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•Facile single-step synthesis of new magnetic activated carbon materials was carried out at 600 °C.•The combinations of ZnCl2/NiCl2 simultaneously provide excellent textural ...properties and high magnetization.•Maximum SBET and saturation magnetization of 1281 m2 g−1 and 13.29 emu g−1, respectively was attained.•The Qmax of 199.3 and 335.4 mg g−1 for nicotinamide and propranolol, respectively, was achieved.•The efficient total removal of simulated hospital effluents of 99.1 % was obtained.
The present research describes the synthesis of new nanomagnetic activated carbon material with high magnetization, and high surface area prepared in a single pyrolysis step that is used for the carbonization, activation, and magnetization of the produced material. The pyrolysis step of tucumã seed was carried out in a conventional tubular oven at 600 °C under N2-flow. It was prepared three magnetic carbons MT-1.5, MT-2.0, MT-2.5, that corresponds to the proportion of biomass: ZnCl2 always 1:1 and varying the proportion of NiCl2 of 1.5, 2.0, and 2.5, respectively. These magnetic nanocomposites were characterized by Vibrating Sample Magnetometer (VSM), X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, hydrophobic/hydrophilic balance, CHN/O elemental analysis, modified Boehm titration, N2 adsorption-desorption isotherms; and pHpzc. All the materials obtained presented Ni particles with an average crystallite size of less than 33 nm. The MT-2.0 was employed for the removal of nicotinamide and propranolol from aqueous solutions. Based on Liu isotherm, the Qmax was 199.3 and 335.4 mg g−1 for nicotinamide and propranolol, respectively. MT-2.0 was used to treat simulated pharmaceutical industry effluents attaining removal of all organic compounds attaining up to 99.1 % of removal.
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•Tannery sludge was used as carbon precursor for preparation of activated carbon.•The pyrolysis step was carried out using microwave heating.•Adsorption of AB-210 and AR-357 dyes was ...studied using AMWCTS as adsorbent.•The Qmax values of AB-210 and AR-357 are 1108 and 589.5mgg−1, respectively.•AMWCTS is effective for treatment of simulated dye effluents.
An activated carbon was prepared by chemical activation of the sludge collected from tannery wastewater treatment plant (TWTP) using microwave heating. The sludge was mixed with ZnCl2 and lime to form a paste, which was inserted inside a quartz reactor and irradiated by microwave for 10min under N2. After the pyrolysis, the carbonized material was refluxed with a 6.0molL−1 HCl to obtain the activated carbon (AMWCTS). The AMWCTS was characterized by SEM, FTIR, TGA, XRD, BET and BJH analytical techniques. AMWCTS has high BET surface area of 491.0m2g−1 and total pore volume of 0.440cm3g−1 with mesoporous pore size distribution.
The studies of pH, kinetic and equilibrium for adsorption of Acid Black 210 (AB-210) and Acid Red 357 (AR-357) leather dyes onto AMWCTS were investigated at 298K. The kinetic data were best fitted to the Avrami kinetic model. The maximum sorption capacities of AMWCTS for AR-357 and AB-210 are 589.5 and 1108mgg−1, respectively.
Finally, the AMWCTS was tested using simulated effluents (complex mixture of dyes), obtaining an adsorption efficiency of at least 93.79%, showing the potentiality of AMWCTS as adsorbent for treatment real effluents.
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Activated carbons from Brazil nutshells were produced by ZnCl2-activation at different biomass: ZnCl2 ratios of 1.0:1.0 and 1.0:1.5 at 600 °C and the samples were denominated as ...BNS1.0 and BNS1.5, respectively. The obtained activated carbons were used in the adsorption of acetaminophen (paracetamol) and for the treatment of synthetic hospital effluents. Several analytical techniques were used to characterize the activated carbons. The N2 isotherms presented the SBET values of the BNS1.0 and BNS1.5 are very high, 1457 and 1640 m2 g−1, respectively. The FTIR and Boehm titration analysis demonstrated the presence of several surface functional groups on both ACs surfaces, which can influence the acetaminophen adsorption. The adsorption studies revealed that the maximum adsorption capacities (Qmax) are very high for both ACs; however, the BNS1.5 capacity is higher (411.0 mg g−1) than that of BNS1.0 (309.7 mg g−1). The thermodynamic assessments revealed that the process of acetaminophen adsorption is spontaneous, energetically favorable, and exothermic, and the magnitude of enthalpy is compatible with physisorption. Besides, it suggests that the acetaminophen adsorption on both ACs is dominated by van der Walls forces and microporous filling mechanism. The use of activated carbons for treatment of synthetic hospital effluents, containing different pharmaceuticals as well as organics and inorganic salts, presented a high percentage of removal (up to 98.83%). The adsorbent was magnificently regenerated up to 74% with a mixture of 0.1 mol L−1 NaOH + 20% EtOH solution and can be reused up to four cycles ensuring sustainable use of proposed adsorbent for acetaminophen removal from aqueous media. In the light of these results, it is possible to say that Brazil nutshell is an excellent raw material to prepare efficient ACs which can be successfully used in the treatment of real hospital effluents.
