Composite Design Research Articles

Optimizing Sustainable High-performance Green-concrete Characteristics with Minimum Cement Content: Experimental Program

With the increasing cement demand for concrete production, this study aims to optimize the compressive strength and rapid chloride permeability (RCP) of highperformance green concrete (HPGC) with minimum cement content using an experimental and analytical Response Surface Method (RSM). Waste palm oil fuel ash (POFA) was treated by heating and grinding processes to produce ultrafine POFA (UPOFA), which was employed by 0%, 30%, and 60% as a replacement binder with cement in HPGC production. Silica Fume (SF) was replaced by 0%, 10%, 15%, and 20% of the remaining mass of cement. The RSM with a central composite design (CCD) approach was utilized to optimize the mix design parameters. The experimental results showed that HPGC containing 30% UPOFA and 20% SF achieved superior compressive strength at ages of 28 days and 90 days. The combination of 60% UPOFA and 20% SF demonstrated the lowest permeability to chloride. The developed models had statistical significance and demonstrated satisfactory correlation values (R2) of 99.43 and 99.9; 99.46 and 99.67 for compressive strength and RCP at 28 days and 90 days, respectively. Thus, RSM could be an effective strategy for optimizing the mix design and reducing the harmful environment by minimizing waste volume and intensive energy for cement production, thereby harnessing concrete sustainability. Keywords: Concrete sustainability, Green concrete, RSM, UPOFA, Silica fume.

Enhancing physical and chemical stability of a water-in-oil gelled-in-water multiple emulsion containing omega-3 polyunsaturated fatty acids and curcumin by Draper-Lin Composite Design

Enhancing physical and chemical stability of a water-in-oil gelled-in-water multiple emulsion containing omega-3 polyunsaturated fatty acids and curcumin by Draper-Lin Composite Design

Optimisation of phytoremediation of zinc ion by Lemnaceae using response surface methodology

Phytoremediation, an eco-friendly approach, offers a green pathway towards cleaner and safer water resources. The efficiency of zinc ion removal through phytoremediation by Lemnaceae as a function of Lemnaceae species, the mass of duckweed and the initial zinc ion concentration was studied. The central composite design was applied for surface response modelling to analyse the effects of the combination of environmental factors and optimise the phytoremediation process. The model achieved a satisfactory prediction with a coefficient of determination (R2) of 0.985 based on a modified quadratic model for the optimised phytoremediation process. Furthermore, the analysis of variance (ANOVA) was conducted to assess the adequacy and significance of the generated model. The optimal zinc ion removal of 88 % could be achieved by Spirodela polyrhiza, Wolffia arrhiza and Lemna minor at the initial zinc ion concentration of 92.92 mg/L, 39.5 mg/L, and 21.08 mg/L and duckweed mass of 22.56 g, 22.38 g, and 24.81 g under the exposure of ambient conditions with sufficient daylight exposure.

High-performance cellulose acetate fibers-loaded Al[sbnd]ca layered double oxide adsorbents towards efficient elimination of anionic pollutants: Mechanism adsorption and RSM-CCD approach

In the present research, we investigate Congo red (CR) removal by layered double hydroxide and oxide AlCa on cellulose acetate (CA) fiber as anion-adsorbents in aqueous solution. The as-prepared composite was characterized by FE-SEM, XRD, FTIR, EDS-mapping and BET-BJH analyses. The CR adsorption ability on AlCa LDH/CA and AlCa LDO/CA adsorbents was evaluated. The removal property, dye adsorption and filtration properties of the AlCa LDO/CA composite were studied for removal CR based on central composite design (CCD) technique through investigating operational variables (temperature, adsorbent dosage, pH and contact time). The fabricated AlCa LDO/CA composite indicates a high removal efficiency up to 98.7 % for the CR removal in the 16 min. The data of the adsorption equilibrium were described by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms, and exhibited that AlCa LDH/CA fibers and AlCa LDO/CA fibers followed a pseudo-second-order kinetic model and Langmuir isotherm. The stability of Al-Ca-LDO/CA fibers nanocomposite was indicated that it was >95 % after eight cycles for removal of CR in the batch method on stirrer. The findings illustrated that appropriate AlCa LDO/CA fiber could be an efficient technique for CR elimination.

