scholarly journals Adsorption of Silicate Anions from Geothermal Brine Using Chitosan-Polyethylene Glycol Composite to Prevent Silica Scaling on the Dieng Geo Dipa Geothermal Energy System

2021 ◽  
Vol 21 (5) ◽  
pp. 1063
Author(s):  
Nur Hayati ◽  
Hanik Humaida ◽  
Dwi Siswanta
Keyword(s):  
Power Generation ◽  
Polyethylene Glycol ◽  
Geothermal Energy ◽  
Contact Time ◽  
Electricity Generation ◽  
Freundlich Isotherm ◽  
Energy System ◽  
Geothermal Brine ◽  
Pseudo Second Order ◽  
Membrane Adsorbent

Silica scaling is a common problem in geothermal power generation facilities which inhibits electricity generation. In order to provide a solution to this problem, the removal of silicate ions using CPEG-TOMAC (Chitosan-polyethylene glycol–trioctyl methyl ammonium chloride) membrane adsorbent was investigated for geothermal brine from Geo Dipa Energy, Dieng. The process is dependent on contact time, pH, and the concentration of silicate. An adsorption batch study that used adsorbents for the geothermal brine of the Dieng Geo Dipa reactor 28A showed that CPEG TOMAC at pH 6 resulted in an adsorption capacity of 72.6 mg g–1. Furthermore, the adsorption of silicate ions onto the membrane followed pseudo-second-order kinetics and the Freundlich isotherm model.

scholarly journals Synthesis of acid treated carbonized mandarin peel for purification of copper

2020 ◽  
Vol 15 (2) ◽  
pp. 460-471
Author(s):  
T. Unugul ◽  
F. U. Nigiz
Keyword(s):  
Contact Time ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Adsorption Kinetic ◽  
Adsorption Behaviour ◽  
Solution Ph ◽  
Copper Adsorption ◽  
Adsorbent Dosage ◽  
Mandarin Peel ◽  
Pseudo Second Order

Abstract In this study; acid treated carbonized mandarin peel (CMP) adsorbent was prepared and the adsorption behaviour of the adsorbent for copper removal was investigated. In the adsorption studies the effects of initial metal concentration, solution pH, adsorbent dosage and contact time on the removal were investigated. As a result; the highest removal of 100% was achieved when the copper concentration in water was 5 mg/L and the adsorbent dosage was 3.75 g/L at a solution pH of 7. Isotherm studies were also done and the appropriate isotherm was obtained as the Freundlich isotherm. According to the kinetic studies, the copper adsorption onto CMP adsorbent was adopted to the pseudo-second-order adsorption kinetic. After HCl regeneration, the adsorbent maintained 94% of its activity.

Adsorption of Th(IV) on the modified multi-walled carbon nanotubes using central composite design

2019 ◽  
Vol 107 (5) ◽  
pp. 377-386 ◽  
Author(s):  
Cansu Endes Yılmaz ◽  
Mahmoud A.A. Aslani ◽  
Ceren Kütahyalı Aslani
Keyword(s):  
Carbon Nanotubes ◽  
Central Composite Design ◽  
Contact Time ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Thorium Concentration ◽  
Multi Walled Carbon Nanotubes ◽  
Pseudo Second Order ◽  
Walled Carbon Nanotubes ◽  
Central Composite

Abstract Adsorption of thorium onto nitric acid modified multi-walled carbon nanotubes was investigated by central composite design as a function of contact time, pH, initial thorium concentration and temperature. The results showed that optimum uptake capacity was 65.75±2.23 mg·g−1 with respect to pH=4, initial thorium concentration of 100 mg·L−1, 25 °C and 15 min contact time. Thermodynamic parameters [standard enthalpy (ΔH0), entropy (ΔS0), and free energy (ΔG0)] were calculated, and the results indicated that adsorption was endothermic. Langmuir, Freundlich and Dubinin-Radushkevich isotherms have been investigated in order to characterize the adsorption process in the range of 25–100 mg·L−1 initial thorium concentration. The Freundlich isotherm is the best suited as a model because it has the highest correlation coefficient (R2=0.9485). The pseudo-second order kinetics well defined the adsorption process.

