scholarly journals The sorption of Tebuconazole and Linuron from an Aqueous Environment with a Modified Sludge-Based Biochar: Effect, Mechanisms, and Its Persistent Free Radicals Study

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jingjie Yang ◽  
Hongwei Sun ◽  
Yucan Liu ◽  
Xiaohan Wang ◽  
Kamran Valizadeh
Keyword(s):  
Free Radicals ◽  
Kinetic Equations ◽  
Aqueous Environment ◽  
Order Kinetic ◽  
Contributing Factors ◽  
Freundlich Model ◽  
Preparation Conditions ◽  
Short Period ◽  
Spin Resonance ◽  
Pseudo Second Order

In this study, the sludge-based biochar was prepared and utilized as an adsorbent for the removal of two commonly used pesticides in agriculture, namely tebuconazole (Teb) and linuron (Lin) in an aqueous solution. The main contributing factors such as biochar preparation conditions, persistent free radicals as well as contact time, agitation speed, biochar dose, temperature, and pH were investigated. The physicochemical properties were characterized by SEM + EDS, FTIR, BET, EPR, etc. The results showed that the maximum adsorption capacities based on the Langmuir model was 7.8650 mg g−1 for tebuconazole and that based on Freundlich model was 9.0645 mg·g-1 for linuron at 25°C. The pseudo-second-order kinetic equations were all fitted well to the kinetic process of the adsorption of the two pesticides with all R2 ≥ 0.915. The maximum values of tebuconazole adsorption capacity occur at pH = 3. Meanwhile, linuron was not affected by pH. Both Cr6+ (r = −0.793∗∗/ −0.943∗∗) and humic acid (r = −0.798∗∗/ −0.947∗∗) significantly inhibited the adsorption amount of tebuconazole and linuron onto the biochar. Electron spin resonance signals (ESR) indicated that environmentally persistent radicals (EPFRs) are preferentially formed at lower pyrolysis temperatures and lower transition metal concentrations. The g-factors for BC400, BC600, BCF400, and BCF600 were 2.0036, 2.0035, 2.0034, and 2.0033, respectively, indicating that the EPFRs mainly have a carbon-centered structure with adjacent oxygen atoms. In addition, to close to the actual situation, natural water (from YanTai) was collected to simulate pesticide contamination. This study demonstrates that sludge-based biochar can achieve efficient removal of tebuconazole and linuron in aqueous environment in a short period of time with no secondary environmental risk especially on the waste activated sludge.

scholarly journals Removal of Lead(II) from Synthetic Wastewater by Lavandula pubescens Decne Biosorbent: Insight into Composition–Adsorption Relationship

2020 ◽  
Vol 10 (21) ◽  
pp. 7450
Author(s):  
Ali Q. Alorabi ◽  
Fahad A. Alharthi ◽  
Mohamed Azizi ◽  
Nabil Al-Zaqri ◽  
Adel El-Marghany ◽  
...  
Keyword(s):  
Ion Concentration ◽  
Wild Plant ◽  
Synthetic Wastewater ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Liquid Chromatography ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Best Fit

In this work, the widely-abundant, cheap, wild plant Lavandula pubescens Decne was evaluated as an adsorbent for removing Pb(II) ions from wastewater. The chemical composition of the plant was partially isolated and characterized by the corresponding techniques, including gas chromatography–mass spectrometry, gas liquid chromatography, and FTIR spectroscopy. The adsorption capacity of the dried plant material for Pb(II) ions increased with increasing contact time, initial ion concentration, and temperature, while it decreased with increasing adsorbent dosage. The optimum condition for Pb(II) adsorption was determined as 550 mg/L initial metal concentration, pH ≤ 7, and 90 min of contact. The best fit for Pb(II) adsorption isotherms was the linear form of the Freundlich model; however, the maximum capacity indicated by Langmuir was 91.32 mg/g. The experimental data fit better the pseudo-second-order kinetic model (R2 = 0.969), suggesting chemisorption process. Thermodynamic data revealed an endothermic, nonspontaneous, and adsorption process favored at higher concentrations.

scholarly journals Preparation and Adsorption Properties of Biochar/g-C3N4 Composites for Methylene Blue in Aqueous Solution

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Li
Keyword(s):  
Methylene Blue ◽  
Thermodynamic Parameters ◽  
Raw Materials ◽  
Order Kinetic ◽  
Adsorption Effect ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Doping Ratio

Using straw and urea as raw materials, biochar (BC) and g-C3N4 were prepared by oxygen-free pyrolysis at 300°C and 550°C. BC/g-C3N4 was prepared by loading different amounts of g-C3N4 onto the surface of biochar and characterized by SEM and FT-IR. The adsorption effect on methylene blue (MB) was investigated from the aspects of dosage and pH. The studies of adsorption equilibrium isotherms and the kinetic and the thermodynamic parameters on the BC/g-C3N4 adsorbents are discussed. The results showed that BC/g-C3N4 0.16 g/L with a doping ratio of 1 : 3 was added to the MB solution with an initial concentration of 50 mg/L and pH=11. The adsorption rate and adsorption amount were 96.72% and 302.25 mg/g, respectively. The adsorption process included surface adsorption and intraparticle diffusion, which conformed to the pseudo-second-order kinetic model and Langmuir-Freundlich model. Thermodynamic parameters (ΔG0<0, ΔH0>0, and ΔS0>0) showed that the adsorption reaction is spontaneous, which positively correlated with temperature.

