scholarly journals Thermodynamic and kinetics studies of the adsorption of phosphorus by bioretention media

2012 ◽  
Vol 16 (5) ◽  
pp. 1506-1509 ◽  
Author(s):  
Ying Mei ◽  
Xiao-Hua Yang ◽  
Ya-Nan Guo ◽  
Jun He ◽  
Rong Jiang ◽  
...  

The objective of this study is to explore the mechanism of phosphorus adsorption in the bioretention media. The phosphorus adsorption characteristics of four media of bioretention are studied by four isothermal adsorption experiments. The result indicate that the maximal adsorption capacity (qm) of phosphorus of the four bioretention media are found to be media I (0.3365 mg/g), media II (0.3302 mg/g), media III (0.2751 mg/g) and media IV 0.8435 mg/g), respectively. The negative values of Gibbs free energy of phosphorus indicate that each of the phosphorus adsorption process by the four bioretention media is a spontaneous process. The mean sorption energies obtained from DR isotherm were 0.0758, 0.0772, 0.0803 and 0.0632 kJ/mol respectively, which indicate the physical nature of the adsorbate/adsorbent interactions. Two kinetic models including pseudo first-order and pseudo second-order equation were selected to follow the adsorption process. The results showed that the adsorption of phosphorus with the four types of bioretention media could be described by the pseudo second-order equation. The media IV was the better media of bioretention with high phosphorus removal capacity.

2011 ◽  
Vol 356-360 ◽  
pp. 208-216
Author(s):  
Jiang Ying Zhang ◽  
Jian Xu ◽  
Yuan Zhang ◽  
Lei Li ◽  
Ying Zhang ◽  
...  

In the present paper, the adsorption characteristics of aniline onto KSF montmorillonite from aqueous solution were investigated. Experiments were conducted at various pH values, temperatures, ionic strength and surfactant concentrations. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were adopted to investigate the rate parameters, and the pseudo-second-order equation was proved to be able to successfully predict whole process. Optimal adsorption pH was determined at 3.6. Among the selected models (linear, Langmuir, Freundlich, DR (Dubinin–Radusckevich) models), linear and DR models were found to be better fit the experimental data, which revealed the physisorption nature of the adsorption process. Meanwhile, with the increase of reaction temperatures, the adsorption capacity decreased. The results of the calculated thermodynamic parameters demonstrated that the adsorption was an exothermic, spontaneous and unfavorable process.


2014 ◽  
Vol 1010-1012 ◽  
pp. 817-820
Author(s):  
Qing Peng Wei ◽  
Shi You Li ◽  
Shui Bo Xie ◽  
Jian Biao Liao ◽  
Yin Li

Adsorption of uranium(VI) ions by Sodium alginate (SA) immobilized nano-α-Fe2O3 particles beads were investigated in the batch experiments.The influences of the nano-ferric oxide content in beads,cross-linking time, solution pH, initial U(VI) concentration, temperature and contact time on U(VI) sorption were studied. The results indicated that the adsorption capacities are strongly affected by the solution pH, the best adsorption rate can be thought of to be at pH 3. The adsorption was rather fast in the initial 1.5 h, and the equilibrium was established in 9 h with the sorption capacity 2.64 mg/g. The kinetic adsorption data was simulated better by a pseudo-second-order equation. The removal rate increased slowly with temperature ascending . The adsorption process conformed to the Langmuir and Freundlich isothermal adsorption models, and the data fitted the latter better.


2013 ◽  
Vol 864-867 ◽  
pp. 1536-1541
Author(s):  
Yu Wu ◽  
Li Li Zhao ◽  
Jiang Wu ◽  
Yin Xia Cao ◽  
Jia Ming Zha ◽  
...  

Two types of activated carbon for the removal of element mercury in simulated flue gas were studied in the paper. Mercury adsorption process on fixed bed reactor has been researched. The conclusions are as follows: The trend of mercury concentration first decreased and then increased over time; as for two types of activated carbon, the adsorption corresponds to pseudo-first-order equation and pseudo-second-order equation respectively. Because of the high correlation coefficient, the pseudo-second-order equation will correspond to actual adsorption process.