Sorption of Acid Blue 9 on to Wheat Bran: Optimization, Equilibrium and Kinetic Studies

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Rajeshkannan Rajan ◽  
Manivasagan Rajasimman ◽  
Rajamohan Natarajan
Keyword(s):  
Wheat Bran ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Agitation Speed ◽  
Initial Substrate ◽  
Pseudo Second Order ◽  
Langmuir And Freundlich Equations ◽  
Acid Blue ◽  
Adsorbent Dose

In this study, the use of wheat bran as a possible adsorbent has been successfully demonstrated in the removal of Acid blue9 (AB9) from aqueous solution. The effect of different parameters such as temperature, adsorbent dose, contact time, adsorbent size and agitation speed were investigated. The optimum conditions obtained from response surface methodology are: temperature-38.1°C, adsorbent dose (3.1g/L), contact time (206 min), adsorbent size 0.1mm (150mesh), and agitation speed (222rpm). The effect of pH and initial substrate concentration were studied. The pseudo-first order and pseudo-second order kinetics were tested. The sorption equilibrium, expressed by the Langmuir and Freundlich equations, indicated that the process was in compliance with Freundlich isotherm.

scholarly journals Hen feather a bio-waste material for adsorptive removal of methyl red dye from aqueous solutions

2021 ◽  
Author(s):  
Samina Zaman ◽  
Md. Nayeem Mehrab ◽  
Md. Shahnul Islam ◽  
Gopal Chandra Ghosh ◽  
Tapos Kumar Chakraborty
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Methyl Red ◽  
Experimental Conditions ◽  
Potential Applicability ◽  
Pseudo Second Order ◽  
Red Dye ◽  
Adsorbent Dose

Abstract This study investigates the potential applicability of hen feather (HF) to remove methyl red (MR) dye from aqueous solution with the variation of experimental conditions: contact time (1–180 min), pH (4–8), initial dye concentration (5–50 mg/L) and adsorbent dose (3–25 g/L). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) evaluate the surface morphology and chemistry of HF, respectively. The maximum removal of MR by HF was 92% when the optimum conditions were initial MR dye concentration 05 mg/L, pH 4.0, adsorbent dose 07.0 g/L and 90.0 min equilibrium contact time. Langmuir isotherm (R2 = 0.98) was more suited than Freundlich isotherm (R2 = 0.96) for experimental data, and the highest monolayer adsorption capacity was 6.02 mg/g. The kinetics adsorption data fitted well to pseudo-second-order model (R2 = 0.999) and more than one process were involved during the adsorption mechanism but film diffusion was the potential rate-controlling step. The findings of the study show that HF is a very effective and low-cost adsorbent for removing MR dye from aqueous solutions.

scholarly journals Preparation of Modified nano-SiO2 by Bismuth and Iron as a novel Remover of Methylene Blue from Water Solution

2017 ◽  
Vol 61 (3) ◽  
Author(s):  
Farhad Salimi ◽  
Keivan Tahmasobi ◽  
Changiz Karami ◽  
Alireza Jahangiri
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Water Solution ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Adsorption Treatment ◽  
Dyes Adsorption

Modified nano-silica with Bismuth and Iron adsorbent was synthesized to be used as an effective adsorbent material for methylene blue (MB) removal from water solution. The prepared samples were characterized using SEM, FTIR, XRD and TEM. The effect of experimental parameters such as pH, contact time and initial concentration on adsorption treatment were studied. Results indicated that the optimum conditions for maximum <strong>adsorption</strong> of 20 mg/L MB <strong>were:</strong> contact time of 20 minutes, pH= 5-6 and 8 gr/L adsorbent, the remaining MB in solution was 1.75%. Langmuir and Freundlich isotherms were employed to model the experimental results and the Freundlich isotherm was the best-fitting models for the experiment results. The kinetic data were also analyzed through pseudo-first-order and pseudo-second-order models. The pseudo-second-order kinetic model well depicted the kinetics of dyes adsorption on adsorbent.

