Adsorbent Weight Research Articles

Facile synthesis, characterization and application of magnetic Fe3O4-coir pith composites for the removal of methyl violet from aqueous solution: Kinetics, isotherm, thermodynamics and parametric optimization

Dyes are commonly used in coloring clothes; in fertilizers, as anti-freezers, as detergents and so on. The use of such dyes has carcinogenic and genotoxic effects. These dyes require proper removal from the environment. Subsequently, a green and low-cost approach promises to adhere to sustainability of the environment while maximum removal of these toxic dyes. The present study describes removal of methyl violet (MV) dye by adsorption process magnetically separable Fe3O4-coir pith composites. The study was evaluated in batch system taking the optimum conditions as: pH: 7, contact time: 12 h, stirring speed: 200 rpm, concentration of dye: 100 mg/L, adsorbent weight: 3 g/L, temp.: 308 K. The central composite design approach of response surface methodology in design-expert software showed maximum removal efficiency (>98%) for optimal parameters. The experimental equilibrium data fitted reasonably well to Langmuir isotherm model. ANOVA analysis along with Fisher's statistical test was also performed to validate the model. The predicted model was at par with the experimental values with adjusted R2 of 0.9914. A thorough investigation of kinetic (RPseudo second order2 = 0.99; RPseudo second order2=0.97;Rintra−particle diffusion2=0.98), thermodynamic, adsorption isotherm (RLangmuir isotherm2=0.997RFreundlich isotherm2=0.99 and eco-toxicological characteristics were performed for proper evaluations of the properties as well as sustainability of the adsorbent material. The whole research indicated encouraging potential of the developed material for adsorption, reusability and sustainability in applications for industrial scale wastewater treatment.

Effectiveness of Adsorbents Chicken Eggshells and Cassava Skin to Reduce Pollutants in the Electroplating Industry

The electroplating industry has toxic content that is toxic to living things and the environment. This study aims to examine the values of Cu and Cr levels in the electroplating industry based on variations in adsorbent weight comparison. Adsorbents used are chicken eggshell and cassava skin with a contact time of 90 minutes. Adsorbent comparison used is 20:10, 25:10, and 30:10. After processing by applying the adsorbent system in the electroplating industry wastewater obtained the results of research it appears that the comparison of the weight of adsorbents influenced the decline of Cu and Cr metals with a decrease in Cu by 0.003 mg/l or with the efficiency of 99.43% and a decrease in Cr by 0.962 mg/l or with an efficiency of 95.44%.

A comprehensive study on the adsorption-photocatalytic processes using CoFe2O4/SiO2/MnO2 magnetic nanocomposite as a novel photo-catalyst for removal of Cr (VI) under simulated sunlight: Isotherm, kinetic and thermodynamic studies.

The present study aimed to investigate the efficiency of CoFe2O4/SiO2/flower-like MnO2 nanoparticles as a catalyst for Cr (VI) adsorption-photocatalytic processes. The magnetic nanocomposite used was first synthesized and then characterized using TEM, SEM, EDX, XRD, FTIR, XRF and BET advanced techniques. The removal of the Cr (VI) was performed through a batch adsorption approach and the effects of sample pH (A; 2-6), initial chromate concentration (B; 50-100ppm) and adsorbent weight to sample volume ratio (C; 1-3mgml-1), hole scavenger (0.1 -0.3%w/v) and time (E; 30-60min), to evaluate the individual and interactive effects under ultraviolet light conditions, were also studied by the central composite design in the photocatalytic process of adsorption. The adsorption-photocatalytic performance of the CoFe2O4/SiO2/MnO2 composite was high in which 98.1% of Cr(VI) after 30min of photocatalytic treatment in optimum conditions (i.e. pH = 3, catalyst concentration = 2mg L-1, Cr(VI) concentration = 200mg L-1, and hole scavenger concentration = 0.4% (w/ v), At laboratory temperature, speed = 400rpm, under UV radiation).Under optimum conditions, Cr(VI) reductive followed pseudo-second-order kinetics and followed the Langmuir and Temkin isotherms, also, positive value of ΔH° indicates endothermic nature. The results showed that the synthesized CoFe2O4/SiO2/MnO2 magnetic nanocomposite holds a great potential for use as a photocatalyst to remove Cr (VI) in adsorption reactions. It can be used as an effective catalyst in the eradication of Cr (VI) wastewater. The online version contains supplementary material available at 10.1007/s40201-021-00763-1.

