scholarly journals Investigation of the adsorption performance of polystyrenic resin and GAC for the removal of BTEX compounds from industrial wastewater

2015 ◽  
Author(s):  
◽  
Thobeka Pearl Makhathini
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Organic Compounds ◽  
Service Time ◽  
Industrial Wastewater ◽  
Fixed Bed ◽  
Langmuir Model ◽  
Initial Concentration ◽  
Btex Compounds

Industrial wastewater containing organic compounds and/or substances is an increasing problem due to its increasing toxic threat to humans and the environment. The removal of organic compounds has become an imperative issue due to stringent measures that are introduced by the Department of Environmental Affairs in South Africa to enforce regulations concerning wastes that emanate from petrochemical industries. Thus, wastewater containing these compounds must be well understood so as to device adequate treatment processes. In this study, the adsorptive capacity of PAD 910 polystyrenic resin originating from China and granular activated carbon (GAC) was evaluated for the removal of benzene, toluene, ethylbenzene and isomers of xylene (BTEX) from an aqueous solution. Batch studies were performed to evaluate the effects of various experimental parameters such as mixing strength, contact time, internal diffusion, adsorbates and initial concentration on the removal of the BTEX compounds. The experiments were conducted at the mixing strength of 180 rpm, in order to comfortably assume negligible external diffusion. The equilibrium isotherms for the adsorption of the adsorbates on the PAD 910 polystyrenic resin were analyzed by the Langmuir, Freundlich and linearized Dubinin-Radushkevich models at a pH of 5.86. The Langmuir model fitted the data adequately; this result was supported by the work done by Site (2001) which concluded that the Langmuir is the most practical model in representing the adsorption of aromatic compounds. The Langmuir model indicated that resin has the highest adsorption capacity of 79.44 mg/g and GAC has 66.2 mg/g. Resin was found to adsorb 98% of benzene, 88% of toluene, 59% of ethylbenzene, 84% m-;p-xylene and 90% o-xylene at an initial concentration of 14.47 mg/l. BTEX adsorption was a two-stage process: a short, fast initial period then followed by a longer, slow period corresponding to the intra-particle diffusion of BTEX molecules in macropores and micropores. The adsorption capacity was determined by total surface area accessible to BTEX and the availability of active surface chemical groups. The dependence of adsorption capacity on the surface of the two adsorbents and temperature was observed, suggesting the chemical nature of the BTEX adsorption. The interaction between BTEX/activated carbon was however weak and energetically similar to that of hydrogen bonds. Generally, BTEX adsorption was an exothermic process that combined physisorption and chemisorption. The PAD 910 polystyrenic resin had a greater specific surface area (SSA) of 1040 m2/g which yielded in higher capacity compared to GAC which had a low SSA of 930 m2/g. The normalized adsorption capacity was found to be higher for PAD 910 polystyrenic resin than GAC (0.66 and 0.27 mg/m2 respectively) which suggests that the resin has a good potential of the adsorbent for removing BTEX compound compared to GAC. Fixed bed columns were used to evaluate the dynamic adsorption behaviour of BTEX/PAD 910 polystyrenic resin through a dynamic column approach. The performance of small-scale fixed bed columns, each containing PAD 910 polystyrenic resin and the other containing GAC were evaluated using 14.47 mg/L of BTEX concentration. The columns with 32 mm diameter, studied bed depths of 40, 80 and 120 mm and flow rate of 6 ml/min were used in order to obtain experimental breakthrough curves. The bed depth service time (BDST) model was used to analyze the experimental data and design parameters like adsorption capacity, adsorption rate and service time at 20% and 60% breakthrough. BDST was also used to predict the service times of columns operated under different influent concentrations and flow rates to produce theoretical values that were compared to the experimental values. Adsorption model by Dubinin and colleagues (Dubinin, 1960), based on the theory of volume filling micropores was used to fit the measured adsorption isotherms. Agreement between the modelled and experimental results for GAC and PAD 910 polystyrenic resin using Dubinin-Radushkevich equation generally improved with increasing the surface area and produced reasonable fits of the adsorption isotherms for both GAC and PAD 910 polystyrenic resin. Granular activated carbon had a lesser performance compared to the PAD 910 polystyrenic resin, in terms of kinetic studies, and this finding was attributed to the pore structure which made accessibility of BTEX molecules more difficult in this study. The results indicate that PAD 910 polystyrenic resin show potential as an adsorbent for removing low concentrations of BTEX from wastewater. It is suggested that necessary treatment of GAC might improve the performance of this adsorbent by creating more mesopore volume and fraction which is essential to enhance adsorption rate. A substantial different SSA could be achieved through high porosity development in GAC by using templating method with a higher potassium hydroxide mixture ratio.

