scholarly journals Cleaner Approach for Atrazine Removal Using Recycling Biowaste/Waste in Permeable Barriers

Recycling ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 41
Author(s):  
Ana Lago ◽  
Bruna Silva ◽  
Teresa Tavares
Keyword(s):  
Adsorption Capacity ◽  
Fixed Bed ◽  
Pine Bark ◽  
Waste Materials ◽  
Acetonitrile Solution ◽  
Response Model ◽  
Waste Valorization ◽  
Extraction Solvents ◽  
Permeable Barriers ◽  
Adsorption Desorption

This work addresses the rehabilitation of water contaminated with atrazine, entrapping it in a permeable and sustainable barrier designed with waste materials (sepiolite) and with biomaterials (cork and pine bark). Atrazine adsorption was assessed by kinetics and equilibrium assays and desorption was tested with different extraction solvents. Adsorbed atrazine was 100% recovered from sepiolite using 20% acetonitrile solution, while 40% acetonitrile was needed to leach it from cork (98%) and pine bark (94%). Continuous fixed-bed experiments using those sorbents as PRB were performed to evaluate atrazine removal for up-scale applications. The modified dose-response model properly described the breakthrough data. The highest adsorption capacity was achieved by sepiolite (23.3 (±0.8) mg/g), followed by pine bark (14.8 (±0.6) mg/g) and cork (13.0 (±0.9) mg/g). Recyclability of sorbents was evaluated by adsorption-desorption cycles. After two regenerations, sepiolite achieved 81% of atrazine removal, followed by pine with 78% and cork with 54%. Sepiolite had the best performance in terms of adsorption capacity/stability. SEM and FTIR analyses confirmed no significant differences in material morphology and structure. This study demonstrates that recycling waste/biowaste is a sustainable option for wastewater treatment, with waste valorization and environmental protection.

Synthesis of NaY Zeolite and their CO2 Adsorption Properties

2014 ◽  
Vol 1033-1034 ◽  
pp. 399-403
Author(s):  
Ren Juan Ma ◽  
Yong Quan Xu ◽  
Yu Min Liu ◽  
Rui Hong Zhao ◽  
Xiang Jing Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Gas Flow ◽  
Separation Efficiency ◽  
Sol Gel ◽  
Fixed Bed ◽  
Nay Zeolite ◽  
Sol Gel Process ◽  
Curve Method ◽  
Ft Ir ◽  
Adsorption Desorption

NaY zeolite was prepared by a simple sol-gel process. The prepared NaY was characterized by XRD,FT-IR,N2adsorption/desorption isotherms, and scanning electron microscope (SEM). The CO2dynamic adsorption/desorption performance of NaY was tested under atmospheric pressure using adsorption curve method in the fixed bed. The results demonstrate that NaY offeres high separation efficiency for CO2against N2. To further identify the most adsorption conditions, different adsorption temperatures and gas flow rates were investigated respectively. It is shown that NaY zeolite has the largest adsorption capacity of 88 mg/g adsorbent at 60°C,50ml/min, and the sample maintains still strong adsorption capacity and stable structure during 6 consecutive test cycles, which exhibits its stable adsorption/desorption behavior.

scholarly journals Uranium (VI) adsorption equilibrium on purolite resin SGA 600 U/3472

2014 ◽  
Vol 12 (7) ◽  
pp. 769-773 ◽  
Author(s):  
Adriana Botez ◽  
Tanase Dobre ◽  
Eugenia Panturu ◽  
Antoaneta Filcenco-Olteanu
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Equilibrium ◽  
Negative Impact ◽  
Fixed Bed ◽  
Continuous System ◽  
Equilibrium Isotherms ◽  
Ion Content ◽  
Uranium Adsorption ◽  
Industrial Processing ◽  
Adsorption Desorption

