scholarly journals Hydrogen Sulfide Adsorption by Iron Oxides and Their Polymer Composites: A Case-Study Application to Biogas Purification

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4725
Author(s):  
Camilla Costa ◽  
Matteo Cornacchia ◽  
Marcello Pagliero ◽  
Bruno Fabiano ◽  
Marco Vocciante ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Surface Area ◽  
Fixed Bed ◽  
Cost Effective ◽  
Chemical Precipitation ◽  
Breakthrough Curves ◽  
Operating Conditions ◽  
Precipitation Method ◽  
Inert Matrix ◽  
Biogas Purification

An experimental study of hydrogen sulfide adsorption on a fixed bed for biogas purification is proposed. The adsorbent investigated was powdered hematite, synthesized by a wet-chemical precipitation method and further activated with copper (II) oxide, used both as produced and after pelletization with polyvinyl alcohol as a binder. The pelletization procedure aims at optimizing the mechanical properties of the pellet without reducing the specific surface area. The active substrate has been characterized in its chemical composition and physical properties by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), thermogravimetric analysis (TGA) and N2 physisorption/desorption for the determination of surface area. Both powders and pellets have been tested as sorbents for biogas purification in a fixed bed of a steady-state adsorption column and the relevant breakthrough curves were determined for different operating conditions. The performance was critically analyzed and compared with that typical of other commercial sorbents based on zinc oxide or relying upon specific compounds supported on a chemically inert matrix (SulfaTreat®). The technique proposed may represent a cost-effective and sustainable alternative to commercial sorbents in conventional desulphurization processes.

scholarly journals Synthesis and application of CeO2/sawdust nanocomposite for removal of As (III) ions from aqueous solutions using a fixed bed column system

2016 ◽  
Vol 19 (1) ◽  
pp. 7-16 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Flow Rate ◽  
Fixed Bed ◽  
Cost Effective ◽  
Sorption Process ◽  
Breakthrough Curves ◽  
Precipitation Method ◽  
Thomas Model ◽  
Influent Concentration ◽  
Column System

<p>In this study, nanocomposite of ceria sawdust (CeO<sub>2</sub>/SD) synthesized by precipitation method was utilized for removal of As (III) ions from aqueous solutions. Study of the process was done in column system. Characterization of the nano sized adsorbent particles was carried out using XRD and SEM techniques. The effects of important parameters, such as the value of initial pH, the flow rate, the influent concentration of arsenic and bed depth were studied in the column system. The Thomas model was applied for treatment of the adsorption data at different flow rate, influent concentration and bed depth. The bed-depth/service time analysis (BDST) model was also applied at different bed depth to predict the breakthrough curves. The two models were found suitable for describing the bio sorption process of the dynamic behavior of the CeO<sub>2</sub>/SD adsorbent in column investigation. Based on Thomas model, the equilibrium adsorption reached 8.28 mg g<sup>−</sup><sup>1</sup> when a As(III) polluted solution with influent concentration of As 10 mg l<sup>-1 </sup>passed through the column with a flow rate of 2 ml min<sup>−</sup><sup>1</sup>. All the results suggested the presented nanocomposite as an efficient and cost effective adsorbent for removal of As (III) ions from aqueous solutions.</p>

Hydroxyapatite as a bifunctional nanocatalyst for solventless Henry reaction: A demonstration of morphology dependent catalysis

2022 ◽  
Author(s):  
Smriti Mukherjee ◽  
Iyyappan E ◽  
Keerthi Satheesh ◽  
Elsa Maria Jordi ◽  
Saranya S ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Precipitation ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
Current Investigation ◽  
Henry Reaction

In the current investigation, HA nanorods and nanoplates with a high surface area have been synthesized using the chemical precipitation method via alcogel formation employing L-arginine as a crystal growth...

scholarly journals Sorption of Ag+ and Cu2+ by Vermiculite in a Fixed-Bed Column: Design, Process Optimization and Dynamics Investigations

2018 ◽  
Vol 8 (11) ◽  
pp. 2221 ◽  
Author(s):  
Olga Długosz ◽  
Marcin Banach
Keyword(s):  
Flow Rate ◽  
Continuous Process ◽  
Fixed Bed ◽  
Copper Ion ◽  
Cost Effective ◽  
Breakthrough Curves ◽  
Fixed Bed Column ◽  
Column System ◽  
Total Percentage ◽  
Bed Height

