Promising Biosorbent Research Articles

A novel biowaste-based biosorbent material for effective purification of methylene blue from water environment

The biowaste left over from the fixed oil biorefinery process of Nigella sativa L. plant was used as a new biosorbent for the biosorption of synthetic dye of methylene blue from water environment in this study. The main variables of biosorption operation such as methylene blue concentration, time, pH, and biosorbent amount were optimized by the batch-type experiments. The characterization, kinetics, equilibrium, and thermodynamics works were conducted to show the nature of methylene blue biosorption. The studies of Fourier transform infrared spectroscopy and Scanning electron microscopy indicated that the biosorbent possessed an inhomogeneous surface morphology including many cavities and protuberances, and a rich functional group profile. The optimum values of operating variables studied for the biosorption of methylene blue were determined as methylene blue concentration of 15 mg L−1, time of 360 min, pH of 8, and biosorbent amount of 10 mg. The experimental data of methylene blue biosorption followed the kinetics and isotherm models of pseudo-second-order (R 2: 0.98, AdjR 2: 0.98, and RMSE: 8.97) and Dubinin-Radushkevich (R 2: 0.99, AdjR 2: 0.98, and RMSE: 6.84), respectively, based on the statistical tests of coefficient of determination (R 2), adjusted coefficient of determination (AdjR 2), and root mean squared error (RMSE). The biosorption of methylene blue was a physical, spontaneous, and energetically favorable process (E DR: 3.48 kJ mol−1 and ΔG°: (−14.51) − (−10.02) kJ mol−1). This residual biological material from the fixed oil biorefinery process exhibited higher biosorption performance (187.46 mg g−1) than own unrefined (virgin) form and its modified, activated, and composite forms and many other sorbents reported in the literature. Hereby, the current work showed that this novel biowaste-based material could be used as an environmentally and economically promising biosorbent to effectively purify methylene blue from aquatic environment.

Tratamento químico de bagaço de cana-de-açúcar e sua influência na adsorção de glifosato

ABSTRACT Due to the production rates of sugarcane, nowadays, the sugarcane bagasse stemming in the sugar and alcohol industry is the agro-industrial waste produced in greater volume throughout in Brazil. In 2019, about 192 million tons of this waste were generated. The use of this waste has been the aim of researches around the world, with emphasis on applications that aim to meet the prerogatives of the concept of circular economy. Within this scenario, sugarcane bagasse (SB) was treated in an alkaline medium, forming an adsorbent material, SBNaOH. The effects of chemical treatment were evaluated for surface properties and for glyphosate removal in an aqueous medium. The adsorptive phenomenon was studied through isotherm tests. The results obtained were fitted to classical models of Langmuir, Freundlich and Dubinin-Radushkevich. The characterization indicated that the chemical treatment promoted an important change in the surface of the residue, increasing the surface area. SB and SBNAOH had a feasible behavior as adsorbent and good performance in the removal of the herbicide, presenting values greater than 65% of under all working conditions. The theoretical adsorption saturation governed by Dubinin-Radushkevich (qS) was in the order of 8.988 mg/g (R2=0.988) for SB at 120 minutes of contact and maximum adsorption capacity by Langmuir (Qmax) was 13.720 mg/g (R2=0.984) for SBNaOH at 40 minutes of contact. The process was governed by the exchange or sharing of electrons. The adsorbate is distributed heterogeneously on the SB surface, justifying the presence of active sites with greater ionic strength, and homogeneously on the SBNaOH surface (monolayer). In general, the treated sugarcane bagasse, coming from an agro-industrial residue, proved to be an alternative and promising biosorbent for the removal of glyphosate from aqueous systems, thus generating a new application of this residue.