Porous activated carbons (ACs) prepared from a lignocellulosic waste, Caesalpinia ferrea seed pod wastes (CF) were utilised for removing captopril pharmaceutical from synthetic hospital effluents and ...aqueous effluents. Chemical activation using ZnCl2 was performed. It was utilised the following proportions CF-Biomass: ZnCl2 (1: 0.5, 1:1 and 1:1.5, obtaining CFAC.0.5, CFAC.1.0, and CFAC.1.5 activated carbons. These mixtures were pyrolysed at 600 °C in a conventional furnace. The ACs were characterised by FTIR, hydrophobic/hydrophilic ratio (HI), CHN/O elemental analysis, Boehm titration, surface areas (SBET), total pore volumes, and pore size distribution. These analyses show that the ACs presents several functional groups on AC surfaces and there is a predominance of hydrophilic surfaces. All the activated carbons prepared presented surface area 1050–1480 m2 g−1. Regarding the adsorption process, the kinetics data were fitted to General-order kinetic model and equilibrium of adsorption data were well represented by and Liu isotherm model. The maximum adsorption capacity of 535.5 mg g−1 was obtained at 25 °C for the sample CFAC.1.5. The thermodynamic studies have shown that the adsorption process of captopril is spontaneous and favourable. The employment of the ACs for treating simulated effluents, with different emerging contaminants, showed an excellent removal (up to 97.67%). This result is evidence that Caesalpinia ferrea seed pod wastes were a high-efficiency precursor for AC preparation and that such activated carbons could be used for treating hospital effluents containing pharmaceuticals.
•Caesalpinia ferrea seed pods were used as carbon source for preparation of activated carbon.•Efficient removal of captopril pharmaceutical from hospital effluents was obtained.•Maximum captopril sorption capacity of 776.2 mg g−1.•The several functional groups of ACs surface leads to a hydrophilic surface of ACs.
► Improvement of sorption capacity by exposure of the biomass to non-thermal plasma. ► Plasma cleans the biomass surface by auto generated acid and also the functionalizing of surface. ► The maximum ...adsorption capacities were found at pH 2 and 323K. ► The values were 40.94 and 65.63mgg−1 for JN and JP, respectively. ► JP was effective to treat a simulated dye-house effluent.
Jatropha curcas shell an abundant residue of the biocombustible industry, was used in its natural form (JN) and treated by non-thermal plasma (JP) as biosorbents for the removal of Reactive Red 120 (RR-120) dye from its aqueous solutions. These biosorbents were characterized by infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and by nitrogen adsorption/desorption curves. The effects of pH, shaking time and temperature on adsorption capacity were studied. In the acidic pH region (pH 2.0), the adsorption of the dye was favorable using both adsorbents. The contact time to obtain equilibrium isotherms at 298–323K was fixed at 10h for both biosorbents. The general order kinetic model provided the best fit to the experimental data compared with pseudo-first order and pseudo-second order kinetic adsorption models. For RR-120 dye, the equilibrium data (298–323K) were best fitted to the Liu isotherm model. The maximum sorption capacity for adsorption of the dye occurred at 323K, attaining values of 40.94 and 65.63mgg−1 for JN and JP, respectively. Simulated dyehouse effluents were used to check the applicability of the proposed biosorbents for effluent treatment (removal of 68.2 and 94.6%, for JN and JP, respectively) in a medium with high saline concentration.
In this study, avocado seed was successfully used as raw material for producing activated carbons by conventional pyrolysis. In order to determine the best condition to produce the activated carbons, ...a 2
2
full-factorial design of experiment (DOE) with three central points was employed by varying the temperature and time of pyrolysis. The two evaluated factors (temperature and time of pyrolysis) strongly influenced the
S
BET
, pore volumes, hydrophobicity–hydrophilicity ratio (HI) and functional groups values; both factors had a negative effect over
S
BET
, pore volumes and functional groups which means that increasing the values of factors leads to decrease of these responses; on the other hand, with regards to HI, both factors caused a positive effect which means that increasing their values, the HI has an enhancement over its values. The produced activated carbon exhibited high specific surface areas in the range of 1122–1584 m
2
g
−1
. Surface characterisation revealed that avocado seed activated carbons (ASACs) have hydrophilic surfaces and have predominantly acidic groups on their surfaces. The prepared ASACs were employed in the adsorption of 25 emerging organic compounds such as 10 pharmaceuticals and 15 phenolic compounds which presented high uptake values for all emerging pollutants. It was observed that the activated carbon prepared at higher temperature of pyrolysis (700 °C), which generated less total functional groups and presented higher HI, was the activated carbon with higher sorption capacity for uptaking emerging organic contaminants. Based on results of this work, it is possible to conclude that avocado seed can be employed as a raw material to produce high surface area and very efficient activated carbons in relation to treatment of polluted waters with emerging organic pollutants.