2012 ◽  
Vol 16 (5) ◽  
pp. 1358-1361 ◽  
Author(s):  
Ying Mei ◽  
Xiao-Hua Yang ◽  
Rong Jiang ◽  
Chong-Li Di ◽  
Xue-Jun Zhang

This study aims to identify mulch of bioretention which has high phosphorus sorption capacity. The phosphorus adsorption characteristics of five types of mulch of bioretention are studied by three isothermal adsorption experiments. Results show that the Langmuir eqution is suitable for describing absorption characteristics of five types of mulch. The positive values of Gibbs free energy for phosphorus indicate that the phosphorus biosorption by five mulches is a non-spontaneous process, and the values of mean sorption free energy of mulch are less than 8 kJ/mol, which proves that the adsorption process can be dominated by physical forces. The vermiculite is the better mulch of bioretention based on high phosphorus removal capacity.


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.


2021 ◽  
Vol 348 ◽  
pp. 01016
Author(s):  
Rajaa Bassam ◽  
Marouane El Alouani ◽  
Nabila Jarmouni ◽  
Jabrane Maissara ◽  
Mohammed El Mahi Chbihi ◽  
...  

Heavy metals are the most dangerous inorganic pollutants Due to their bioaccumulation and their nonbiodegradability, for this, several studies have focused on the recovery of these metals from water using different techniques. In this context, our study consists of evaluating an efficient and eco-friendly pathway of competitive recovery of heavy metals (Cd, Cr and As) from aqueous solutions by adsorption using raw rock. This adsorbent was characterized before and after the adsorption process by several techniques. The multi-metals adsorption process in the batch mode was undertaken to evaluate the effect of adsorbent mass, contact time, pH, Temperature, and initial heavy metals concentration. The kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic models. According to the modeling of the experimental results, the adsorption kinetics of heavy metals were adapted to the pseudo-second-order model. The adsorption isotherms were evaluated by the Langmuir and Freundlich isotherm models. The experimental isotherm data of heavy metals were better fitted with the Langmuir model rather than Freundlich isotherm models. The maximum experimental adsorption capacities (Qmax) predicted by the Langmuir model are 15.23 mg/g for Cd (II), 17.54 mg/g for Cr (VI) and 16.36 mg/g for As (III). The values of thermodynamic parameters revealed that the heavy metals adsorption was exothermic, favorable, and spontaneous in nature. The desorption process of heavy metals showed that this raw rock had excellent recycling capacity. Based on the results, these untreated clays can be used as inexpensive and environmentally friendly adsorbents to treat water contaminated by heavy metals.


Author(s):  
Nur Hidayatul Nazirah Kamarudin ◽  
Herma Dina Setiabudi ◽  
Aishah Abdul Jalil ◽  
Siti Hazirah Adam ◽  
Nur Fatien Muhamad Salleh

This study applied ultrasonic irradiation technique to remove acid orange 52 (AO52) and in the meantime utilizing the potential adsorbent, Lapindo volcanic mud (LVM). LVM was collected from the erupted mud in Sidoarjo, Indonesia and calcined prior the adsorption process. Previously in another study, Lapindo was proven to be efficient for adsorption of dyes in single adsorption method. In this study, the combination of adsorption with ultrasound, or as known as sono-sorption shows that the adsorptivity increased from 95.54 mg/g to 129.5 mg/g. The isotherm study shows that this process obeyed Langmuir isotherm model with adsorption capacity of 833.33 mg/g. The enhancement of sono-sorption method as compared to conventional method is believed to be resulted from the facilitated mass transfer driven by the ultrasound, along with the adsorption ability of LVM. The kinetic study fit to the pseudo second order equation. Copyright © 2019 BCREC Group. All rights reservedReceived: 1st October 2018; Revised: 22nd December 2018; Accepted: 7th January 2019; Available online: 25th January 2019; Published regularly: April 2019How to Cite: Kamarudin, N.H.N., Setiabudi, H.D., Jalil, A.A., Adam, S.H., Salleh, N.F.M. (2019). Utilization of Lapindo Volcanic Mud for Enhanced Sono-sorption Removal of Acid Orange 52. Bulletin of Chemical Reaction Engineering & Catalysis, 14 (1): 189-195 (doi:10.9767/bcrec.14.1.3326.189-195)Permalink/DOI: https://doi.org/10.9767/bcrec.14.1.3326.189-195  