Electrochemical Synthesis of Polyaniline@Nano Zinc Oxide/Modified Multiwalled Carbon Nanotubes Nanocomposite Coating for Solid Phase Microextraction of Some Polycyclic Aromatic Hydrocarbons in Coffee and Grilled Meat.

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds resulting from incomplete burning of organic materials. This work describes the successful layer-by-layer fabrication of a novel zinc oxide nanocomposite made of zinc oxide nanoparticles, aniline, sodium dodecyl sulfate, and modified multi-walled carbon nanotubes on a stainless steel wire by electrodeposition. The coating and extraction conditions were screened, optimized, and validated using factorial design and central composite design, respectively. The prepared nanocomposites were characterized by the Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray diffraction analysis, and Brunauer-Emmett-Teller techniques. It featured a porous structure, excellent heat stability, and a high extraction capacity. It also adhered well to the steel surface. Extracting PAHs was optimized through experimental design. The optimal conditions obtained for extraction were 60min, 30%, and 30°C for extraction time, amount of salt, and extraction temperature, respectively. The validated method generally showed a linear range between 0.01 to 1.50 µg/mL with a linearity of (R2) of 0.9902-0.9992, limits of detection less than 0.003 µg/mL, limit of quantification lower than 0.010 µg/mL, and relative standard deviation percent less than 45. Recovery values of the analytes in food samples varied between 53.4% and 110.1%. The proposed method was employed in the extraction and determination of some PAHs in some food samples while naphthalene, anthracene, phenanthrene, benzo[a]pyrene, and benz[a]anthracene were detected in certain food samples. Overall, our research suggests a novel nanocomposite as a potential fiber coating that enables high-capacity PAH extraction.

Development of a novel encystment medium: Enhancing diagnostic potential of Acanthamoeba spp.

Background and Aim: Acanthamoeba spp. are pathogenic microorganisms linked to severe infections in humans and animals, requiring a deeper understanding of their encystation process for effective diagnostics and research. This study focused on developing a novel encystment medium to induce synchronized encystation of Acanthamoeba spp. efficiently and rapidly. Materials and Methods: The study employed response surface methodology with a central composite design to optimize the encystment medium formulation. The key components included Tris-HCl, NaCl, glucose, and MgCl2. The optimized liquid medium was spray-dried to produce a dehydrated powder for practical application. The encystation efficiency of different Acanthamoeba strains was assessed using hemocytometry and fluorescence microscopy. Results: The optimized medium, comprising 3.152 g/L Tris-HCl, 5.55 g/L NaCl, 8% (w/v) glucose, and 5.0 mM MgCl2 at pH 9.0, demonstrated exceptional encystation efficiency with rates ranging from 99% to 100%. A spray-dried powdered version of this medium was equally effective, achieving a 98.77% encystation rate for A. castellanii American Type Culture Collection 50739 in glucose-free conditions. Notably, optimal glucose concentrations varied among Acanthamoeba strains, with certain strains reaching maximum encystation at 6–8% glucose. Conclusion: This study successfully developed an innovative encystment medium that promotes rapid and efficient cyst production in Acanthamoeba spp. The medium enhances laboratory research and diagnostic capabilities, paving the way for future advancements in understanding and managing Acanthamoeba infections. Keywords: Acanthamoeba, diagnostic tools, encystation, medium optimization, response surface methodology.

Response surface methodology and artificial neural network based media optimization for pullulan production in Aureobasidium pullulans.

The selection and optimization of carbon and nitrogen sources are essential for enhancing pullulan production in Aureobasidium pullulans. In this study, combinations of carbon (sucrose, fructose, glucose) and nitrogen sources ((NH4)2SO4, urea, NaNO3) were screened, where sucrose and NaNO3 offered the highest pullulan yield (9.33gL-1). Plackett-Burman design of experiment identified KH2PO4, NaCl, and sucrose as significant factors, which were further optimized using a central composite design. A hyperparameter-optimized artificial neural network (ANN) model with a 3-6-2-1 architecture demonstrated superior predictive accuracy (R2: 0.96) and generalizability (R2CV: 0.74) over a reduced quadratic model (R2: 0.82). The predicted pullulan yield (31.9gL-1) under ANN model optimized conditions (sucrose: 79.9gL-1, KH2PO4: 0.25gL-1, NaCl: 4.3gL-1) closely matched with the observed yield (30.17gL-1), while quadratic model showed a significant deviation (39.7gL-1 vs. 21.0gL-1), highlighting the reliability of the ANN model.

