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 ◽  
...  

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.

2010 ◽  
Vol 171-172 ◽  
pp. 41-44
Author(s):  
Xiao Cun Xiao ◽  
Gai Xia Fang ◽  
Er Li Zhao ◽  
Lv Bin Zhai ◽  
Jun Shuai Shi

The objective of this study is to assess the environmentaly friendly Ni(II) adsorption from synthetic wastewater using Pseudomonas alcaligenes biomass (PA-2). The ability of PA-2 to remove the Ni(II) ions was investigated by using batch biosorption procedure. The effects such as pH, dosage of biosorbent, Ni(II) initial concentration and sorbate–sorbent contact time and agitating speed on the adsorption capacities of PA-2 were studied. Biosorption equilibriums were rapidly established in about 60 min and the adsorption kinetics followed the pseudo-second order kinetic model. The maximum Ni(II) adsorption capacity determined from Langmuir isotherm were 82.23 mg/g PA-2 at pH 5.0, at 25±2°C and shaker speed 150 rpm, respectively. The carboxyl , hydroxyl and amino groups of the PA-2 were involved in chemical interaction with the Ni(II) ions depicted by Fourier transform infrared spectroscopic (FTIR) results. The study points to the potential of new use of Pseudomonas alcaligenes biomass as an effective biosorbent for the removal of Ni(II) and from environmental and industrial wastewater.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Li

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.


2017 ◽  
Vol 75 (10) ◽  
pp. 2316-2321 ◽  
Author(s):  
Hao Peng ◽  
Zuohua Liu ◽  
Changyuan Tao

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.


2020 ◽  
Vol 14 (3) ◽  
pp. 316-326 ◽  
Author(s):  
Josephraj Jegan ◽  
Saravanan Praveen ◽  
Thillainayagam Bhagavathi Pushpa ◽  
Ravindran Gokulan

In the present study, bioremediation of Basic Violet 03 is examined using biochar derived from agricultural wastes. The pyrolytic studies revealed that ideal temperature for maximum yield of biochar derived from Coconut Shell (CSB), Ground nut Shell (GnSB) and Rice Husk (RHB) was obtained as 400 °C, 350 °C and 300 °C respectively. Further from the batch mode of operations, it was concluded that the optimum conditions of biochar dose, pH, temperature and initial concentration are 4 g/L, 8, 40 °C and 75 mg/L with a maximum uptake of 15.79 mg/g, 17.28 mg/g, and 12.64 mg/g for CSB, GnSB and RHB. The adsorption isotherm studies concluded that the three-parameter Sips model was obtained to be the best fit with a maximum correlation coefficient (R2) of 0.9937, 0.9935 and 0.9965. The pseudo second order kinetic model was found to well represent the experimental kinetic data. The characterization results of biochar through SEM, EDX and FTIR revealed that there was a strong binding capacity of adsorbent was observed before and after adsorption process. The promising results concluded that biochar derived from agricultural wastes can potentially be utilized for the removal of cationic dyes.


2017 ◽  
Vol 49 (3) ◽  
pp. 235-246 ◽  
Author(s):  
Nina Obradovic ◽  
Suzana Filipovic ◽  
Jelena Rusmirovic ◽  
Georgeta Postole ◽  
Aleksandar Marinkovic ◽  
...  

In this paper, synthesis of porous wollastonite-based ceramics was reported. Ceramic precursor, methylhydrocyclosiloxane, together with micro-sized CaCO3, was used as starting material. After 20 min of ultrasound treatment, and calcination at 250 oC for 30 min, yeast as a pore-forming agent was added to the as-obtained powders. Sintering regime was set up based on the results obtained by differential thermal analysis. Prepared mixture was pressed into pallets and sintered at 900 oC for 1 h. After the sintering regime, porous wollastonite-based ceramics was obtained. The phase composition of the sintered samples as well as microstructures was analyzed by X-ray diffraction method and SEM. In a batch test, the influence of pH, contact time and initial ion concentration on adsorption efficiency of As+5, Cr+6, and phosphate ions on synthesized wollastonite-based ceramics were studied. Time-dependent adsorption was best described by pseudo-second-order kinetic model and Weber-Morris model that predicted intra-particle diffusion as a rate-controlling step of overall process. High adsorption capacities 39.97, 21.87, and 15.29 mgg-1 were obtained for As+5, Cr+6, and phosphate ions, respectively.


