Production Of Activated Carbon Research Articles

Machine Learning-Based Prediction of the Adsorption Characteristics of Biochar from Waste Wood by Chemical Activation.

This study employs machine learning models to predict the adsorption characteristics of biochar-activated carbon derived from waste wood. Activated carbon is a high-performance adsorbent utilized in various fields such as air purification, water treatment, energy production, and storage. However, its characteristics vary depending on the activation conditions or raw materials, making explaining or predicting them challenging using physicochemical or mathematical methods. Therefore, using machine learning techniques to determine the adsorption characteristics of activated carbon in advance will provide economic and time benefits for activated carbon production. Datasets, consisting of 108 points, were used to predict the adsorption characteristics of biochar-activated carbon derived from waste wood. The input variables were the activation conditions, and the iodine number of activated carbon was used as the output variable. The datasets were randomly split into 75% for training and 25% for model validation and normalized by the min-max function. Four models, including artificial neural networks, random forests, extreme gradient boosting, and support vector machines, were used to predict the adsorption properties of biochar-activated carbon. After optimization, the artificial neural network model was identified as the best model, with the highest coefficient determination (0.96) and the lowest mean squared error (0.004017). As a result of the SHAP analysis, activation time was the most crucial variable influencing the adsorption properties. The machine learning model precisely predicts the adsorption characteristics of biochar-activated carbon and can optimize the activated carbon production process.

Sustainable Activated Carbon from Agricultural Waste: A Study on Adsorption Efficiency for Humic Acid and Methyl Orange Dyes

In this study, porous activated carbon was produced from coffee waste and used as an effective adsorbent for the removal of humic acid (HA) from seawater and methyl orange (MO) dye from aqueous solutions. Phosphoric acid H3PO4 was used as an activating agent for the chemical activation of these agricultural wastes. The characterization of the activated carbon obtained using a scanning electron microscope (SEM), Fourier-transform infrared (FTIR) spectroscopy analysis, X-ray diffraction (XRD) and the Brunauer–Emmett–Teller (BET) method revealed that the activated carbon products exhibited high porosity and the formation of various functional groups. The effects of different parameters were examined using batch adsorption experiments, such as the adsorbent masses, pH, initial pollutant concentration and contact time. The results show that the performance increased with an increased adsorbent mass (up to 0.25 g/L) and decreased initial concentration of the adsorbent tested. On the other hand, this study clearly showed that the adsorption efficiency of the MO on the raw spent coffee grounds (SCGs) waste was around 43%, while no removal was observed for the humic acid. The experiments demonstrated that the activated carbon synthesized from the used coffee grounds (the efficiency was compared with commercial activated carbon (CAC) with a difference of 13%) was a promising alternative to commercially available adsorbents for the removal of humic acid from seawater. To understand and elucidate the adsorption mechanism, various isothermal and kinetic models were studied. The adsorption capacity was analyzed by fitting experimental data to these models. The experimental data for methyl orange dyes were analyzed using Langmuir and Freundlich isothermal models. The Freundlich isotherm model provided a superior fit to the equilibrium data, as indicated by a higher correlation coefficient (R2) than that of the Langmuir model. The maximum adsorption was observed at pH 3. The Freundlich adsorption capacity was found to be 333 mg/g adsorbent. The PAC showed a high adsorption capacity for the MO and HA. The PAC showed the highest adsorption capacities for the HA and MO compared with the other adsorbents used (SCGs and CAC) and would be a good material to increase the adsorption efficiency for humic acid removal in the seawater pretreatment process. In addition, the prepared AC BET surface area was 520.40 m2/g, suggesting a high adsorption capacity. This makes the material potentially suitable for various applications that require a high surface area. These results indicate that high-quality sustainable activated carbon can be efficiently produced from coffee waste, making it suitable for a wide range of adsorbent applications targeting various pollutants.

High-performance activated carbon from coconut shells for dye removal: study of isotherm and thermodynamics.