Impregnation of ZnO over a new hydrogel bead based conducting polymer and alginate for textile dye treatment: Interface charge transfer assessment, real wastewater treatment, and dye selectivity

In this study, we have taken a novel approach to dye removal and real wastewater treatment by employing dual smart strategies: surface charge transfer engineering and developing an easily recoverable photocatalyst. The removal of acid blue 92 (AB92) dye by using a novel 3D polypyrrole-zinc oxide-sodium alginate (PPy-ZnO-SA) nanocomposite under UV-C, visible light, and natural sunlight was investigated. The nanocomposite hydrogel was characterized using various techniques, including XRD, Raman, FESEM, TEM, XPS, PL, DRS, and CV analyses, and the type of effective interactions in different stages of removal was investigated by FTIR analysis. The optimum conditions (reaction time = 284 min, dye concentration = 19.37 mg/L, and dose of beads 36 g/L) were optimized by the central composite design (CCD) approach, and the removal efficiency of AB92 was achieved at 93.80 % and 97.16 % for UV and visible light, respectively. The nanocomposite's performance on various dyes was studied, and the catalyst successfully removed an average of 71.64 % of the cationic dyes and 95.13 % of the anionic dyes under light. After examining both photocatalytic and coagulation treatments, our analysis of actual textile wastewater revealed a COD reduction of 94.04 % and 84.62 % under UV and visible light, respectively.

Optimization of PVA/ alkali treated ramie fiber-based composite film for green packaging application using response surface methodology approach

Natural fiber-reinforced composites have gained significant attention as eco-friendly alternatives in sustainable packaging due to their biodegradability, renewability, and low environmental impact. This study aimed to produce an optimum composite film by combining PVA with alkali-treated-ramie fiber using a central composite design (CCD). This research investigates the effects of two independent factors, PVA (60-100 wt%) and alkali-treated ramie fiber (0-40 wt%), on three dependent variables: tensile strength, elongation at break (%), and contact angle of the composite film. Response surface methodology (RSM) determined that the optimal film composition for packaging application is 80 wt% PVA and 20 wt% alkali treated-ramie fiber. This combination resulted in a tensile strength of 46.03 MPa, an elongation limit of 251.4 %, and a contact angle of 66.75°. The film, which was produced utilizing the optimal outcomes, was then subjected to several characterization methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, contact angle measurement, water vapor transmission rate analysis, and FTIR spectroscopy. This outcome exemplified the optimal use of processed Ramie fiber in a polymer matrix for the purpose of eco-friendly packaging.

Synthesis and characterization of novel lignocellulosic biomass-derived activated carbon for dye removal: Machine learning optimization, mechanisms, and antibacterial properties

Transforming waste materials into valuable products plays a crucial role in promoting sustainability and protecting environment. In this study, activated carbon derived from sugarcane bagasse, a lignocellulosic biomass source, was coated with iron and manganese for the adsorption and photodegradation of Acid Black 1 (AB1) dye from aqueous solutions. The effects of various parameters were investigated using Central Composite Design (CCD) and a Multi-Layer Perceptron (MLP) algorithm. The results of the characterization indicated that the iron and manganese particles were uniformly dispersed on the activated carbon. While CCD determined ideal parameters to be an initial concentration of 20.15 mg L−1, a dose of 25 mg/30 mL, a pH of 5, and a time of 40 min, the MLP Algorithm proposed slightly different conditions: an initial concentration of 26.66 mg L−1, dose of 25 mg, pH of 5.0, and a time of 25.05 min. Despite these differences, both methods projected impressive AB1 removal efficiency, 100 % for CCD and 99.02 % for MLP, underscoring the potential effectiveness of these strategies in AB1 mitigation. Concentration emerged as the predominant factor influencing the removal process, as determined by the MLP algorithm. The results showed that the major active species in the degradation of AB1 were ecb− and •O2−, while hvb + species also participated to some extent, and triethanolamine (TEOA) had a minor effect on the degradation efficiency. The nanocomposite exhibited a high antibacterial activity against Staphylococcus aureus, resulting in a large zone of inhibition. The optimized nanocomposite could be used as an effective nanomaterial to remove hazardous contaminants.

