradation of aniline by Sodium Persulfate (PS) activated with UV-ferric oxalate[UV-Fe(C2O4)33-] was studied. The effects of Fe(C2O4)33- concentration, PS concentration, and pH on PS activation and aniline degradation were investigated. Results showed that Fe(C2O4)33- concentration and pH determined the reduction process of Fe3+ into Fe2+, which had significant effects on the oxidative degradation of aniline by PS. With an increase in Fe(C2O4)33- concentration, PS decomposition increased; however, when concentrations were>0.75 mmol·L-1, aniline degradation efficiency decreased due to competition with oxalate ions (C2O42-) for SO4·-. Aniline degradation efficiency in processes with different initial Fe(C2O4)33- concentrations followed the sequence:5 mmol·L-1 < 0.25 mmol·L-1 < 0.5 mmol·L-1 < 1 mmol·L-1 < 0.75 mmol·L-1. Neutral and alkaline conditions were not conducive to Fe2+ formation via photochemical reaction. However, with initial pH values of 7 and 9, PS activation efficiency reached 74% and 67% respectively after 300 min due to pH decline during the reaction; aniline removal efficiency was as high as 91% and 97%, respectively, higher than under initial acidic conditions. Furthermore, increased PS concentration was conducive to improvement of aniline degradation efficiency, but when PS concentration was>10 mmol·L-1, the aniline degradation process followed the pseudo first-order reaction kinetics model instead of the second-order reaction kinetics model. PS efficiency for aniline degradation decreased significantly due to the reaction between excessive PS and sulfate radicals.

A highly ordered honeycomb-like nickel(III/II) oxide-enhanced photocatalytic fuel cell for effective degradation of bisphenol A.

The honeycomb-like nickel(III/II) oxide interpenetrated framework arrays labelled as H-NiOx are used as cathode catalysts for the degradation of bisphenol A (BPA) in visible light-excited fuel cells. The nanoparticle close-packed NiOx aggregates (C-NiOx) and H-NiOx are prepared by conventional electrodeposition (ED) and advanced oxidation-associated electrodeposition (AO-ED) strategies, carried out by multiple voltammetry controlled in the potential ranges of 0 to -1.3 V and 1.3 to -1.3 V (vs. SCE), respectively. Compared with C-NiOx, the H-NiOx frameworks with smaller charge transfer resistance and higher surface-confined redox-active centers exhibit larger cathode electrocatalytic activity for the photocatalytic degradation of BPA. The NaClO can act as a sacrificial agent to sustain the integrity and stability of H-NiOx cathode. The H-NiOx-assisted BPA degradation conditions are optimized by changing process variables. The BPA is degraded by 48.5% within 120 min in photocatalytic BPA (1.0 mmol L-1, pH 13) fuel cell employing H-NiOx cathode, CdS/TiO2 photoanode and 0.2 mol L-1 NaClO catholyte, and its degradation rate conforms to the first-order reaction kinetic model. The H-NiOx can remarkably enhance the performances of the photocatalytic fuel cell, achieving a 4.1-fold or 15.2-fold increase in the short circuit current and maximum power density compared with that using bare cathode.

Green synthesis of the innovative super paramagnetic nanoparticles from the leaves extract of Fraxinus chinensis Roxb and their application for the decolourisation of toxic dyes

Abstract The leaves extract of Fraxinus chinensis Roxb was used for the synthesis of the innovative phytogenic magnetic nanoparticles (PMNPs) without adding toxic surfactants. The formation, morphology, elemental composition, size, thermal stability, structure and magnetic properties of these PMNPs were examined by UV-visible spectrophotometry, FT-IR, XRD, SEM, EDX, TEM, VSM, XPS, BET and TGA. The reactivity of the obtained PMNPs against decolourising toxic dyes, namely, malachite green (MG), crystal violet (CV) and methylene blue (MB), were investigated by UV-vis spectrophotometry. Further, the factors affecting the removal of dyes, including solution pH, adsorbent dosages, initial concentration of dyes, reaction temperature and contact time, were also investigated. The results revealed the decolourisation of 99.12% of MG and 98.23% of CV within 60 min, and 97.52% of MB within 200 min by the PMNPs using dyes concentration of 25 mg/l at pH 6.5 and 298.15 K. The kinetics outcome indicated that the degradation of dyes matched well to the pseudo first-order reaction kinetics model. Furthermore, the probable degradation mechanism of dyes by the PMNPs, including the adsorption of cationic dye molecules onto the negatively charged surface of adsorbent and the oxidation of the Fe° in the solution, were discussed. Thus, the PMNPs can be produced by the bulk and have great potential to be employed for biomedical/environmental remediation.

Novel triazolium-based ionic liquids as effective catalysts for transesterification of palm oil to biodiesel

Novel triazolium-based ionic liquids (ILs) have been designed and synthesized for the transesterification of palm oil with methanol to produce biodiesel. It is found that triazolium-based ILs herein possessed better thermal stability and higher catalytic activity than the common imidazolium-based ILs. The investigation of reaction condition is conducted for the optimization of the biodiesel production. The yield of biodiesel can therefore reach up to 99.75% under optimal reaction conditions. The reaction kinetic study indicated that pseudo first-order reaction kinetic model is available for the reaction system herein, and the activation energy (Ea) is 86.48kJ·mol−1usingthe optimal catalyst.

Thermal degradation kinetics of ascorbic acid, thiamine and riboflavin in rosehip (Rosa canina L) nectar

Abstract In this paper, the loss of L-ascorbic acid, thiamine and riboflavin in rosehip nectar with the heating periods (0, 5, 10, 15, 20 and 30 min) at temperatures ranging from 70 to 95 °C is analyzed and experimental results are presented. Firstly, dried rosehip fruits were processed to rosehip nectar and then thermal treatment is performed. Liquid chromatographic (HPLC) method was used for the analysis of the contents of L-ascorbic acid, thiamine and riboflavin and examined compounds are thoroughly separated within 25 min. During thermal processing, degradation of L-ascorbic acid, thiamine and riboflavin in rosehip nectar were fitted to a first-order reaction kinetic model. Arrhenius relationship was used for the description of temperature dependence of reaction. Activation energies for L-ascorbic acid, thiamine and riboflavin between 70 to 95 oC were found to be 55.30, 36.38 and 37.15 kJ/mol, respectively. To the best of the author’s knowledge, due to lack of study on the thermal degradation of L-ascorbic acid, thiamine and riboflavin in rosehip nectar, this manuscript will be the first reported study to enable future analysis.