Author(s):  
Jurgita Seniūnaitė ◽  
Rasa Vaiškūnaitė ◽  
Kristina Bazienė

Research studies on the adsorption kinetics are conducted in order to determine the absorption time of heavy metals on coffee grounds from liquid. The models of adsorption kinetics and adsorption diffusion are based on mathe-matical models (Cho et al. 2005). The adsorption kinetics can provide information on the mechanisms occurring be-tween adsorbates and adsorbents and give an understanding of the adsorption process. In the mathematical modelling of processes, Lagergren’s pseudo-first- and pseudo-second-order kinetics and the intra-particle diffusion models are usually applied. The mathematical modelling has shown that the kinetics of the adsorption process of heavy metals (copper (Cu) and lead (Pb)) is more appropriately described by the Lagergren’s pseudo-second-order kinetic model. The kinetic constants (k2Cu = 0.117; k2Pb = 0,037 min−1) and the sorption process speed (k2qeCu = 0.0058–0.4975; k2qePb = 0.021–0.1661 mg/g per min) were calculated. After completing the mathematical modelling it was calculated that the Langmuir isotherm better reflects the sorption processes of copper (Cu) (R2 = 0.950), whilst the Freundlich isotherm – the sorption processes of lead (Pb) (R2 = 0.925). The difference between the mathematically modelled and experimen-tally obtained sorption capacities for removal of heavy metals on coffee grounds from aqueous solutions is 0.059–0.164 mg/l for copper and 0.004–0.285 mg/l for lead. Residual concentrations of metals in a solution showed difference of 1.01 and 0.96 mg/l, respectively.


2020 ◽  
Vol 168 ◽  
pp. 00026
Author(s):  
Liliia Frolova ◽  
Mykola Kharytonov ◽  
Iryna Klimkina ◽  
Oleksandr Kovrov ◽  
Andrii Koveria

Plasma method is used to synthesize manganese ferrite. The basic properties of ferrite are determined by IR spectroscopy, UV spectroscopy, X-ray phase analysis, vibration magnetometry. The paper shows that the use of magnetically controlled sorbent allows to purify waste waters from chromium (III). The process of adsorption of chromium cations (III) is investigated. The kinetics of the process is studied. To describe the equilibrium isotherms, the experimental data are analysed by the models of Langmuir, Freundlich isotherms. Pseudo-first order, pseudo-second-order, and Weber-Morris are used to elucidate the kinetic parameters and mechanism of the adsorption process. It has been established that the removal of Cr (III) cations is described by the pseudo-second order of the Langmuir reaction and mechanism.


2019 ◽  
Vol 79 (4) ◽  
pp. 676-687 ◽  
Author(s):  
Zou Junyu ◽  
Song Zefeng ◽  
Yang Yuesuo

Abstract Preparation of sludge-derived mesoporous carbon materials (SMCs) through pyrolysis of excess activated sludge from urban municipal sewage plants is an effective means of reducing pollution and utilizing a waste resource. This paper presented a method of SMC preparation in which calcium oxide (CaO), polyacrylamide (PAM), and chitosan (CAS) flocculating agents were used as pore-forming additives. Physical and chemical characterizations of the prepared SMCs were conducted by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). The prepared SMCs were used to adsorb a tetracycline (TC) antibiotic pollutant. The influences of pH, adsorption time, temperature, and pollutant concentration on TC adsorption capacity were determined. The experiments demonstrated that weakly acidic conditions were conducive to TC adsorption, which mainly occurs via electrostatic and π-π interactions. The TC adsorption process by SMCs conformed better to the pseudo-second-order models, indicating that chemical adsorption was the dominant adsorption process. The isothermal adsorption of TC by the SMCs conformed to the Freundlich model. This implied that TC easily adhered onto the SMC surfaces via multilayer homogeneous adsorption. Thermodynamic studies revealed that the adsorption of TC onto SMCs was spontaneous and endothermic.


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