Visualizing fiber end geometry effects on stress distribution in composites using mechanophores.

Localized stress concentrations at fiber ends in short fiber-reinforced polymer composites (SFRCs) significantly affect their mechanical properties. Our research targets these stress concentrations by embedding nitro-spiropyran (SPN) mechanophores into the polymer matrix. SPN mechanophores change color under mechanical stress, allowing us to visualize and quantify stress distributions at the fiber ends. We utilize glass fibers as the reinforcing material and employ confocal fluorescence microscopy to detect color changes in the SPN mechanophores, providing real-time insights into the stress distribution. By combining this mechanophore-based stress sensing with finite element analysis (FEA), we evaluate localized stresses that develop during a single fiber pull-out test near different fiber end geometries-flat, cone, round, and sharp. This method precisely quantifies stress distributions for each fiber end geometry. The mechanophore activation intensity varies with fiber end geometry and pull-out displacement. Our results indicate that round fiber ends exhibit more gradual stress transfer into the matrix, promoting effective stress distribution. Also, different fiber end geometries lead to distinct failure mechanisms. These findings demonstrate that fiber end geometry plays a crucial role in stress distribution management, critical for optimizing composite design and enhancing the reliability of SFRCs in practical applications. By integrating mechanophores for real-time stress visualization, we can accurately map quantified stress distributions that arise during loading and identify failure mechanisms in polymer composites, offering a comprehensive approach to enhancing their durability and performance.

Construction of a Tungsten Trioxide Modified Smart-Polymers as a NIR-Responsive Platform for Photo-Thermal Therapy on Hepatocellular Cancer

Cancer remains a predominant contributor to both mortality and morbidity on a global scale, with over 10 million new cases diagnosed annually. The aim of this work was to prepare and evaluate erlotinib hydrochloride loaded tungsten trioxide modified with smart polymers for their anticancer potential. The morphology, crystallinity, chemical bonding, and thermal behavior of the nanoadsorbent were characterized using field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and thermogravimetric analyses. The optimization of the drug on the synthesized adsorbent was investigated utilizing response surface methodology-central composite design. The maximum sorption efficiency of 90.18% was achieved at the initial drug concentration of 32.82 mg L-1, a pH of 8.17, a temperature of 32.93 °C, and a contact time of 16.08 min. The drug sorption process follows the Langmuir isotherm and it displays pseudo-first-order kinetics. The nanocarrier showed a significant release profile for 6 h with a maximum release percentage of 99.81% in simulated cancer fluid at high temperatures. The nanocarrier showed low drug release without near-infrared laser irradiation and a rapid release rate over 15 min of near-infrared laser irradiation. The drug release properties fit the Korsmeyer-Peppas model, with a diffusion exponent indicative of both diffusion and erosion release mechanisms. In-vitro cytotoxicity of the nanocarrier in normal cells indicated that it had no significant cytotoxicity. The cytotoxicity of the nanocarrier in Hep-G2 hepatocellular carcinoma cell lines was evaluated by MTT assay, and the data showed that the nanocarrier has excellent cytotoxic activity (75.45%).

Parametric Optimization of Surface Roughness of Ni-W-P Electroless Coating Using Central Composite Design Coupled with Fuzzy Logic Approach

Parametric Optimization of Surface Roughness of Ni-W-P Electroless Coating Using Central Composite Design Coupled with Fuzzy Logic Approach

Algal biochar: A natural solution for the removal of Congo red dye from textile wastewater

The present study was aimed at synthesizing algae-derived biochar to examine its effectiveness and adsorption capacity to remove Congo red dye. The independent variables such as dye concentration, adsorbent dose, and adsorption time were optimized by using a central composite design (CCD). An adsorption experiment was conducted to evaluate equilibrium using a detailed experimental design and characterized through XRD, TGA, SEM, EDX, and FTIR analysis. This paper also focuses on evaluating non-linear adsorption isotherm and kinetics to describe the adsorption mechanism along with applying an Artificial neural network to validate the removal efficiency. The maximum Congo red removal efficiency (96.14 %) and maximum adsorption capacity of algal biochar (186.94 mg/g) were achieved with the optimized parameters of 1 mg/L of dye concentration, 0.1 g of adsorbent dose, and 240 min of contact time. Adsorption behavior was well described by Langmuir isotherm and Pseudo-nth order. A multilayer perceptron (MLP) MLP 2–5–1 structure best validates the response. Overall, the study sheds light that Algal-derived biochar is a potential material for the elimination of Congo red dye and contributes to achieving sustainable development goals.

