scholarly journals Continuous Phenol Removal Using a Liquid–Solid Circulating Fluidized Bed

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3839
Author(s):  
Nandhini Sureshkumar ◽  
Samiha Bhat ◽  
Shwetha Srinivasan ◽  
Nirmala Gnanasundaram ◽  
Murugesan Thanapalan ◽  
...  

A liquid-solid circulating fluidized bed (LSCFB) helps to overcome the shortcomings of conventional fluidized beds by using a particle separation and return system as an integral part of the overall reactor configuration. Batch adsorption experiments were carried out for the removal of phenol from a synthetically prepared solution using fresh activated-carbon-coated glass beads. The morphological features and surface chemistry of the adsorbent were analyzed via SEM and FTIR techniques. The adsorbent dosage, contact time and temperature were varied along with solution pH to assess their effects on the adsorbent performance for phenol removal. Isotherm modeling showed that the phenol removal using the activated-carbon glass beads followed the Langmuir model. Effectively, it was observed at an adsorbent loading of 2.5 g/150 mL of feed volume and a contact time of 3 h produced an 80% efficiency in the batch study. Furthermore, on scaling it up to the column, the desired 98% phenol-removal efficiency was obtained with an adsorbent dosage of 250 g and contact time of 25 min. Adsorbent regeneration using 5% (v/v) ethanol showed a 64% desorption of phenol from the sorbent within 20 min in the LSCFB.

2020 ◽  
Vol 12 (1) ◽  
pp. 167-177
Author(s):  
Ayuba Abdullahi Muhammad ◽  
Nyijime Thomas Aondofa

Carbonized Bambara GroundNut Shell (CBGNS) was used as adsorbent for the adsorption of paraquat dichloride (PQ) from aqueous solution. The prepared adsorbent was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy methods. Several parameters that might affect the adsorption process including pH, contact time, adsorbent dosage, temperature and initial concentration were investigated and optimized using batch adsorption technique. Results of the study revealed that maximum removal efficiency (98%) was achieved using 0.05g adsorbent dosage, solution pH of 5 and 60 min of contact time. The equilibrium experimental result revealed that Langmuir model best described the adsorption process with R2 value of 0.956.The heat of adsorption process was estimated from Temkin Isotherm model to be 19.99J/mol and the mean free energy was estimated from Duninin-Radushkevich (DRK) isotherm model to be 0.289KJ/mol indicating chemisorptions process. The kinetic and thermodynamic studies revealed that the adsorption processes followed pseudo-second-order kinetics with R2 value of 0.999 and the value of ∆G (- 27.74 kJ mol-1), ∆H (13.145 kJ mol-1) indicate the spontaneous and endothermic nature of PQ adsorption on CBGNS. The results suggested that CBGNS had the potential to become a promising material for PQ contaminated water treatment. Keywords: Adsorption, Paraquat dichloride, Carbonized Bambara Ground nut shell, Water treatment.


2020 ◽  
Author(s):  
Fola Temilade Akinhanmi ◽  
Edwin Andrew Ofudje ◽  
Idowu Abideen Adeogun ◽  
Aina Peter ◽  
Joseph Mayowa Ilo

Abstract The presence of heavy metals in polluted water is known not only to cause stern harm to marine organisms but also to terrestrial plants and animals including human beings. This research applied low-cost and environmental benign adsorbent primed from waste orange peel (OP) for the removal of Cd(II) ions from aqueous solution via batch adsorption process. The surface properties of the orange peel powder were studied using Scanning Electron Microscopy (SEM), X-ray spectroscopy (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). Operational conditions like temperature, contact time, sorbent dosage, solution pH and initial adsorbate concentration were investigated. The utmost uptake of Cd(II) ion was obtained at a contact time of 120 mins, initial metal concentration of 240 mg/L, adsorbent dosage of 0.04 g/L, temperature of 45 °C and solution pH of 5.5. Equilibrium results showed that the orange peel adsorbent has an adsorption capacity of 128.23 mg/g as obtained from the Langmuir isotherm. The adsorption kinetics data followed a pseudo-first-order kinetic model with correlation coefficient (R2) >0.9 and low standard % error values. The adsorption process was found to be endothermic in nature with enthalpy of 0.0046 kJ mol−1 and entropy of-636.865 Jmol-1K-1 respectively. Results from the optimization study indicated that higher adsorbent dosage and lower Cd(II) ion concentration increased the percentage of Cd (II) ion removal. Thus, orange peel could be used in the removal of Cd(II) ion from aqueous solutions.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jatindra N. Bhakta ◽  
Piyali Bhakta Majumdar ◽  
Yukihiro Munekage