AbstractThis paper characterizes uranium (VI) sorption from synthetic solutions using a fixed bed Purolite resin SGA 600 U/3472 system. The effect of the sulphate anion presence in the liquid phase on sorbtion dynamics and equilibrium is analysed. In the industrial processing of solutions obtained from leaching of uranium ore (alkaline/acid), in a continuous system, there are several compounds which strongly compete with uranium for ion exchange sites and consequently these substances depress the uranium adsorption. The influence of vanadate, molybdate, chloride, and nitrate is known, therefore, in this paper, the adsorption equilibrium isotherms for uranium (VI) are obtained for different sulphate ion concentrations in solution. The adsorption capacity variation of the Purolite resin SGA 600U/3472 with the number of adsorption/desorption cycles is also studied. The experimental results reveal the negative impact of high sulphate ion content in solution on the adsorption capacity of the resin Purolite SG 600 U / 3472 with uranium (VI) and therefore it is considered one of the compounds which strongly affect the uranium adsorption.

Continuous fixed bed adsorption of Cu(II) by halloysite nanotube–alginate hybrid beads: an experimental and modelling study

2014 ◽  
Vol 70 (2) ◽  
pp. 192-199 ◽  
Author(s):  
Yanyan Wang ◽  
Xiang Zhang ◽  
Qiuru Wang ◽  
Bing Zhang ◽  
Jindun Liu
Keyword(s):  
Adsorption Capacity ◽  
Flow Rate ◽  
Fixed Bed ◽  
Halloysite Nanotubes ◽  
Fixed Bed Column ◽  
Factors Affecting ◽  
Bed Height ◽  
Column Adsorption ◽  
Fixed Bed Adsorption ◽  
Adsorption Desorption

We used natural resources of halloysite nanotubes and alginate to prepare a novel porous adsorption material of organic–inorganic hybrid beads. The adsorption behaviour of Cu(II) onto the hybrid beads was examined by a continuous fixed bed column adsorption experiment. Meanwhile, the factors affecting the adsorption capacity such as bed height, influent concentration and flow rate were investigated. The adsorption capacity (Q0) reached 74.13 mg/g when the initial inlet concentration was 100 mg/L with a bed height of 12 cm and flow rate of 3 ml/min. The Thomas model and bed-depth service time fitted well with the experimental data. In the regeneration experiment, the hybrid beads retained high adsorption capacity after three adsorption–desorption cycles. Over the whole study, the new hybrid beads showed excellent adsorption and regeneration properties as well as favourable stability.

CO2 Capture onto Zeolite 13X and Zeolite 4A by Pressure Swing Adsorption in a Fixed Bed

2014 ◽  
Vol 592-594 ◽  
pp. 1456-1460 ◽  
Author(s):  
Lalhmingsanga Hauchhum ◽  
P. Mahanta
Keyword(s):  
Adsorption Capacity ◽  
Pressure Swing Adsorption ◽  
Fossil Fuels ◽  
Gas Adsorption ◽  
Fixed Bed ◽  
Fuel Gas ◽  
Zeolite 13X ◽  
Zeolite 4A ◽  
Pressure Swing ◽  
Adsorption Desorption

Combustion of fossil fuels is one of the major sources of greenhouse gas CO2, it is therefore necessary to develop technologies that will allow us to utilize the fossil fuels while reducing the emissions of greenhouse gases. Pressure swing adsorption (PSA) is a potential technique for removing CO2from high-pressure fuel gas streams. Zeolites are suitable candidate sorbents for use in the PSA process. Studies of the gas adsorption of CO2onto zeolite 13X and zeolite 4A were conducted at a temperature of 25 °C, 35 °C, 45 °C and 60 °C up to a pressure of 1 bar. The data fitting is accomplished with the Toth and Sips adsorption models which are generally used for micro-porous adsorbents such as zeolites. Moreover, regeneration studies have been conducted in order to verify the possibility of adsorbents reutilization, to determine its CO2adsorption capacity within consecutive cycles of adsorption–desorption. Zeolite with higher surface area showed higher CO2adsorption capacity. There is no full reversibility for the two zeolites.