Use of the Solid By-Product of Anaerobic Digestion of Biomass to Remove Anthropogenic Organic Pollutants with Endocrine Disruptive Activity

Anaerobic digestion of biomass has increasing implementation for bioenergy production. The solid by-product of this technology, i.e., the digestate, has relevant potential in agricultural and environmental applications. This study explored the capacity of a digestate from mixed feedstock to remove from water four endocrine-disrupting chemicals, namely the pesticides metribuzin (MET) and boscalid (BOS) and the xenoestrogens bisphenol A (BPA) and 4-tert-octylphenol (OP). The surface micromorphology and functional groups of the digestate were investigated using scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy, respectively. Results of sorption kinetics showed that all compounds reached the steady state in a few hours according to a pseudo-first-order model in the cases of MET and OP, a pseudo-second-order model for BOS and both models in the case of BPA. Data of adsorption isotherms were fitted to the Henry, Freundlich, Langmuir and Temkin equations. The adsorption of MET preferentially followed the non-linear Freundlich model, whereas the adsorption of the other compounds was properly described by both the linear and Freundlich models. The organic carbon partition coefficients, KOC, were 170, 1066, 256 and 2180 L kg−1 for MET, BOS, BPA and OP, respectively. The desorption of BOS, BPA and OP was slow and incomplete, indicating a phenomenon of hysteresis. In conclusion, the digestate showed a remarkable efficiency in the removal of the compounds, especially those with high hydrophobicity, thus behaving as a promising biosorbent for environmental remediation.

A State-of-the-Art Review on Biowaste Derived Chitosan Biomaterials for Biosorption of Organic Dyes: Parameter Studies, Kinetics, Isotherms and Thermodynamics.

Chitosan is a second-most abundant biopolymer on earth after cellulose. Its unique properties have recently received particular attention from researchers to be used as a potential biosorbent for the removal of organic dyes. However, pure chitosan has some limitations that exhibit lower biosorption capacity, surface area and thermal stability than chitosan composites. The reinforcement materials used for the synthesis of chitosan composites were carbon-based materials, metal oxides and other biopolymers. This paper reviews the effects of several factors such as pH, biosorbent dosage, initial dye concentration, contact time and temperature when utilizing chitosan-based materials as biosorbent for removing of organic dyes from contaminated water. The behaviour of the biosorption process for various chitosan composites was compared and analysed through the kinetic models, isotherm models and thermodynamic parameters. The findings revealed that pseudo-second-order (PSO) and Langmuir isotherm models were best suited for describing most of the biosorption processes or organic dyes. This indicated that monolayer chemisorption of organic dyes occurred on the surface of chitosan composites. Most of the biosorption processes were endothermic, feasible and spontaneous at the low temperature range between 288 K and 320 K. Therefore, chitosan composites were proven to be a promising biosorbent for the removal of organic dyes.

Effect of Salinity on Cr(VI) Bioremediation by Algal-Bacterial Aerobic Granular Sludge Treating Synthetic Wastewater

Heavy metal-containing wastewater with high salinity challenges wastewater treatment plants (WWTPs) where the conventional activated sludge process is widely applied. Bioremediation has been proven to be an effective, economical, and eco-friendly technique to remove heavy metals from various wastewaters. The newly developed algal-bacterial aerobic granular sludge (AGS) has emerged as a promising biosorbent for treating wastewater containing heavy metals, especially Cr(VI). In this study, two identical cylindrical sequencing batch reactors (SBRs), i.e., R1 (Control) and R2 (with 1% additional salinity), were used to cultivate algal-bacterial AGS and then to evaluate the effect of salinity on the performance of the two SBRs. The results reflected that less filamentation and a rougher surface could be observed on algal-bacterial AGS when exposed to 1% salinity, which showed little influence on organics removal. However, the removals of total inorganic nitrogen (TIN) and total phosphorus (TP) were noticeably impacted at the 1% salinity condition, and were further decreased with the co-existence of 2 mg/L Cr(VI). The Cr(VI) removal efficiency, on the other hand, was 31–51% by R1 and 28–48% by R2, respectively, indicating that salinity exposure may slightly influence Cr(VI) bioremediation. In addition, salinity exposure stimulated more polysaccharides excretion from algal-bacterial AGS while Cr(VI) exposure promoted proteins excretion.

