Development of highly porous activated carbon from Jacaranda mimosifolia seed pods for remarkable removal of aqueous-phase ketoprofen

In this work, a high porous activated carbon from Jacaranda mimosifolia was developed and employed for ketoprofen adsorption. After the pyrolysis process at 973.15 K, the material presented cavities with different sizes allocated on the particle surface. The material presented a pH at the point of zero charge of 4.1 with the best adsorption at pH 2. The best adsorbent dosage was 0.72 g L−1, corresponding to a removal of 96%. The system reached the adsorption equilibrium after 120 min and was described by the linear driving force model. The isotherms revealed that the adsorption capacity decreased with the temperature and followed the Langmuir model, with a maximum adsorption capacity of 303.9 mg g−1. This high capacity can be associated with the high surface area (928 m2 g−1) and pore volume (0.521 cm3 g−1) values. The thermodynamic values indicated that the adsorption system is spontaneous and exothermic. The enthalpy value indicates that the interactions between the adsorbent and adsorbate are physical. Regeneration tests showed a decreasing percentage of removal of 7.86% after 5 cycles. Finally, the adsorbent showed efficiency when treating a simulated effluent containing drugs and inorganic salts, showing the removal of 71.43%

Adsorption of ketoprofen and paracetamol and treatment of a synthetic mixture by novel porous carbon derived from Butia capitata endocarp

In this work, endocarp of the species Butia capitata was employed as precursor material to prepare a novel activated carbon with intrinsic properties to remove ketoprofen and paracetamol from water efficiently. The activated carbon presented a predominantly microporous structure, with an average pore diameter of 1.23 nm, a total pore volume of 0.449 cm3 g−1, and a high specific surface area, 820 m2 g−1. The adsorption kinetics showed a rapid initial decay for both pharmaceuticals, with the system entering equilibrium after 120 min for ketoprofen and 180 min for paracetamol. The pseudo-second-order model presented the best fit for ketoprofen and the Elovich model for paracetamol. The adsorption equilibrium data show that temperature can increase or decrease the adsorption capacity, being found a maximum adsorption capacity of 108.79 and 100.60 mg g−1 for the ketoprofen and paracetamol, respectively. The Freundlich and Langmuir models presented the best statistical adjustments for the adsorption of ketoprofen and paracetamol, respectively. The thermodynamic analysis confirmed an endothermic process for ketoprofen (ΔH0 = 11.98 kJ mol−1) and exothermic for paracetamol (ΔH0 = -13.37 kJ mol−1). The recycle tests revealed that the adsorbent has an average decrease for removal percentage of only 1.88 % for ketoprofen and 1.57 % for paracetamol. Estimations costs indicate that the price of 1 kg of activated carbon costs is 2.39 USD at minimum. Last, the material presented a highly efficient adsorptive activity to treat a synthetic mixture containing several pharmaceutical compounds and salts, reaching 84.82% removal

Interpretations on the mechanism of In(III) adsorption onto chitosan and chitin: A mass transfer model approach

International audienceOur objective is to develop miniaturised Lab‐on‐a‐Chip (LOC) analysers, for medical diagnostics and for monitoring of the health status of ill persons. The complete system will make use of disposable chip sensors of the size of a credit card and a control unit of the size of a book. The principle of sensors will be based on the determination of the concentration of “protein markers”, which are related to various illnesses. In order to achieve this objective, it is necessary to integrate some optical components in the Chip. In this contribution we describe a successful development of electrophoretic separation LOC with monolithically integrated optics. These optical components are used for the excitation and for the detection of the fluorescence signal from separated bio‐molecules. The developed module can be considered as one of the main building‐block of the completed diagnostic Chip. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim

A comprehensive study on paracetamol and ibuprofen adsorption onto biomass-derived activated carbon through experimental and theoretical assessments

The paper reports an experimental and theoretical work about the adsorption of paracetamol (PCM) and ibuprofen (IBP) onto a new activated carbon synthesized starting from the tree pods deriving from Erythrina speciosa. The adsorbent shows good porous properties, with a BET surface area of 795.1 m2/g, and an average pore volume of 0.422 cm3 g−1. Adsorption tests are carried out by varying the most important operating parameters. The adsorption capacity of both IBP and PCM results to be maximum at pH = 3, i.e., where the adsorbate molecules are found in neutral form. Adsorption isotherms indicated that IBP adsorption capacity increases with temperature up to 96.28 mg g−1, while an opposite trendwas retrieved for PCM, which decreased until 50.40 mg g−1. For a theoretical analysis, a double layer model (DLM) is adopted in order to provide an interpretation of the occurring adsorption mechanisms. The theoretical approach indicates that both IBP and PCM are adsorbed bya multi-molecular way, i.e. each functional group on the adsorbent surface accommodates more than one molecule at the same time. Finally, the adsorption energy reveals that a physical adsorption is responsible for both IBP and PCM adsorption on the synthesized adsorbent

