Modeling of the Adsorption/Desorption Characteristics and Properties of Anthocyanins from Extruded Red Cabbage Juice by Macroporous Adsorbent Resin

2019 ◽  
Vol 15 (1-2) ◽  
Author(s):  
Pingjing Zhang ◽  
Liping Wang ◽  
Sheng Fang

AbstractThe adsorption/desorption characteristics, modeling and properties of anthocyanins from extruded red cabbage juice by macroporous resins were investigated. The static adsorption and desorption capacities of red cabbage anthocyanins on five macroporous resins were measured and compared. The X-5 resin showed the best capacities and was selected for the adsorption kinetics, isotherms and elution studies. The pseudo-second-order kinetic model and Langmuir isotherm model were used to describe the adsorption process and mechanism. Dynamic adsorption and desorption tests were performed on a fixed-bed column, and the loading and eluent conditions were optimized. The purity of anthocyanins in freeze-dried purified powder by the resin adsorption process is 21.3 ± 0.9 wt % and shows better stability in the air than the unpurified one. Finally, the antioxidant activity and color properties including color density, color intensity, color tonality and degradation index of the purified powders were measured.

2014 ◽  
Vol 28 (4) ◽  
pp. 479-490 ◽  
Author(s):  
Sunita Rani ◽  
Dhiraj Sud Sant

Abstract Experiments were conducted to study the sorption behaviour of dimethoate in three Indian soils at different temperatures. A kinetic study showed that adsorption equilibrium was reached within 15 h at different initial levels of pesticide concentration. Applicability of the pseudo second order kinetic model suggested that the adsorption process was complex and several mechanisms were involved. The Freundlich model explained the adsorption behaviour adequately and the isotherms were of S-type. The adsorption process was found to be strongly affected by temperature. The Gibbs free energy change, ΔGº values (from -15.81 to -16.60 kJ mol-1) indicated that the process was spontaneous and exothermic in nature. The change in enthalpy of adsorption, ΔH° values (from -17.729 to -21.539 kJ mol-1) suggested that relatively weak H-bond forces were the main driving forces for adsorption. Desorption was found to be concentration- and temperature-dependent with higher desorption occurring at higher temperature and concentration levels. The results signify the importance of temperature in controlling the mobility of dimethoate in water bodies.


2020 ◽  
Vol 26 (4) ◽  
pp. 200250-0
Author(s):  
Abdul Rahman Abdul Rahim ◽  
Iswarya ◽  
Khairiraihanna Johari ◽  
Nasir Shehzad ◽  
Norasikin Saman ◽  
...  

Desiccated coconut waste (DCW) is an agricultural waste that originates from the coconut milk processing industry. In this study, it was utilized for the removal of copper (Cu(II)) and nickel (Ni(II)) via adsorption process. The physicochemical characterization of the DCW adsorbent shows that the adsorbent have a surface area of 6.63 m<sup>2</sup>/g, have high elemental carbon content and existences of important functional groups on its surface. The adsorptive capability of DCW adsorbent in removing the heavy metal were conducted in batch studies. DCW adsorbent performed highest Ni(II) and Cu(II) adsorption capacity at pH 6, where equilibrium is achieved at 450 minutes. The kinetic analysis showed the adsorption agreed with pseudo-second order kinetic model, indicating the Cu(II) and Ni(II) adsorption were a chemical adsorption, limited by the film diffusion. The DCW adsorbent still retained its effective adsorption capacity after 2 adsorption-desorption cycles, which is one of the excellent criteria of a good adsorbent for an adsorption process.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Di-Hua Li ◽  
Yan Wang ◽  
Yuan-Shan Lv ◽  
Jun-Hong Liu ◽  
Lei Yang ◽  
...  

The preparative purification of liriodendrin fromSargentodoxa cuneatausing macroporous resin combined with crystallization process was evaluated. The properties of adsorption/desorption of liriodendrin on eight macroporous resins were investigated systematically. X-5 resin was selected as the most suitable medium for liriodendrin purification. The adsorption of liriodendrin on X-5 resin fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. Dynamic adsorption/desorption tests were performed using a glass column packed with X-5 resin to optimize the separation process of liriodendrin. After one treatment with X-5 resin, the content of liriodendrin in the product was increased 48.73-fold, from 0.85% to 41.42%, with a recovery yield of 88.9%. 97.48% liriodendrin was obtained by further crystallization and determined by HPLC. The purified product possessed strong antioxidant activity. In conclusion, purification of liriodendrin might expend its further pharmacological researches and further applications in pharmacy.


2021 ◽  
Author(s):  
Maoling Wu ◽  
Ling Ding ◽  
Jun Liao ◽  
Yong Zhang ◽  
Wenkun Zhu

Abstract In this work, the efficient extraction of uranium in solution using Al2O3-SiO2-T was reported. Kinetics and isotherm models indicated that the removal process of uranium onAl2O3-SiO2-T accorded with pseudo-second-order kinetic model and Langmuir isotherm model, which showed that the adsorption process was a uniform mono-layer chemical behavior. The maximum adsorption capacity of Al2O3-SiO2-T reached 738.7 mg g-1, which was higher than AlNaO6Si2 (349.8 mg g-1) and Al2O3-SiO2-NT (453.1 mg g-1), indicating that the addition of template could effectively improve the adsorption performance of Al2O3-SiO2 to uranium. Even after five cycles of adsorption-desorption, the removal percentage of uranium on Al2O3-SiO2-T remained 96%. Besides, the extraction efficiency of uranium on Al2O3-SiO2-T was 72.5% in simulated seawater, which suggested that the Al2O3-SiO2-T was expected to be used for uranium extraction from seawater. Further, the interaction mechanism between Al2O3-SiO2-T and uranium species was studied. The results showed that the electrostatic interaction and complexation played key roles in the adsorption process of Al2O3-SiO2-T to uranium.