Characterization of Egg Shell Waste As Adsorbent for Cooking Oil Waste Purification

Eggshell has a shaft and a high surface area, so it has the potential to become an adsorbent. The adsorbent is an adsorbent in the filtration process. Waste cooking oil can be reused as raw material with economic value. So far, the waste bank that accommodates used waste has not gone through the filtration process, so the selling price is low. Waste cooking can be filtered using various adsorbent media, including activated carbon, commercial silica, and local adsorbents such as eggshells. A filtration process on waste cooking oil is expected to increase income for waste banks. The objective of this study was to investigate formulations adsorbent from eggshells for purification waste cooking oil. The variables used were a variety of particle size adsorbents (60, 80 mesh) and adsorbent weight (10, 15 g). The optimal result for the decreased acidic number was obtained at 60 mesh particle size, weight 15 grams.

The Improvement of Natural Thai Bentonite Modified with Cationic Surfactants on Hexavalent Chromium Adsorption from an Aqueous Solution

This work was performed to evaluate the adsorption properties of modified Thai bentonites (MTBs) on hexavalent chromium (Cr(VI)) by using a popularly capable surfactant (hexadecyltrimethylammonium bromide (HDTMA)) compared to an alternative surfactant (cetylpyridinium chloride (CPC)). The adsorption properties of the surfactant load, adsorbent weight, contact time, initial Cr(VI) concentration, and temperature of the MTBs were evaluated. The results revealed that a higher surfactant load significantly affected the Cr(VI) adsorption, and the equilibrium adsorption was achieved at 60 min. The adsorption capacity improved when the adsorbent weight, contact time, initial concentration, and temperature increased as the highest adsorption capacities of 1CPC and 1HDTMA were 45.55 and 46.03 mg g-1, respectively. The isotherm and kinetic adsorptions were described by the Freundlich model and pseudo-second-order model, respectively, while thermodynamics indicated endothermic adsorption. After adsorption, X-ray absorption near-edge structure and extended X-ray absorption fine structure data showed that Cr ions did not change the valency state between Cr(VI) and Cr(III). Additionally, the adsorption mechanism can be depicted as the ion exchange between the Cr(VI) ion and the surfactant molecule. Structural evaluations by XRD, FTIR, FESEM, EDS, and TEM found that both MTBs (1CPC and 1HDTMA) with the best adsorption performance for Cr(VI) had obvious changes at both the interlayer structure and the external surface. The interlayer spacing was expanded from 14.85 Å to 20.48 Å (1CPC) and 18.79 Å (1HDTMA), and the new functional groups (CH2 scissoring, C–H symmetric stretching, C–H asymmetric stretching, and N–CH3 scissoring) and elemental compositions (Br and Cl) were observed in both MTBs. They demonstrated that the complete intercalation of surfactant molecules on bentonite structures supported Cr(VI) adsorption. Overall, the data indicate that MTBs were perfectly adsorbed on Cr(VI), and CPC was demonstrated to be a cheap alternative agent due to its adsorption capacity compared to the popularly capable HDTMA.

Removal of tartrazine, ponceau 4R and patent blue V hazardous food dyes from aqueous solutions with ZnAl-LDH/PVA nanocomposite

Zinc-aluminum-based layered double hydroxide-polyvinyl alcohol (ZnAl-LDH/PVA) nanocomposite has been synthesized by one-pot co-formation method. An intercalation approach was realized using (ZnAl LDH/PVA) nanocomposite as adsorbent and photocatalyst for adsorption and solar photodegradation of hazardous food dyes—tartrazine, ponceau 4R and patent blue V. The characterization of synthesized nanocomposite was carried out by XDR, SEM, FTIR and UV-Vis. The adsorption of dyes onto the synthesized adsorbent was carried out under different initial dye concentrations, pH, adsorbent weight and three different temperatures. The optimal pH for tartrazine, ponceau 4R and patent blue V was determined as 2.0, 7.0 and 2.0, respectively. The optimal temperature at optimal pH was 303 K after 40 min. Pseudo-first-order kinetic model, Langmuir and Temkin isotherm models were represented well for the definition of the adsorption mechanism of tartrazine. The adsorption of ponceau 4R and patent blue V on the ZnAl-LDH/PVA nanocomposite follows the Freundlich isotherm. The value of the slope of 1/n for ponceau 4R and patent blue V is more close to the unit (1/n = 0.668 and 0.768, respectively), which indicates the possibility of the adsorption process according to the Freundlich model. Because the adsorbent shows a photocatalytic property, after high effective sorption, the cyclic reusability of the sorbent was ensured by keeping the sample in its dye solution at 308 K in bright sunlight for 5 hours. The completely decolorized sorbent has shown high efficiency in subsequent sorption experiments.

