Characterization of adsorption behaviors of U(VI) on bentonite colloids: batch experiments, kinetic evaluation and thermodynamic analysis

2022 ◽  
Author(s):  
Chen Liu ◽  
Qiangwei Xu ◽  
Yuwei Xu ◽  
Bo Wang ◽  
Haoqi Long ◽  
...  
Keyword(s):  
Thermodynamic Analysis ◽  
Batch Experiments ◽  
Kinetic Evaluation ◽  
Adsorption Behaviors

Nitrate and nitrite reduction by ferrous iron minerals in polluted groundwater: Isotopic characterization of batch experiments

2020 ◽  
Vol 548 ◽  
pp. 119691
Author(s):  
Rosanna Margalef-Marti ◽  
Raúl Carrey ◽  
José Antonio Benito ◽  
Vicenç Marti ◽  
Albert Soler ◽  
...  
Keyword(s):  
Ferrous Iron ◽  
Nitrite Reduction ◽  
Batch Experiments ◽  
Iron Minerals ◽  
Isotopic Characterization ◽  
Nitrate And Nitrite

scholarly journals Surface Modification of Olive Stone Waste for Enhanced Sorption Properties of Cadmium and Lead Ions

2018 ◽  
Vol 26 (2) ◽  
pp. 281-306 ◽  
Author(s):  
Mahmoud Belalia ◽  
Meriem Bendjelloul ◽  
Abdallah Aziz ◽  
El Hadj Elandaloussi
Keyword(s):  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Lead Removal ◽  
Batch Experiments ◽  
Olive Stone ◽  
Cadmium And Lead ◽  
Tga And Dsc ◽  
Sodium Form ◽  
C Nmr

Abstract This paper reports the synthesis and characterization of an efficient anionic olive stone waste-based material as new ion-exchanger adsorbent. The olive stone waste was subjected to an alkaline pretreatment in order to enhance their reactivity towards maleic anhydride. The maleate-derived material MOS was characterized by FTIR, 13C NMR, TGA and DSC. The resulting sodium form of material NaMOS was subjected to batch experiments in order to evaluate its cadmium and lead removal efficiency. Adsorption experimental data showed a uniform and rapid process. Both Langmuir and Freundlich isotherm models were found to fit adequately the equilibrium isotherm data. The sorption capacities reached 240.96 mg Cd g−1 and 127.38 mg Pb g−1. The thermodynamic parameters showed that the process was exothermic and the adsorption occurred spontaneously. The desorption experiments show a quantitative recovery of the metal ions from NaMOS material.

scholarly journals Steel Wool for Water Treatment: Intrinsic Reactivity and Defluoridation Efficiency

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 265 ◽  
Author(s):  
Benjamin Hildebrant ◽  
Arnaud Igor Ndé-Tchoupé ◽  
Mesia Lufingo ◽  
Tobias Licha ◽  
Chicgoua Noubactep
Keyword(s):  
Bearing Steel ◽  
Fluoride Removal ◽  
Batch Experiments ◽  
Steel Wool ◽  
Column Leaching ◽  
Leaching Experiments ◽  
Series Of Experiments ◽  
Intrinsic Reactivity

Studies were undertaken to characterize the intrinsic reactivity of Fe0-bearing steel wool (Fe0 SW) materials using the ethylenediaminetetraacetate method (EDTA test). A 2 mM Na2-EDTA solution was used in batch and column leaching experiments. A total of 15 Fe0 SW specimens and one granular iron (GI) were tested in batch experiments. Column experiments were performed with four Fe0 SW of the same grade but from various suppliers and the GI. The conventional EDTA test (0.100 g Fe0, 50 mL EDTA, 96 h) protocol was modified in two manners: (i) Decreasing the experimental duration (down to 24 h) and (ii) decreasing the Fe0 mass (down to 0.01 g). Column leaching studies involved glass columns filled to 1/4 with sand, on top of which 0.50 g of Fe0 was placed. Columns were daily gravity fed with EDTA and effluent analyzed for Fe concentration. Selected reactive Fe0 SW specimens were additionally investigated for discoloration efficiency of methylene blue (MB) in shaken batch experiments (75 rpm) for two and eight weeks. The last series of experiments tested six selected Fe0 SW for water defluoridation in Fe0/sand columns. Results showed that (i) the modifications of the conventional EDTA test enabled a better characterization of Fe0 SW; (ii) after 53 leaching events the Fe0 SW showing the best kEDTA value released the lowest amount of iron; (iii) all Fe0 specimens were efficient at discoloring cationic MB after eight weeks; (iv) limited water defluoridation by all six Fe0 SW was documented. Fluoride removal in the column systems appears to be a viable tool to characterize the Fe0 long-term corrosion kinetics. Further research should include correlation of the intrinsic reactivity of SW specimens with their efficiency at removing different contaminants in water.

