scholarly journals High Efficiency of the Removal Process of Pb(II) and Cu(II) Ions with the Use of Fly Ash from Incineration of Sunflower and Wood Waste Using the CFBC Technology

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1771
Author(s):  
Tomasz Kalak ◽  
Ryszard Cierpiszewski ◽  
Małgorzata Ulewicz

In these research studies, fly ash (SW-FA) resulting from the incineration of sunflower (20%) and wood (80%) waste employing the circulating fluidized bed combustion (CFBC) technology was used to analyze the possibility of removing Pb(II) and Cu(II) ions in adsorption processes. Currently, great emphasis is placed on circular economy, zero waste or climate neutrality strategies. The use of low-cost SW-FA waste seems to fit well with pro-ecological, economic and energy-saving trends. Hence, this material was characterized by various techniques, such as granulation analysis, bulk density, SEM-EDX, XRD and XRF analysis, BET, BJH, thermogravimetry, zeta potential, SEM morphology and FT-IR spectrometry. As a result of the conducted research, the factors influencing the effectiveness of the adsorption process, such as adsorbent dosage, initial and equilibrium pH, initial metal concentration and contact time, were analyzed. The maximum removal efficiency were achieved at the level of 99.8% for Pb(II) and 99.6% for Cu(II), respectively. The kinetics analysis and isotherms showed that the pseudo-second-order equation and the Freundlich isotherm models better describe these processes. The experiments proved that SW-FA can act as an appropriate adsorbent for highly effective removal of lead and copper from wastewater and improvement of water quality.

2016 ◽  
Vol 74 (5) ◽  
pp. 1069-1078 ◽  
Author(s):  
Mohammad Hossein Rasoulifard ◽  
Soghra Khanmohammadi ◽  
Azam Heidari

In the present study, we have used a simple and cost-effective removal technique by a commercially available Fe-Al-SiO2 containing complex material (hardened paste of Portland cement (HPPC)). The adsorbing performance of HPPC and modified HPPC with perlite for removal of cefixime from aqueous solutions was investigated comparatively by using batch adsorption studies. HPPC has been selected because of the main advantages such as high efficiency, simple separation of sludge, low-cost and abundant availability. A Taguchi orthogonal array experimental design with an OA16 (45) matrix was employed to optimize the affecting factors of adsorbate concentration, adsorbent dosage, type of adsorbent, contact time and pH. On the basis of equilibrium adsorption data, Langmuir, Freundlich and Temkin adsorption isotherm models were also confirmed. The results showed that HPPC and modified HPPC were both efficient adsorbents for cefixime removal.


Nova Scientia ◽  
2019 ◽  
Vol 11 (23) ◽  
pp. 01-25 ◽  
Author(s):  
Rafael Romero Toledo ◽  
Víctor Ruiz Santoyo ◽  
Luis M. Anaya Esparza ◽  
Alejandro Pérez Larios ◽  
Merced Martínez Rosales

Arsenic is a toxic element for human health. It persists in the environment as a result of natural and anthropic contamination, generating nocive effects for consumers. Some of them can be cancer, cardiovascular disorders, hypotension, metabolic disease and peripheral neuropathy. Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. The objective of this study was to generate a low cost agglomerated alumina adsorbent (A-1) for the effective removal of arsenic (V) from water and its comparison with a commercial agglomerated alumina (A-2). Both of them of 5 mm of diameter. The physicochemical properties of the adsorbents were characterized by various techniques, such as: XRF, zeta potential, XRD, adsorption-desorption of N2 and FE-SEM/EDS. Batch experiments were performed to evaluate the efficiency of removal of As (V) from water by A-1 and A-2. The point of zero charge of A-1 and A-2 was at pH 8.5 and 8.1, respectively. The experimental results in batches indicated that agglomerate A-1 has a higher adsorption capacity than A-2 (1.212 mg∙g-1; 1.058 mg∙g-1) in similar conditions, concentration of 15 mg∙L-1 of As (V), temperature (20± 2 °C) and pH 7. The adsorption processes of As (V) in A-1 and A-2 followed the kinetics of Pseudo-first order kinetic and the Freundlich isotherm. The results showed that the agglomerate A-1 is an attractive adsorbent for the effective removal of As (V) from water.


2018 ◽  
Vol 914 ◽  
pp. 151-159
Author(s):  
Ya Hong Xu ◽  
Zhong Hui Xu ◽  
Zao Jiang ◽  
Na Li ◽  
Ping Li ◽  
...  