Recovery of Pd(II) from Aqueous Solution by Polyethylenimine-Crosslinked Chitin Biosorbent

This study reports the recovery of Pd(II) from acid solution by a polyethylenimine (PEI)-crosslinked chitin (PEI-chitin) biosorbent. FE-SEM analysis demonstrated that there are many slot-like pores on PEI-chitin. The N2 adsorption–desorption experiment revealed that the average pore size was 47.12 nm. Elemental analysis verified the successful crosslinking of PEI with raw chitin. The Langmuir model better explained the isotherm experimental data and the theoretical maximum Pd(II) uptake was 57.1 mg/g. The adsorption kinetic data were better described by the pseudo-second-order model and the adsorption equilibrium was achieved within 30 min for all initial Pd(II) concentrations of 50–200 mg/L. In the fixed-bed column, the adsorption of Pd(II) on PEI-chitin showed a slow breakthrough and a fast saturation performance. The desorption experiments achieved a concentration factor of 8.4 ± 0.4; in addition, the adsorption–desorption cycles in the fixed-bed column were performed up to three times, consequently confirming the good reusability of PEI-chitin for Pd(II) recovery. Therefore, the PEI-chitin can be used as a promising biosorbent for the recovery of Pd(II) in practical applications.

Biosorption of copper ions from aqueous solution using Kappaphycus striatum

Biosorption is an eco-friendly alternative technology for the removal of heavy metals from industrial waste and effluents using low-cost and effective biosorbent. Abundant of natural materials like agricultural biomass, industrial waste, and microbial biomass can be used as a promising biosorbent. In the present study, red algae Kappaphycus striatum biomass will be used for the adsorption of copper ions in aqueous solution. The free (non-immobilized) and immobilized form of red algae Kappaphycus striatum biomass and biosorption rate were investigated for the adsorption process. The maximum biosorption of copper ions was achieved when immobilized form of algae biomass were used at the condition pH of 5, biomass dosage, 0.25 g/L, contact time of 90 minutes, and at the temperature of 50 °C with a 65.8% of removal. The experiment data for biosorption rate with time also was used to evaluated two kinetic models (pseudo-first-order and pseudo-second-order) and two isotherm models (Langmuir and Freundlich). The results reveal that metallic ions biosorption on the immobilized Kappaphycus striatum followed the pseudo-second-order kinetic model with a R 2=0.9996 and Langmuir isotherm model with a R 2=0.9999. The present work shows that the red algae of Kappaphycus striatum as a potential biosorbent for the removal of heavy metal ions from aqueous solution.

Lanthanum biosorption using sericin/alginate particles crosslinked by poly(vinyl alcohol): Kinetic, cation exchange, and desorption studies

Nowadays, lanthanum removal from wastewater has received attention due to its importance in various industrial applications. Biosorption has been considered a promising process for lanthanum removal from secondary sources. This study aimed to evaluate the use of sericin/alginate/poly(vinyl alcohol) (SAPVA) particles for lanthanum biosorption in batch system. The effect of pH on the biosorption of lanthanum showed that both lanthanum‐uptake (0.103 mol/kg) and calcium‐release (0.155 mol/kg) reach a maximum at equilibrium pH 5.22. Biosorption kinetics was carried in three lanthanum initial concentrations (0.0005, 0.0011, and 0.0017 mol/dm3). The results revealed that the equilibration time was reached between 210 and 450 min and biosorption capacity at equilibrium between 0.050 and 0.152 mol/kg. The kinetic followed the pseudo-second order model and the external diffusion was the main limiting step. Evaluation of cation exchange mechanism showed that the lanthanum biosorption is related to a stoichiometric reaction (2:3 ratio) between calcium and lanthanum. Calcium nitrate under acidic conditions was able to retrieve lanthanum biosorbed in the particles with high efficiency (96.07 ± 2.02%). Regeneration kinetics showed a longer equilibration time (630 min) and lower biosorption capacity at equilibrium (0.138 mol/kg) for the lanthanum initial concentration of 0.0015 mol/dm3. In this case, the experimental kinetic profile of calcium released throughout the lanthanum biosorption was not stoichiometric. Characterization analyzes suggest that the main mechanism involved in lanthanum capture and calcium release was cation exchange between functional groups on the biosorbent particles and lanthanum. Thus, SAPVA particles are a promising biosorbent for lanthanum removal from aqueous solutions.

