scholarly journals Comparative studies on the adsorption of Pb(II) ions by fly ash and slag obtained from CFBC technology

2019 ◽  
Vol 21 (4) ◽  
pp. 72-81 ◽  
Author(s):  
Tomasz Kalak ◽  
Ryszard Cierpiszewski
Keyword(s):  
Fly Ash ◽  
Circulating Fluidized Bed ◽  
Chemical Properties ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Maximum Adsorption Capacity ◽  
Fluidized Bed Combustion ◽  
Freundlich Model ◽  
Pseudo Second Order ◽  
Physical And Chemical

Abstract Fly ash and slag were examined for the removal processes of Pb(II) ions from water in batch experiments under different conditions of adsorbent dosage, initial concentration, pH and contact time. The materials are industrial waste generated from the high temperature treatment of sewage sludge by the circulating fluidized bed combustion (CFBC) technology. Physical and chemical properties, as well as adsorption efficiency and calculated maximum adsorption capacity of Pb(II) ions were determined using a variety of methods. The kinetic analysis revealed that the adsorption process is better described by the pseudo-second order equation and it is well fitted to the Freundlich model.

Mechanism of Mn(II) Absorption and Desorption with CFBC Fly Ash Modified by Alkaline Wet Ball Milling

2018 ◽  
Vol 914 ◽  
pp. 151-159
Author(s):  
Ya Hong Xu ◽  
Zhong Hui Xu ◽  
Zao Jiang ◽  
Na Li ◽  
Ping Li ◽  
...  
Keyword(s):  
Fly Ash ◽  
Adsorption Capacity ◽  
Circulating Fluidized Bed ◽  
Low Cost ◽  
Fluidized Bed Combustion ◽  
Freundlich Isotherms ◽  
Elovich Equation ◽  
Pseudo Second Order ◽  
Cfbc Fly Ash ◽  
Physical And Chemical

In this study, the adsorption properties of modified circulating fluidized-bed combustion (CFBC) fly ash by alkali wet millingwere investigated for Mn (II) cations. The effects ofNaOH content,milling speed and milling timeon the modification processof CFBC fly ashwerestudied. Preliminary statistical analysis has indicated thatmetal concentration, time, pH, fly ash dosage and temperaturewere the most importantvariables that affect the adsorption capacity. Results lead towards the conclusion that alkali wet millingtreatment cansignificantly increasethe adsorption capacity of the CFBC fly ash. The adsorption mechanism of the modified CFBCfly ash was determined using Langmuir, Freundlich isotherms and the Lagergren pseudo-first-order, pseudo-second-order, Elovich equation and the intraparticle diffusion equation, which indicated it was not thesole rate determiningstep, and the adsorption process was controlled by physical and chemical adsorption.The results showed that theCFBC fly ash can be utilized as a low-cost adsorbent for the removal of Mn (II) ionsfrom solution.

Chemical Properties and Reactivity of CFBC Fly Ash

2016 ◽  
Vol 722 ◽  
pp. 132-139 ◽  
Author(s):  
Tomáš Váchal ◽  
Rostislav Šulc ◽  
Tereza Janků ◽  
Pavel Svoboda
Keyword(s):  
Thermal Properties ◽  
Fly Ash ◽  
Circulating Fluidized Bed ◽  
Chemical Properties ◽  
Total Content ◽  
Calorimetric Measurement ◽  
Fluidized Bed Combustion ◽  
Cfbc Fly Ash ◽  
Circulating Fluidized Bed Combustion ◽  
Methods Of Measurement

This paper describes chemical properties of fly ash from Circulating fluidized Bed Combustion (CFBC). There are shown thermal properties of fly ash using calorimetric measurement and the total content of calcium oxide CaO was determined. This paper describes the methods of measurement for determining these properties including granulometric measurement and chemical analysis. Also there were described and evaluated properties of fly ash and the reactivity of the fly ash was compared.

Removal of Mn(II) from Aqueous Solution Using Saponified Garlic Peel

2014 ◽  
Vol 694 ◽  
pp. 382-386 ◽  
Author(s):  
Bo Liang ◽  
Wan He Zhao ◽  
Kai Huang ◽  
Hong Min Zhu
Keyword(s):  
Metal Ion ◽  
Chemical Properties ◽  
Correlation Coefficients ◽  
Ion Concentration ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Physical And Chemical ◽  
Garlic Peel

The removal of Mn (II) ion by saponified garlic peel (S-GP) was investigated using batch adsorption. SEM and FT-IR were employed to investigate the physical and chemical properties of S-GP. The adsorption was evaluated as a function of initial metal ion concentration, contact time and temperature. The maximum adsorption capacity for Mn (II) was 0.51 mol/kg, and the adsorption process followed the Langmuir model. Pseudo-second-order models fitted the experimental data well and kinetic parameters, rate constants, equilibrium sorption capacity and related correlation coefficients at various temperatures were calculated and discussed. A possible adsorption mechanism based on a cation exchange was proposed for the adsorption of Mn (II).