This study investigates the production of high-performance activated carbon (AC) from coconut shells (CS) through acid and base activation processes, along with pre- and post-functionalization of the biochar, aiming to effectively remove dyes from aqueous solutions. The resulting AC exhibited outstanding adsorption capabilities, with the Langmuir model providing a good fit to the experimental data. Maximum adsorption capacities were observed at different temperatures: 805 mg g-1 at 298 K, 904 mg g-1 at 318 K, and 1000 mg g-1 at 338 K for NaOH-activated AC, and 252 mg g-1 at 298 K, 295 mg g-1 at 318 K, and 305 mg g-1 at 338 K for H2SO4-activated AC. The presence of active sites and functional groups on the surface of AC facilitated dye adsorption. The influence of various parameters, including adsorbent dosage, dye concentration, pH, and temperature, on the adsorption process were also examined, identifying the ideal conditions for dye removal. Thermodynamic analysis confirmed the endothermic nature of the adsorption process, with higher temperatures leading to increased adsorption capacities. Overall, the research highlights the potential of various activation routes for the production of high-value AC as a sustainable and effective adsorbent for dye removal from wastewater.

Roles of lignin in pore development during activation of peach wood

Cellulose, hemicellulose, and lignin are major components in typical woody biomasses. They have varied reaction networks in activation and thus contribute to pore development in different ways. Removal of one component might significantly affect pore characteristics of resulting activated carbon (AC). This was investigated herein by activation of peach wood (PW), delignified peach wood (DLPW), lignin, and a mixture of lignin/DLPW with K2C2O4 at 800 °C. The results disclosed that delignification increased abundance of aliphatic structures relatively and enhanced mass transfer of volatiles and permeability of K2C2O4 through creating voids. These features together intensified cracking reactions in activation of delignified PW, enhancing bio-oil yield (60.9 vs 56.1 % from PW), diminishing production of AC (17.4 vs 20.2 % from PW), promoting pore development (1218.5 versus 1099.4 m2g-1 from PW), enlarging pore size of micropores and creating more mesopores and macropores in AC. This rendered the AC of superior performance for adsorption of phenol. Co-activation of DLPW and lignin suggested that reactions between DLPW-derived volatiles and lignin-derived char formed carbonaceous deposits that filled pores of AC, diminishing overall specific surface area. The characterization of the activation process with in-situ IR technique indicated that more intensive cracking reactions in activation of DLPW even hindered aromatization but facilitated pore development.

Modification of activated carbon through chemical-physical activation method with KOH and 60Co gamma irradiation from banana leaf waste

Abstract Until now waste is still a problem in many big cities in Indonesia. In addition, the amount of waste increases as the population increases. Banana leaf waste is no exception, which is included in other types of waste, which accounts for 6.33% of the total waste in Indonesia in 2022. Utilization of banana leaf waste as a raw material for activated carbon production can also be an alternative to reducing the amount of wasted banana leaf waste because they contain various kinds of organic compounds. Activated carbon is widely used as an adsorbent in various sectors, especially in the industrial sector. Production of activated carbon must go through an activation process to enlarge the surface pores either chemically or physically, or even both. This study aims to compare the results of activated carbon surface area and functional groups using the chemical-physical activation method from banana leaf biomass raw materials with KOH and gamma irradiation at various doses. The research method used is an experimental method consisting of 4 stages: dehydration, carbonization, activation, and characterization. The research was started by dehydrating the leaves and continued with the carbonization stage at 350°C for 30 minutes. Carbon was divided into four samples that consisted of 1 blank and 3 test materials that activated with 30% (w/v) KOH solution for 24 hours and gamma-irradiated with a dose of 10, 30, and 50 kGy. Results were characterized using FTIR and BET. The effect of gamma 60Co irradiation on the activated carbon material from banana leaf waste can increase the peak transmittance value of the activated carbon functional group due to the formation and reaction of free radicals on its surface. Increase in the surface area (from 6.504 to 24.04 m2/g) is also associated with an increase in the absorbed dose due to the formation of more free radicals. However, the surface area obtained is not as expected due to the possibility of pore blockage and excessive activation time, which causes the surface area of the material to be small.