Zeolite/Cerium Oxide Coat-on Activated Alumina Ball for Arsenite Removal via Fixed- Bed Continuous Flow Adsorption Column

Arsenite (As(III)) has threatened human life for ages. It is a necessity to remove As(III) from the contaminated water before general use. With the improvement of adsorption, higher As(III) removal can be achieved. This study aimed to develop zeolite/cerium oxide coat-on activated alumina ball adsorbent (CeZ-ball) with the aid of PVA binder and apply it to a fixed-bed continuous flow column for As(III) adsorption. The coating percentage of CeZ-ball was studied. Cerium ions leaching from CeZ-ball were monitored throughout the 2,880-min-column run to confirm the stability of CeZ attached to an activated alumina ball. Surface area, pH point of zero charge, and structural property of CeZ-ball were characterized. An average CeZ coating of 83.3% and rare leaching of cerium proved the coating method. The models proposed by Yoon-Nelson provided the most satisfactory fit with the breakthrough curve (r2 = 0.985, MPSD = 2.547, and q0 = 3.481 mg·g–1) under experimental conditions of the flow rate of 5 mL·min–1, As(III) influent concentration of 1 mg·L–1, and CeZ-ball weight of 40 g. The half-time of breakthrough (τ) was 1,228.739 min. The effects of the key parameters, including initial adsorbent weight, initial flow rate, and initial As(III) concentration, were investigated for the performance of As(III) adsorption. Simulated from the Yoon-Nelson model, the τ increased as well as the adsorbent weight but decreased as the flow rate increased, thus impacting the As(III) concentration. With the optimal condition, the fixed-bed continuous column with CeZ-ball could be used in As(III) removal from contaminated water.

Sorptive removal of malachite green from aqueous solution by magnetite/coir pith supported sodium alginate beads: Kinetics, isotherms, thermodynamics and parametric optimization

The present study deals with facile synthesis of magnetite/coir pith supported sodium alginate beads from naturally available waste materials which was further employed for removal of malachite green dye from synthetic aqueous solution underaparametric optimized condition of the adsorption process. Several operating parameters such as stirring speed (50–250 rpm), adsorbent weight (0.5–7 g/L), pH (2–9), temperature (35–55 °C), and initial malachite green dye concentration (50–250 mg/L) were used to study the adsorption in a batch operation. The central composite design approach of response surface methodology in design-expert software revealed maximum removal efficiency of malachite green at pH of 7; initial malachite green dye concentration of 150 mg/L; adsorbent weight of 3g and temperature of 35 °C which showed adsorption efficiency (>98%). Analysis of Variance (ANOVA) suggested the equation to be significant for the process with a greater impact of adsorbent weight and malachite green concentration rather than the other three contributing parameters. Extensive kinetic, isotherm, thermodynamic, and eco-toxicological studies were performed to understand the behavior and sustainability of the developed materials. Final observation assured the reusability of the processed beads and hence showed gigantic potential for implementation on industrial-scale evaluation for the treatment of wastewater. • Malachite green (MG) dye was adsorbed using low-cost composite material. • Facile synthesis followed by application of Fe/coir pith supported sodium alginate beads for MG dye removal. • Developed materials has intrinsic capability for high degree of MG dye removal (>97%). • Optimizations of the operating parameters were validated by response surface methodology technique (R 2 >0.98). • Toxicity assessment of the developed material showed the non-harmful effects on non-specific targets.

Removal of Congo Red and Procion Red Using Zn/Fe Pillared Bentonite

The process of pillarization of metal oxide Zn/Fe compounds in bentonite has been carried out. The study of adsorbent weight, pH, adsorption time, and initial concentration were investigated to get the optimum reduction of Congo red and Procion red concentration. In addition, the pseudo kinetic also determined to investigate the rate and type of adsorption. From the experiment, the optimum conditions for removal of Congo red for the adsorbent weight, pH, and adsorption time were 0.02 g, 2, 20 minutes, respectively, while for the removal of Procion red was 0.04 g, 2, 20 minutes, respectively and both of adsorbent followed the pseudo-second-order model kinetics with chemisorption mechanism. Although the optimum conditions for removal of the two dyes were similar, in fact the percentage removal of the Congo red dye was greater. In conclusion, the Zn/Fe pillared bentonite was more suitable for the removal of the Congo red than Procion red.