The study attempted to develop the activated carbon of cotton fibre (ACCF) from cotton waste as a high Hg2+adsorbent media and characterize physicochemical properties using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and Hg2+adsorption kinetic by batch adsorption study with the function of contact time, solution pH, dosages of ACCF, and Hg concentration. The SEM-EDS study revealed that ACCF is composed of carbon (95.1%) and phosphorus pentoxide (4.9%). Obtained results of adsorption kinetics showed that 15 min of contact time is required to achieve the equilibrium state and wide range of pH (4.08–7) is favourable for maximum Hg adsorption. The Hg2+adsorption capacity showed a decreasing trend with increasing dose of ACCF, whereas a reverse response of adsorption capacity was pronounced with increasing Hg concentration. The data was well described by Freundlich isotherm model and determined the high Hg2+adsorption capacity of ACCF (169.2 mg/g). To our knowledge, the application of ACCF in removing Hg2+is the first study. High Hg2+adsorption capacity, economic feasibility, availability of cotton fibre waste, and simple preparation method concluded that it could be used as a novel low-cost and environmentally sound adsorbent media for removing high rate of Hg2+from aqueous phase.


Author(s):  
Aderonke Adetutu, Okoya ◽  
Raliat Modupeola Anjous – Alao ◽  
Kehinde Nurudeen Awokoya

Sorption efficiencies of activated carbon prepared from walnut shell for the removal of Halogenated Acetonitriles (HANs) from surface water was investigated in this study, as an ethically sound-way of utilizing this unexploited abundant natural resource, and was also compared with burgoyne commercial activated carbon (BCAC). Major HANs created during the disinfection process consist of dichloroacetonitrile (DCAN) and bromoacetonitrile, (BCAN). Physicochemical properties of both raw and chlorinated water were determined using standard methods, and concentration of DCAN were determined from water treatment plant at different stages of treatment using High Performance liquid Chromatography (HPLC). Recovery experiments were carried out to validate experimental procedure. Batch adsorption experiments were carried out and different parameters such as adsorbent dosage (0.2, 0.4, 0.8 g), contact time (30, 60, 90 minutes), pH (5, 7, 9), and concentration (0.006 mg/L, 0.009 mg/L and 0.012 mg/L) were optimized for removal of DCAN using walnut shell activated carbon (WSAC). Experimental sorption data from different initial concentrations of DCAN were used to test conformity with Freundlich and Langmuir adsorption isotherms. Percentage recovery from experimental procedure is 86.01±0.62 to 100.0±0.00 for DCAN. Mean percentage adsorption efficiencies for simulation experiment is 16.670±0.467 to 41.67±1.103 for DCAN. Optimum conditions for DCAN were 0.8g adsorbent dosage, 60 minutes contact time, pH 9 and 0.012 mg/L initial concentration. Optimum values of theses parameters used for adsorption of DCAN in raw and chlorinated water serving the treatment plant gave an adsorption efficiency of 69.00±1.43% and 79.00±0.03 respectively. Adsorption efficiency of BCAC gave 94.4±0.42 and 98.00±1.41 for raw and chlorinated water respectively, with a total decrease in all physicochemical parameters examined after adsorption experiment. Adsorption isotherm studies indicated that Langmuir model was more suitable for the experimental data than Freundlich isotherm model. Conclusively, the effective adsorbent properties displayed by WSAC in the removal of DCAN indicate its potentials in treatment of water contaminations.


2013 ◽  
Vol 864-867 ◽  
pp. 710-714
Author(s):  
Piaw Phatai ◽  
Songkot Utara ◽  
Nantana Hatthapanit

The study aimed to investigate the adsorption efficiency of methyl violet (MV) dye on activated carbon (AC) derived from coffee residues. A batch adsorption study was performed to examine various contributory parameters including contact time, solution pH, adsorbent dose and initial dye concentration. The morphology of the AC was studied by means of scanning electron microscopy (SEM). The results showed that maximum adsorption of MV dye on activated carbon occurred with a contact time of 60 min, solution pH of 9.0 and adsorbent dose of 0.3 g. The equilibrium adsorption data were analysed using Freundlich and Temkin isotherms. The adsorption isotherm was found to follow the Freundlich isotherm. Adsorption behavior of MV dye follows mechanism of physical adsorption which is occurred by heterogeneous surface. The results indicate that the AC from coffee residues is a suitable adsorbent for the adsorption of dyes.


2017 ◽  
Vol 29 (1) ◽  
pp. 9-13
Author(s):  
Masuma Sultana Ripa ◽  
Rafat Mahmood ◽  
Sabrina Khan ◽  
Easir A Khan

Adsorption separation of phenol from aqueous solution using activated carbon was investigated in this work. The adsorbent was prepared from coconut shell and activated by physical activation method. The coconut shell was first carbonized at 800°C under nitrogen atmosphere and activated by CO2 at the same temperature for one hour. The prepared activated carbon was characterized by Scanning Electron Microscope (SEM) and BET Surface Analyzer and by the determination of iodine number as well as Boehm titration. The iodine number indicates the degree of relative activation of the adsorbent. The equilibrium adsorption isotherm phenol from aqueous solution was performed using liquid phase batch adsorption experiments. The effect of experimental parameters including solution pH, agitation time, particle size, temperature and initial concentration was investigated. The equilibrium data was analyzed using Langmuir and Freundlich adsorption model to describe the adsorption isotherm and estimate the adsorption isotherm parameters. The results indicate the potential use of the adsorbent for removal of phenol from the aqueous solution.Journal of Chemical Engineering, Vol. 29, No. 1, 2017: 9-13


2021 ◽  
Author(s):  
Abdulkareem AS ◽  
Hamzat WA ◽  
Tijani JO ◽  
Bankole MT ◽  
Titus Egbosiuba ◽  
...  