Activated carbon from agricultural industry waste for use as an adsorbent of sulfamethazine: Fascinating and environmentally friendly process

Lignocellulosic wastes have garnered interest in activated carbon (AC) production owing to their abundance and cost-effectiveness. This research utilized coffee husk as a precursor for AC. The methodology involves impregnating the waste with varying proportions of phosphoric acid (H3PO4), 1:1 and 1:3 (masswaste:massH3PO4), and activation in a microwave oven, with different power and activation times. The N2 adsorption/desorption results demonstrated high surface areas (SBET) for the ACs. The optimized AC (C1:3-1000-10) was obtained using a time of 10 min, high impregnation ratio, and power, resulting in an SBET of 1200 m2 g−1. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra confirmed the presence of functional groups, such as hydroxyl and ester, on the AC surface. Adsorption tests with sulfamethazine (SMZ) showed a 225 mg g−1 remotion capacity, highlighting the waste potential for sustainable and economical AC production. This underscores the importance of optimizing activation parameters to enhance performance and application versatility in AC production from lignocellulosic sources.

Adsorption of cadmium from wastewater with activated carbons derived from pig fur biowaste: A comparative study of in-situ and ex-situ activation routes

The environmental challenges associated with cadmium contamination in wastewater have necessitated the development of high-performing activated carbons (ACs) for effective wastewater treatment. Adsorption capacity depends on both the surface area and the adsorption-active functional groups developed on the adsorbent's surface during activation. Proper manipulation of key process variables using the appropriate activation route produces highly efficient and economically viable ACs. This research investigates the viability of pig fur biowaste as a novel precursor for activated carbons using two distinct activation methods—in-situ and ex-situ. Using a central composite design (CCD) of the Response Surface Methodology (RSM), the study systematically examines the effects of impregnation ratio, carbonization temperature, and carbonization time on the cadmium adsorption capacities of the resulting ACs. The optimal conditions for in-situ activation were found to be 691 °C, 175.11 min, and an impregnation ratio of 1.784 g/g, resulting in a cadmium adsorption capacity of 91.57 %. For ex-situ activation, the optimal conditions were 468.8 °C, 80.81 min, and an impregnation ratio of 2.915 g/g, which achieved a higher cadmium adsorption capacity of 91.21 %. Both types of activated carbons maintained high efficiency after five regeneration cycles, indicating they are suitable for long-term applications requiring repeated regeneration. Although both methods produced ACs with comparable cadmium removal efficiency, the ex-situ activation route proved to be more economically viable due to its lower temperature and shorter processing time. This study demonstrates the potential of pig fur biowaste as a sustainable and underutilized resource for AC production and highlights the ex-situ activation route as the more cost-effective approach for producing high-performance adsorbents.

Syngenetic effects in co-activation of willow wood with homogenous biochar facilitate pore generation in activation

Mixing feedstocks of varied aromatic/aliphatic content is a simple method for tailoring pore structures of activated carbon (AC) in activation. Herein, willow wood and homogenous biochar produced at 300 or 500°C, which have distinct content of aliphatic component, were co-activated with K2C2O4, at 800°C for changing pore characteristics of resulting AC. The results indicated that co-activation of willow and biochar diminished production of AC and impacted evolution of organics and gases through intensive volatiles-char interactions. The AC from the co-activation of willow with either biochar-300 or biochar-500 exhibited higher specific surface area than that from direct activation of willow (1409.7 or 1297.0 m2 g−1 versus 1243.6 m2 g−1), which was also higher than calculated average of that from feedstock (ca. 1160 m2 g−1). This resulted from intensified gasification of the biochar with H2O/CO2 derived from willow, creating additional macropores and micropores of enlarged pore sizes. The enhanced gasification also reduced crystallinity of graphitic carbon, lowered O content via accelerated deoxygenation and diminished CO on nascent AC. Volatiles-char interactions also minimized pore filling from carbonaceous deposit generated from secondary condensation of primary volatiles. Additionally, direct activation of aliphatic-rich willow tended to form more micropores, while more mesopores were formed from aromatic-rich biochar.