Vermiculite has been used for the removal of Cu 2 + and Ag + from aqueous solutions in a fixed-bed column system. The effects of initial silver and copper ion concentrations, flow rate, and bed height of the adsorbent in a fixed-bed column system were investigated. Statistical analysis confirmed that breakthrough curves depended on all three factors. The highest inlet metal cation concentration (5000 mg/dm3), the lowest bed height (3 cm) and the lowest flow rate (2 and 3 cm3/min for Ag + and Cu 2 + , respectively) were optimal for the adsorption process. The maximum total percentage of metal ions removed was 60.4% and 68.7% for Ag+ and Cu2+, respectively. Adsorption data were fitted with four fixed-bed adsorption models, namely Clark, Bohart–Adams, Yoon–Nelson and Thomas models, to predict breakthrough curves and to determine the characteristic column parameters. The adsorbent was characterized by SEM, FTIR, EDS and BET techniques. The results showed that vermiculite could be applied as a cost-effective sorbent for the removal of Cu 2 + and Ag + from wastewater in a continuous process.

scholarly journals Far-infrared optical constants of ZnO and ZnO/Ag nanostructures

RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 20902-20908 ◽  
Author(s):  
Reza Zamiri ◽  
Avito Rebelo ◽  
Golriz Zamiri ◽  
Atena Adnani ◽  
Ajay Kuashal ◽  
...  
Keyword(s):  
Optical Constants ◽  
Far Infrared ◽  
Cost Effective ◽  
Chemical Precipitation ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
Ag Nanoparticle ◽  
Wet Chemical ◽  
Wet Chemical Precipitation

We report on the synthesis of ZnO nanoplates and ZnO nanoplate/Ag nanoparticle heterostructures via a simple and cost effective wet chemical precipitation method.

scholarly journals Stannous Oxide Thick Film Nanosensors Design by Screen Printing Technology: Structural, Electrical Parameters and H2s Gas Detection Study

2021 ◽  
Vol 18 (1) ◽  
pp. 66-74
Author(s):  
Umesh Jagannath Tupe ◽  
Arun Vitthal Patil ◽  
Madhukar Sarvottam Zambare ◽  
Prashant Bhimrao Koli
Keyword(s):  
Hydrogen Sulfide ◽  
Thick Film ◽  
Screen Printing ◽  
Sno2 Nanoparticles ◽  
Average Particle Size ◽  
Cost Effective ◽  
Surface Characteristic ◽  
Precipitation Method ◽  
Average Particle ◽  
Stannous Oxide

The present research deals with the fabrication of stannous oxide nanoparticles by conventional and cost effective co precipitation method. The thick film sensors of SnO2 nanoparticles were prepared by standard screen-printing technique by photolithography. The prepared SnO2 material was characterized by several techniques to confirm the structural properties. Initially, the prepared nanoparticles of SnO2 were investigated by x-ray diffraction technique to confirm the synthesis of prepared material within nanoscale. From XRD data the average particle size of prepared thick films was found to be 21.87 nm calculated using Debye-Scherer formula. The material was further characterized by using scanning electron microscopy (SEM) to investigate the structural and surface characteristic of SnO2. SEM data clearly indicates the heterogeneous surface, and some voids present over the surface of SnO2 nanoparticles. The Fourier transfer infra red technique was employed to investigate the metal oxygen frequency of SnO2 material. The prepared sensor was exclusively utilized to sense the hydrogen sulfide gas vapors at various concentrations. The prepared sensor was found to be highly sensitive to H2S vapors nearly 63.8% sensitivity was recorded. The response and recovery study shows the response time of 9 seconds and recovery time of 19 seconds for hydrogen sulfide gas vapors. The SnO2 sensor was further utilized for recycling performance to get the firm results of sensitivity in four turns with period of 15 days.

Treatment of landfill leachate by preozonation and adsorption in activated carbon columns

1996 ◽  
Vol 34 (9) ◽  
pp. 33-40 ◽  
Author(s):  
J. Fettig ◽  
H. Stapel ◽  
C. Steinert ◽  
M. Geiger
Keyword(s):  
Activated Carbon ◽  
Landfill Leachate ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Operating Conditions ◽  
Practical Case ◽  
Leachate Treatment ◽  
Homogeneous Surface ◽  
Adsorption Processes ◽  
Cost Efficient

Landfill leachate pretreated in an aerobic biological stage was studied with respect to the adsorption behaviour of its organic components with and without preoxidation by different amounts of ozone. Isotherm data evaluated by adsorption analysis showed that the fractions of non-adsorbable and weakly adsorbable species had been increased after preoxidation. As a result, the carbon capacity in a fixed-bed adsorption process was expected to be significantly lower for preoxidized leachate. This conclusion was confirmed by data from column experiments. The breakthrough curves under operating conditions typical for leachate treatment could be predicted quite well by the homogeneous surface diffusion model when no preoxidation was applied. After preozonation about 40% of the remaining organic substances were biodegradable. Data evaluation revealed that biodegradation took place inside the activated carbon beds. Therefore the total removal of ozonated leachate in activated carbon columns will be higher than the removal due to adsorption processes. An economic analysis must show in any practical case whether a combination of preoxidation and adsorption will be more cost-efficient than either of the single processes. The modelling technique applied in this study can be a useful tool for that purpose.