scholarly journals Kinetic and Thermodynamic Study of Adsorption of Copper (II) Ion on Moroccan Clay

2019 ◽  
Vol 9 (2) ◽  
pp. 102-115
Author(s):  
Hanane Essebaai ◽  
Ilham Ismi ◽  
Ahmed Lebkiri ◽  
Said Marzak ◽  
El Housseine Rifi
Keyword(s):  
Contact Time ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increase With Increase ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Kinetic And Thermodynamic Study

Highly efficient low-cost adsorbent was applied for copper (II) ions uptake from aqueous solution. Characteristics of natural adsorbent were established using scanning X-ray diffraction (XRD), X-ray fluorescence, electron microscope (SEM) and Fourier Transform Infra-Red (FTIR). Various physicochemical parameters such as contact time, initial copper(II) ions concentration, adsorbent dosage, pH of copper (II) ions solution and temperature were investigated. The result showed that the adsorption of copper (II) ions by natural clay was favorable at pH=5,5. The adsorption was found to increase with increase in initial copper (II) ions concentration, and contact time. Equilibrium adsorption data were fitted using three isotherms and kinetic data tested with four kinetic models. Freundlich isotherm best described the adsorption of copper (II) ions onto utilised clay, the maximum monolayer adsorption capacity (qmax) was 8 mg/g. Pseudo-second-order model best described the kinetics of the adsorption process. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were determined. It was found that copper (II) ions adsorption was spontaneous (ΔG°<0) and endothermic (ΔH°>0).

scholarly journals Adsorption of Se(IV) in aqueous solution by zeolites synthesized from fly ashes with different compositions

2019 ◽  
Vol 9 (4) ◽  
pp. 506-519
Author(s):  
Xiao Zhang ◽  
Xinyuan Li ◽  
Fan Zhang ◽  
Shaohao Peng ◽  
Sadam Hussain Tumrani ◽  
...  
Keyword(s):  
Fly Ash ◽  
Contact Time ◽  
High Capacity ◽  
Freundlich Isotherm ◽  
Fly Ashes ◽  
Order Model ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Equilibrium Data ◽  
Pseudo Second Order

Abstract Low-calcium fly ash (LC-F) and high-calcium fly ash (HC-F) were used to synthesize corresponding zeolites (LC-Z and HC-Z), then for adsorption of Se(IV) in water. The results showed that c zeolites can effectively adsorb Se(IV). The optimal adsorption conditions were set at contact time = 360 min; pH = 2.0; the amount of adsorbent = 5.0 g·L−1; temperature = 25 °C; initial Se(IV) concentration = 10 mg·L−1. The removal efficiency of HC-Z was higher than the LC-Z after it had fully reacted because the specific surface area (SSA) of HC-Z was higher than LC-Z. The adsorption kinetics model of Se(IV) uptake by HC-Z followed the pseudo-second-order model. The Freundlich isotherm model agreed better with the equilibrium data for HC-Z and LC-Z. The maximum Se(IV) adsorption capacity was 4.16 mg/g for the HC-Z and 3.93 mg/g for the LC-Z. For the coexisting anions, barely affected Se(IV) removal, while significant affected it. Regenerated zeolites still had high capacity for Se(IV) removal. In conclusion, zeolites synthesized from fly ashes are a promising material for adsorbing Se(IV) from wastewater, and selenium-loaded zeolite has the potential to be used as a Se fertilizer to release selenium in Se-deficient areas.