Analytical quality by design guided white analytical chemistry driven green in the development of LC-ICP-MS method for arsenic speciation analysis in HEK-293 cells.

An analytical quality by design-guided LC-ICP-MS method for simultaneous arsenic speciation analysis in HEK-293 cells was optimized and validated. Initially, critical method variables (CMVs) were identified to achieve the targeted critical quality attribute (CQA) of the analytical target profile (ATP). Based on knowledge and risk assessments, formic acid (X1), citric acid (X2), and pH (X3) were studied for their effect on method responses such as resolutions (Y1, Y2) and retention time of As(V), As(III) and DMA (Y3, Y4, and Y5) using central composite design (CCD). ANOVA analysis indicated that variable interaction was significant in method responses with curvature effect on resolution (Y1 and Y2). The method operable design region (MODR) afforded a 0.1% formic acid, citric acid strength of 20-30mM, and pH 5.6-6.8 as a robust region for the appropriate method performance. Hence, the final method was optimized on the ZORBAX RRHD SB-Aq column using a mobile phase consisting of 0.1% Formic acid: Citric acid (22.5mM) (50:50% v/v; pH 5.6). The optimized method eluted As(V), As(III), and DMA at 2.5±0.1, 2.7±0.1, and 3.1±0.1min, respectively, with an acceptable resolution. The LOD of the method was 4.78, 3.39, 5.35ppb respectively for As(V), As(III), and DMA whilst the linearity was established at 30-1000ppb for all species with respective r2-value of 0.9967, 0.9996, and 0.9972, respectively. The % recovery (77.11-99.64%) and precision (0.25-1.95%) were acceptable. The method has proven robust for method variables. Notably, we conducted the Green-white analytical chemistry assessment for the developed method by three different assessment tools viz., AGREES, GAPI, and RGB of 12 algorithms. The developed method demonstrated robustness, environmental friendliness, and user-friendliness.

Fruit Leather Melon Formulation with Supplementation of Pineapple Puree, Carrageenan and Sorbitol

Melon is a fruit with high water content so that processing is needed to increase its economic value and shelf life. An alternative that can be done is to process it into fruit leather. The characteristics of fruit leather are influenced by pectin, sugar, and acid. The purpose of this study was to determine the optimum formula based on the addition of pineapple puree, carrageenan, and sorbitol to the chemical and sensory characteristics of melon fruit leather. The study used Response Surface Methodology with a Central Composite Design. The factors studied were pineapple puree, carrageenan, and sorbitol. The research stages carried out included preliminary research, formulation optimization, data analysis, verification and validation, and characterization of the optimum product. The results showed that increasing the concentration of pineapple puree caused an increase in water content, total sugar, titrated acid, and a decrease in texture sensory, while preferences tended to be stable. Increasing the carrageenan concentration caused an increase in total sugar and texture, but decrease in water content, titrated acid, and preference. Increasing the sorbitol concentration caused an increase in texture and preference, but a decrease in water content, total sugar and titrated acid. The optimum formula obtained of melon fruit leather based on 15% pineapple puree, 0.6% carrageenan, and 8% sorbitol with a desirability level of 0.723. The optimum formula had a water content of 17.9%; total sugar 20.0%; titratable acid 1.6%, which was lower compared to the control. Vitamin C content 52.2 mg/100 g; soluble solids of 83.2 oBrix, colour of 3.9; taste of 3.6, texture of 3.7; and preference 3.8; which were higher compared to the control. While the aroma sensory 3.044 was the same as the control.