Activated Carbon Design from Sludge to Remove Red Scarlet Nylosan “F3GL” in Aqueous Solution

2018 ◽  
Vol 762 ◽  
pp. 87-92 ◽  
Author(s):  
Farhat Bensalah ◽  
Abdelkader Iddou ◽  
Hafida Hentit ◽  
Abdallah Aziz ◽  
Andrei Shishkin
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Industrial Wastewater ◽  
Treatment Plant ◽  
Langmuir Model ◽  
Toxic Substances ◽  
Industrial Wastewaters ◽  
Batch Tests ◽  
Mixed Treatment

Activated carbon prepared from industrial wastewater treatment plant dry sludge was proven to be efficient for the removal of refractory dye red scarlet nylosan (F3GL). Mixed treatment (chemical followed by thermal) considerably improved the adsorption capacity of the sludge. Batch tests at 40 °C gave maximal adsorption capacity. Application of Langmuir model gave 434.78 mg/g for treated material (SNHC) and 169.49 mg/g for the unmodified material (S). Thermodynamic parameters indicated that the adsorption is favored by an increase of temperature. The values of the enthalpy revealed physic-sorption. The results clearly showed that the mixed treatment of the adsorbent is the most adequate for the removal of toxic substances such as dyes present in industrial wastewaters.

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Initial Concentration

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0，enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.

scholarly journals STUDI ADSORPSI ZAT WARNA NAPHTHOL YELLOW S PADA LIMBAH CAIR MENGGUNAKAN KARBON AKTIF DARI AMPAS TEBU

Jurnal Kimia ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 104
Author(s):  
W. P. Utoo1 ◽  
E. Santoso ◽  
G. Yuhaneka ◽  
A. I. Triantini ◽  
M. R. Fatqi ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Contact Time ◽  
Adsorption Process ◽  
Activation Process ◽  
Adsorption Model ◽  
High Adsorption ◽  
Prolonged Contact ◽  
Test Result

The aim of this research is to get activated carbon from sugarcane bagasse with high adsorption capacity to Naphthol Yellow S and to know factors influencing the adsorption capacity. Activated carbon is prepared by incomplete combustion of sugracane bagasse. The resulting carbon is activated with H2SO4 with concentration variation of 0.5; 1.0; 1.5 and 2.0 M and is continued by calcination at 400 °C. The measurement of the surface area of ??activated carbon by the methylene blue method indicates that the activation process successfully extends the surface area of carbon from 31.87 m2/g before activation to 66-72 m2/g after activation. Activated carbon with concentration of 2.0 M H2SO4 showed the highest surface area of ??71.85 m2/g, however, the best adsorption was shown by activated carbon with a concentration of 0.5 M H2SO4 with the adsorption capacity of 83.93%. The adsorption test showed that the best amount of adsorbent was 0.2 g with contact time for 30 minutes. Prolonged contact time can decrease the amount of Naphthol Yellow S adsorbed. The best adsorption test result was shown by sample with activator concentration of 0,5 M, mass of 0,2 g and contact time of 30 min with adsorption capacity 95,81% or amount of dye adsorbed equal to 143,72 mg/g. The adsorption study also showed that the entire Naphthol Yellow S adsorption process followed the Langmuir isothemal adsorption model. Qualitative testing of real batik waste indicates that activated carbon can reduce the dyes waste containing Naphthol Yellow Sexhibited by the color of batik waste which is more faded.  

scholarly journals Pinecone-Derived Activated Carbons as an Effective Medium for Hydrogen Storage

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2237
Author(s):  
Sara Stelitano ◽  
Giuseppe Conte ◽  
Alfonso Policicchio ◽  
Alfredo Aloise ◽  
Giovanni Desiderio ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Hydrogen Storage ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Hydrogen Adsorption ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Textural Properties ◽  
Biomass Waste ◽  
Wavelength Dispersive Spectrometry

Pinecones, a common biomass waste, has an interesting composition in terms of cellulose and lignine content that makes them excellent precursors in various activated carbon production processes. The synthesized, nanostructured, activated carbon materials show textural properties, a high specific surface area, and a large volume of micropores, which are all features that make them suitable for various applications ranging from the purification of water to energy storage. Amongst them, a very interesting application is hydrogen storage. For this purpose, activated carbon from pinecones were prepared using chemical activation with different KOH/precursor ratios, and their hydrogen adsorption capacity was evaluated at liquid nitrogen temperatures (77 K) at pressures of up to 80 bar using a Sievert’s type volumetric apparatus. Regarding the comprehensive characterization of the samples’ textural properties, the measurement of the surface area was carried out using the Brunauer–Emmett–Teller method, the chemical composition was investigated using wavelength-dispersive spectrometry, and the topography and long-range order was estimated using scanning electron microscopy and X-ray diffraction, respectively. The hydrogen adsorption properties of the activated carbon samples were measured and then fitted using the Langmuir/ Töth isotherm model to estimate the adsorption capacity at higher pressures. The results showed that chemical activation induced the formation of an optimal pore size distribution for hydrogen adsorption centered at about 0.5 nm and the proportion of micropore volume was higher than 50%, which resulted in an adsorption capacity of 5.5 wt% at 77 K and 80 bar; this was an increase of as much as 150% relative to the one predicted by the Chahine rule.