Catalytic pyrolysis of plastic waste using activated carbon from cotton waste

This study introduces a novel approach to plastic waste management and energy recovery by synthesizing highly porous activated carbon from an often-overlooked resource, waste cotton fabric (WCF), using H3PO4 as an activating agent. The synthesized waste cotton fabric activated carbon samples (WCF-AC) were utilized as a solid acid catalyst in the catalytic pyrolysis of low-density polyethylene (LDPE), with the aim of converting LDPE into fuel-range hydrocarbons. This research highlights the potential of bio-based waste materials in the synthesis of eco-friendly and cost-effective catalysts for feedstock recycling. The impact of the H3PO4 impregnation ratio and the carbonization/activation temperature on the physicochemical properties of the resulting WCF-AC samples was investigated, providing valuable insights into the optimization of activated carbon production. The catalytic activity of the synthesized WCF-AC samples was evaluated, demonstrating a reduction of 12°C in the LDPE degradation temperature. Furthermore, this work revealed a substantial increase in the formation of carbocyclic compounds, with light aromatics such as benzene, toluene, and xylene constituting up to 43 % of the pyrolysis output. In certain instances, a decrease in heavier hydrocarbons beyond C11 was observed, indicating the selective yield of specific range hydrocarbons. This study underscores the potential of bio-based acid catalysts, such as the synthesized activated carbon presented here, in plastic recycling. The approach adopted in this research aligns with the principles of the circular economy, promoting resource efficiency and sustainability.

Hydraulic Drag of a Layer of Crushed Plant Waste in Screw Transportation during Activated Carbon Production

Hydraulic Drag of a Layer of Crushed Plant Waste in Screw Transportation during Activated Carbon Production

New biocatalyst produced from fermented biomass: improvement of adsorptive characteristics and application in aroma synthesis.

This study presents a novel approach to producing activated carbon from agro-industrial residues, specifically cocoa fruit peel, using solid-state fermentation (SSF) with Aspergillus niger. The process effectively degrades lignin, a major impediment in traditional activated carbon production, resulting in a high-quality carbon material. This carbon was successfully utilized for enzyme immobilization and aroma synthesis, showcasing its potential as a versatile biocatalyst. The study meticulously evaluated the physical and chemical attributes of activated carbon derived from fermented cocoa peel, alongside the immobilized enzymes. Employing a suite of analytical techniques-electrophoresis, FTIR, XRD, and TG/DTG the research revealed that fermentation yields a porous material with an expansive surface area of 1107.87 m2/g. This material proves to be an excellent medium for lipase immobilization. The biocatalyst fashioned from the fermented biomass exhibited a notable increase in protein content (13% w/w), hydrolytic activity (15% w/w), and specific activity (29% w/w), underscoring the efficacy of the fermentation process. The significant outcome of this research is the development of a sustainable method for activated carbon production that not only overcomes the limitations posed by lignin but also enhances enzyme immobilization for industrial applications. The study's findings have important implications for the agro-industrial sector, promoting a circular economy and advancing sustainable biotechnological processes.

