scholarly journals Removal of U (VI) From Aqueous Solution By Effective Bio-Adsorbent From Walnut Shell And Cellulose Composites Stabilized Iron Sulfide Nanoparticle

2021 ◽  
Author(s):  
Huifang Wang ◽  
Renrong Liu ◽  
Li Han ◽  
Baowei Hu ◽  
Muqing Qiu
Keyword(s):  
Aqueous Solution ◽  
Reaction Mechanism ◽  
Iron Sulfide ◽  
Cost Effective ◽  
Reduction Reaction ◽  
Walnut Shell ◽  
Order Kinetic ◽  
Modified Method ◽  
Ion Exchange Reaction ◽  
Cellulose Composites

Abstract FeS nanoparticles were easily aggregated and oxidized in the natural environment due to van der Waals forces between nanoparticles. Biochar could be used as a carrier to inhibit the agglomeration and oxidization of FeS nanoparticles. An efficient bio-adsorbent (CFeS-WS) from walnut shell (WS) and cellulose composites stabilized iron sulfide nanoparticle was synthesized by the modified method. It also was determined by SEM, EDS, XRD and FT-IR, respectively. The removal of U(VI) ions from aqueous solution by CFeS-WS were conducted. The reaction mechanism between CFeS-WS and U(VI) ions also were discussed in details. The experimental results were showed that the biochar successfully was supported with cellulose/FeS composites (CFeS). CFeS-WS exhibited an excellent removal performance for U(VI) ions in solution. The adsorption process of U(VI) ions by CFeS-WS was more consistent with pseudo second-order kinetic model and Langmuir isotherm model. The proposed reaction mechanism of U(VI) ions removal by CFeS-WS mainly consisted of ion exchange reaction, reduction reaction, hydrogen bonding and functional group, and pore of adsorbent filling. Recycle experiment indicated that CFeS-WS was a cost-effective bio-adsorbent.

scholarly journals SURFACE MODIFICATION OF CANARIUM OVATUMENGL.(PILI) SHELL AS ADSORBENT OF LEAD(Pb2+) FROM AQUEOUS SOLUTION

2021 ◽  
Author(s):  
Ernesto Jr. S. Cajucom ◽  
◽  
Lolibeth V. Figueroa ◽  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Cost Effective ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Carboxylic Groups ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Surface Modified

This study was carried out to investigate the efficiency of raw pili shell (RPS) and the surface modified pili shell using EDTA (EMPS) and oxalic acid (OMPS). A comparative study on the adsorption capacity of the adsorbents was performed against lead (Pb2+) from aqueous solution. The adsorbents were characterized by FTIR, which showed higher peak of adsorption bands of carboxylic groups on the acid modified pili shells. Scanning electron microscope orSEM was also used to describe the surface morphology of the adsorbents. The linear form of Langmuir and Freundlich models were applied to represent adsorption data. The calculated equilibrium data of Pb (II) best fitted to Langmuir compare to Freundlich isotherm model with maximum adsorption capacity (qmax) of 27.03 mg/g and 45.45 mg/g using EMPS and OMPS, respectively. Kinetic sorption models were used to determine the adsorption mechanism and the kinetic data of all the adsorbents correlated (R2=1) wellwith the pseudo second order kinetic model. Among the three adsorbents, OMPS shown higher percent removal of lead compared to RPS and EMPS. The large adsorption capacity rate indicated that chemically modified pili shell in present study has great potential to be used as a cost-effective adsorbent for the removal of lead ions from the water.

scholarly journals Removal of amoxicillin from aqueous solution using sludge-based activated carbon modified by walnut shell and nano-titanium dioxide

2020 ◽  
Author(s):  
Xiaorong Kang ◽  
Yali Liu ◽  
Can Yang ◽  
Han Cheng
Keyword(s):  
Aqueous Solution ◽  
Titanium Dioxide ◽  
Activated Carbon ◽  
Adsorption Process ◽  
Removal Rate ◽  
Total Pore Volume ◽  
Raw Material ◽  
Walnut Shell ◽  
Order Kinetic ◽  
Nano Titanium Dioxide