Film-like chitin/polyethylenimine biosorbent for highly efficient removal of uranyl-carbonate compounds from water

Uranium contamination in groundwater has been increasingly reported, while biosorbents for the decontamination attracts growing attention because of their distinct advantages of abundant raw materials and eco-friendliness. Herein, a film-like chitin/polyethylenimine biosorbent (CH-PEI) was prepared and employed in the removal of uranyl-carbonate compounds from water. Fourier transform infrared spectra, element analysis, scanning electron microscopy/energy dispersive X-ray spectroscopy, N2 adsorption-desorption isotherms and X-ray photoelectron spectroscopy were used to characterize the biosorbent. Besides, thermodynamic calculation and various batch experiments were conducted to investigate the adsorption performances of CH-PEI for uranyl removal from carbonate solution. The results showed that the biosorbent possessed a unique hierarchically porous structure and a high nitrogen content. The batch experiments exhibited that it obtained the maximum adsorption capacity at pH = 6. Notably, CH-PEI could reach sorption equilibrium within 4 h at the initial concentration of 50 mg/L. The maximum adsorption capacity were 247.04 mg/g and 1023.74 mg/g at the initial concentrations of 50 mg/L and 300 mg/L. The kinetics and isotherm data were well fitted by pseudo-second-order and Langmuir models. It could remove 98.9% of uranium in the simulated groundwater. The biosorbent showed fast regeneration, good structural stability and reusability in 5 cycles. Furthermore, the adsorption mechanism was confirmed to be anion exchange and electrostatic attraction between nitrogen species and uranyl-carbonate complexes through FT-IR and XPS analysis. Considering its low costs, high efficiency and easy collection, CH-PEI would be a promising biosorbent for uranium removal from groundwater. This study provides a potential technique for uranium removal using chitin-based adsorbents.

Evaluation of phase transfer kinetics and thermodynamic equilibria of Reactive Orange 16 sorption onto chemically improved Arachis hypogaea pod powder

Biosorbent from pods of Arachis hypogaea (AhP) were inducted with sulphuric acid treatment and then the activated materials were employed to sequester a sulphonated textile dye; Reactive Orange 16 (RO16) from water system. The characteristic features of the surface functionalized AhP (Ct-AhP) were analysed using instrumentation techniques. The biosorption influencing variables like operating pH, agitating time, initial RO16 concentration and temperature effects were investigated. One-factor optimization revealed that 0.5 g Ct-AhP was sufficient to achieve maximum removal of RO16 (20–120 mg/L) within 180 min agitation at 150 rpm. The isotherm data were applied to non-linear isotherms viz., Freundlich, Langmuir and Temkin models as well as rate limiting steps were elucidated using kinetic models. Freundlich isotherm showed good fit and pseudo-second order kinetic data explained RO16 removal by Ct-AhP followed chemisorption. The outcome of thermodynamic parametric values infer that RO16 biosorption was spontaneous, feasible and involved exothermic type of heat. Elovich and intraparticle diffusion revealed the biosorption mechanisms. The maximum RO16 biosorption (56.48 mg/g) by 0.5 g Ct-AhP were witnessed in the system containing 120 mg/L RO16 agitated at 150 rpm operating at pH 7.0, 303 K for a span of 180 min. Thus, the Ct-AhP is considered to be a promising biosorbent which can be employed in treating the textile effluents.