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.


2021 ◽  
Vol 46 (2) ◽  
Author(s):  
C. M. Ngwu ◽  
O. K. Amadi ◽  
M. O. Mac-Kalunta ◽  
J. Onyeuwaoma

This study investigated the potential of iron filings as low cost and environmentally friendly adsorbent for removing Naphthol AS dye from aqueous solutions. The batch-adsorption experiments were performed as a function of pH, temperature, concentration, contact time as well as dynamics of the process. The Langmuir, Freundlich and Dubinin-Raduskevich isotherm models for the adsorption processes were tested but Freundlich isotherm provided the best description for adsorption of the dye solution onto the iron filings, suggesting a physisorption controlled adsorption. The adsorption process was highly pH-dependent and the result indicates that the optimum pH for adsorption of Naphthol AS onto the adsorbent occurred at 4.0 having a maximum removal efficiency of 88 % respectively. Pseudo first-order and second-order as well as the intra-particle diffusivity kinetic models were applied to the experimental data and results showed that the pseudo second-order provided best fit for the experimental data. Kinetic studies also showed that the adsorption transport mechanism was particle-diffusion controlled.


2017 ◽  
Vol 76 (12) ◽  
pp. 3307-3318 ◽  
Author(s):  
Tingting Qin ◽  
Zhaowei Wang ◽  
Xiaoyun Xie ◽  
Chaoran Xie ◽  
Junmin Zhu ◽  
...  

Abstract The biochar was prepared by pyrolyzing the roots of cauliflowers, at a temperature of 500 °C under oxygen-limited conditions. The structure and characteristics of the biochar were examined using scanning electron microscopy, an energy dispersive spectrometer, a zeta potential analyzer, and Fourier transform infrared spectroscopy. The effects of the temperature, the initial pH, antibiotic concentration, and contact time on the adsorption of norfloxacin (NOR) and chlortetracycline (CTC) onto the biochar were investigated. The adsorption kinetics of NOR and CTC onto the biochar followed the pseudo-second-order kinetic and intra-particle diffusion models. The adsorption isotherm experimental data were well fitted to the Langmuir and Freundlich isotherm models. The maximum adsorption capacities of NOR and CTC were 31.15 and 81.30 mg/g, respectively. There was little difference between the effects of initial solution pH (4.0–10.0) on the adsorption of NOR or CTC onto the biochar because of the buffering effect. The biochar could remove NOR and CTC efficiently in aqueous solutions because of its large specific surface area, abundant surface functional groups, and particular porous structure. Therefore, it could be used as an excellent adsorbent material because of its low cost and high efficiency and the extensive availability of the raw materials.


2021 ◽  
Vol 241 ◽  
pp. 01002
Author(s):  
Tumeletso Lekgoba ◽  
Freeman Ntuli ◽  
Bernard Mosweu

Coal fly ash obtained from a local power station was used as an adsorbent in the removal of sulphates in an aqueous solution. The coal fly ash was characterised using an x-ray fluorescence (XRF) which revealed that it was class C and sub-bituminous type fly ash, an x—ray diffractometer (XRD) which revealed the dominance of a large amorphous phase and a Fourier Transform Infrared Spectroscopy (FTIR) which showed the presence of both organic and inorganic functional groups. Adsorbent dosage, contact time, temperature and solution pH were varied and all the parameters showed a higher uptake of sulphate ions with their increase, except pH which showed a decreasing uptake. The pseudo second order model showed a better fit for the sorption data with lower error values than the pseudo first order model. The uptake of sulphate ions followed both the Langmuir and the Freundlich isotherm models with RL values for the Langmuir within the range 0 < RL < 1 and n-values for the Freundlich within the range 0 < n < 10 showing a favourable sorption for both models. All the thermodynamic parameters (ΔG°, ΔH° and ΔS°) were positive indicating a non – spontaneous, endothermic and a random solid – liquid interface. The process was shown to follow a unimolecular layer approach with chemical adsorption as the dominating mechanism. Generally, coal fly ash showed a higher affinity for sulphates leading to its effective removal.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3106
Author(s):  
Tomasz Kalak ◽  
Kinga Marciszewicz ◽  
Joanna Piepiórka-Stepuk

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.


2014 ◽  
Vol 629-630 ◽  
pp. 306-313 ◽  
Author(s):  
Mao Chieh Chi ◽  
Ran Huang ◽  
Te Hsien Wu ◽  
Toun Chun Fou

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%.


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