scholarly journals MgO Dispersed on Activated Carbon as Water Tolerant Catalyst for the Conversion of Ethanol into Butanol

2019 ◽  
Vol 9 (7) ◽  
pp. 1371 ◽  
Author(s):  
Stefano Cimino ◽  
Jessica Apuzzo ◽  
Luciana Lisi
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Fixed Bed ◽  
High Water ◽  
Fixed Bed Reactor ◽  
High Dispersion ◽  
Water Tolerance ◽  
Butanol Yield

MgO supported on activated carbon (AC) with a load ranging from 10% to 30% has been investigated as catalyst for the conversion of ethanol into butanol at 400 °C in a fixed bed reactor at different GHSV. Catalysts have been characterized by XRD, SEM/EDX, and N2 physisorption at 77 K. The high dispersion of MgO into the pores of the support provides strongly enhanced performance with respect to bulk MgO. MgO/AC catalysts have been also tested under wet feed conditions showing high water tolerance and significantly larger butanol yield with respect to an alumina supported Ru/MgO catalyst. After wet operation, the increased surface area of the catalyst leads to better performance once dry feed conditions are restored.

scholarly journals Effect of Salinity and PH on the Industrial Effluent Treatment by Activated Carbon: Modeling of the Kinetic Adsorption and Equilibrium Isotherms

2019 ◽  
Vol 8 (1) ◽  
pp. 77 ◽  
Author(s):  
E. F. Mohamed ◽  
G. Awad ◽  
C. Andriantsiferana ◽  
H. Delmas
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Organic Compounds ◽  
Inorganic Salt ◽  
Industrial Effluent ◽  
Effluent Treatment ◽  
Effect Of Temperature ◽  
Ambient Conditions ◽  
Solution Ph ◽  
Carbon Modeling

In recent years, interest has been focused on the removal of phenols from contaminated by using a variety of purification techniques. Adsorption of bio-industrial effluent on commercial activated carbon S23 was investigated at ambient conditions. In this wok, phenol and p-hydroxyl benzoic acid (PHBA) was studied as an example of the organic compounds present in the industrial effluent. The effect of temperature, pH, and the presence of inorganic salt NaCl on the pollutants adsorption were studied to give further comprehension of the optimal conditions of the organic compounds adsorption onto activated carbon. It was noted that the increase in temperature resulted in a decrease in phenols adsorption capacity by S23. Lower phenol adsorption was also observed at the solution pH 2 and 10, whereas, favourable adsorption was reached at neutral solution pH, and the coexisting inorganic salt NaCl exerts slightly positive effect on the adsorption process. The isotherms obtained at pH 2.2 and 3.5 (non-buffered solution) are very similar and showed a higher adsorption capacity compared with that obtained at pH 7 and 10 for PHBA which is more adsorbable than phenol. The kinetic of the adsorption processes can be better represented by the pseudo-second order. The results showed also that the total organic carbon (TOC) of the industrial effluent reduced for about 20 %. Freundlich, Langmuir and Jovanovic adsorption models were used for mathematical description of adsorption equilibrium of phenols. The results showed that the experimental data fitted very well to the Freundlich and Jovanovic models.

Volatile organic compound adsorption in a gas-solid fluidized bed

2004 ◽  
Vol 50 (4) ◽  
pp. 233-240 ◽  
Author(s):  
Y.L. Ng ◽  
R. Yan ◽  
L.T.S. Tsen ◽  
L.C. Yong ◽  
M. Liu ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Residence Time ◽  
Fixed Bed ◽  
Gas Concentration ◽  
Adsorption Characteristics ◽  
Bubbling Bed ◽  
Intraparticle Mass Transfer

