scholarly journals Sorption of Eu (III) onto Nano-Sized H-Titanates of Different Structures

2019 ◽  
Vol 9 (4) ◽  
pp. 697
Author(s):  
Vladimir Petrov ◽  
Zhong Chen ◽  
Anna Romanchuk ◽  
Valeria Demina ◽  
Yuxin Tang ◽  
...  
Keyword(s):  
Water Treatment ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Polluted Water ◽  
Batch Experiments ◽  
Ph Values ◽  
Sorption From Aqueous Solutions ◽  
Hydrothermal Methods

Hydrogen titanates (H-titanates) of different nanostructures (nanotubes, nanowires, nanosheets) have been synthesized by hydrothermal methods. The europium (III) sorption from aqueous solutions onto nano-sized H-titanates was studied as a function of contact time, pH values, and initial Eu (III) concentration in batch experiments. Reversibility of adsorption of europium has been investigated as well. Nano-sized H-titanates can be used for tri-valent f-elements removal in polluted water treatment due to fast and efficient sorption of Eu (III).

scholarly journals Removal of Cr(VI) from Aqueous Environments Using Micelle-Clay Adsorption

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohannad Qurie ◽  
Mustafa Khamis ◽  
Adnan Manassra ◽  
Ibrahim Ayyad ◽  
Shlomo Nir ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Continuous Flow ◽  
Contact Time ◽  
Langmuir Adsorption Isotherm ◽  
Optimal Conditions ◽  
Batch Experiments ◽  
Langmuir Adsorption ◽  
Ph Values ◽  
Aqueous Environments

Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques.

scholarly journals Batch studies of phosphonate adsorption on granular ferric hydroxides

2020 ◽  
Vol 81 (1) ◽  
pp. 10-20 ◽  
Author(s):  
T. Reinhardt ◽  
M. Gómez Elordi ◽  
R. Minke ◽  
H. Schönberger ◽  
E. Rott
Keyword(s):  
Contact Time ◽  
Room Temperature ◽  
Adsorption Process ◽  
Ferric Hydroxide ◽  
Batch Experiments ◽  
Batch Studies ◽  
Influence Of Temperature ◽  
Ph Values ◽  
Adsorption Desorption ◽  
Granular Ferric Hydroxide

Abstract Phosphonates are widely used in various industries. It is desirable to remove them before discharging phosphonate-containing wastewater. This study describes a large number of batch experiments with adsorbents that are likely suitable for the removal of phosphonates. For this, adsorption isotherms for four different granular ferric hydroxide (GFH) adsorbents were determined at different pH values in order to identify the best performing material. Additionally, the influence of temperature was studied for this GFH. A maximum loading for nitrilotrimethylphosphonic acid (NTMP) was found to be ∼12 mg P/g with an initial concentration of 1 mg/L NTMP-P and a contact time of 7 days at room temperature. Then, the adsorption of six different phosphonates was investigated as a function of pH. It was shown that GFH could be used to remove all investigated phosphonates from water and, with an increasing pH, the adsorption capacity decreased for all six phosphonates. Finally, five adsorption–desorption cycles were carried out to check the suitability of the material for multiple re-use. Even after five cycles, the adsorption process still performed well.

Removal of Xylenol Orange from Solutions by γ-Cyclodextrin-Grafted Carboxymethyl Cellulose

2011 ◽  
Vol 204-210 ◽  
pp. 1180-1183 ◽  
Author(s):  
Xiao Li Xiong ◽  
Chen Bin Shao
Keyword(s):  
Free Energy ◽  
Aqueous Solutions ◽  
Carboxymethyl Cellulose ◽  
Contact Time ◽  
Xylenol Orange ◽  
Free Energy Change ◽  
Energy Change ◽  
Batch Experiments ◽  
Adsorption Capacities ◽  
Adsorption Temperature

The potential to remove xylenol orange (XO) from aqueous solutions through adsorption on γ-cyclodextrin-grafted carboxymethyl cellulose (CCMC) was investigated in batch experiments. The effects of contact time, adsorption temperature and initial XO concentration were discussed. Results of batch experiments showed that CCMC exhibited some sorption capacities towards XO. It was found that isotherm fitted Languir and Freundlich models for the adsorption of XO on CCMC. On the basis of the Langmuir analysis, the maximum adsorption capacities were determined to be 29.9, 27.1, 21.9, 16.2 and 16.1 mg of XO per gram of CCMC at 283, 288, 293, 298 and 303K, respectively. The negative values of free energy change indicated the spontaneous nature of adsorption.

scholarly journals Al (III) removal from wastewaters by natural clay and coconut shell