Cellular responses and phenol bioremoval by green alga Scenedesmus abundans: Equilibrium, kinetic and thermodynamic studies

Abstract This research aims to study the effect of phenol on growth, metabolism, antioxidant activity and its bioremoval by Scenedesmus abundans. High phenol concentrations reduced the chlorophyll and dry weight of S. abundans. As phenol concentration increased, the total lipid, protein and amino acid content increased. The hydroxyl radical scavenging activity, ferric reducing antioxidant power, total antioxidant capacity and catalase enzyme were generally enhanced by phenol concentrations. The biosorption ability of dried S abundans biomass for the phenol removal from the aqueous solution was also examined as a function of pH, biosorbent dosage, contact time and initial phenol concentrations. The optimum biosorption was achieved at pH 6, 0.5 g/100 ml algal dose, 90 min contact time and 100 mg/L phenol concentration. The biosorption models of Langmuir, Freundlich, Dubinin–Radushkevich and Temkin were well applied, providing the experimental data with the best fit. The maximum biosorption capacity was 57.8 mg/g at the optimum conditions. The kinetic biosorption was also well described by the pseudo-first order, with film and intra-particle controlled the biosorption mechanism. The thermodynamic parameters revealed that the process of biosorption was feasible, spontaneous and endothermic. The Δ G 0 values indicate that physisorption is the process of phenol biosorption on S. abundans. Additionally, by scanning electron microscopy, Fourier transform infrared and X-ray diffraction analysis, the biosorbent characterization was assessed. Therefore, S. abundans could be used as a promising biosorbent for removal of phenol and other organic contaminants. The removal capability of phenol by S. abundans can also encourage the use of the wasted biomass as a feedstock for biofuel production giving it a green environmentally sustainable operation.

Application of novel butane-1,4-dioic acid-functionalized cellulosic biosorbent for aqueous cobalt ion sequestration

The study involved the synthesis of a novel adsorbent via the direct carbonylation of butane-1,4-dioic acid impregnated Alhagi root powder to its acid anhydride analogue and the subsequent esterification of the highly cellulosic plant material by the anhydride to an ester of high carboxyl content. The high carboxyl content of the synthesized adsorbent was recorded as 451.76 m.eq –COOH/100 g sample. The adsorbent was effectively characterized using Scanning electron microscopy, Energy dispersion X-ray, and Fourier-transform infrared spectroscopy, as well as utilized for aqueous cobalt ion sequestration. Similarly, the effect of the process variable on the carboxyl content and adsorption capacity of ‘ATAG’ was elucidated. The Dubinin–Radushkevich model satisfactorily predicted the isotherm data. Meanwhile, the intraparticle diffusion model was best at predicting the kinetic data at adsorbate concentration of 300 and 450 mg/L, while the pseudo-first-order model emerged as the best fit at 600 mg/L concentration. The maximum adsorption capacity of 188.67 mg/g was recorded at optimum adsorption conditions (pH 6.0, 60 min, and 30 °C), and the adsorption mechanism was also proposed. The abundant surface oxygenous functional groups on ‘ATAG’ positively influenced its adsorption capacity; thus, making it a promising biosorbent for aqueous Co (II) uptake.

Ipomoea carnea: a novel biosorbent for the removal of methylene blue (MB) from aqueous dye solution: kinetic, equilibrium and statistical approach

The biosorption potential of cost-effective and agricultural residue, Ipomoea carnea wood (ICW) was examined by the removal of cationic dye, methylene blue (MB) from aqueous solution. The surface morphology, structural and thermal properties of untreated ICW were analyzed using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Thermo-gravimetric Analysis (TGA), respectively. The effects of different parameters namely concentration of biosorbent, initial pH, initial MB composition and temperature on biosorption capacity and biosorption (%) were studied. The kinetic and equilibrium models were developed to fit the experimental data on MB biosorption. The maximum biosorption capacity of 39.38 mg g−1 was obtained at 40 °C using Langmuir model. The removal of MB was found to be significantly varying with temperature. Box–Behnken design was applied to optimize the biosorption parameters. The optimized condition for MB biosorption was evaluated as dosage of 3.1 g L−1, pH of 7.04, Temperature of 49.1 °C, MB concentration of 30.48 mg L−1 and maximum biosorption (%) of 83.87. The regeneration of ICW was investigated by five cycles using a suitable eluting agent. Hence, ICW without any pretreatment and chemical modification is a potential candidate for the removal of MB in terms of availability and economy of the process. Novelty statement Ipomoea carnea wood (ICW) without any pretreatment explored a potential biosorbent for the removal of methylene blue (MB) in terms of availability and economy of the process. The physico-chemical properties of ICW characterized using Scanning Electron Microscopy, Fourier transform infrared spectroscopy and Thermo-gravimetric Analysis showed ICW as a promising biosorbent for MB removal. Presence of heterogeneous with rugged morphological structure, cavities, irregular shape and size of large pores provide the better biosorption capability for MB molecules using ICW without any pretreatment or chemical modification. Analysis of kinetic and isotherm models was performed to examine the better fitness of experimental data with model. Thermodynamic parameters indicating feasible and endothermic MB biosorption. Statistical design of experiments is used to optimize the condition and corresponding maximum MB removal using Derringer’s desired function methodology. Untreated ICW is a potential reusable biosorbents, effectively employed in successive biosorption and desorption process for the removal of MB from aqueous solutions.