Adsorption kinetics and isotherm of vanadium with melamine

2017 ◽  
Vol 75 (10) ◽  
pp. 2316-2321 ◽  
Author(s):  
Hao Peng ◽  
Zuohua Liu ◽  
Changyuan Tao
Keyword(s):  
Adsorption Kinetics ◽  
Impact Factors ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm ◽  
Langmuir And Freundlich Models

Melamine, possessing three free amino groups and three aromatic nitrogen atoms in its molecule, has great potential as an adsorbent for metal ions. We investigated three impact factors of the adsorption process: the initial pH of the vanadium solution, contact time and reaction temperature. The adsorption kinetics could be accurately described by the pseudo-second-order kinetic model. Langmuir and Freundlich models fitted well with the experimental equilibrium data, and the maximal adsorption capacity was found to be 1,428.57 mg vanadium/g melamine, and the Freundlich model showed the adsorption is privilege type.

The sorption of lead, cadmium, copper and zinc ions from aqueous solutions on a raw diatomite from Algeria

2012 ◽  
Vol 65 (10) ◽  
pp. 1729-1737 ◽  
Author(s):  
Messaouda Safa ◽  
Mohammed Larouci ◽  
Boumediene Meddah ◽  
Pierre Valemens
Keyword(s):  
Metal Ions ◽  
Low Cost ◽  
Kinetic Equations ◽  
Sorption Process ◽  
Second Order ◽  
Order Kinetic ◽  
Reaction Conditions ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Sorption Parameters

The adsorption of Cu2+, Zn2+, Cd2+ and Pb2+ ions from aqueous solution by Algerian raw diatomite was studied. The influences of different sorption parameters such as contact pH solution, contact time and initial metal ions concentration were studied to optimize the reaction conditions. The metals ions adsorption was strictly pH dependent. The maximum adsorption capacities towards Cu2+, Zn2+, Cd2+ and Pb2+ were 0.319, 0.311, 0.18 and 0.096 mmol g−1, respectively. The kinetic data were modelled using the pseudo-first-order and pseudo-second-order kinetic equations. Among the kinetic models studied, the pseudo-second-order equation was the best applicable model to describe the sorption process. Equilibrium isotherm data were analysed using the Langmuir and the Freundlich isotherms; the results showed that the adsorption equilibrium was well described by both model isotherms. The negative value of free energy change ΔG indicates feasible and spontaneous adsorption of four metal ions on raw diatomite. According to these results, the high exchange capacities of different metal ions at high and low concentration levels, and given the low cost of the investigated adsorbent in this work, Algerian diatomite was considered to be an excellent adsorbent.

On the use of linearized pseudo-second-order kinetic equations for modeling adsorption systems

Desalination ◽  
2010 ◽  
Vol 257 (1-3) ◽  
pp. 93-101 ◽  
Author(s):  
Mohammad I. El-Khaiary ◽  
Gihan F. Malash ◽  
Yuh-Shan Ho
Keyword(s):  
Kinetic Equations ◽  
Second Order ◽  
Order Kinetic ◽  
Pseudo Second Order ◽  
Adsorption Systems

scholarly journals Adsorption of Zn(II) ions from aqueous environment by surface modified Strychnos potatorum seeds, a low cost adsorbent

2013 ◽  
Vol 15 (3) ◽  
pp. 35-41 ◽  
Author(s):  
P. Senthil Kumar
Keyword(s):  
Experimental Data ◽  
Low Cost ◽  
Agricultural Waste ◽  
Coefficient Of Determination ◽  
Aqueous Environment ◽  
Freundlich Model ◽  
Shrinking Core ◽  
Pseudo Second Order ◽  
Strychnos Potatorum ◽  
Surface Modified

Abstract The surface modified Strychnos potatorum seeds (SMSP), an agricultural waste has been developed into an effective adsorbent for the removal of Zn(II) ions from aqueous environment. The Freundlich model provided a better fit with the experimental data than the Langmuir model as revealed by a high coefficient of determination values and low error values. The kinetics data fitted well into the pseudo-second order model with the coefficient of determination values greater than 0.99. The influence of particle diffusion and film diffusion in the adsorption process was tested by fitting the experimental data with intraparticle diffusion, Boyd kinetic and Shrinking core models. Desorption experiments were conducted to explore the feasibility of regenerating the spent adsorbent and the adsorbed Zn(II) ions from spent SMSP was desorbed using 0.3 M HCl with the efficiency of 93.58%. The results of the present study indicates that the SMSP can be successfully employed for the removal of Zn(II) ions from aqueous environment.