Two-Step Water Splitting Using Mixed-Metal Ferrites: Thermodynamic Analysis and Characterization of Synthesized Materials

2008 ◽  
Vol 22 (6) ◽  
pp. 4115-4124 ◽  
Author(s):  
Mark D. Allendorf ◽  
Richard B. Diver ◽  
Nathan P. Siegel ◽  
James E. Miller
Keyword(s):  
Water Splitting ◽  
Thermodynamic Analysis ◽  
Mixed Metal ◽  
Synthesized Materials

Migration of Radionuclides in Fracture Columns

1990 ◽  
Vol 212 ◽  
Author(s):  
Pirkko Hölttä ◽  
Martti Hakanen ◽  
Aimo Hautojärvi
Keyword(s):  
Tritiated Water ◽  
Chloride Ions ◽  
Drill Core ◽  
Rock Matrix ◽  
Batch Experiments ◽  
Fracture Surfaces ◽  
The Core ◽  
Set Up ◽  
And Diffusion

ABSTRACTRadionuclides transported by ground water flowing through fractures may be delayed by interactions with the fracture surfaces. The migration of radionuclides in fractures was studied under well defined laboratory conditions using tonal-ite drill core columns with a fracture running parallel to the core axis. The hydrodynamic characterization of the columns was performed using tritiated water, pertechnetate and chloride ions as non-sorbing tracers. Strontium and neptunium were used to study the retardation of radionuclides on the fracture surfaces.The experimental set-up is described, and break-through curves of non-sorbing tracers, strontium and neptunium are presented. The results were interpreted using models for dispersion and diffusion into the rock matrix. From the shape of the break-through curves it was concluded that for non-sorbing tracers there was very little or no diffusion at all into the rock matrix. Retardation of strontium in a column with intact tonalite surfaces indicated a Ka factor identical with that earlier determined by batch experiments. The break-through curve of neptunium indicated a non-sorbing fraction.

scholarly journals Chemometric characterization of the hydrogen bonding complexes of secondary amides and aromatic hydrocarbons

2012 ◽  
Vol 66 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Branislav Jovic ◽  
Aleksandar Nikolic ◽  
Slobodan Petrovic
Keyword(s):  
Principal Component Analysis ◽  
Hydrogen Bonding ◽  
Hierarchical Clustering ◽  
Thermodynamic Analysis ◽  
Aromatic Hydrocarbons ◽  
Principal Component ◽  
Chemometric Methods ◽  
Secondary Amides ◽  
Good Agreement

The paper reports the results of the study of hydrogen bonding complexes between secondary amides and various aromatic hydrocarbons. The possibility of using chemometric methods was investigated in order to characterize N-H???? hydrogen bonded complexes. Hierarchical clustering and Principal Component Analysis (PCA) have been applied on infrared spectroscopic and Taft parameters of 43 N-substituted amide complexes with different aromatic hydrocarbons. Results obtained in this report are in good agreement with conclusions of other spectroscopic and thermodynamic analysis.

scholarly journals Equilibrium study of Cr (VI) removal from aqueous solution by stalks from three tobacco species (Nicotiana) grown in Bulgaria

2019 ◽  
Vol 75 (3) ◽  
pp. 46-54
Author(s):  
Tsvetko Prokopov ◽  
Milena Nikolova ◽  
Tanya Ivanova ◽  
Venelina Popova ◽  
Milen Dimov ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Equilibrium Isotherms ◽  
Nicotiana Species ◽  
Equilibrium Study ◽  
Promising Source ◽  
Langmuir And Freundlich Models ◽  
Maximum Removal

Agricultural and processing activities generate enormous amounts of tobacco waste, and the stalks left after harvesting of the leaves constitute a significant share. The stalks of common tobacco (N. tabacum L.) were considered a promising source for processing and recycling, but very little is known about the properties of the stalks from other Nicotiana species. The aim of present study was to examine the performance of stalk powders from three Nicotiana species grown side-by-side in Bulgaria for the ability to remove Cr (VI) ions from aqueous solutions. The characterization of applied biosorbents was conducted by FTIR analysis. Batch experiments were carried out and the effects of different adsorption process parameters were determined. Maximum removal efficiencies of 99.13±0.55%, 98.33±0.58% and 95.00±0.50% for N. tabacum, N. rustica L. and N. alata Link&Otto, respectively, were obtained at pH 3.0, adsorbent dosage 5 g/L, initial Cr (VI) concentration 10 mg/L, temperature 25.0 ± 0.5oC, agitation speed 200 rpm and contact time 60 min. The Langmuir and Freundlich models fitted well the equilibrium isotherms experimental data. Based on the values determined for the maximum adsorption capacity, the powder from N. alata stalks was found to have higher affinity (9.87 mg/g) for Cr (VI) ions than those obtained from N. tabacum (8.38 mg/g) and N. rustica (6.96 mg/g) stalks.

Sign in / Sign up

Export Citation Format

Share Document