Investigation of biochar from Cedrella fissilis applied to the adsorption of atrazine herbicide from an aqueous medium

Biochar was produced from the sawdust of the wood forest species Cedrella fissilis and later used as an adsorbent to remove atrazine herbicide from aqueous media. Biochar showed high thermal stability, an amorphous structure, and a highly irregular surface, mainly composed of carbon-containing bonds. The isothermal curves confirmed that the increase in temperature favored the adsorption of the herbicide. The Langmuir model best suited the experimental equilibrium data, with the maximum adsorption capacity of 7.68 mg g-1 at 328 K. The thermodynamic parameters confirmed a spontaneous process of an endothermic nature governed by physical interactions (interactions of van der Waals and hydrogen bonds). Kinetic studies showed that equilibrium was reached within 180 min. The linear driving force model (LDF) showed good statistical adjustment to the experimental data, where it was observed that the diffusion coefficient increased with the concentration of adsorbate. Biochar can be reused in up to three cycles. Finally, the adsorbent showed good efficiency in real water samples from rivers contaminated with atrazine, with 76.58% and 71.29% removal

Preparation of activated carbons from fruit residues for the removal of naproxen (NPX): analytical interpretation via statistical physical model

In this work, physical statistical models were employed to provide reasonable information regarding the adsorption of naproxen onto different activated carbons. The activated carbons were prepared from different biomasses (pitaya peels, jabuticaba peels, or grape residues from the winery process) using ZnCl2 as an activator. All the adsorbents were characterized regarding their functional groups and morphological surfaces. The maximum capacity obtained for the activated carbons (at 328 K) was found to be: 167.0 mg g−1 for jabuticaba peels at pH 4; 158.81 mg g−1 for pitaya peels at pH 6.7; and last., grape residues the capacity was 176.0 mg g−1 at pH 7. The equilibrium data of the three adsorbents were well fitted to the monolayer with two energy sites adsorption model, assuming that NPX adsorption on the carbon surfaces occurs via two different functional groups. This statistical physics model calculated the number of NPX molecules bound on the surface and the saturated adsorption capacity for both functional groups at different temperatures. The obtained results indicate that the naproxen molecules can be adsorbed in a parallel and horizontal manner according to the material employed. The receptor density tends to increase with the temperature evolution, indicating that thermal energy and solubility play an important role in adsorption. Configurational entropy indicates similar thermodynamic behavior for all materials where higher disorder is found at the early stages of the adsorption, followed by and decrease a possible organization of the molecules on the surface. The Gibbs free energy shows that adsorption of naproxen is spontaneous in all cases and internal energy is proportional to the adsorption capacity indicating that the system releases energy as the adsorption occurs. Therefore, this article reports new findings to understand the adsorption mechanism of naproxen molecules on activated carbons prepared from lignocellulosic biomass

A review of the toxicology presence and removal of ketoprofen through adsorption technology

The present review was carried out to analyze the works developed using the adsorption technology to remove the anti-inflammatory ketoprofen (KET). The main factors that inflated the KET adsorption were analyzed. It was found that, among the developed adsorbents, those from ZnAl/biochar, algae-derived porous carbon, and powdered activated carbon were highly efficient, reaching maximum capacities of 1081, 443, and 362 mg g−1, respectively. It was found that the adsorption capacity tends to be higher when the pH is close to the value of pKa of the KET and when the adsorbent has a higher pHpzc. From the kinetics of KET adsorption, it was found that the adsorbent dosage and the initial KET concentration causes an inverse effect on the equilibrium time and adsorption capacity for all the system. Isothermal studies confirmed the predominance of monolayer adsorption present on homogeneous surfaces corresponding to the Langmuir isotherm; however, it is also possible to observe more heterogeneous surfaces corresponding to the Freundlich and Sips isotherm. The thermodynamics nature of the process was found to be exothermic and endothermic, demonstrating a possible relation with the Gibbs solvation energy. The adsorption mechanism indicates that the KET tends to be adsorbed due to physical interactions (hydrogen bonding, π-π interactions). In general, the adsorption technique proved to be an efficient technology in removing KET, where several adsorbents have already been developed and successfully applied in its removal. The next step is to overcome the laboratory scale barrier and apply these materials to treat real effluents. In addition, studies should be more focused on continuous and multi-component processes, providing results for future real-scale applications

Development of a new hyper crosslinked resin based on polyamine-isocyanurate for the efficient removal of endocrine disruptor bisphenol-A from water