Activated Carbons for Removing Ammonia from Piggery Vent Air: A Promising Tool for Mitigating the Environmental Impact of Large-Scale Pig Breeding

Unsustainable pig breeding is a great threat to the environment. Ammonia is one of the main pollutants emitted in piggery vent air. This work is a comparative survey that presents the findings on the effectiveness of ammonia adsorption from air using various activated carbons (ACs). Detailed consideration is given to the effects of (i) type of raw material (wood char, wood pellet, and commercial lignite-based char), (ii) preparation method (CO2, steam, and KOH activation), and (iii) activation conditions (temperature and KOH/char ratio), on the porous structure of ACs and their ammonia sorption capacity and reversibility. Response surface methodology and genetic algorithm were used to find optimum KOH activation conditions. Economic analyses of AC production were performed using process modeling in Aspen software. It was found that ACs obtained from wood char in KOH activation show a maximum ammonia capacity of 397 g/kg, which is at least 2.5-fold higher than that reached on ACs from physical activation. A lower activation temperature (<750 °C) and a higher KOH/char ratio (>3) were preferred for effective adsorption, regardless of the type of feedstock. High sorption reversibility was achieved (87–96%). This makes the obtained sorbents promising sorbents for ammonia removal from piggery vent air with potential subsequent application as nitrogen-enriched biochar for crop fertilization. Thus, it facilitates sustainable pig breeding.

Effect of Surface Area, Particle Size and Acid Washing on the Quality of Activated Carbon Derived from Lower Rank Coal by KOH Activation

The use of coal-derived activated carbon (AC) for water treatment applications demands more sustainable production methods, with chemical activation emerging as a promising alternative to thermal activation due to its higher AC quality, lower carbon burn-off, and higher yield. The study explored the effect of surface area, particle size and acid washing on the quality of AC derived from three seams of lower-rank Collie coal under the same activation conditions with potassium hydroxide (KOH). The quality of AC was determined by surface area and iodine number. The study demonstrates that Collie coal, suitable for AC production via KOH activation, yielded iodine numbers of 640 and 900 mg/g, with yields of 53 and 57 wt.%. Particle size influenced AC yield, with finer particle sizes yielding AC at 57–59 wt.%, whereas coarser ones yielded around 58–65 wt.%. SEM analysis shows the well-developed porous structure in Collie coal-derived activated carbons, with cleaner particles after acid washing. A positive correlation exists between coal surface area and AC iodine numbers, with higher values in coal samples correlating to increased iodine numbers in resulting AC. The regression model’s predicted values yield a coefficient of determination (R²) of 0.99.

Optimization of activated carbon production from cajuput biomass as a desiccant

Abstract Effective food preservation methods encompass a range of approaches, among which drying stands out for its convenience in storage and distribution. The drying process and subsequent storage of food, however, are significantly influenced by environmental conditions. To address this, the utilization of activated carbon derived from renewable biomass sources emerges as a sustainable solution for moisture sorption applications. This research delves into optimizing the production of activated carbon from cajuput biomass, harnessing its exceptional desiccant properties through the Taguchi method. The study rigorously investigates crucial parameters, namely carbonization temperature (400, 600, 800 °C), carbonization time (1, 2, 3 hours), NaOH concentration (1, 2, 3%), and impregnation time (1, 2, 3 hours). Employing a two-step approach involving carbonization followed by chemical activation with NaOH, the impact of these variables on the activated carbon’s moisture adsorption capacity is comprehensively evaluated. Remarkably, the optimized conditions of carbonization temperature at 400 °C, carbonization time of 3 hours, NaOH concentration of 3%, and impregnation time of 3 hours yield a maximum moisture adsorption capacity of 0.4076 g/g. These findings emphasize the transformative potential of cajuput biomass as a valuable feedstock for producing activated carbon, endowed with remarkable moisture sorption attributes. This cajuput-derived activated carbon presents an alternative desiccant for efficient moisture adsorption in the food drying process and optimal moisture control during food product storage.

Design and Fabricate of Coconut Shell Activated Carbon for Groundwater Filtration System

This paper presents the design and fabrication of activated carbon (AC) filters from agricultural coconut shells for groundwater filtration systems. The AC had been acting as a filter medium to filtrate the water. The production of AC from local agricultural wastes is the most environmentally friendly solution by transforming negative value wastes into valuable materials. The chemical and physical characteristics of AC produced were tested by adsorption capacity using Freundlich Adsorption Isotherm. Test results showed that AC with favourable physico-chemical properties can be produced locally from agricultural waste. Moreover, four parameters were measured to determine the filter's effectiveness: pH, turbidity, total suspended solids (TSS), and ammonia (NH3 –N). Consequently, the percentage removal of turbidity is 62% to 63%, TSS is 82% to 79%, and NH3-N is 12% to 4%, meeting the water quality standard. Overall, removing water quality parameters in groundwater filtration systems is more efficient with powdered AC than with granular size.