Characterization of Novel Sorbents for Mercury Removal at Elevated Temperature

2015 ◽  
Vol 656-657 ◽  
pp. 23-27
Author(s):  
Han Wen Cheng ◽  
Ching Tsung Yu
Keyword(s):  
Elevated Temperature ◽  
Transition Metals ◽  
Surface Area ◽  
Fixed Bed ◽  
Elemental Mercury ◽  
Fixed Bed Reactor ◽  
Mercury Removal ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Retention Capacity

The novel carbonate sorbents of Mg–Al–CO3 and (Mg3−x, Cux)–Al–CO3, were synthesized by co-precipitation method with individual nitrate salt of metal ions under alkaline conditions. The synthetic sorbent was characterized by analysis techniques such as BET surface area analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Elemental mercury capture experiments were carried out in a fixed-bed reactor including Hg permeation source, furnace, and Hg analyzer, which was conducted at temperature ranging from 30 to 300 o C. The major results showed that the surface area of material was significantly increased via incorporating Cu2+ into Mg–Al–CO3, accordingly enhancing Hg retention capacity of sorbents. SEM imagines displayed the layer appearance of Mg/Al and Mg/Cu/Al sorbents. Crystalline analysis indicated lamella structure accompanied with metal oxides within materials. Mercury removal tests demonstrated that the breakthrough time increased with temperature by adding transition metals to Mg–Al–CO3 as (Mg3−x, Cux)–Al–CO3. Hg uptake by the (Mg3−x, Cux)–Al–CO3 sorbent rapidly increased with elevated temperature up to 200 o C and reached the maximum capacity of 12.93 μg/g, and then gradually decreased after 300 o C. Surface area and unique properties of transition metals are the reason toward improving Hg capture sorbent. These results represent the feasibility of using such Hg sorbents for elemental mercury removal under elevated temperature conditions, and the detail mechanism is needed to be further studied.

Synthesis of luminescent nanoparticle embedded polymer nanocomposites for scintillation applications

2011 ◽  
Vol 1312 ◽  
Author(s):  
Thomas Rogers ◽  
Chenlu Han ◽  
Brent Wagner ◽  
Jason Nadler ◽  
Zhitao Kang
Keyword(s):  
Polymer Matrix ◽  
Gamma Ray ◽  
Cost Effective ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Colloidal Solutions ◽  
Index Matching ◽  
Luminescent Nanoparticle ◽  
Matrix Nanocomposite ◽  
Selection Of

ABSTRACTDetecting gamma-ray emission from radionuclides hidden within containers is a significant concern to national security and can be accomplished with scintillating materials such as NaI:Tl, LaBr3:Ce crystals. However, the use of these high quality crystals limits the functionality of the detectors due to their high cost and scalability issues. Therefore the development of more durable, more easily manufactured, and more cost effective scintillating materials is desired. The incorporation of nanophosphors or Quantum Dots (QDs) into a polymer matrix to produce a transparent nanocomposite could potentially provide an alternative method to fabricate scintillating detectors. Embedded in a suitable polymer matrix, nanocomposite detectors may be easily made suitably large for portal monitors. Also, preparation of suitable particle sizes and/or compositions permits selection of a photon wavelength that optimally matches the photodetector response curve to increase the number of photons collected per pulse. In this paper a series of LaF3:Ce nanophosphors with varying doping concentrations (1–30mol%Ce) were synthesized using a chemical precipitation method. Photoluminescence and photoluminescence excitation characterizations indicated that the highest luminescent intensity was obtained from the 20%Ce doped sample with a peak emission at 325 nm. The refractive indices of the nanoparticles were identified by index matching measurements. Then an index matched epoxy was selected for incorporation of these nanoparticles to prepare transparent nanocomposite scintillators. In addition, colloidal solutions of CdTe QDs with various emitting colors were synthesized and incorporated into a Polymethyl-methacrylate (PMMA) matrix to make transparent nanocomposites. An initial evaluation of the scintillation behavior of these nanocomposites was evaluated by exposure to gamma rays.

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