Bisphenol A (BPA) is a diphenylmethane derivative often used as a building block of polycarbonate in the production of plastic and plastic additives. Different sectors of the chemical industry release daily high concentrations of BPA in treatment plants, leading to polluting the environment. Due to chemical characteristics, BPA is considered highly toxic to animals and humans health. Adsorption is considered one of the promising techniques for the removal of BPA from water. In this study, we report the synthesis of a new polyamine-isocyanurate-based hyper crosslinked resin (ICYAN-PA) for the adsorptive removal of BPA from aqueous solution. The porous resin showed good thermal stability with a surface marked by smooth porous layers covered by particles of different sizes. The resin exhibited optimum removal of BPA at pH 5, with an adsorption capacity of 260 mg g−1. The isothermal studies suggested that adsorption was favored with increasing temperature (318 K). The Koble-Corrigan model was more adequate to represent the isothermal data. Moreover, the adsorption process was favorable, spontaneous, and endothermic (ΔH0 = 50.9 kJ mol−1). Furthermore, the magnitude of ΔH° was compatible with physical adsorption. The kinetic profiles indicated that the adsorption equilibrium was attained in <180 min of contact time, and the pseudo-first order model best represented the kinetic data. Given the relatively fast kinetics and high thermal stability (Td < 220 °C), ICYAN-PA holds a promise in the decontamination of effluents containing BPA

Correction to: Hexavalent chromium adsorption onto environmentally friendly mesquite gum-based polyurethane foam

The authors regret the mistake due to the omission of two references works carried out by Acuña et al. [1] and Ranote et al. [2]. 2.2. Preparation of adsorbents Crude Mesquite gum was purified based on the reported procedure by Acuña et al. [1] and Ranote et al. [2]. The samples of gum were subjected to drying at 80°C for 120 min and powdered through mortar and pestle. The obtained powdered gum was used further by dissolving 10.0 g in 250 mL of deionized water along with 10% of acetone. The mixture is allowed for mixing using a stirrer and results in the precipitation of pure gum. The obtained pure gum was a second time treated with 100 mL acetone. Finally, the pure gum obtained as precipitates was washed and dried. The resultant 5 g of purified gum acts as the source of bio-polyol, which was transferred into 5 mL of deionized water followed by 0.05 g DABCO, 0.06 g silicone oil, and 0.1 g Sargassum under the condition of constant stirring. The content was treated with the gradual addition of 1.5 g MDI associated with high stirring. These follow the foam formation with rapid solidification in the form of MG-PUF and Sa-MG-PUF, which were washed using deionized water and oven-dried at 60°C for 24 h , and used as adsorbents. These adsorbent performances were compared with commercial polyurethane form (CPF) adsorbents. The authors would like to apologize for any inconvenience caused. The original article has been corrected

A review of the antibiotic ofloxacin: Current status of ecotoxicology and scientific advances in its removal from aqueous systems by adsorption technology

It is estimated that the growth of the population, the augmented expectancy of life, and the emergence of new pandemics will significantly increase the consumption of pharmaceutical drugs in the coming years. Due to its high efficiency, the group of fluoroquinolones, where the antibiotic ofloxacin hydrochloride (OFL) is found, is widely used to combat bacterial infections in humans and animals. The big problem is concentrated in the effluents generated by industries and hospitals. Additionally, most of the drug is not absorbed by the body and is released directly into domestic effluents. On the other hand, treatment stations have removal limitations for small concentrations. This review analyzed all adsorbents developed and used in OFL removal, listing the main parameters influencing the process. In the end, the other existing technologies in the literature and the gaps and future prospects were described. OFL adsorption in most studies occurs under basic conditions (pH between 6.5 and 8). The increase in concentration provides an increase in adsorption capacity. The adsorbents analyzed showed moderate kinetics, reaching equilibrium before 250 min for most studies. The pseudo-second-order model showed the best statistical fit. In most of the studies, the increase in temperature (313, 315, and 328 K) favored the adsorption of OFL. The Langmuir monolayer model represented most of the isothermal studies. The adsorption capacity varied from 3702 to 0.3986 mg g−1. In this aspect, factors such as OFL concentration and textural characteristics of the adsorbent exerted great influence. The thermodynamic parameters were compatible with the isothermal data, where the endothermic nature of the studies was confirmed. Physical interactions (π-π stacking, H bonding, hydrophobic and electrostatic interactions) governed the main adsorption mechanism. Although some studies stated that chemosorption occurred, thermodynamic parameters cannot validate the same. Coexisting ions in the solution can positively and negatively influence OFL adsorption. The listed studies are all applied to batch processes, where fixed bed studies should be better explored. From this review, it can be concluded that adsorption is a promising technique for OFL removal. However, it is extremely necessary to break the laboratory scale barrier and analyze possible conditions for applying these materials in treating real effluents together with combining technologies