Producing Efficient Adsorbents from Kraft Lignin for the Removal of Contaminants from Water—A Full Factorial Design

This work aimed at optimizing the preparation of activated carbon (AC) from Kraft lignin for the adsorption of methylene blue (MB) and amoxicillin (AMX) from water. A full factorial design of three factors (precursor:activating agent (H3PO4) ratio, pyrolysis temperature, and residence time) at two levels was used to optimize the AC production. Eight AC products were obtained and evaluated considering the following responses: product yield, specific surface area (SBET), energy consumption, and adsorptive removal of the contaminants under study. The produced AC presented satisfactory SBET, ranging between 750 and 1335 m2 g−1, and efficient adsorption of MB and AMX from water, achieving up to 99% removal under the studied experimental conditions (100 mg L−1 of MB and AMX solution and material dose of 1 g L−1). Statistical analysis showed that product yield and energy consumption for AC production were influenced by temperature and residence time. The determination of a desirability function indicated a precursor/H3PO4 ratio of 1:2, pyrolysis at 700 °C, and residence time of 60 min as the optimal production conditions. The optimized AC presented SBET 1335 m2 g−1 and maximum adsorption capacity of 210 and 280 mg g−1 for MB and AMX, respectively.

Utilization of agro waste activated carbons as carbon black replacement in electron beam irradiated styrene butadiene rubber composites

Purpose This study aims to prepare activated carbon (AC) and activated biochar (BC) from sugarcane bagasse (SCB) can be used as carbon black (CB) replacement for styrene butadiene rubber (SBR) composites cured by electron beam (EB) radiation. Design/methodology/approach This study is carried out to investigate the effect of partial replacement of CB (as traditional filler) by AC or BC prepared from low-cost agricultural wastes (SCB) to improve the properties of SBR rubber cured by EB radiation (doses from 25 to 150 kGy). Findings The results indicated that the addition of AC or BC leads to improve the physical and mechanical properties of SBR with increasing irradiation dose [especially at concentration of 10 parts per hundred part of rubber (phr) from BC]. Also in this study, this paper examines how exposure of SBR rubber composites to ultraviolet (UV) radiation changes the mechanical properties for these composites, to do that, the specimens were examined before and after they were exposed to UV radiation for 300 h. The results showed that, the irradiated SBR composites, UV exposure, exhibit better retention in mechanical properties as compared with unirradiated ones, and the samples loaded with CB hybrid with ACs had an increased value of tensile strength (TS) retention as compared with blank sample. Originality/value The importance of this study is that, the production of AC from SCB offers a huge opportunity to overcome the problem of the disposal of SCB.

Activation of cotton with transition metal-based chlorides: Correlation of generation of pore structures with evolution of oxygen-containing species

Lewis acidity of chlorides is known to significantly impact fragmentation/condensation reactions in activation of biomass. Herein, activation of cellulose-rich cotton with CuCl2, ZnCl2 or FeCl3, the chlorides with low to strong Lewis acidity, was performed and the influences of varied chlorides on evolution of the pyrolytic products and pore structures of activated carbon (AC) were studied. The results indicated that ZnCl2 and FeCl3 with strong Lewis acidic sites catalyzed condensation of reaction intermediates of light or heavier ones to form AC with yield higher than that from cotton pyrolysis by 6.7 % and 53.3 %, respectively. Increasing AC production was mainly due to retainment of more oxygen (23.8 % of oxygen content for AC-FeCl3 and 20.7 % for AC-ZnCl2 versus 11.5 % from blank experiment). CuCl2 with weak Lewis acidity promoted dehydration of sugary structures, forming more sugar-derivatives in bio-oil but diminished production of AC. However, higher Lewis acidity does not meant higher capability for creating pores. Specific surface area for AC-ZnCl2-500 was much bigger than that of AC-FeCl3-500 (1783.9 versus 22.8 m2/g). Characterization of the activation with in-situ IR indicated that ZnCl2 catalyzed rapid dehydration of -OH and condensation of carbonyls below 500°C, transforming oxygen in stable C-O-C form and carbon in olefinic CC form for maintaining generated pore structures.