Adsorption of 2,4,6-trichlorophenol on bentonite modified with benzyldimethyltetradecylammonium chloride

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Infrared Spectroscopy ◽  
Contact Time ◽  
Removal Rate ◽  
Organic Pollutant ◽  
Freundlich Isotherm ◽  
Solution Concentration ◽  
Isotherm Models ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pseudo Second Order

The objective of this study is to evaluate the performance and capacities of the bentonite of Maghnia, modified with benzyldimethyltetradecylammonium chloride, to remove the organic pollutant 2,4,6-Trichlorophenol (TCP). The modified sample was studied by X-ray diffraction (XRD) technique, infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) methods. The best removal rate (99.52%) was obtained at 19°C, pH 4, solution concentration of 50 mg/L, stirring speed of 180 rpm and contact time of 60 min. The results were well fitted by both Langmuir and Freundlich isotherm models and the pseudo-second-order is the best model to describe the process.

scholarly journals Adsorption of Chromium from Aqueous Solution by Lignocellulosic Biomass (Pinus palustris): Studies on Equilibrium Isotherm, and Kinetics

2020 ◽  
Vol 9 (1) ◽  
pp. 77-84
Keyword(s):  
Lignocellulosic Biomass ◽  
Contact Time ◽  
Pinus Palustris ◽  
Freundlich Isotherm ◽  
Percentage Increase ◽  
Adsorption Model ◽  
Characteristic Parameters ◽  
Global Environmental ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order

Different methods to convert biomass into useful materials and products without generating pollutants will be useful for global environmental protection. The present study deals with the preparation of adsorbent from a suitable lignocellulosic biomass, Pinus palustris seeds. The adsorbent thus prepared will be used for the removal of heavy metals from aqueous solutions. Factors influencing the adsorption characteristics under batch conditions were studied for chromium concentrations in range of 30 – 150 ppm. The studies were conducted to optimize the size of the adsorbent, temperature and contact time. The maximum adsorption is attained at a pH of 6.5 and a dosage of 3g. The effective temperature for the reaction was at 37oC. The removal percentage increase when the optimized condition of different parameters such as size, temperature, contact time, concentration, pH and dosage. The adsorption isotherms showed that the Freundlich Isotherm is a better adsorption model and the characteristic parameters were determined. The results of the kinetic models showed that the pseudo second order kinetics was found to correlate with the experimental data. The present analysis, the absorbent that is produced from Pinus palustris seed has an efficient adsorption for chromium.

scholarly journals Assessment of wind energy potential ofthe Murmansk Regionand performance of Kola wind farm

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (4) ◽  
pp. 376-386
Author(s):  
V. F. Beley ◽  
G. V. Kotsar
Keyword(s):  
Power Generation ◽  
Wind Energy ◽  
Electricity Generation ◽  
Wind Farm ◽  
Reactive Power ◽  
Energy System ◽  
Energy Potential ◽  
Murmansk Region ◽  
Wind Energy Potential ◽  
Wind Activity

The paper gives an analysis of perspectives for development of wind power generation, information on the share of wind energy in electricity generation in the world and in Russian Federation is provided as well. Data on gross, technical, economic potential of wind energy of Russia and the Murmansk Region has been presented. When calculating the gross wind energy potential of the region, data from the last 10 years of observations carried out at 37 meteorological stations have been used. The territory of the region has been divided into 6 distinctive zones, based on the wind activity. Gross energy potential has been calculated for each zone: for the heights of 10, 50, 100, and 150 m. Gross wind energy potential of the region at the height of 150 m has thus been estimated at 23,090 billion kWh. The Murmansk Region's 201 MW Kola wind farm, which consists of 57 Siemens Gamesa SG 3.4-132 wind turbines with a unit capacity of 3.465 MW, is to be constructed by 2021 under the direction of Enel Green Power. Wind energy potential and annual power generation of the Kola wind farm have been assessed. The difference between the obtained results and calculations of Enel Group's specialists amounts to less than 15 %. For the cases of relocation of Kola wind farm to different wind zones, the annual power generation of the wind farm has been estimated. It has been determined, that in case of Kola wind farm's relocation to the zone with the highest wind activity its annual electricity generation could be increased up to 1.5 times. A model of the Kola energy system has been developed in NEPLAN software, its validity has been proven. The calculations of the wind farm's operation modes show that voltage levels of the system nodes and powerflows are within the boundaries defined by normative documents. The effectiveness of reactive power regulation of the wind farm has been shown.

Sign in / Sign up

Export Citation Format

Share Document