Biochars prepared from rabbit manure for the adsorption of rhodamine B and Congo red: characterisation, kinetics, isotherms and thermodynamic studies

2020 ◽  
Vol 81 (3) ◽  
pp. 436-444
Author(s):  
Wen Huang ◽  
Min Zhang ◽  
Yinhai Wang ◽  
Jiao Chen ◽  
Jianqiang Zhang
Keyword(s):  
Rhodamine B ◽  
Congo Red ◽  
Molecular Layer ◽  
Suitable Model ◽  
Related Factors ◽  
Adsorption Sites ◽  
Rate Limiting Step ◽  
Layer Adsorption ◽  
Pseudo Second Order ◽  
Rate Limiting

Abstract Biochar was prepared from rabbit faeces (RFB550) at 550 °C through pyrolysis and was characterised using elemental analysis, scanning electron microscopy, Brunauer–Emmett–Teller analysis and Fourier transform infrared spectroscopy (FTIR). The related factors, kinetics, isothermal curves and thermodynamics of the adsorption behaviours were investigated by conducting batch experiments. The results revealed the adsorption equilibrium of rhodamine B (RhB) and Congo red (CR) onto RFB550 with initial concentrations of 30 mg · L−1 at 25 °C and 210 min, and the best adsorption was observed when the pH of the RhB and CR solutions was 3 and 5, respectively. Pseudo-second-order kinetics was the most suitable model for describing the adsorption of RhB and CR onto RFB550, indicating that the rate-limiting step was mainly chemical adsorption. The isotherm data were best described by the Freundlich model, and the adsorption process was multi-molecular layer adsorption. Thermodynamic parameters revealed the spontaneous adsorption of RhB and CR onto RFB550. According to the results of the FTIR analysis, the oxygen-containing functional groups and aromatic structures on the surface of RFB550 provided abundant adsorption sites for RhB and CR, and the adsorption mechanism was potentially related to the hydrogen bonds and π–π bonds.

Adsorption properties of cationic rhodamine B dye onto metals chloride-activated castor bean residue carbons

2016 ◽  
Vol 75 (4) ◽  
pp. 864-880 ◽  
Author(s):  
Lee Lin Zhi ◽  
Muhammad Abbas Ahmad Zaini
Keyword(s):  
Rhodamine B ◽  
Castor Bean ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties ◽  
Rate Limiting Step ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Enthalpy And Entropy ◽  
Rate Limiting

This work was aimed to evaluate the feasibility of castor bean residue based activated carbons prepared through metals chloride activation. The activated carbons were characterized for textural properties and surface chemistry, and the adsorption data of rhodamine B were established to investigate the removal performance. Zinc chloride-activated carbon with specific surface area of 395 m2/g displayed a higher adsorption capacity of 175 mg/g. Magnesium chloride and iron(III) chloride are less toxic and promising agents for composite chemical activation. The adsorption data obeyed Langmuir isotherm and pseudo-second-order kinetics model. The rate-limiting step in the adsorption of rhodamine B is film diffusion. The positive values of enthalpy and entropy indicate that the adsorption is endothermic and spontaneous at high temperature.

scholarly journals Kinetics and thermodynamics of adsorption of congo red on cellulose

2010 ◽  
Vol 8 (4) ◽  
pp. 906-912 ◽  
Author(s):  
Babak Samiey ◽  
Mohammad Dargahi
Keyword(s):  
Congo Red ◽  
Kinetics Of Adsorption ◽  
First Order ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Initial Adsorption ◽  
Initial Adsorption Rate ◽  
Rate Limiting ◽  
Kinetics Of ◽  
Cellulose Surface

AbstractThermodynamics and kinetics of adsorption of congo red (CR) on cellulose are studied at 308–328 K. In the used concentration range of CR, interaction of CR with cellulose is exothermic and CR molecules adsorb chemically on cellulose surface. The effects of contact time, temperature and initial concentration of CR on kinetics of its adsorption on cellulose were investigated. The process proceeds according to the pseudo-second-order equation. Initial adsorption rate of adsorption is first-order in CR and the intraparticle diffusion of CR molecules within cellulose is identified as the main rate-limiting step.