Enhancing the adsorption capacity of organic and inorganic pollutants onto impregnated olive stone derived activated carbon

This study presents a sustainable approach to activated carbon production from olive stones in comparison to commercial ones, using various activating agents such as H3PO4, KOH, and ZnCl2, for enhancing the adsorption properties and versatile adsorption capability to remove a range of pollutants including copper ion, methylene blue, and 2,4-Dichlorophenoxyacetic acid from aqueous solutions. The performances of activated carbons across varying conditions such as pollutant concentrations, temperatures, pH levels, and adsorbent amounts were tested. Increased initial pollutant concentrations correlated with higher adsorption capacities. Maximum adsorption capacities were achieved at pH levels of 5, 10, and 2 for Cu, MB, and 2,4-D, respectively. For KOSAC, Cu removal rose from 27 % to 52 %, for ZOSAC, MB removal increased from 39 % to 65 %, and for ZOSAC, 2,4-D removal surged from 33 % to 99 % at varying adsorbent amounts. Model validation was carried out utilizing the kinetic models (PFO, PSO) and isotherm models (Langmuir, Redlich-Peterson). The PFO kinetic model and Langmuir isotherm model proved more suitability for Cu adsorption, whereas PFO and PSO kinetic models, along with Redlich-Peterson isotherm models, were more prominent for MB and 2,4-D adsorption. Thermodynamic analysis revealed that the adsorption of Cu and 2,4-D was exothermic, while MB adsorption was endothermic. By optimization of experimental conditions, the maximum adsorption capacities were attained at 30.34 °C and 297.65 mg L−1 for KOSAC-Cu, 48.62 °C and 269.37 mg L−1 for ZOSAC-MB, and 30.31 °C and 299.02 mg L−1 for ZOSAC-2,4-D sorption. This research highlights ZOSAC's potential as a cost-effective, eco-friendly solution for water treatment, contributing to environmental sustainability and economical feasibility.

Experimental Study on the Preparation of Lignin-Based Activated Carbon and the Adsorption Performance for Phenol.

Biomass waste and wastewater are important wastes in the process of industrialization, which need to be effectively treated and utilized. In this work, an innovative method of collaborative treatment of biomass waste and phenol-containing wastewater is proposed. Biomass waste was used to produce activated carbon (AC), and then AC was used for phenol removal in wastewater treatment. Two kinds of typical biomass waste material, namely, coconut shell and lignin, were used. Physical activation (steam activation) and chemical activation methods were compared. Results show that steam activation is an effective method for coconut shell AC production. The largest Brunauer-Emmett-Teller (BET) surface area was 1065 m2/g at 800 °C. Chemical activation could produce AC samples with higher BET specific surface area. The lignin AC with K2CO3 activation has the largest BET surface of 1723.8 m2/g at 800 °C. FTIR results indicated that K2CO3 activation could greatly enhance the formation of surface oxygen-containing functional groups. Both coconut shell AC and lignin AC samples show excellent performance for phenol removal. The highest phenol removal efficiency for coconut shell AC and lignin AC are 96.87% and 98.22%, respectively. Adsorption kinetic analysis show that the pseudo-first-order kinetic model is able to describe the adsorption characteristics of phenol in wastewater treatment. Recycling properties show that regeneration of lignin AC could maintain high adsorption performance for phenol.