Foam investigation and optimization by Response Surface Methodology of electrocoagulation process for textile wastewater decolorization in single-channel reactor

This research investigates foam formation during decolorization of synthetic textile effluent by the electrocoagulation process in a single-channel reactor. This study aims to optimize the process by examining multiple responses, including the foam layer thickness, under different operating conditions such as current intensity (0.5-2.5A), recirculation flowrate (40-100L.h−1), electrolysis time (10-40min), and active electrode area (69-621cm2).The active electrode area and the recirculation flowrate impact foam distribution, with thicker foam layers observed in compartments housing active electrodes, influenced by the reactor's geometry. Current intensity and electrolysis time are key factors affecting foam shape and volume. A higher recirculation flowrate (100L.h−1) reduces foam volume in active compartments due to increased mixing, which hinders effective liquid-solid separation. The foam thickness in the last active compartment increased 6.5 times as electrolysis time extended from 10 to 60minutes at 1.5A when 5 pairs of electrodes are active.Response Surface Methodology was employed to optimize the electrocoagulation process using Central Composite Design as a second-order mathematical model. Optimal conditions were identified at a current intensity of 1A, electrolysis time of 32.5min, recirculation flowrate of 65.5L.h−1, and 9 pairs of electrodes (621cm2). These conditions yielded a predicted decolorization efficiency of 42.72%, energy consumption of 26Wh.m−3, total foam layer volume of 166.92cm3, and last active compartment foam volume of 5.24cm3.

Development of Novel Microwave-safe Platinum Decoration: Functionalization of Decorative Layer Based on the Composition Design of Resinate

Development of Novel Microwave-safe Platinum Decoration: Functionalization of Decorative Layer Based on the Composition Design of Resinate

Optimization of plasma-activated water-assisted extraction of basil seed (Ocimum basilicum L.) mucilage: Effect on phenols, flavonoids, antioxidant, thermal and morphological properties

This study aimed to enhance basil seed mucilage extraction using plasma-activated water (PAW). The response surface method (RSM) and rotating center composite design (RCCD) were used, considering the activation time of deionized water with cold plasma (0–15 min), water temperature (55–85 °C), and seed-water ratio (1:33–1:65). Optimal conditions for extraction were identified as a temperature of 78.39 °C, an activation time of 15 min, and a seed-water ratio of 1:50, leading to a 2.11 times higher extraction yield (7.6 %) compared to untreated samples (3.6 %) which had the same conditions. PAW-treated samples showed improved biological activities, including higher levels of total phenolic compounds (58.56 mg GAE/100 g), total flavonoids (87.81 mg QE/g), and DPPH inhibitory activity (60.98 %). Additionally, PAW treatment raised the melting point of basil seed mucilage, with minimal change in melting enthalpy. These alterations were attributed to plasma chemical reactions and increased surface energy of polysaccharide granules.

Tetracycline removal from aqueous media and hospital wastewater using a magnetic composite of mango lignocellulosic kernel biochar/MnFe2O4/Cu@Zn-BDC MOF.

This study explored the use of mango lignocellulosic kernel biochar (MKB) modified with MnFe2O4 magnetic nanoparticles and a Cu@Zn-BDC metal-organic framework (MOF) (MKB/MnFe2O4/Cu@Zn-BDC MOF) for tetracycline (TC) removal from aqueous solutions and hospital wastewater. The modified biochar exhibited strong magnetic properties (19.803 emu/g) and a specific surface area of 30.456 m2/g, facilitating easy separation after adsorption. Using Response Surface Methodology-Central Composite Design (RSM-CCD), the adsorption model demonstrated high accuracy (F-value: 315.510, p < 0.0001, R2 = 0.9959). Thermodynamic analysis indicated that the process was endothermic and spontaneous, driven by physical interactions, with positive enthalpy and negative Gibbs free energy values. The pseudo-second-order kinetic model best described the adsorption, highlighting significant chemical interactions, while the Freundlich isotherm suggested adsorption on heterogeneous surfaces. The maximum TC adsorption capacities for MKB and its magnetic composite were 27.050 mg/g and 42.670 mg/g, respectively. The RL, n, and E parameters confirmed the desirability and physical nature of the interactions (0-1,〉1, and < 8 kJ/mol, respectively). The intraparticle diffusion model indicated multiple mechanisms were involved, and the biochar maintained excellent performance across reuse cycles, making it a highly effective and reusable adsorbent for water and wastewater treatment.