Highly efficient separation and removal of fluorinated liquid crystal monomers employing N-doped coconut shell-based biocarbon as adsorbent.

This study investigated the feasibility of using/reusing commercial activated carbon (CAC) for the capture of high molecular weight and high-boiling point volatile organic compounds (HBPVOCs). The CAC was first characterized using proximate analysis, heat value analysis, iodine value analysis, element analysis, inductively coupled plasma spectrometry, and specific surface area analysis. We then assessed the adsorption/desorption performance of a CAC-based PSA system for the removal of Butyl Cellosolve (BCS), a HBPVOC commonly used in paints, coatings, cleaners, and industrial processes. This involved deriving the BCS adsorption capacity of CAC as a function of adsorbent quantity (2.5, 5, and 10 g), flow rate (4, 6, and 8 L/min), and pressure (1.3, 2.3, and 3.4 kg/cm2). The BCS adsorption capacity of the CAC varied with pressure as follows: 1.3 kg/cm2 (652.85 mg/g), 2.3 kg/cm2 (817.20 mg/g) and 3.4 kg/cm2 (1324.05 mg/g). The adsorption mode most closely resembled pseudo-first-order kinetics (i.e. single-layer physical adsorption). Desorption was performed using an adjustable tubular high-temperature furnace under a nitrogen atmosphere (0.93 kg/cm2). Following desorption with a set desorption duration of 1 hr, the BET values varied with temperature as follows: 350°C (75.58% of the original value) and 450°C (86.04% of the original). Desorbed CAC (DCAC) was also examined to detect changes in pore structure due to the effects of recycling. We obtained breakthrough curves and a dsorption capacity curves of CAC as functions of flow rate and pressure. We also investigated adsorption performance under pressure swing conditions from the perspective of reaction kinetics and density functional theory. Our results demonstrate the efficacy of CAC in the adsorption of BCS as well as the recyclability of this material. Implications: This study demonstrates the potential for reusing commercial activated carbon (CAC) to capture high molecular weight and high-boiling point volatile organic compounds (HBPVOCs). Through comprehensive characterization and performance evaluation, we found that CAC effectively adsorbs Butyl Cellosolve (BCS), a common industrial solvent, with adsorption capacity increasing with pressure. The adsorption process follows pseudo-first-order kinetics, indicating single-layer physical adsorption. Additionally, the study highlights the recyclability of CAC, as desorption and subsequent analysis revealed minimal changes in pore structure, maintaining a significant portion of its original BET value. These findings suggest that CAC is not only effective for BCS adsorption but also sustainable for repeated use, offering an efficient and eco-friendly solution for managing industrial HBPVOCs.

In this study, removal of Cr(Ⅵ) from synthetic groundwater by adsorption onto commercial activated carbon (CAC) made up of coconut shell is investigated in batch studies. Surface modification of CAC with sulfuric acid is also conducted to evaluate its removal performance. It is evident that CAC chemically modified with sulfuric acid (sulfuric-treated CAC) demonstrates higher Cr(Ⅵ) removal efficiency than non-treated CAC in dealing with contaminated groundwater with the pH is about 7.0, suggesting that sulfuric-treated CAC is suitable for the in-situ remediation of Cr(Ⅵ) contaminated groundwater. Adsorption of Cr(Ⅵ) is strongly affected by pH, the granular sulfuric-treated CAC exhibits the highest Cr(Ⅵ) adsorption capacity at pH 1.5 and the maximum Cr(Ⅵ) adsorption capacity of which estimated with the Langmuir model was 8.24mg/g.

Enhanced removal of crystal violet using rawfava bean peels, its chemically activated carbon compared with commercial activated carbon

Energy-saving optimization of coking wastewater treated by aerobic bio-treatment integrating two-stage activated carbon adsorption

High efficiency removal of heavy metals using tire-derived activated carbon vs commercial activated carbon: Insights into the adsorption mechanisms

Potentials of algae-based activated carbon for the treatment of M.orange in wastewater

A new methodology for the prediction of optimal conditions for dyes' electrochemical removal; Application of copula function, machine learning, deep learning, and multi-objective optimization

Application of locally available materials for the treatment of organic polluted water

Hydrocolloids of Pereskia aculeata Miller (OPNH) are potential ingredients in food industry as emulsifiers and stabilizers. The extraction process of OPNH requires the removal of pigments with activated carbon. Because this step is critical to the quality of the ingredient and has an impact on costs, a new activated carbon has been developed with residues from the same process. Residues activated with NaOH and H3PO4 (300 °C, 1 h) were subjected to batch adsorption tests in model solutions of malachite green (MG), carbohydrate and protein. Residue treated with 85% H3PO4 (OPNAC) had higher productivity and MG adsorption capacity, displaying a predominantly microporous surface (MEV/BET) with chemical activation confirmed by TG/FTIR. OPNAC showed higher MG and protein adsorption capacity than the commercial activated carbon (CAC) did. Results for MG-adsorption capacity by OPNAC did not show significant differences in the presence of protein and carbohydrate, presenting the higher affinity of the adsorbent for the dye. Adsorption isotherms showed OPNAC to be more favorable to MG adsorption than CAC, and to have a good fit to Langmuir-Freundlich model. OPNAC made it possible to reduce costs and allowed the sustainability of the process, leading to increased efficiency in selective pigment removal compared with CAC.