Abstract Dewatered municipal sludge was used as raw material to prepare activated carbon (SAC), and the SAC was modified by walnut shell and nano-titanium dioxide (MSAC). The results showed that the MSAC had a higher specific surface area (SBET) (279.147 m2/g) and total pore volume (VT) (0.324 cm3/g) than the SAC. Simultaneously, the functional groups such as C-O, C = O, and Ti-O-Ti on the surface of MSAC were enhanced due to modification. These physicochemical properties provided prerequisites for the diffusion and degradation of pollutants in MSAC. Furthermore, the MSAC was applied to adsorb amoxicillin (AMX) from aqueous solution, in batch experiments, the maximum removal rate (88.19%) was observed at an initial AMX concentration of 30 mg/L, MSAC dosage of 5.0 g/L, pH of 8, contact time of 180 min, and temperature of 25 °C. In addition, the adsorption process was well described by the Freundlich isotherm model and pseudo-second-order kinetic model, indicating that the adsorption of AMX onto MSAC was dominated by multilayer chemisorption. Also, the adsorption thermodynamics suggested that the adsorption process of AMX onto MSAC was endothermic, feasible and spontaneous.

scholarly journals Investigation of effectiveness of pyrolysis products on removal of alizarin yellow GG from aqueous solution: a comparative study with commercial activated carbon

2020 ◽  
Vol 81 (6) ◽  
pp. 1191-1208 ◽  
Author(s):  
Nihan Kaya ◽  
Zeynep Yildiz Uzun
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Surface Area ◽  
Bet Surface Area ◽  
Walnut Shell ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Pine Cone ◽  
Alizarin Yellow

Abstract The increasing use of dyestuff in industrial applications brings with it environmental problems. These dyes, which are an eco-toxic hazard, are common water pollutants, even at very low concentrations in water resources. Therefore, they must be removed in an economical way. In this study, low-cost biosorbents such as pine cone char, walnut shell char, and hazelnut shell char were prepared by pyrolysis process at different carbonization temperatures in the range of 400–700 °C. Biochars with the highest surface area were used to remove alizarin yellow GG from aqueous solution and the adsorption capacities of these materials were compared to commercially available activated carbon. Biomasses and prepared biochars were characterized using Fourier transform infrared spectroscopy, thermogravimetric/differential thermogravimetry analysis, Brunauer–Emmett–Teller (BET), scanning electron microscopy/energy dispersive X-ray spectroscopy, partial and elemental analysis techniques. Operational parameters such as contact time, temperature, pH, adsorbent dosage, and initial dye concentration were considered as variables for the batch adsorption experiments. Among the biochars used, the highest adsorption efficiency (82%) was obtained in pine cone char (BET surface area 259.74 m2/g) at pH = 3, T = 45 °C, adsorbent dosage of 8 g/L, and initial dye concentration of 20 ppm. The adsorption mechanism has been investigated by applying different kinetic and isotherm models with the aid of time-dependent adsorption data. The adsorption process was best described by Langmuir isotherm and pseudo-second order kinetic model.

scholarly journals CHROMIUM (III) ADSORPTION FROM AQUEOUS SOLUTION BY Rhizophora apiculata TANNINS

2010 ◽  
Vol 7 (2) ◽  
pp. 180-184 ◽  
Author(s):  
C. W. Oo ◽  
K. Jain
Keyword(s):  
Aqueous Solution ◽  
Linear Regression Analysis ◽  
Basic Solution ◽  
Order Kinetic ◽  
Chemically Modified ◽  
Ion Exchange Reaction ◽  
Rhizophora Apiculata ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Adsorption of Cr3+ from aqueous solution by Rhizophora apiculata tannins was investigated in batch shaking experiments. Tannins extracted from R. apiculata mangrove barks was chemically modified with formaldehyde in the basic solution of sodium hydroxide. The performance of the produced adsorbent on the adsorption of Cr3+ was evaluated based on the effect of several parameters like initial pH, adsorbent dosage, initial Cr3+ concentration and contact time. Equilibrium adsorption data was analyzed by Langmuir, Freundlich, Sips and Dubinin-Raduskhevich (D-R) isotherms. The fitness of the isotherms to the experimental data was determined by non-linear regression analysis. Adsorption capacity calculated from Langmuir isotherm was found to be 10.14 mg Cr3+/g of adsorbent at optimum adsorption pH of 4.5. Mean energy of adsorption with the value of 10.35 kJ/mol indicated that adsorption Cr3+ on Rhizophora apiculata tannins followed ion-exchange reaction. Kinetic study showed that the adsorption process followed the pseudo second-order kinetic model.   Keywords:  Rhizophora apiculata, tannins, isotherms, kinetic, chromium.