Removal of Mg from spring water using natural clinoptilolite

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 81-92 ◽  
Author(s):  
S. Tomić ◽  
N. Rajić ◽  
J. Hrenović ◽  
D. Povrenović
Keyword(s):  
Ion Exchange ◽  
Kinetic Studies ◽  
Spring Water ◽  
Zeolite A ◽  
Zeolitic Tuff ◽  
Rate Limiting Step ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Natural Clinoptilolite ◽  
Rate Limiting

AbstractNatural zeolitic tuff from Brus (Serbia) consisting mostly of clinoptilolite (about 90%) has been investigated for the reduction of the Mg concentration in spring water. The sorption capacity of the zeolite is relatively low (about 2.5 mg Mg g-1for the initial concentration of 100 mg Mg dm-3). The zeolitic tuff removes Mg from water solutions by ion exchange, which has been demonstrated by energy dispersive X-ray analysis (EDS). The extent of ion exchange was influenced by the pH and the initial Mg concentration. Kinetic studies revealed that Lagergen's pseudo-second order model was followed. Intra-particle diffusion of Mg2+influenced the ion exchange, but it is not the rate-limiting step. Rather than having to dispose of the Mg-loaded (waste) zeolite, a possible application was tested. Addition to a wastewater with a low concentration of Mg showed that it could successfully make up for the lack of Mg micronutrient and, accordingly, enabled the growth of phosphate-accumulating bacteriaA. Junii, increasing the amount of phosphate removed from the wastewater.

scholarly journals Removal of Paracetamol from Wastewater by Calcined Gypsum: Adsorption and Kinetics Study

2020 ◽  
Vol 3 (1) ◽  
pp. 11-18
Author(s):  
Hossam Al-Itawi
Keyword(s):  
Aqueous Solutions ◽  
Minor Effect ◽  
Recrystallization Process ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Calcined Gypsum ◽  
A Minor ◽  
Two Stages ◽  
Rate Limiting ◽  
Best Fit

It has been established that the presence of paracetamol in wastewaters can cause a potential risk to the environment. This work examined the possibility of using calcined gypsum in removing paracetamol from aqueous solutions. At neutral pH conditions, calcined gypsum was successful in removing paracetamol via adsorption, from aqueous solutions with a removal efficiency that ranged between 56.8 to 65.3 % of an initial concentration of 600 ppm. Increased temperature (from 20 to 500C) had a minor effect on the removal % of paracetamol while increasing the initial calcined gypsum dose (from 0.5 gm to 3 gm) and contact time (up to 15 min) increased by the removal % of paracetamol. Thermodynamically, the adsorption of paracetamol by calcined gypsum process was found to be spontaneous and endothermic, and more likely a physical process, while kinetically; the Pseudo-Second order model was found to be the best fit compared to the Elovich model. The removal process mainly consists of two stages, and it could be deduced from the kinetic behavior of paracetamol adsorption that the recrystallization process can be another rate-limiting step in the process.

scholarly journals Chlorates(VII) removal on Dowex™PSR-2 resin

2016 ◽  
Vol 71 (1) ◽  
pp. 105
Author(s):  
Dorota Kołodyńska ◽  
Aleksandra Łyko ◽  
Marzena Gęca ◽  
Zbigniew Hubicki
Keyword(s):  
Solution Concentration ◽  
Intraparticle Diffusion ◽  
Optimum Conditions ◽  
Order Model ◽  
Experimental Conditions ◽  
Freundlich Model ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Pseudo Second Order ◽  
Rate Limiting

<p>Lately there has been observed the increased presence of chlorates(VII) in the natural environment which can affect human health negatively. Therefore the removal of chlorate(VII) ions using the gel type resin functionalized with the tri-n-butyl ammonium (Dowex<sup>™</sup>PSR-2) from waters was studied. The main aim was to evaluate the effects of experimental conditions including contact time, initial solution concentration, pH and temperature on chlorate(VII) ions removal as well as the anion exchanger properties on chlorate(VII) ions sorption. It was found that only the pseudo second order model described the experimental data well and the intraparticle diffusion was not the rate-limiting step. According to the Freundlich model, the q<sub>e</sub> value was to be 69.26 mg/g at optimum conditions (pH 7.0 at 25 <sup>o</sup>C).<strong></strong></p>

scholarly journals Evaluation of Pb (II) Removal from Water Using Sodium Alginate/Hydroxypropyl Cellulose Beads