The Adsorption/Desorption Dynamics Properties of N-Alkanes in Light Naphtha on 5A Zeolites

2013 ◽  
Vol 807-809 ◽  
pp. 2643-2646
Author(s):  
Xiang Ji ◽  
Qing Sheng Zhang ◽  
Qun Cui ◽  
Hai Yan Wang
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Fixed Bed ◽  
Light Naphtha ◽  
Bet Specific Surface Area ◽  
Purge Gas ◽  
Adsorption Desorption

Self-made JH4 zeoite was characterized by BET, mercury and other methods. The dynamic adsorption capacity of nC5/nC6 in light naphtha on JH4 zeolite fixed bed was investigated. The effect of cyclic purge exhaust composition, which simulate different condensation conditions, on desorption performance of JH4 zeolite bed was studied. The results shows that, the microporous BET specific surface area and pore volume of JH4 zeolite is 710.05 m2/g and 0.32 cm3/g; macropore specific surface area and pore volume is 3.64 m2/g and 0.29 cm3/g, respectively. Under the adsorption conditions of 0.1 MPa, 165 °C, adsorption capacity of n-pentane and n-hexane in light naphtha on JH4 zeolite reaches, 7.24 g/100gadsand 3.11 g/100gadsrespectively.If the content of pentane and hexane achieves 3.68% and 0.21% in nitrogen purge gas, total desorption amount of JH4 zeolite is 2.07 g/100gads, falling 60.19% than that of pure N2purge.

scholarly journals Adsorption Capacity and Selectivity of Molecularly Imprinted Polymers towards β-Sitosterol

2019 ◽  
Vol 31 (11) ◽  
pp. 2527-2531
Author(s):  
St. Fauziah ◽  
N.H. Soekamto ◽  
P. Budi ◽  
P. Taba
Keyword(s):  
Adsorption Capacity ◽  
Molecularly Imprinted Polymers ◽  
Solid Phase ◽  
Polymerization Reaction ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Sample Extract ◽  
Uv Visible ◽  
Adsorption Desorption ◽  
Isothermal Equation

Molecularly imprinted polymers (MIP) as an adsorbent has been synthesized using β-sitosterol as molecule template on free radical polymerization reaction. The capacity and selectivity of the adsorption from MIP to β-sitosterol was studied in this study. The β-sitosterol concentration in the adsorption-desorption test and the MIP selectivity test were analyzed by UV-visible and HPLC. The MIP obtained from the synthesis results in a high adsorption capacity. Based on the Freundlich adsorption isothermal equation, the adsorption capacity (k) was found to be 1.24 mg/g. The MIP can adsorb 100 % β-sitosterol while cholesterol was only 3 %. The MIP is most selective to β-sitosterol, therefore, has high potential to apply as adsorbent at solid phase extraction method to isolate β-sitosterol from sample extract.

scholarly journals Biochar of Spent Coffee Grounds as Per Se and Impregnated with TiO2: Promising Waste-Derived Adsorbents for Balofloxacin

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2295
Author(s):  
Marwa El-Azazy ◽  
Ahmed S. El-Shafie ◽  
Hagar Morsy
Keyword(s):  
Adsorption Capacity ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Spent Coffee Grounds ◽  
Thermal Stabilities ◽  
Coffee Grounds ◽  
Bet Analysis ◽  
Pseudo Second Order ◽  
Set Up ◽  
Adsorption Desorption