2019 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Acid Treatment ◽  
Adsorption Process ◽  
Coconut Shell ◽  
Maximum Adsorption Capacity ◽  
Agitation Rate ◽  
Batch Experiments ◽  
Natural Clay ◽  
Initial Ph

<p>This paper describes the adsorption of Al3+ ions from aqueous solutions, by natural clay (from Sakarya's Yenigün district) and coconut shell modified by means of acid treatment. Batch experiments were carried out to determine the effect of various factors such as initial pH (4-9), temperature (20, 40, 70 oC), initial concentration (10 to 200 mg L-1) and contact time (1-120 minute) on the adsorption process. The adsorption experiments were performed at a temperature of 20 ±2 oC), at 200 rpm agitation rate, with an adsorbent level of 1 g L-1, produced 98.95% (at pH 6) and 92.83% (at pH 7) maximum Al3+ removal efficiency for clay and coconut shell based adsorbents respectively. Furthermore, the process was found to be exothermic for clay and endothermic for coconut. XRF and XRD analyses of the clay variety used in adsorption analyses revealed it to be saponite clay, within the larger group of smectite clay minerals. The application of Langmuir revealed maximum adsorption capacity of 149.25 mg g-1 for natural clay adsorbent (NCA), and 120.482 mg g-1 for coconut shell adsorbent (CSA). Moreover, adsorption kinetics were found to be consistent with the second order kinetics (R2 &gt; 0.95). The result shows that, natural clay and coconut shell adsorbents are effective adsorbents to remove Al3+ from aqueous solutions with good adsorption rate (&gt;92.8%).</p>

Complex coagulants produced from bulk waste and industrial products

2021 ◽  
pp. 13-18
Author(s):  
E. N. Kuzin ◽  
◽  
N. E. Kruchinina ◽  
Keyword(s):  
Water Treatment ◽  
Aqueous Solutions ◽  
Titanium Tetrachloride ◽  
High Efficiency ◽  
Ferrous Metal ◽  
Acid Leaching ◽  
Teaching Staff ◽  
Treatment Efficiency ◽  
High Ph ◽  
Ph Values

A series of experiments has been conducted and samples of complex coagulants have been obtained from the by-products of apatite-nepheline ore flotation (nepheline concentrate) and from refractory production waste — i. e. synthetic brucite. It was established that aqueous solutions of titanium tetrachloride can be used as an acid leaching reagent. The authors examined the process of recovering the principal active components with aqueous solutions of titanium tetrachloride and identified the priority mechanism behind leaching of metallic components with highly diluted aqueous solutions of titanium tetrachloride. The quantitative and qualitative composition of the obtained solutions of complex coagulants was analyzed. Modified magnesium coagulants were found to demonstrate high efficiency at high pH values of the treated water. At neutral pH values, complex aluminiumbearing reagents proved to be significantly more efficient than the conventional coagulants (i.e. aluminium sulphates and aluminium (oxy)chlorides). The obtained reagents were analyzed for their coagulation ability. Run-off and waste waters generated by an off gas purification unit in use at a non-ferrous metal casting site were used for the analysis. The analysis showed that, with the same dosage used, the modified aluminium coagulant is 30–35% more efficient than the conventional reagents. Experiments aimed at analyzing the water treatment efficiency in the case of water with high pH values (e.g. wastewater generated by a cement plant) showed that due to the use of inoculants in magnesium coagulants the water treatment efficiency can be increased by more than 20%. It was proved that the introduction of titanium compound hydrolysis products helps to significantly increase the water treatment efficiency irrespective of the principal component of the coagulant (aluminium or magnesium salt). This research was carried out as part of the funding programme aimed to support young research and teaching staff of D. Mendeleev University of Chemical Technology of Russia (Application: З-2020-013.).

Adsorption of methylene blue from aqueous solutions using water treatment sludge modified with sodium alginate as a low cost adsorbent

2016 ◽  
Vol 75 (2) ◽  
pp. 281-295 ◽  
Author(s):  
Hamid Poormand ◽  
Mostafa Leili ◽  
Marzieh Khazaei
Keyword(s):  
Methylene Blue ◽  
Water Treatment ◽  
Aqueous Solutions ◽  
Sodium Alginate ◽  
Contact Time ◽  
Low Cost ◽  
Drinking Water Treatment ◽  
Water Treatment Sludge ◽  
Maximum Sorption Capacity ◽  
Adsorbent Dose