2020 ◽  
Vol 148 ◽  
pp. 02002 ◽  
Author(s):  
Rodel Guerrero ◽  
Catherine Acibar ◽  
Christine Marie Alarde ◽  
Jane Maslog ◽  
Christine Joy Pacilan
Keyword(s):  
Adsorption Capacity ◽  
Sodium Alginate ◽  
Contact Time ◽  
Hydroxypropyl Cellulose ◽  
Order Kinetic ◽  
Hydrogel Beads ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Rate Limiting ◽  
Adsorption Kinetic Model

This study examined the removal of Pb2+ ions from aqueous solution with two different lead concentrations using a hydrogel-forming polymer based on hydroxypropyl cellulose (HPC) and sodium alginate (SA). The feasibility of the adsorption behavior of SA/HPC beads has been investigated with three varying ratios of 50:50, 75:25 and 100:0 under a stir condition. The adsorption experiments were done to determine the effects of contact time, lead concentration and SA-HPC ratio to the adsorption capacity of SA-HPC hydrogel beads. The results showed that the ratio 75:25 showed higher adsorption capacity compared to 100:0 and 50:50. It showcased 47.72 mg/g adsorption capacity and 95.45% adsorption percentage after three hours of contact time. The adsorption kinetic model indicated that the adsorption of Pb2+ ions onto the beads followed a pseudo-second order kinetic equation. This means that the adsorption mechanism shows a chemisorption process and its sole rate-limiting step is intraparticle diffusion.

Removal of toxic elements from aqueous solution using bentonite modified with l-histidine

2014 ◽  
Vol 70 (12) ◽  
pp. 2022-2030 ◽  
Author(s):  
E. N. Bakatula ◽  
E. M. Cukrowska ◽  
I. M. Weiersbye ◽  
L. Mihaly-Cozmuta ◽  
H. Tutu
Keyword(s):  
Aqueous Solution ◽  
Freundlich Isotherm ◽  
Batch Mode ◽  
Operating Variables ◽  
Ph Values ◽  
Surface Areas ◽  
Rate Limiting Step ◽  
Thermodynamic Constants ◽  
Pseudo Second Order ◽  
Rate Limiting

This study proposes the use of bentonite modified with l-histidine for the removal of Cu, Co, Cr, Fe, Hg, Ni, U and Zn from aqueous solutions such as those impacted by acidic drainage. The surface areas of natural bentonite and bentonite–histidine were 73.8 and 61.2 m2 g−1, respectively. Elemental analysis showed an increase in the amount of carbon (0.258%) and nitrogen (0.066%) for the bentonite–histidine. At a fixed solid/solution ratio, the operating variables affecting the adsorption of metal ions from aqueous solution such as pH, initial concentration, contact time and temperature were studied in batch mode. The Freundlich isotherm model yielded a better fit than the Langmuir for the adsorption of Cu, Co, Ni and Zn, implying adsorption on a heterogeneous surface. Adsorption kinetics followed a pseudo-second-order model, suggesting chemisorption as the rate-limiting step. The apparent activation energy was greater than 40 kJ mol−1 for Cu, Zn, Ni, Co and U, which is characteristic of a chemically controlled reaction. Thermodynamic constants ΔG and ΔH showed that the adsorption of metals was endothermic and spontaneous. Adsorption of heavy metals onto bentonite–histidine was efficient at low pH values, meaning that the adsorbent could be useful for remediating acid mine water.

scholarly journals Behavior of mesoporous activated carbon used as a remover in Congo red adsorption process

2018 ◽  
Vol 2017 (1) ◽  
pp. 170-183 ◽  
Author(s):  
Hasan Sayğılı ◽  
Fuat Güzel
Keyword(s):  
Activated Carbon ◽  
Congo Red ◽  
Low Cost ◽  
Solution Temperature ◽  
Maximum Adsorption Capacity ◽  
Tomato Paste ◽  
Rate Limiting Step ◽  
Intra Particle Diffusion ◽  
Optimized Conditions ◽  
Rate Limiting