Removal of barium (II), cobalt (II), and strontium (II) from aqueous solution using chemically modified poly (acrylonitrile‐butadiene‐styrene) pellets

The adsorption behavior of Ba2+, Co2+, and Sr2+ ions from aqueous solutions by sulfonated poly (acrylonitrile‐butadiene‐styrene) (ABS-SO3H) was investigated. The structure of (ABS-SO3H) was confirmed using available spectroscopic tools such as Scanning Electron Microscope (SEM) and FT-IR together with DSC and TGA analyses in addition to EDX spectra. Various parameters including contact time, pH, adsorbent weight, and the initial metal concentration that affect the adsorption process, were investigated. The results indicated that the removal of Ba2+, Sr2+, and Co2+ increased with the increasing pH of a solution until pH =7 at a contact time of 1 h. The maximum adsorption capacity was calculated, and it was found to be 157.3, 107.5, 177 mg/g for Ba2+, Co2+, and Sr2+ ions, respectively. The kinetic study indicated that the adsorption process of Ba2+, Sr2+, and Co2+ using ABS-SO3H could be fitted to the pseudo second-order kinetic model (R2 =0.998). The Freundlich isotherm could be used to interpret the adsorption mechanism of Ba2+, Sr2+, and Co2+ by (ABS-SO3H). The separation feasibility of Ba2+, Sr2+, and Co2+ from a simulated aqueous solution was also discussed.

Oyster Shell Waste (Crassostrea Gigas) as A Cheap Adsorbent for Adsorption Of Methylene Blue Dyes: Equilibrium and Kinetics Studies

In this study, Oyster (Crassostrea gigas) shell powder which contains calcium carbonate (CaCO3) was converted into calcium oxide (CaO). The Oyster shell powder that had been activated was utilized for the adsorption of the methylene blue (MB) dyeing material, which is one of waste water concerns. Oyster shells were crushed and sieved into 100 mesh sized powder and then calcinated at a temperature of 600℃ and 800℃ both for 4 hours period. To determine the adsorption equilibrium, methylene blue (MB) solution was used with varying concentration from 10 to 50 mg/L in which the adsorbent weighing 3 g was put into a conical flash and shaken until the adsorption equilibrium was reached. As for the adsorption kinetics, 250 mL MB solution was used with initial concentrations of 10, 20 and 30 mg/L, with an adsorbent weight of 3 g and a solution at pH 11 for each concentration. The evaluation of the experimental data from the adsorption process is well explained by the Freundlich equation, with the correlation coefficient value (R2) found to be 0.9999, where the value of the adsorption intensity (n) is close to unity; this shows that the adsorption is multilayer or in other words the adsorption energy is heterogeneous. The kinetics study also shows that pseudo second-order model is the most applicable to the adsorption process. From the pseudo-second-order model, with the correlation coefficient between 0.9984 - 0.9999 can explain that the methylene blue (MB) adsorption process is chemically based sorption or in other words termed as chemisorption.

Synthesis, characterization and γ-rays irradiation of cobalt-based metal-organic framework for adsorption of Ce(III) and Eu(III) from aqueous solution

Metal-organic frameworks (MOFs) have important applications in adsorption, because of high porosity, diverse functionalities, and easy modification. Cobalt metal organic frame work (Co-MOF) based on diallylamine as the ligand was synthesized for the adsorption of Ce(III) and Eu(III) from aqueous solutions. Co-MOF was characterized by different spectroscopic techniques such as Fourier Transform-Infrared (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The effects of adsorbent weight, pH of solutions, contact time, metal ion concentrations and gamma irradiation dose were studied. The adsorption efficiency of Ce(III) and Eu(III) onto Co-MOF was 93.3 and 27.47%, respectively, at pH 5.1. The distribution coefficient (Kd) of Ce(III) increased from 17.46 to 2791.30 ml/g, while for Eu(III) increased from 13.15 to 75.75 ml/g with changed the pH from 1.01 to 5.1. The Ce(III) and Eu(III) adsorption data were well fitted to the pseudo second order kinetic and Langmuir adsorption model. The maximum adsorption capacity of Ce(III) and Eu(III) onto Co-MOF were 102.24 and 52.93 mg/g respectively. The adsorption of Ce and Eu was slightly reduced by about 10% with increase dose of gamma radiation up to 400 kGy.