2019 ◽  
Vol 80 (9) ◽  
pp. 1643-1653
Author(s):  
Hassan Younes ◽  
Hani Mahanna ◽  
Hisham Kh. El-Etriby

Abstract In this study, the removal of phosphate (PO4−) from wastewater using glauconite was investigated. Glauconite was characterized by N2 adsorption–desorption isotherm, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, and Fourier transform infrared (FTIR) spectroscopy. The effects of contact time, pH, initial phosphate concentrations, adsorbent dose, and temperature were investigated by batch experiments. The isotherms, kinetics and thermodynamics for phosphate removal were studied. The results showed that glauconite had a rough surface and abundant pores. The determined Brunauer–Emmett–Teller (BET) surface area was 55 m2/g with a pore radius of 1.99 nm and the pore volume was 0.032 cm3/g. FTIR analysis revealed that the abundance of various functional groups on the surface of glauconite may play an important role for the adsorption process. The optimum pH was 11 with complete removal of phosphate in a short time (nearly 1 min). The experimental data fitted very well with the Langmuir isotherm (R2 = 0.999) with a maximum adsorption capacity of 32.26 mg/g at 50 °C. Adsorption kinetic data were best fitted with the pseudo-second-order kinetic model (R2 = 0.999). Thermodynamic study confirmed the spontaneous, endothermic and irreversible adsorption process. Therefore, glauconite is a promising natural low-cost adsorbent for phosphate removal from wastewater.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3575-3595
Author(s):  
Wanting Li ◽  
Ruifeng Shan ◽  
Yuna Fan ◽  
Xiaoyin Sun

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.


2014 ◽  
Vol 34 (2) ◽  
pp. 341-351 ◽  
Author(s):  
Cristiane Kreutz ◽  
Fernando H. Passig ◽  
Karina Q. de Carvalho ◽  
Juliana B. R. Mees ◽  
Simone D. Gomes

This paper sought to evaluate the behavior of an upflow Anaerobic-Aerobic Fixed Bed Reactor (AAFBR) in the treatment of cattle slaughterhouse effluent and determine apparent kinetic constants of the organic matter removal. The AAFBR was operated with no recirculation (Phase I) and with 50% of effluent recirculation (Phase II), with θ of 11h and 8h. In terms of pH, bicarbonate alkalinity and volatile acids, the results indicated the reactor ability to maintain favorable conditions for the biological processes involved in the organic matter removal in both operational phases. The average removal efficiencies of organic matter along the reactor height, expressed in terms of raw COD, were 49% and 68% in Phase I and 54% and 86% in Phase II for θ of 11h and 8h, respectively. The results of the filtered COD indicated removal efficiency of 52% and k = 0.0857h-1 to θ of 11h and 42% and k = 0.0880h-1 to θ of 8h in the Phase I. In Phase II, the removal efficiencies were 59% and 51% to θ of 11h and 8h, with k = 0.1238h-1 and k = 0.1075 h-1, respectively. The first order kinetic model showed good adjustment and described adequately the kinetics of organic matter removal for θ of 11h, with r² equal to 0.9734 and 0.9591 to the Phases I and II, respectively.


Author(s):  
Xiaochun Yin ◽  
Nadi Zhang ◽  
Meixia Du ◽  
Hai Zhu ◽  
Ting Ke

Abstract In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.


2018 ◽  
Vol 77 (6) ◽  
pp. 1734-1743 ◽  
Author(s):  
Abhay Prakash Rawat ◽  
D. P. Singh

Abstract Adsorption behavior of mentha (mint) plant biochar (MPB) in removal of malachite green (MG) dye from aqueous solution was analyzed as a function of different pH (4.0–10.0), initial dye concentration (20–100 mg/L), contact time (0–45 min) and dose of adsorbent (0.05–0.3 g/100 mL). The zeta potential of the MPB particles was found to be −37.9 mV, indicating a negatively charged sorption surface of MPB particles. MPB was found to be more effective in removal of MG dye at pH 6.0 due to combined action of physico-chemisorption and a reductive electron transfer reaction. Results on the Brunauer–Emmett–Teller (BET) analysis of the N2 adsorption–desorption isotherm of MPB as adsorbent showed sigmoidal shape similar to the type IV isotherm and mesoporous nature. The cyclic voltammetric analysis of MG dye showed a reversible, coupled redox reaction at the interface of dye molecules and MPB particles. The maximum monolayer adsorption capacity (qmax) of MPB was found to be 322.58 mg g−1. The separation factor (RL) value was between 0 and 1, indicating a favourable adsorption of MG dye onto MPB. The results fitted well to a pseudo-second-order kinetic model. Further results from desorption experiments showed recovery of MG dye by about 50% in the presence of 1 N HCl.


2019 ◽  
Vol 233 (2) ◽  
pp. 201-223 ◽  
Author(s):  
Khalida Naseem ◽  
Rahila Huma ◽  
Aiman Shahbaz ◽  
Jawaria Jamal ◽  
Muhammad Zia Ur Rehman ◽  
...  

Abstract This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.


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