Abstract The adsorption characteristics of Congo red (CR) dye on activated carbon produced under optimized conditions from tomato paste waste were evaluated. The effects of adsorbent dose, initial dye concentration, contact time, ionic strength and solution temperature on adsorption were investigated. Adsorption kinetic was better described by the pseudo-first order model. Results of the intra-particle diffusion model show that the pore diffusion is not the only rate-limiting step. Adsorption isotherm was well defined by the Langmuir isotherm. The maximum adsorption capacity of the activated carbon was 435 mg g−1 at 328 K. The dimensionless separation factor RL revealed the favorable nature of the isotherm of the activated carbon–dye system. Adsorption energy was found to be 4.20–4.55 kJ mol−1 indicating that the mechanism of adsorption is physical in nature. Thermodynamic studies showed that CR adsorption onto activated carbon was feasible, spontaneous and endothermic. Desorption of the used activated carbon was studied using ethanol as solvent and desorption efficiency of 56.4% was obtained after five cycles. The findings indicated that the activated carbon is a very effective and low-cost adsorbent for removal of CR dye from aqueous solutions.

scholarly journals Adsorption Process and Properties Analyses of a Pure Magadiite and a Modified Magadiite on Rhodamine-B from an Aqueous Solution

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 565
Author(s):  
Mingliang Ge ◽  
Zhuangzhuang Xi ◽  
Caiping Zhu ◽  
Guodong Liang ◽  
Yinye Yang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Rhodamine B ◽  
Cetyltrimethylammonium Bromide ◽  
Low Cost ◽  
Order Kinetic ◽  
Exchange Method ◽  
Layer Adsorption ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Order Kinetic Equation

The result of an adsorption experiment indicated that the pure magadiite (MAG) and the modified MAG via cetyltrimethylammonium-bromide (CTAB-MAG) possessed pronounced affinity to the Rhodamine-B (Rh-B) dye molecules. CTAB-MAG was synthesized with an ion-exchange method between MAG and cetyltrimethylammonium-bromide (CTAB) in an aqueous solution. The adsorption capacities of CTAB-MAG and MAG on Rh-B were 67.19 mg/g and 48.13 mg/g, respectively; while the pH and the time were 7 and 60 min, respectively; however, the initial concentration of Rh-B was 100 mg/L, and adsorbent dosage was 1 g/L. Whereas, the adsorption capacity of CTAB-MAG was increased by 40% over MAG which indicated that CTAB-MAG can be used as an efficient low-cost adsorbent. Adsorption kinetics were consistent with the pseudo-second-order kinetic equation; the adsorption processes were dominated by film diffusion process which belonged to monomolecular layer adsorption.

scholarly journals Equilibrium, Kinetics and Thermodynamics of the Bleaching of Palm Oil Using Activated Nando Clay

2018 ◽  
pp. 1-13
Author(s):  
Nwabanne, Joseph T. ◽  
Onu, Chijioke E. ◽  
Nwankwoukwu, Okwudili C.
Keyword(s):  
Palm Oil ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Bleaching Efficiency ◽  
Rate Limiting Step ◽  
Equilibrium Data ◽  
Intra Particle Diffusion ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
Rate Limiting

The effectiveness of Nando clay in the bleaching of palm oil was studied in this work. The clay was prepared by activating it with hydrochloric acid. The bleaching was carried out at different temperatures, adsorbent dosage and particle sizes. The result suggests that increase in temperature and adsorbent dosage increases the bleaching efficiency while the increase in particle size decreases the bleaching efficiency. Both the pseudo-first-order and the pseudo-second-order kinetic models describe efficiently the experimental data of the bleaching process. Intra-particle diffusion though involved in the adsorptive bleaching mechanism, is not the sole rate-limiting step in the bleaching of palm oil with activated Nando clay. The equilibrium data were described better by Langmuir and Freundlich models. The enthalpy, entropy and activation energy were determined to be 6.127 KJ/mol, 3.982 KJ/mol and 15.281 KJ respectively. The free energy was found to vary between- 3.999 to- 3.760 KJ/mol. The result indicates that bleaching efficiency of up to 96% can be obtained with the activated clay as an adsorbent.

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