Removal of Bismarck Brown G dye over composites of metalized copper oxide nanoparticles with nitrogen and activated carbons

The present work describes preparation of composites of iron metalized copper oxide nanoparticles (Fe/CuONPs) using co-precipitation method. Then new composites were prepared by combination of Fe/CuONPs with each of nitrogen and activated carbons(ACs). Activated carbons was both natural (AC1) and physically activated AC (AC2). This yielding tertiary systems N/Fe/CuONPs, AC1/Fe/CuONPs, and AC2/Fe/CuONPs. These prepared materials were investigated using different techniques and analytical methods such as Fourier transform infrared spectroscopy (FTIR), X- rays diffraction (XRD) technique, BET specific surface area, Scanning electron microscopy (SEM), Atomic absorption spectroscopy (AAS), and CHN microelemental analysis. The adsorption ability of these materials was investigated via following removal of Bismarck Brown G dye (BBG) from simulated industrial wastewaters over a suspension of these prepared materials. Different adsorption parameters and conditions were investigated such as effect of weight of adsorbent, effect of adsorption temperatures, and effect of pH of the dye solution. Besides that, adsorption isotherms were undertaken involving applying each of Langmuir and Freundlich adsorption isotherms was undertaken. From the obtained results it was found that, the optimum removal efficiency for this dye was noted when using AC2/Fe/CuONPs as adsorbent under these conditions. Also from adsorption isotherms, it was found that, the results were more fitted with Langmuir adsorption isotherm.

Mechanistic insights into the ultra-deep desulfurization of liquid fuel on date-seed derived hierarchical porous carbon

This study described the synthesis of activated carbon and its application in the removal of DBT and DMDBT from isooctane using both experimental and DFT calculations. The effect of synthesis conditions (pyrolysis temperature, precursor-activator ratio and ramping rate) on the properties of activated carbon were also presented. Activated carbon (AC) of high surface area and porosity was synthesized from an agricultural waste material (date seeds) using Zn-acetate as an activator. Thorough study of the characteristic activity and selectivity of this adsorbent in the removal of organosulfur compounds; dibenzothiophene (DBT) and dimethyldibenzothiophene (DMDBT) at room temperature were carried out. DFT simulations predicted the selectivity of AC towards DMDBT promoted by the charge donation and the positive inductive (+ I) effects of the methyl groups resulting in strong van der Waals interactions and theoretical adsorption energy of – 12.3 kcal/mol. It was observed that surface area, porosity, and surface chemistry of the adsorbent highly depends on the process parameters. The adsorbent pyrolyzed at 1000 °C and 10 °C/min performs better and shows exceptional capability to remove DBT and DMDBT (200 ppmw-S) in model fuel to almost sulfur-free fuel at minimum adsorbent weight (200 mg). However, the precursor-activator ratios at optimum pyrolysis temperature and ramping rate had little effect on the adsorbents’ performance. DMDBT was found to preferentially adsorb on the adsorbents with increasing pore size and volume than DBT. The kinetics and isotherms studies confirmed that the obtained data fitted more to pseudo-second order and Langmuir model.

Polyacrylonitrile/Ag nanoparticles nanofibers as an efficient adsorbent for natural gas condensate desulfurization

In this work, the optimization of the synthesis of PAN/Ag nanofiber composites via electrospinning was investigated via Taguchi experimental design approach. The adsorption capacity of sulfur compounds from natural gas condensate was considered as an objective function. The PAN/Ag nanofiber with 11 wt% PAN, 45 wt% AgNO3, 15 kV applied voltage, and 15 cm for distance of needle to a collector showed the highest adsorption capacity. The SEM, EDX, TEM, XRD, and FT-IR techniques were employed to elucidate the optimized PAN/Ag nanofiber structure. The results showed the successful synthesis of PAN/Ag nanofibers with diameters in 100-300 nm range and well distribution of Ag nanoparticles in the polymeric matrix. In addition, optimization of the adsorption capacity of PAN/Ag nanofiber in desulfurization of natural gas condensate in batch mode was performed via central composite design. Four factors including adsorbent weight, sulfur concentration in the natural gas condensate, the volume of sample, and the adsorption time were considered as effective factors each in three levels. The ANOVA analysis showed the more important factors on adsorbent performance are the concentration of sulfur in gas condensate and the weight of the adsorbent. The interaction terms between time and concentration and between volume and concentration are also important in response. Moreover, the response surface analysis of interaction terms showed the adsorptive nature of desulfurization.