Low-cost carbon derived from coal-coke for high-performance supercapacitors

Unburned material from biomass combustion as low-cost adsorbent for amoxicillin removal from wastewater

Methylene blue was efficiently removed from aqueous solution by foam flotation using a rhamnolipid biosurfactant as a dye collector. The effects of four parameters, namely, pH (1.5–11.5), frother concentration (5–65 ppm), aeration rate (2–6 L/min) and rhamnolipid to methylene blue weight ratio (0.5–6.5), on dye removal were studied and optimized using response surface methodology. Results showed that dye removal increases by increasing of all parameters; however, the nonlinear trend was observed for the effects of frother concentration and rhamnolipid to methylene blue ratio. Optimum removal conditions, resulting in about 93% dye removal, was achievedat pH value of 11.5, methyl isobutyl carbinol (MIBC) concentration of 35 ppm, airflow rate of 4 L/min, and rhamnolipid to methylene blue ratio of 3.5, after only 10 min flotation. Investigations also showed that the presence of electrolyte can significantly decrease the removal efficiency. Kinetics study revealed that the process follows the first-order model with a rate constant of about 0.288 sec- This study demonstrates that rhamnolipid could be considered as a potentially efficient and environment-friendly collector for the treatment of dye contaminated wastewater.

Pirina, a waste of olive oil factory, was used as an adsorbent for the removal of remazol brilliant blue R (RBBR) from aqueous solution by adsorption process. The pirina was pretreated with HNO3 before batch adsorption experiments. The effects of contact time, initial concentration, pH, temperature, and ionic strength on dye removal were investigated. While the amount of the dye removed by the pirina was increasing with increasing initial concentration and temperature, it decreased with an increase in pH. Moreover, commercial activated carbon (CAC) was also used to compare with the pirina in removing the RBBR. The maximum amounts of the RBBR removed by the pirina and the CAC were 23.63 and 199.45 mg g−1 per unit mass of the adsorbents, and the removal efficiencies of them were found as 94.52 and 99.72 %, respectively. Ionic strength in the presence of NaCl and KCl had also a reducing effect on the removal efficiency. The adsorption isotherm was in the best harmony with Langmuir, Freundlich, and Temkin models. The adsorption kinetic obeyed the pseudo-second-order and the intra-particle diffusion models. The values of the r 2 from the pseudo-second-order kinetic and intra-particle diffusion were between 0.984–0.999 and 0.85–0.996, respectively. From thermodynamic studies, it was seen that the adsorption was of spontaneous and endothermic nature. The values of ΔG° of the adsorption were between −3,218 and −8,867 J mol−1. The values of ΔH° and ΔS° were 50,134 J mol−1 and 179 J mol−1 K−1, respectively. Moreover, SEM and FT-IR studies were also performed.

Wastewater containing medical dyes is one among the foremost essential contamination effects of natural aquatic ecosystems. The current study investigates the optimal operating conditions for removal of dye (Yellow No.6 (C16H10N2Na2O7S2)) from synthetic wastewater. Experiments were conducted on activated carbon (AC) prepared from waste polymer through microwave irradiated. Effects of the adsorption parameters (initial dye concentration, amount of adsorbent, and system temperature) on the dyes removal efficiency were study and optimized by response surface methodology (RSM). The optimal operating conditions for dye removal were establish at an initial dye concentration of 30 mg/l, amount of adsorbent of 0.022 g and system temperature of 32°C with an adsorption removal efficiency of 98.72%. The adsorption removal efficiency increased with increasing the dosage of activated carbon from 0.005 to 0.03 g. While the increase in initial dye concentration from 25 to 100 mg/L and system temperature from 25 to 50°C caused decrease in removal efficiency. The adsorption removal efficiency increased with increasing the dosage of activated carbon from 0.005 to 0.03 g. While the increase in initial dye concentration from 25 to 100 mg/L and system temperature from 25 to 50°C caused a decrease in removal efficiency.

To remove gaseous formaldehyde (HCHO) and rationally utilize agriculture wastes, chemical activation method using ZnCl2 as activating agent was employed to develop high-class biomass activated carbons (BACs) derived from agricultural straws for HCHO removal at ambient temperature. Proximate analysis and ultimate analysis testified that these agricultural straws were appropriate BACs precursors. BACs’ physicochemical properties were characterized by BET, SEM, FTIR and TGA, which demonstrated BACs with large specific surface area had the potential as ideal adsorbents. Systemic tests investigated the effects of activating agent (ZnCl2) and the concentrations of O2 and HCHO on adsorption performances of BACs, and compared them with two commercial activated carbons (CACs). Results showed ZnCl2 brought enormously positive effects but O2 had a prohibitive effect on the adsorption performance. BACs exhibited better performance than CACs, and BACM (BAC derived from maize straw) could obtain more than 80% removal efficiency under 1ppm HCHO after 40h. Desorption and regeneration tests were conducted to evaluate the security of the adsorbent and recycle regenerated adsorbent. The desorption temperature all above 50°C could ensure use security indoors. Saturated BACM through 1 or 2 run regeneration still exhibited better adsorption performance compared with virgin CAC from coal, indicating that the regeneration was significantly meaningful in practical application.