scholarly journals Removal of Basic Orange 2 dye and Ni2+ from aqueous solutions using alkaline-modified nanoclay

2021 ◽  
Author(s):  
Armin Geroeeyan ◽  
Ali Niazi ◽  
Elaheh Konoz
Keyword(s):  
Experimental Data ◽  
High Efficiency ◽  
Adsorption Process ◽  
Kinetic Equations ◽  
Dye Adsorption ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Diffusion Kinetic ◽  
Pseudo Second Order

Abstract In the present research, the removal of Basic Orange 2 (BO2) dye using alkaline-modified clay nanoparticles was studied. To characterize the adsorbent, XRD, FTIR, FESEM, EDX, BET and BJH analyses were performed. The effect of the variables influencing the dye adsorption process such as adsorbent dose, contact time, pH, stirring rate, temperature, and initial dye concentration was investigated. Furthermore, the high efficiency of Ni2+ removal indicated that it is possible to remove both dye and metal cation under the same optimum conditions. The experimental data were analyzed by Langmuir and Freundlich isotherm models. Fitting the experimental data to Langmuir isotherm indicated that the monolayer adsorption of dye occurred at homogeneous sites. Experimental data were also analyzed with pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetic equations for kinetic modeling of the dye removal process. The adsorption results indicated that the process follows a pseudo-second-order kinetic model. The thermodynamic parameters of the dye adsorption process such as enthalpy, entropy, and Gibbs free energy changes were calculated and revealed that the adsorption process was spontaneous and endothermic in nature. The results presented the high potential of the modified nanoclay as a cost-effective adsorbent for the removal of BO2 dye and Ni2+ from aqueous medium.

scholarly journals Utilization of Sawdust Waste Biomass as an Eco-Friendly Biosorbent for Bioremediation of Manganese Pollution in Aqueous Environment

2019 ◽  
Vol 2 (3) ◽  
pp. 823-830
Author(s):  
Fatih Deniz
Keyword(s):  
Operating Conditions ◽  
Aqueous Environment ◽  
Order Kinetic ◽  
Waste Biomass ◽  
Equilibrium Studies ◽  
Manganese Removal ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

In this study, the sawdust waste biomass was used as an eco-friendly biosorbent material for the bioremediation of manganese pollution in aqueous environment. The effects of various environmental variables such as pH, biosorbent amount, metal concentration and contact time on the manganese biosorption were studied in batch operating conditions. The kinetic and equilibrium studies were performed to elucidate the biosorption behavior of biosorbent material. The biosorption capacity of biosorbent was strongly influenced by the operating parameters. The experimental data were more successfully modeled by the pseudo-second-order kinetic model and Langmuir isotherm model compared to other models applied in the study. The maximum manganese removal capacity of biosorbent was found to be 25.655 mg g-1. These findings showed that the sawdust waste biomass can be used as an eco-friendly biosorbent material for the bioremediation of manganese pollution in aqueous environment.

Effectiveness and Mechanism of the In Situ Formed Iron Hydroxide (FeOxHy) towards the Removal of Phosphate by Coagulation and Adsorption

2013 ◽  
Vol 807-809 ◽  
pp. 1251-1257 ◽  
Author(s):  
Li Hua Sun ◽  
Xiao Lu Qi ◽  
Ya Jun Zhang
Keyword(s):  
Iron Hydroxide ◽  
Iron Phosphate ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Molar Ratios ◽  
Beneficial Effects ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Hydrolysis Of

This study prepares the in situ formed iron hydroxide (In situ FeOxHy) by the interactions between Fe3+ and OH- at different molar ratios of 1:0,1:1,1:2,and 1:3, and investigates the performance and mechanism involved in the removal of phosphate. The removal efficiency increases with elevated doses of FeOxHy and the maximum removal is observed to be in neutral pH ranges. The elevated ratios of OH- to Fe3+ inhibit the removal of phosphate whereas at low alkalinity,the introduction of OH- shows beneficial effects. The abovementioned four kinds of FeOxHy can rapidly adsorb most phosphate within 15 s, and the adsorption process can be well described by the Pseudo-second-order kinetic model. Freundlich model can well describe the adsorption of phosphorus onto these four FeOxHy. The adsorption of phosphate significantly decreases the zeta potential of these in situ FeOxHy. The MINITEQ software can indicate the species distribution of phosphate and iron salts, and the theoretical calculation indicates that the introduced OH- can promote the hydrolysis of Fe3+ especially in low alkalinity system,which can easily adsorb H2PO4- and HPO42- and form the multinuclear hydroxy iron phosphate complexes thereafter.

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