Kinetic Study of Removal of Congo Red and Direct Green

The pillarization process of Al/Fe metal oxide compound in bentonite has been carried. The study of weight adsorbent, pH, adsorption time, concentration and temperature adsorption were investigated to get the optimum condition of Congo red and Direct green removal. In addition, the pseudo kinetic and isotherm model were also determined to investigate the rate and type of adsorption. From the experiment, the optimum weight of adsorbent, pH, adsorption time, concentration and temperature were 0.3 g, 2, 45 minute, 90 mg/L, respectively. Thus, the pseudo kinetic model follow the pseudo second order while the Freundlich model was use as the isotherm model. As conclusion, The Pillarization success to enhance the adsorption capacity of bentonite to remove the Congo red and Direct green dyes.

Preparation and evaluation of poly-o-toluidine sulfochromate as a promising nanocomposite for selective adsorption of copper

ABSTRACT In this study, Poly-o-toluidine sulfochromate (POTSC) nancomposite was synthesised for adsorption of Cu(II) from aqueous solutions. The structure of POTSC nanocomposites was characterised by FTIR, XRD, SEM, EDX, and TG-DTA techniques. The calculated average crystallite size of OTS and POTSC was 15 and 24 nm respectively. The effects of various parameters such as pH, adsorbent weight, time, and initial Cu(II) concentration on the absorption capacity have been studied. Results showed that the adsorption maximum occurs at pH 5 and adsorption equilibrium was achieved in 30 min. The adsorption capacity of Cu(II) was found to be 30.3 mg/g and kinetic modelling was used to described the adsorption mechanism of Cu(II). The isotherm study reveals that the adsorption data provided by the Langmuir model is stronger than that of Freundlich. The adsorption efficiencies of Cu (II), Zn(II), Ni(II), Ga(II), and Cd(II) on POTSC nanocomposite were 77, 7, 22.7, 2, and 2.8% respectively, which implied that POTSC nanocomposite is good selectivity for Cu (II) than other cations. POTSC nanocomposite may be used to separate copper radionuclides from the irradiated targets.

Chicken Bone Based Adsorbent for Adsorption of Pb(II), Cd(II), and Hg(II) Metals Ion Liquid Waste

High productivity of chicken meat for supplying society also make some impact in high productivity of chicken bone and because it’s unraveling properties makes this become waste. Pharmaceutical’s Waste comes from production process, adstertion of production tools, laboratory activities and rejected product. Laboratory’s routine analysis also producing residual waste analysis, one of the source is come from heavy metals analysis of Pb, Cd, dan Hg. General process for waste treatment producing high quantity of sludge, mean while using third party service have impact in high costing of transportation and treatment process. An alternatif way for this case is using sorption treatment. Initial research starts from preparation of chicken bone-based adsorbent and its characterization using SEM and FTIR, followed by quality analysis of fresh waste (which is waste A and waste B) observed at pH, COD, TDS, TSS also Pb, Cd, dan Hg metals. Adsorption process was observed from adsorbent’s graying temperature, adsorbent’s particle size, contact time, pH of waste, and adsorbent’s weight. Best result from adsorption process were applicated at fresh waste and simulation waste of Pb, Cd, and Hg metals also re-testing quality analysis of fresh waste and simulation waste for before-after result comparing purpose. The purpose of this research is for characterizing chicken bone-based adsorbent, observing adsorption process of Characterization of chicken bone ash based adsorbent has been carried out in adsorbing Pb, Cd, and Hg metals in pharmaceutical laboratory waste. Functional group analysis with Fourier Transform Infrared Spectrophotometer (FTIR) showed that the chicken bone ash adsorbent contained the mineral compound apatite carbonate. Surface morphology with a Scanning Electron Microscope (SEM) shows that the adsorbent surface is porous and appears to be adsorbing metals. From the adsorption observations, it was found that the best adsorption conditions were at an ashing temperature of 800 oC, particle size of 80 mesh, contact time of 30 minutes, waste conditions at pH 6 and an adsorbent weight of 600 mg. Application chicken bone-based adsorbent against pharmaceutical waste shows its existence improve the quality of waste but still do not meet the quality standard requirements for Hg metal.