Influence of Milling on some Chemical Properties and Reactivity of CFBC Fly Ash

2018 ◽  
Vol 760 ◽  
pp. 73-80 ◽  
Author(s):  
Tomáš Váchal ◽  
Rostislav Šulc ◽  
Tereza Janků ◽  
Pavel Svoboda
Keyword(s):  
Fly Ash ◽  
Chemical Analysis ◽  
Circulating Fluidized Bed ◽  
Chemical Properties ◽  
Total Content ◽  
Calorimetric Measurement ◽  
Fluidized Bed Combustion ◽  
Cfbc Fly Ash ◽  
Circulating Fluidized Bed Combustion ◽  
Methods Of Measurement

This paper describes influence of milling on chemical properties of fly ash from Circulating fluidized Bed Combustion (CFBC). Specific properties of fly ash was determined using calorimetric measurement. It was determined heat properties and total content of calcium oxide CaO. The following methods of measurement were also performed: granulometric measurement and chemical analysis. The ash properties of non-milled and milled ashes were also described and evaluated and the ash reactivity was compared.

scholarly journals Facile Synthesis of Cross-linked Hyperbranched Polyamidoamines Dendrimers for Efficient Hg(Ⅱ) Removal From Water

2021 ◽  
Vol 9 ◽  
Author(s):  
Xue Geng ◽  
Rongjun Qu ◽  
Xiangyu Kong ◽  
Shengnan Geng ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Metal Ion ◽  
Large Scale ◽  
Chemical Properties ◽  
Diglycidyl Ether ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Pseudo Second Order ◽  
Physical And Chemical

Dendrimers as commonly used metal ions adsorption materials have the advantages of good adsorption performance and high reuse rate, but the high cost limits its extensive use. Compared with dendrimers, hyperbranched dendrimers have similar physical and chemical properties and are more economical. Therefore, hyperbranched dendrimers are more suitable for industrial large-scale adsorption. The hyperbranched polyamidoamine (HPAMAM) gels were prepared by cross-linking hyperbranched polyamidoamine (HPAMAM-ECH-x and HPAMAM-EGDE-x) with different amounts of epichlorohydrin (ECH) and ethylene glycol diglycidyl ether (EGDE), respectively. The as-synthesized adsorbents were characterized by FT-IR, SEM and XPS. The prepared adsorbents were used to adsorb Hg(Ⅱ) in aqueous solution, and the effects of solution pH, contact time, temperature and initial concentration of metal ion on the adsorption capacity were investigated. The effect of solution pH indicated that the optimum condition to Hg(Ⅱ) removing was at pH 5.0. The adsorption kinetic curves of the two kinds of materials were in accordance with the pseudo-second-order model. For the HPAMAM-ECH samples, the adsorption thermodynamic curves fitted the Langmuir model, while for the HPAMAM-EGDE samples, both Langmuir and Freundlich equations fitted well. The maximum adsorption capacity of HPAMAM-ECH-3 obtained from Langmuir model toward Hg(Ⅱ) was 3.36 mmol/g at pH 5.0 and 35°C.

scholarly journals Highly Effective Adsorption Process of Ni(II) Ions with the Use of Sewage Sludge Fly Ash Generated by Circulating Fluidized Bed Combustion (CFBC) Technology

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk
Keyword(s):  
Fly Ash ◽  
Sewage Sludge ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Fluidized Bed Combustion ◽  
Nickel Ions ◽  
Suitable Material ◽  
Circulating Fluidized Bed Combustion

Recently, more and more attention has been paid to the removal of nickel ions due to their negative effects on the environment and human health. In this research, fly ash obtained as a result of incineration of municipal sewage sludge with the use of circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Ni(II) ions in adsorption processes. The properties of the material were determined using analytical methods, such as SEM-EDS, XRD, BET, BJH, thermogravimetry, zeta potential, SEM, and FT-IR. Several factors were analyzed, such as adsorbent dose, initial pH, initial concentration, and contact time. As a result of the conducted research, the maximum sorption efficiency was obtained at the level of 99.9%. The kinetics analysis and isotherms showed that the pseudo-second order equation model and the Freundlich isotherm model best suited this process. In conclusion, sewage sludge fly ash may be a suitable material for the effective removal of nickel from wastewater and the improvement of water quality. This research is in line with current trends in the concepts of circular economy and sustainable development.