Fluidization finds many process applications in the areas of catalytic reactions, drying, coating, combustion, gasification and microbial culturing. This work aims to compare the dynamic adsorption characteristics and adsorption rates in a bubbling fluidized bed and a fixed bed at the same gas flow-rate, gas residence time and bed height. Adsorption with 520 ppm methanol and 489 ppm isobutane by the ZSM-5 zeolite of different particle size in the two beds enabled the differentiation of the adsorption characteristics and rates due to bed type, intraparticle mass transfer and adsorbate-adsorbent interaction. Adsorption of isobutane by the more commonly used activated carbon provided the comparison of adsorption between the two adsorbent types. With the same gas residence time of 0.79 seconds in both the bubbling bed and fixed bed of the same bed size of 40 mm diameter and 48 mm height, the experimental results showed a higher rate of adsorption in the bubbling bed as compared to the fixed bed. Intraparticle mass transfer and adsorbent-adsorbate interaction played significant roles in affecting the rate of adsorption, with intraparticle mass transfer being more dominant. The bubbling bed was observed to have a steeper decline in adsorption rate with respect to increasing outlet concentration compared to the fixed bed. The adsorption capacities of zeolite for the adsorbates studied were comparatively similar in both beds; fluidizing, and using smaller particles in the bubbling bed did not increase the adsorption capacity of the ZSM-5 zeolite. The adsorption capacity of activated carbon for isobutane was much higher than the ZSM-5 zeolite for isobutane, although at a lower adsorption rate. Fourier transform infra-red (FTIR) spectroscopy was used as an analytical tool for the quantification of gas concentration. Calibration was done using a series of standards prepared by in situ dilution with nitrogen gas, based on the ideal gas law and relating partial pressure to gas concentration. Concentrations up to 220 ppm for methanol and 75 ppm for isobutane were prepared using this method.

scholarly journals Preparation of Nano-Porous Carbon-Silica Composites and Its Adsorption Capacity to Volatile Organic Compounds

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 372 ◽  
Author(s):  
Lipei Fu ◽  
Jiahui Zhu ◽  
Weiqiu Huang ◽  
Jie Fang ◽  
Xianhang Sun ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Volatile Organic Compounds ◽  
Adsorption Capacity ◽  
Organic Compounds ◽  
Retention Rate ◽  
Reaction System ◽  
Carbon Powder ◽  
Volatile Organic ◽  
Adsorption Desorption ◽  
Better Than

Carbon-silica composites with nanoporous structures were synthesized for the adsorption of volatile organic compounds (VOCs), taking tetraethyl orthosilicate (TEOS) as the silicon source and activated carbon powder as the carbon source. The preparation conditions were as follows: the pH of the reaction system was 5.5, the hydrophobic modification time was 50 h, and the dosage of activated carbon was 2 wt%. Infrared spectrum analysis showed that the activated carbon was dispersed in the pores of aerogel to form the carbon-silica composites material. The static adsorption experiments, dynamic adsorption-desorption experiments, and regeneration experiments show that the prepared carbon-silica composites have microporous and mesoporous structures, the adsorption capacity for n-hexane is better than that of conventional hydrophobic silica gel, and the desorption performance is better than that of activated carbon. It still has a high retention rate of adsorption capacity after multiple adsorption-desorption cycles. The prepared carbon-silica composites material has good industrial application prospects in oil vapor recovery, providing a new alternative for solving organic waste gas pollution.

Adsorption Kinetics of Oxytetracycline onto Activated Carbon in a Closed-Loop Fixed Bed Reactor

2013 ◽  
Vol 11 (1) ◽  
pp. 569-576 ◽  
Author(s):  
Djamila Djedouani ◽  
Malika Chabani ◽  
Abdeltif Amrane ◽  
Aicha Bensmaili
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Closed Loop ◽  
Solid Phase ◽  
Positive Impact ◽  
Fixed Bed ◽  
Sorption Process ◽  
Fixed Bed Reactor ◽  
Dynamic Interactions ◽  
Initial Concentration

Abstract Batch experiments were carried out for the adsorption of oxytetracycline (OTC) onto powdered activated carbon (PAC). The operating variables examined were the initial concentration (20–150 mg L−1) and the adsorbent concentration (0.75–1.75 g L−1). As observed increasing the initial concentration, while decreasing the adsorbent dosage, had a positive impact on the amount of OTC uptake (mg g−1). The kinetics was examined in a closed-loop fixed bed adsorber to propose an adsorption mechanism, to understand the dynamic interactions of OTC with ECA08 activated carbon and to predict its fate with time. The sorption results were analyzed using chemical and physical kinetics models. For concentrations lower than 70 mg L−1, the sorption process was found to be controlled by both surface reactions and mass transfer. The average external mass transfer coefficient and intraparticle diffusion coefficient were found to be 0.0051 min−1 and 1.97 mg g−1 min−0.5, respectively. For concentrations higher than 70 mg L−1, mass transfer became rapid and the chemical reaction at the surface of the solid phase was the rate-limiting step. The results showed that the adsorption reaction was accurately described by the pseudo-second-order model.

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