scholarly journals Adsorption-Desorption Profile of Methylene Blue Dye on Raw and Acid Activated Kaolinite

2020 ◽  
Vol 20 (4) ◽  
pp. 755
Author(s):  
Nurul Ain Safiqah Md Sandollah ◽  
Sheikh Ahmad Izaddin Sheikh Mohd Ghazali ◽  
Wan Nazihah Wan Ibrahim ◽  
Ruhaida Rusmin
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Cost Effective ◽  
Blue Dye ◽  
Order Kinetic ◽  
Kaolinite Clay ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

The efficiencies of raw (RK) and acid activated (0.5 M AAK) kaolinite clay minerals to remove methylene blue (MB) dyes in aqueous solution were investigated and compared. The 0.5 M AAK was prepared by treatment of RK in dilute 0.5 M HCl aqueous solution under reflux. Kaolinite adsorbents were characterized and their MB removal performances were evaluated via the batch method. MB desorption from spent kaolinites was investigated at pH 4 to 8. The MB removal was increased with increasing initial dye concentration, agitation speed and adsorbent dosage in 60 min reaction time at pH 6. Both kaolinites showed high MB removal (up to 97%). The Freundlich model has the best-fit equilibrium adsorption isotherm model for RK and 0.5 M AAK. The kinetic data for both adsorbents showed strong agreement with the pseudo second order kinetic model (r2 > 0.98). Nevertheless, the spent RK adsorbent demonstrated a significant higher MB retention than 0.5 M AAK in desorption experiments. Kaolinite clays have great potential as cost-effective materials for dyes removal in wastewater treatment.

Using of modified-bentonite as low-cost sorbent for removal of methylene blue dye from aqueous solution

2020 ◽  
Vol 27 (2) ◽  
pp. 45-54
Author(s):  
Saraa Muwafaq Ibrahim ◽  
Ziad T. Abd Ali
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Silanol Group ◽  
Infrared Spectrometry ◽  
Blue Dye ◽  
Ammonium Bromide ◽  
Vibration Band ◽  
Order Kinetic ◽  
Methylene Blue Dye ◽  
Modified Bentonite

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.

A Paramedic Treatment for Modeling Explicitly Solvated Chemical Reaction Mechanisms

2018 ◽  
Author(s):  
Yasemin Basdogan ◽  
John Keith
Keyword(s):  
Reaction Mechanism ◽  
Chemical Reaction ◽  
Reaction Mechanisms ◽  
Reaction Pathway ◽  
Optimization Procedure ◽  
Cost Effective ◽  
Chemical Reaction Mechanisms ◽  
Solvent Molecules ◽  
Dynamics Simulations ◽  
Mbh Reaction

<div> <div> <div> <p>We report a static quantum chemistry modeling treatment to study how solvent molecules affect chemical reaction mechanisms without dynamics simulations. This modeling scheme uses a global optimization procedure to identify low energy intermediate states with different numbers of explicit solvent molecules and then the growing string method to locate sequential transition states along a reaction pathway. Testing this approach on the acid-catalyzed Morita-Baylis-Hillman (MBH) reaction in methanol, we found a reaction mechanism that is consistent with both recent experiments and computationally intensive dynamics simulations with explicit solvation. In doing so, we explain unphysical pitfalls that obfuscate computational modeling that uses microsolvated reaction intermediates. This new paramedic approach can promisingly capture essential physical chemistry of the complicated and multistep MBH reaction mechanism, and the energy profiles found with this model appear reasonably insensitive to the level of theory used for energy calculations. Thus, it should be a useful and computationally cost-effective approach for modeling solvent mediated reaction mechanisms when dynamics simulations are not possible. </p> </div> </div> </div>