Developing a simple box–behnken experimental design on the removal of doxorubicin anticancer drug using Fe3O4/graphene nanoribbons adsorbent

This paper aims to develop a Box–Behnken experimental design system to optimize the removal process of doxorubicin anticancer drugs. For this goal, Fe3O4/graphene nanoribbons was selected as adsorbent and removal of doxorubicin anticancer drug optimized using Box–Behnken experimental design with a selection of four effective factors. A three-level, four-factor Box–Behnken experimental design was used to assess the relationship between removal percentage as a dependent variable with adsorption weight (0.0015–0.01 mg), pH (3–9), temperature (15–45 °C) and time (1–15 min) as independent variables. Optimized condition by Behnken experimental design (pH = 7.36; time = 15 min; adsorbent weight = 0.01 mg and temperature = 29.26 °C) improved removal of doxorubicin anticancer drug about 99.2% in aqueous solution. The dynamic behavior, adsorption properties and mechanism of doxorubicin molecule on Fe3O4/graphene nanoribbon were investigated based on ab initio molecular dynamics (AIMD) simulations and density functional theory calculations with dispersion corrections. A closer inspection of the adsorption configurations and binding energies revealed that π-π interactions were the driving force when the doxorubicin molecule adsorbed on Fe3O4/graphene nanoribbon. The observed negative adsorption energy signifies a favourable and exothermic adsorption process of the various adsorbate-substrate systems. Besides, AIMD and phonon dispersion calculations confirm the dynamic stability of Fe3O4/graphene nanoribbon.

Performance evaluation of nanotubular halloysites from weathered pegmatites in removing heavy metals from water through novel artificial intelligence-based models and human-based optimization algorithm

The efforts of this study aimed to evaluate the feasibility of the nanotubular halloysites in weathered pegmatites (NaHWP) for removing heavy metals (i.e., Cd2+, Pb2+) from water. Furthermore, two novel intelligent models, such as teaching-learning-based optimization (TLBO)-artificial neural network (ANN), and TLBO-support vector regression (SVR), named as TLBO-ANN and TLBO-SVR models, respectively, were proposed to predict the Cd2+ and Pb2+ absorption efficiencies from water using the NaHWP absorbent. Databases used, including 53 experiments for Pb2+ absorption and 56 experiments for Cd2+ absorption from water, under the catalysis of different conditions, such as initial concentration of Pb2+ and Cd2+, solution pH, adsorbent weight, and contact time. Subsequently, the TLBO-ANN and TLBO-SVR models were developed and applied to predict the efficiencies of Cd2+ and Pb2+ absorption from water, aiming to evaluate the role as well as the effects of different conditions on the absorption efficiencies using the NaHWP absorbent. The standalone ANN and SVM models were also taken into consideration and compared with the proposed hybrid models (i.e., TLBO-ANN and TLBO-SVR). The results showed that the NaHWP detected in a Kaolin mine (Vietnam) with 70% nanotubular halloysites is a potential adsorbent for water treatment to eliminate heavy metals from water. The two novel hybrid models proposed, i.e., TLBO-ANN and TLBO-SVR, also yielded the dominant performances and accuracies in predicting the Cd2+ and Pb2+ absorption efficiencies from water, i.e., RMSE = 1.190 and 1.102, R2 = 0.951 and 0.957, VAF = 94.436 and 95.028 for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Pb2+ absorption efficiency from water; RMSE = 3.084 and 3.442, R2 = 0.971 and 0.965, VAF = 96.499 and 96.415 for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Cd2+ absorption efficiency from water. Furthermore, the validation results also demonstrated these findings in practice through 23 experiments with the accuracies of 98.3% and 98.37% for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Pb2+ absorption efficiency from water; the accuracies of 98.3% and 97.46% for the TLBO-ANN and TLBO-SVR models, respectively, in predicting the Cd2+ absorption efficiency from water. Besides, solution pH was evaluated as the most critical parameter that can be adjusted to enhance the performance of the absorption of the heavy metals in this study. By using the NaHWP absorbent and the novel proposed intelligent models developed, heavy metals can be eliminated entirely from water, providing pure water/clean freshwater without any risk of adverse health effects for the short term or long term.