2020 ◽  
Vol 12 (3) ◽  
pp. 1174 ◽  
Author(s):  
Lulit Habte ◽  
Natnael Shiferaw ◽  
Mohd Danish Khan ◽  
Thenepalli Thriveni ◽  
Ji Whan Ahn

In the present work, waste eggshells were used as a precursor for the synthesis of aragonite crystals through the wet carbonation method. Cadmium (Cd2+) and lead (Pb2+) were removed by the synthesized aragonite from synthetic wastewater. The influence of initial solution pH, contact time, Cd2+ and Pb2+ concentration, and sorbent dosage were evaluated. The major sorption was observed in the first 100 mins and 360 mins for Pb2+and Cd2+ respectively reaching sorption equilibrium at 720 mins (12 hr). The sorption capacity toward Pb2+ was much higher than toward Cd2+. Both heavy metals displayed high sorption capacities at initial pH 6. The pseudo-second-order kinetic model fits well with the experimental data with a higher correlation coefficient R2. Two isotherm models were also evaluated for the best fit with the experimental data obtained. Langmuir isotherm best fits the sorption of the metals on aragonite synthesized from eggshells. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) results of sorbent after sorption showed that the mechanism of sorption was dominated by surface precipitation. Therefore, aragonite crystals synthesized from waste eggshells can be a potential substitute source for the removal of Cd2+ and Pb2+ from contaminated water.


2019 ◽  
Author(s):  
Chem Int

An easy route for preparation emulsion of kaolinite (Al2Si2O5.4H2O) from Sweileh sand deposits, west Amman, Jordan by hydrochloric acid under continuous stirring for 4 h at room temperature was performed and nano kaolinite powder was used as an adsorbent for the removal of Cu(II), Zn(II) and Ni(II) ions. Nano kaolinite was characterized by XRD, FT-IR and SEM techniques. Effect of pH, adsorbent dose, initial metal ion concentration, contact time and temperature on adsorption process was examined. The negative values of ΔGo and the positive value of ΔHo revealed that the adsorption process was spontaneous and endothermic. The Langmuir isotherm model fitted well to metal ions adsorption data and the adsorption capacity. The kinetic data provided the best correlation of the adsorption with pseudo-second order kinetic model. In view of promising efficiency, the nano kaolinite can be employed for heavy metal ions adsorption.


2013 ◽  
Vol 807-809 ◽  
pp. 1251-1257 ◽  
Author(s):  
Li Hua Sun ◽  
Xiao Lu Qi ◽  
Ya Jun Zhang

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Hamid Raza ◽  
Aqsa Sadiq ◽  
Umar Farooq ◽  
Makshoof Athar ◽  
Tajamal Hussain ◽  
...  

Batch scale studies for the adsorption potential of novel biosorbentPhragmites karka(Trin), in its natural and treated forms, were performed for removal of mercury ions from aqueous solution. The study was carried out at different parameters to obtain optimum conditions of pH, biosorbent dose, agitation speed, time of contact, temperature, and initial metal ion concentration. To analyze the suitability of the process and maximum amount of metal uptake, Dubinin-Radushkevich (D-R) model, Freundlich isotherm, and Langmuir isotherm were applied. The values ofqmaxfor natural and treated biosorbents were found at 1.79 and 2.27 mg/g, respectively. The optimum values of contact time and agitation speed were found at 50 min and 150 rpm for natural biosorbent whereas 40 min and 100 rpm for treated biosorbent, respectively. The optimum biosorption capacities were observed at pH 4 and temperature 313 K for both naturalP. karkaand treatedP. karka.RLvalues indicate that comparatively treatedP. karkawas more feasible for mercury adsorption compared to naturalP. karka. Both pseudo-first-order and pseudo-second-order kinetic models were applied and it was found that data fit best to the pseudo-second-order kinetic model. Thermodynamic studies indicate that adsorption process was spontaneous, feasible, and endothermic.


2017 ◽  
Vol 19 (3) ◽  
pp. 120-129 ◽  
Author(s):  
Wojciech Konicki ◽  
Małgorzata Aleksandrzak ◽  
Ewa Mijowska

Abstract In this study, the adsorption of Ni2+ and Fe3+ metal ions from aqueous solutions onto graphene oxide (GO) have been explored. The effects of various experimental factors such as pH of the solution, initial metal ion concentration and temperature were evaluated. The kinetic, equilibrium and thermodynamic studies were also investigated. The adsorption rate data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order kinetic model and the intraparticle diffusion model. Kinetic studies indicate that the adsorption of both ions follows the pseudo-second-order kinetics. The isotherms of adsorption data were analyzed by adsorption isotherm models such as Langmuir and Freundlich. Equilibrium data fitted well with the Langmuir model. The maximum adsorption capacities of Ni2+ and Fe3+ onto GO were 35.6 and 27.3 mg g−1, respectively. In addition, various thermodynamic parameters, such as enthalpy (ΔHO), entropy (ΔSO) and Gibbs free energy (ΔGO), were calculated.


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