High-surface-area activated carbons were prepared from an agroindustrial residue,
Bertholletia excelsa
capsules known as capsules of Para cashew (CCP), that were utilized for removing amoxicillin ...from aqueous effluents. The activated carbons were prepared with the proportion of CCP:ZnCl
2
1:1, and this mixture was pyrolyzed at 600 (CCP-600) and 700 °C (CCP700). The CCP.600 and CCP.700 were characterized by CHN/O elemental analysis, the hydrophobic/hydrophilic ratio, FTIR, TGA, Boehm titration, total pore volume, and surface area. These analyses show that the adsorbents have different polar groups, which confers a hydrophilic surface. The adsorbents presented surface area and total pore volume of 1457 m
2
g
−1
and 0.275 cm
3
g
−1
(CCP.600) and 1419 m
2
g
−1
and 0.285 cm
3
g
−1
(CCP.700). The chemical and physical properties of the adsorbents were very close, indicating that the pyrolysis temperature of 600 and 700 °C does not bring relevant differences in the physical and chemical properties of these adsorbents. The adsorption data of kinetics and equilibrium were successfully adjusted to Avrami fractional-order and Liu isotherm model. The use of the adsorbents for treatment of simulated hospital effluents, containing different organic and inorganic compounds, showed excellent removals (up to 98.04% for CCP.600 and 98.60% CCP.700).
Graphical abstract
Activated carbons (ACs) prepared from tucumã seed (Astrocaryum aculeatum) were used for 2-nitrophenol removal from aqueous solutions. The ACs were characterized by elemental analysis, FTIR, N
2
...adsorption/desorption isotherms, TGA, hydrophobicity/hydrophilicity balance, and total of acidic and basic groups. The ACs showed to have hydrophilic surfaces and they presented high specific surface areas (up to 1318 m
2
g
−1
). In batch optimization studies, maximum removal was obtained at pH 7, contact time of 30 min, adsorbent dosage 1.5 gL
−1
and temperature of 50°C. The general-order kinetic model and Liu isotherm model best fit the kinetic and equilibrium adsorption data with a maximum adsorption capacity of 1382 mg g
−1
at 50°C. Effect of temperature and thermodynamic studies revealed that the adsorption processes of 2-nitrophenol onto ACs are dependent on temperature and are exothermic and spontaneous, respectively. About the applicability of the ACs for treating simulated effluents, the tucumã seed-activated carbon showed an excellent outcome in the treatment of simulated effluents, evidencing its high efficiency for phenolic compound adsorption. Tucumã seed-ACs showed to be cost effective and highly efficient adsorbents for efficient removal of 2-nitrophenol from aqueous solutions.
•Complexes of carboxy-methylated lignin with Al and Mn were used as adsorbents.•The optimum adsorption conditions were achieved at pH 2 and 298K.•Maximum adsorption capacities are 73.52mgg−1 (CML-Al) ...and 55.16mgg−1 (CML-Mn).•CML-Al could remove ca. 95.83% of dye-contaminated industrial effluents.•CML-Al and CML-Mn are effective for treatment of simulated dye-house effluents.
A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al3+ (CML-Al) and Mn2+ (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pHPZC. The established optimum pH and contact time were 2.0 and 5h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16mgg−1 at 298K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone+50% of 0.05molL−1 NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents.
In this work, SiO
2
/Nb
2
O
5
(SiNb) material was prepared using sol-gel method and employed as adsorbent for removal of crystal violet dye (CV). The material was characterized using nitrogen ...adsorption-desorption isotherms, FTIR spectroscopy, pH
pzc
, and SEM-EDS. The analysis of N
2
isotherms revealed the presence of micro- and mesopores in the SiNb sample with specific surface area as high as 747 m
2
g
−1
. For the CV adsorption process, variations of several parameters such as of pH, temperature, contact time, and concentration of dye of the process were evaluated. The optimum initial pH of the CV dye solution was 7.0. The adsorption kinetic and equilibrium data for CV adsorption were suitably represented by the general-order and Liu models, respectively. The maximum adsorption capacity of the CV dye by SiNb was achieved at 303 K, which attained 116 mg g
−1
at this temperaure. Dye effluents were simulated and used to check the applicability of the SiNb material for treatment of effluents - the material showed very good efficiency for decolorization of dye effluents.
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