Biochars (BC) of spent coffee grounds, both pristine (SCBC) and impregnated with titanium oxide (TiO2@SCBC) were exploited as environmentally friendly and economical sorbents for the fluroquinolone antibiotic balofloxacin (BALX). Surface morphology, functional moieties, and thermal stabilities of both adsorbents were scrutinized using SEM, EDS, TEM, BET, FTIR, Raman, and TG/dT analyses. BET analysis indicated that the impregnation with TiO2 has increased the surface area (50.54 m2/g) and decreased the pore size and volume. Batch adsorption experiments were completed in lights of the experimental set-up of Plackett-Burman design (PBD). Two responses were maximized; the % removal (%R) and the adsorption capacity (qe, mg/g) as a function of four variables: pH, adsorbent dosage (AD), BALX concentration ([BALX]), and contact time (CT). %R of 68.34% and 91.78% were accomplished using the pristine and TiO2@SCBC, respectively. Equilibrium isotherms indicated that Freundlich model was of a perfect fit for adsorption of BALX onto both adsorbents. Maximum adsorption capacity (qmax) of 142.55 mg/g for SCBC and 196.73 mg/g for the TiO2@SCBC. Kinetics of the adsorption process were best demonstrated using the pseudo-second order (PSO) model. The adsorption-desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 66.32% after the fifth cycles.

Synthesis and Characterization of Different γ-Al2O3 Nanocatalysts for Methanol Dehydration to Dimethyl Ether

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Seyyed Ya'ghoob Hosseini ◽  
Mohammad Reza Khosravi Nikou
Keyword(s):  
Dimethyl Ether ◽  
Solid Acid Catalyst ◽  
Fixed Bed ◽  
Operating Parameter ◽  
Textural Properties ◽  
Ammonia Solution ◽  
Precipitation Method ◽  
High Yield ◽  
Methanol Dehydration ◽  
Adsorption Desorption

Abstract A simple co-precipitation method was utilized to synthesize γ-Al2O3 catalysts using aluminum nitrate nonahydrate as the source of aluminum cations for methanol dehydration to dimethyl ether (DME). Different precipitating agents comprising ammonium carbonate, ammonium bicarbonate and ammonia solutions were used for preparation of the samples. The catalysts were characterized by XRD, FTIR, SEM, NH3-TPD and N2 adsorption-desorption techniques. The sample prepared by ammonia solution had the highest acidity among the synthesized catalysts. Also, N2 adsorption-desorption results showed suitable textural properties for all of the synthesized samples. Vapor phase dehydration of methanol to DME was performed in the fixed bed micro reactor over the synthesized catalysts and commercial one for comparison purposes. The effects of different characteristics of catalysts such as surface area, acidity, sintering factor and temperature as an operating parameter on performance of catalysts were investigated. The catalyst prepared by ammonia solution showed best catalytic activity due to the suitable textural properties and high amount of acidic sites. Also, the results showed that only high acid strength can’t result high yield of DME for a solid acid catalyst.

Removal of Cd(II) from Water System Using Novel Biosorbent Derived from Persimmon Fallen Leaves

2015 ◽  
Vol 1130 ◽  
pp. 685-688
Author(s):  
Rui Yi Fan ◽  
Qing Ping Yi ◽  
Qing Lin Zhang ◽  
Zheng Rong Luo
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Water System ◽  
Raw Material ◽  
Batch Adsorption ◽  
Diospyros Kaki ◽  
Cadmium Metal ◽  
Fallen Leaves ◽  
Adsorption Desorption

A biosorbent was prepared by treating the persimmon (Diospyros kaki Thunb.) fallen leaves with sodium hydroxide (NaOH). The NaOH concentration and stirring period for the preparation of the biosorbent were adjusted to optimise the Cd(I) adsorption capacity of the biosorbents. Removal of highly toxic Cadmium metal ions from water system using the optimal biosorbent named ‘NPFL’ was investigated using a mimic industrial column. The result showed that NPFL could remove Cd(II) in large quantities from aqueous solution with coexisting metal ions. The raw material, NPFL and Cd(II) loaded NPFL were characterized by SEM-EDS. The reusability of NPFL was also studied by batch adsorption-desorption test.

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