In this research, aluminum-based drinking water treatment sludge is used as a starting material and immobilized by sodium alginate to develop low cost adsorbent for the removal of methylene blue (MB) from aqueous solutions. The studied variables included pH, adsorbent dose, initial MB concentration and contact time. Characteristics of the adsorbent were also studied using scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR). It was revealed from kinetic tests that removal efficiency of MB was 88.5% under the optimum conditions of pH 8, initial MB concentration of 50 mg/L, contact time of 60 min, and adsorbent dose of 0.3 g/L. The oxygen functional groups such as –OH, C–O–C and C=O were found on the surface of developed adsorbent by FTIR. In addition, the adsorption data fitted well the Langmuir adsorption model with the maximum sorption capacity of 909.1 mg/g, and followed the pseudo-second-order kinetics. Findings of this study indicate that the prepared adsorbent is promising for further development of an effective and economical adsorbent material in the near future.

scholarly journals Comparative Assessment of the Efficiency of Rice Husk Biochar and Conventional Water Treatment Method to Remove Chlorpyrifos from Pesticide Polluted Water

2020 ◽  
pp. 1-11 ◽  
Author(s):  
Aderonke A. Okoya ◽  
Oyeyemi S. Adegbaju ◽  
Oyindamola E. Akinola ◽  
Abimbola B. Akinyele ◽  
Omotayo S. Amuda
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Water Sample ◽  
Rice Husk ◽  
Contact Time ◽  
Simulation Experiment ◽  
Polluted Water ◽  
Surface Water Sample ◽  
Initial Concentration ◽  
Rice Husk Biochar

Nigeria is currently the largest rice producing country in Africa. High volumes of waste such as rice husk are inevitable with high production. Also pesticides used to rid of pests, diseases and improve crop yield find their ways into available surface water that serves domestic purpose. This study therefore determined the efficiency of conventional water treatment procedure for pesticide/pesticide residue removal and evaluated the performance of rice husk-based biochar as adsorbent to remove chlorpyrifos from domestic water supply with a view to manage  solid waste (rice husk) for treating pesticide polluted water. Batch adsorption studies were carried out to assess the adsorption efficiency of rice husk biochar (RHB) for chlorpyrifos pesticide removal from surface water. Adsorbent dosage, initial concentration, contact time and dosage were optimized during simulation experiment. RHB and commercial activated carbon (CAC) were used for the removal of chlorpyrifos from surface water sample using the optimum condition from the simulation experiment after which the concentrations were determined using Gas Chromatography with Mass Spectrometry detector. Both Langmuir and Freundlich adsorption isotherms were investigated. RHB gave percentage moisture (5.27±0.94), carbon yield (39.44±0.47), ash (41.96±0.96), fixed carbon (35.24±0.55), volatile matter (35.67±1.01 mg/g), Iodine number (85.57±0.81), surface area (97.20 m2/g), pH (7.90±0.14) and Electrical conductivity (298.8±1.14). Of the elements present in the char, Carbon has the highest percentage of 59.14%. Best adsorption conditions for RHB in this study were 2.8 mg/L initial concentration; 0.8 g of adsorbent dosage; pH of 5 and contact time of 30 min. The data fitted Freundlich than Langmuir model (R2 0.996 and 0.8315 respectively). Percentage removal of chlorpyrifos for CAC and RHB was 93.7±3.96 and 94.5±5.23 respectively for the surface water sample. Results concluded that RHB was efficient for removal of chlorpyrifos present in water and could be used as alternative for CAC in water treatments.

Preliminary investigation of electrocoagulation as a substitute for chemical coagulation

2002 ◽  
Vol 2 (5-6) ◽  
pp. 73-76 ◽  
Author(s):  
M. Han ◽  
J. Song ◽  
A. Kwon
Keyword(s):  
Water Treatment ◽  
Zeta Potential ◽  
Preliminary Investigation ◽  
Batch Experiments ◽  
Turbidity Removal ◽  
Chemical Coagulation ◽  
Ph Values ◽  
Water Ph ◽  
Removal Efficiencies ◽  
Particle Characteristic

Recently electrocoagulation has been considered as one of the promising coagulation processes and was increasingly used as a substitute for chemical coagulation in many water treatment fields. However, there have not been many fundamental studies performed on it. In this research, a preliminary investigation was carried out to verify the effectiveness of the electrocoagulation compared with conventional chemical coagulation through a set of batch experiments. Turbidity removal efficiencies, using various aluminium dosages and at different water pH values, were investigated. In addition, the zeta potential was studied to develop understanding of particle characteristic after applying both electrocoagulation and chemical coagulation. It can be concluded from the results that electrocoagulation is more efficient than chemical coagulation in turbidity removal.

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