Abstract Comparative adsorption study of some toxic metals (Ni, Fe, Cu, Cd, and Pb) from battery industrial effluent by purified and polyethylene glycol-modified carbon nanotubes (CNTs) is reported. The as-prepared CNTs via chemical vapour deposition method (A-CNTs), its acid purified form (P-CNTs), and polyethylene glycol functionalized form (PEG-CNTs) were characterized by HRTEM, BET, HRSEM, FTIR and XRD. The HRSEM and HRTEM micrograph revealed the formation of multi-walled tubular network structures of different inner and outer diameter. The BET study of PEG-CNTs and purified CNTs showed surface areas of 970.81 m2/g and 781.88 m2/g, respectively. The nanomaterials batch adsorption effect of various parameters such as contact time, nano-adsorbent dosage and temperature was conducted. The optimum equilibrium to achieve maximum removal of Cd (83.41 %), Ni (92.79 %), Fe (95.93%), Pb (97.16 %) Cu (99.9 9%) using PEG-CNTs was 90 min of contact time, 0.3 g of nano-adsorbent dosage and 60 oC temperature. While the maximum percentage removal efficiencies accomplished using P-CNTs under the same applied conditions were Cd (78.64 %), Ni (76.12 %), Fe (92.87 %), Pb (90.7 2%) Cu (99.09 %). PEG-CNTs was seen as more effective than P-CNTs. Adsorption data of Ni on P-CNTs followed Langmuir isotherm while the adsorption equilibrium model (Freundlich isotherm) of Ni, Fe, Cu and Pb on PEG-CNTs were fitted well. However, in both cases, the sorption kinetic study followed the pseudo-second-order model. The thermodynamics showed that the removal of toxic metals from battery wastewater was spontaneous and endothermic irrespective of the nano-adsorbents. The study found that surface modification of CNTs by polyethylene glycol adequately improved the nanotubes, thus leading to relatively adsorption capacities of heavy metals from industrial battery effluent.


2020 ◽  
Vol 15 (2) ◽  
pp. 460-471
Author(s):  
T. Unugul ◽  
F. U. Nigiz

Abstract In this study; acid treated carbonized mandarin peel (CMP) adsorbent was prepared and the adsorption behaviour of the adsorbent for copper removal was investigated. In the adsorption studies the effects of initial metal concentration, solution pH, adsorbent dosage and contact time on the removal were investigated. As a result; the highest removal of 100% was achieved when the copper concentration in water was 5 mg/L and the adsorbent dosage was 3.75 g/L at a solution pH of 7. Isotherm studies were also done and the appropriate isotherm was obtained as the Freundlich isotherm. According to the kinetic studies, the copper adsorption onto CMP adsorbent was adopted to the pseudo-second-order adsorption kinetic. After HCl regeneration, the adsorbent maintained 94% of its activity.


2011 ◽  
Vol 8 (2) ◽  
pp. 803-808 ◽  
Author(s):  
U. V. Ladhe ◽  
S. K. Wankhede ◽  
V. T. Patil ◽  
P. R. Patil

Adsorptions of Erichrome Black T dye in aqueous solution on cotton stem activated carbon have been studied as a function of contact time, concentration and pH. Effect of various experimental parameters has been investigated at 39±1°C under batch adsorption technique. The result shows that cotton stem activated carbon adsorbs dye to a sufficient extent. The physicochemical characterization and chemical kinetics was also examined for the same dye. The overall result shows that it can be fruitfully used for the removal of dye from wastewaters.


2012 ◽  
Vol 164 ◽  
pp. 297-301 ◽  
Author(s):  
Wei Fang Dong ◽  
Li Hua Zang ◽  
Qing Chao Gong ◽  
Cun Cun Chen ◽  
Cai Hong Zheng ◽  
...  

Low cost carbonaceous materials were evaluated for their ability to remove phenol from wastewater. The effects of adsorbents dosage, contact time and maximum adsorption capacity were investigated for granular activated carbon, powdered activated carbon, petroleum coke and multi-walled carbon nanotube (MWNT). Equilibrium studies were conducted in 50mg/L initial phenol concentration, solution pH of 5 and at temperature of 23°C. The results showed the adsorption process was fast and it reached equilibrium in 3 h. Petroleum coke and MWNT had poor adsorption which could reach the removal efficiency of phenol with 43.18% and 36.64% respectively. The granular activated carbon possessed good adsorption ability to phenol with 96.40% at the optimum dosage 5g and optimum time 90min.The powdered activated carbon was an effective adsorbent with a maximum adsorption capacity of 42.32 mg/g.


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