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%

Utilization of Pacara Earpod tree (Enterolobium contortisilquum) and Ironwood (Caesalpinia leiostachya) seeds as low-cost biosorbents for removal of basic fuchsin

Wastes from the Pacara Earpod tree (Enterolobium contortisilquum) and Ironwood (Caesalpinia leiostachya) seeds were studied as biosorbents for the removal of basic fuchsin from waters. Both biosorbents were prepared and characterized by different analytical methods. The characterization data showed that both materials were mainly composed of lignin, cellulose, and hemicellulose. Both biosorbents exhibited roughened surfaces and surface functional groups such as C-H, C=O, C=C, C-O, C-N, and OH bonds. Furthermore, the XRD pattern shows an amorphous phase with a wide peak from 10 to 30° due to the lignin. In terms of dosage and pH, the use of 1 g L−1 and 9.0, respectively, is recommended. The initial concentrations for the biosorption kinetics ranged from 50 to 500 mg L−1, where the Pacara ear and the Ironwood reached an adsorption capacity of 145.62 and 100.743 mg g−1 for the 500 mg L−1. The pseudo-second-order was found to be the proper model for describing biosorption of basic fuchsin onto Pacara Earpod tree and Ironwood, respectively. For the isotherm experiments, the maximum experimental biosorption capacity was found to be 166.858 and 110.317 mg g−1 for the Pacara Earpod and Ironwood for the initial concentration of 500 mg L−1 at 328 K. The Langmuir and the Tóth models were the best for representing the equilibrium curves for the basic fuchsin on the Pacara Earpod and the Ironwood, respectively. Maximum adsorption capacities of 177.084 mg g−1 and 136.526 mg g−1 were achieved for the Pacara Earpod tree and Ironwood, respectively. The biosorption process was spontaneous, endothermic, and favorable for both biosorbents. The biosorbents were also applied for coloration removal of simulated textile effluents, reaching 66% and 54% for the Pacara Earpod and Ironwood, respectively. For the final application, the materials were used in fixed-bed biosorption, with an initial concentration of 200 mg L−1, reaching breakthrough times of 710 and 415 min, leading to biosorption capacities of the column of 124.5 and 76.5 mg g−1, for the Pacara Earpod and Ironwood, respectively

High-performance removal of 2,4-dichlorophenoxyacetic acid herbicide in water using activated carbon derived from Queen palm fruit endocarp (Syagrus romanzoffiana)

In this work, an activated carbon sample with a high adsorptive performance for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was prepared from queen palm endocarp (Syagrus romanzoffiana) by pyrolysis process. The activated carbon presented an XRD pattern related to carbon graphite and functional groups such as C–H, C˭O, O–H. The material particles presented a highly-porous structure, being beneficial to the adsorption process. The activated carbon showed a remarkable specific surface area of 782 m2 g−1 and pore volume of 0.441 cm3 g−1. The solution pH presented a strong influence on the adsorption process, with ideal pH = 2, being the best adsorbent dosage, 0.5 g L−1. The correspondent removal percentage was 95.4%. The pseudo-second-order model represented kinetic data, presenting R2 > 0.992 and MSR 0.997) and lowest values of MSR (< 92.04 (mg g−1)2), indicating a maximum capacity of 367.77 mg g−1. The thermodynamic study indicated a spontaneous operation, with ΔG0 ranging from –23.2 to −32.6 kJ mol−1 and endothermic process (ΔH0 = 67.30 kJ mol−1), involving physical interactions in the adsorbent/adsorbate system. The adsorbent could be regenerated by NaOH and used 7 times with the same adsorption capacity. Hence, overall, the activated carbon prepared from the Jerivá endocarp corresponds to a promising adsorbent in removing 2,4-D herbicide in wastewater

Powdered biosorbent from pecan pericarp (Carya illinoensis) as an efficient material to uptake methyl violet 2B from effluents in batch and column operations

The application of dyes in industrial processes has become a growing preoccupation due to the high quantities of colored effluents generated, which need previous treatment before being discarded in water bodies. A powdered biosorbent was then prepared from pecan pericarp and HCl, in order to treat colored effluents containing the dye methyl violet 2B (MV2B) using batch and fixed-bed operation modes. The new biosorbent, so-called powdered pecan pericarp (PPP), was characterized by functional groups related to cellulose, lignin, and hemicellulose. In addition, the material was composed of particles with different sizes, amorphous structure, and rugous surface. The best pH for MV2B biosorption on the PPP was 8.5. The kinetic profile was better described by the general order model, being the equilibrium rapidly reached in the first 5 min for different initial concentrations MV2B. The equilibrium curves were better described by the Langmuir model, indicating homogenous biosorption. The maximum biosorption capacity of 642 mg g−1 was reached at 328 K. Biosorption was favorable and endothermic. PPP has removed 94.1% of color in the simulated effluent. The fixed-bed assays revealed that the column packed with PPP could operate during 52.5 h with a height of 25 cm. The Thomas, Bohart-Adams, and Yoon-Nelson models were suitable to describe the dynamic curves. Therefore, PPP can be used as an efficient and fast biosorbent to treat textile effluents containing MV2B dye

Adsorption of atrazine herbicide from water by diospyros kaki fruit waste activated carbon

In this work, Diospyros kaki fruit waste was employed as a precursor material to develop a high surface area activated carbon, which efficiently removed the toxic herbicide atrazine (ATZ) from synthetic water solutions and river waters. The alternative activated carbon presented excellent characteristics and structure, including high values of specific surface area (1067 m2 g 1) and pore volume (0.530 cm3 g 1) and some important functional groups on the surface. The temperature positively influenced the adsorption capacity, from 194.20 to 211.51 mg g 1. The Freundlich model was the proper one to represent the equilibrium data. Thermodynamic parameters confirmed the endothermic nature of the adsorption process. Kinetic studies confirmed that equilibrium was reached until 240 min, regardless of ATZ initial concentration. The LDF model adjusted well to the kinetic data, resulting in a diffusion coefficient ranging from 0.89x10-9 to 1.63x10-9 cm2 s 1 as the ATZ concentration increased. The activated carbon also decreased 85% of the ATZ concentration in a river water sample. Overall, the activated carbon developed from Diospyros kaki fruit waste presented an efficient ATZ removal from aqueous matrices