scholarly journals Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

2021 ◽  
Vol 13 (15) ◽  
pp. 8421
Author(s):  
Yuan Gao ◽  
Jiandong Huang ◽  
Meng Li ◽  
Zhongran Dai ◽  
Rongli Jiang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Efficiency ◽  
Low Cost ◽  
Chemical Activation ◽  
Cost Effective ◽  
Coal Gangue ◽  
Order Kinetic ◽  
Practical Applications ◽  
Detailed Structural Analysis ◽  
Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

scholarly journals Development of Biochars Derived from Water Bamboo (Zizania latifolia) Shoot Husks Using Pyrolysis and Ultrasound-Assisted Pyrolysis for the Treatment of Reactive Black 5 (RB5) in Wastewater

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1615
Author(s):  
Thanh Tam Nguyen ◽  
Hung-Hsiang Chen ◽  
Thi Hien To ◽  
Yu-Chen Chang ◽  
Cheng-Kuo Tsai ◽  
...  
Keyword(s):  
Cost Effective ◽  
Reactive Black 5 ◽  
Order Kinetic ◽  
Sem Images ◽  
Zizania Latifolia ◽  
Surface Areas ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ultrasound Assisted ◽  
Green Technique

Adsorbent made by carbonization of biomass under oxygen-limited conditions has become a promising material for wastewater treatment owing to its cost-effective, simple, and eco-friendly processing method. Ultrasound is considered a green technique to modify carbon materials because it uses water as the solvent. In this study, a comparison of Reactive Black 5 (RB5) adsorption capacity between biochar (BC) generated by pyrolysis of water bamboo (Zizania latifolia) husks at 600 °C and ultrasound-assisted biochar (UBC) produced by pyrolysis at 600 °C assisted by ultrasonic irradiation was performed. UBC showed a greater reaction rate and reached about 80% removal efficiency after 4 h, while it took 24 h for BC to reach that level. Scanning electron microscope (SEM) images indicated that the UBC morphology surface was more porous, with the structure of the combination of denser mesopores enhancing physiochemical properties of UBC. By Brunauer, Emmett, and Teller (BET), the specific surface areas of adsorbent materials were analyzed, and the surface areas of BC and UBC were 56.296 m2/g and 141.213 m2/g, respectively. Moreover, the pore volume of UBC was 0.039 cm3/g, which was higher than that of BC at 0.013 cm3/g. The adsorption isotherms and kinetics revealed the better fits of reactions to Langmuir isotherm and pseudo-second-order kinetic model, indicating the inclination towards monolayer adsorption and chemisorption of RB5 on water bamboo husk-based UBC.

scholarly journals Synthesis of Silver-Impregnated Magnetite Mesoporous Silica Composites for Removing Iodide in Aqueous Solution

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 175
Author(s):  
Sang-Eun Jo ◽  
Jung-Weon Choi ◽  
Sang-June Choi
Keyword(s):  
Aqueous Solution ◽  
Langmuir Isotherm ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Maximum Adsorption Capacity ◽  
Initial Contact ◽  
Order Kinetic ◽  
Sorption Ability ◽  
High Sorption

Mag@silica-Ag composite has a high sorption ability for I− in aqueous solution due to its high surface area and strong affinity for the studied anion. The material adsorbed I− rapidly during the initial contact time (in 45 min, η = 80%) and reached adsorption equilibrium after 2 h. Moreover, mag@silica-Ag proved to selectively remove I− from a mixture of Cl−, NO3− and I−. The adsorption behavior fitted the Langmuir isotherm perfectly and the pseudo-second-order kinetic model. Based on the Langmuir isotherm, the maximum adsorption capacity of mag@silica-Ag was 0.82 mmol/g, which is significantly higher than previously developed adsorbents. This study introduces a practical application of a high-capacity adsorbent in removing radioactive I− from wastewaters.

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