Monitoring of Fluctuations in the Physical and Chemical Properties of a High-Calcium Fly Ash

1987 ◽  
Vol 113 ◽  
Author(s):  
Scott Schlorholtz ◽  
Ken Bergeson ◽  
Turgut Demirel
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Physical And Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
High Calcium ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTThe physical and chemical properties of fly ash produced at Ottumwa Generating Station have been monitored since April, 1985. The fly ash is produced from burning a low sulfur, sub-bituminous coal obtained from the Powder River Basin near Gillette, Wyoming. One-hundred and sixty samples of fly ash were obtained during the two year period. All of the samples were subjected to physical testing as specified by ASTM C 311. About one-hundred of the samples were also subjected to a series of tests designed to monitor the self-cementing properties of the fly ash. Many of the fly ash samples were subjected to x-ray diffraction and fluorescence analysis to define the mineralogical and chemical composition of the bulk fly ash as a function of sampling date. Hydration products in selected hardened fly ash pastes, were studied by x-ray diffraction and scanning electron microscopy. The studies indicated that power plant operating conditions influenced the compressive strength of the fly ash paste specimens. Mineralogical and morphological studies of the fly ash pastes indicated that stratlingite formation occurred in the highstrength specimens, while ettringite was the major hydration product evident in the low-strength specimens.

Utilization of Circulating Fluidized Bed Combustion (CFBC) Fly Ash and Coal-Fired Fly Ash in Portland Cement

2014 ◽  
Vol 629-630 ◽  
pp. 306-313 ◽  
Author(s):  
Mao Chieh Chi ◽  
Ran Huang ◽  
Te Hsien Wu ◽  
Toun Chun Fou
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Fluidized Bed ◽  
Building Materials ◽  
Circulating Fluidized Bed ◽  
Setting Time ◽  
Fluidized Bed Combustion ◽  
Initial Setting Time ◽  
Cfbc Fly Ash ◽  
Circulating Fluidized Bed Combustion

Circulating fluidized bed combustion (CFBC) fly ash is a promising admixture for construction and building materials due to its pozzolanic activity and self-cementitious property. In this study, CFBC fly ash and coal-fired fly ash were used in Portland cement to investigate the pozzolanic and cementitious characteristics of CFBC fly ash and the properties of cement-based composites. Tests show that CFBC fly ash has the potential instead of cementing materials and as an alternative of pozzolan. In fresh specimens, the initial setting time of mortars increases with the increasing amount of cement replacement by CFBC fly ash and coal-fire fly ash. In harden specimens, adding CFBC fly ash to replace OPC reduces the compressive strength. Meanwhile, CFBC fly ash would results in a higher length change when adding over 30%. Based on the results, the amount of CFBC fly ash replacement cement was recommended to be limited below 20%.

scholarly journals Features of Waste Chemical Processing Germanium Concentrates

2020 ◽  
Author(s):  
Igor Nikolaevich Tanutrov ◽  
Marina Nikolaevna Sviridova
Keyword(s):  
Chemical Properties ◽  
Average Diameter ◽  
Toxic Waste ◽  
High Temperature Treatment ◽  
High Dispersion ◽  
Chemical Processing ◽  
Particle Sizes ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

In order to increase the extraction of germanium in the technology of production of germanium concentrates, as well as finding ways to eliminate the accumulation of toxic waste using modern techniques and equipment, the physical and chemical properties of waste chemical processing of germanium concentrates (OHGC) of two domestic enterprises were experimentally studied. The main components of OHGC are: sulphate hemihydrate CaSO4·0.5H2O and hypochlorite Ca(OCl)2 calcium. The moisture content of the sludge amounted to 30–50 %. The content of germanium in the cakes of both companies is in the range of 0.20 and 0.27 %, respectively, indicating the feasibility of recovery in the Ge. At the same time, the samples of cakes differ significantly in the content of impurities, which depends on the types of raw materials in the preparation of concentrates. Granulometric composition of cakes is characterized by high dispersion. With an average diameter of 12 μm, all particle sizes are in the range of 0.5-15 μm. The distribution of particle sizes is shifted in interval of 0–15 μm, and the area of the particles less than 3 μm is not more than 10 %. The high dispersion of the cake is reflected in the specific surface area, which is 23.7 m2/g. Thermographic study found that the heating of the sample cake is accompanied by two endothermic effects of dehydration at 110 and 145–168 ∘C calcium sulfate and hypochloride semihydrate with corresponding weight loss of 13.1 and 12.9 %. The presence of toxic impurities (arsenic, zinc and lead), as well as chlorine, presents significant challenges for the development of disposal technology with the extraction of germanium. Assuming that the undiscovered part of the germanium in the concentrate is compounds or solid solutions with silicon dioxide, an effective technology should include their reagent high temperature treatment. Keywords: waste, germanium concentrate, chemical processing, waste, physical and chemical properties

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