Adsorption process of naproxen onto peanut shell‐derived biosorbent: important role of n–π interaction and van der Waals force

AbstractBACKGROUNDLow‐cost biosorbent (derived from peanut shells) with abundant oxygen‐containing functional groups can effectively adsorb the naproxen drug in solution. This study aimed to explore the main interactions responsible for adsorbing naproxen and develop several conventional methods for identifying primary adsorption mechanism. Some important operation parameters strongly effecting the adsorption process and mechanism were investigated and discussed.RESULTSA fast adsorption equilibrium can be reached at approximately 120 min. The Langmuir maximum adsorption capacity of biosorbent towards naproxen (Qomax; mg g−1) was 55.1 mg g−1. The study of adsorption thermodynamics indicated that the adsorption process was spontaneous (∆G° ≈ −21 kJ mol−1) and exothermic (∆H° = −14.9 kJ mol−1), and van der Waals force played an important role in the adsorption mechanism. Another important contribution of n–π interaction between the carbonyl groups on the biosorbent's surface and the aromatic rings in naproxen molecules was confirmed by Fourier‐transform infrared spectroscopy and a traditional method. Such n–π interaction cannot be well performed when carbonyl groups were oxidized into carboxylic groups under H2O2 treatment. Peanut shells exhibited an excellent adsorption capacity to various pollutants such as lead (Qomax = 167 mg g−1), cadmium (103 mg g−1), cobalt (88.8 mg g−1), diclofenac (56.1 mg g−1), and bisphenol A (24.5 mg g−1).CONCLUSIONSSimple methods were developed to identify the important role of van der Waals force and n–π interaction in the adsorption process of naproxen. Such methods might be applied to identify the similar adsorption mechanisms of other aromatic adsorbates onto other materials with similar properties. Peanut shells can serve as a promising biosorbent for eliminating naproxen and other pollutants from water environment. © 2020 Society of Chemical Industry

A characteristic study of Zea mays L. (sweet corn) cobs for synthetic dye degradation from aqueous media.

The current study reports a systematic methodology of Zea mays L. (sweet corn) cobs (ZMLC) for the sequestration of synthetic dye (gentian violet) from aqueous solutions. Adsorbent was scrutinized by using scanning electron microscopy, Fourier transform infra-red spectrometry with pHpzc determination. The impact of various adsorption parameters including pH effect, ZMLC (sorbent) dosage, temperature, concentration and shaking time was examined. The equilibrium sorption isotherms were determined by the batch method from 283 to 303 K at pHpzc. Adsorption data were adjusted to four isothermal models: Langmuir, Freundlich, Dubinin-Radushkevich and Temkin's models, which presented the best adjustment to Freundlich, Dubinin-Radushkevich and Temkin's at 283 K. The kinetic profile fitted well to the pseudo-second order kinetic equation at three distinct concentrations 600, 700, 800 mg/L. Maximum sorption capacity was gained up to 700 mg.g-1 for gentian violet at pH 3, respectively. The adsorption process is endothermic, non-spontaneous, favorable thermodynamically due to positive values of entropy and Gibbs free energy and randomness decreases during the adsorption process. Furthermore, after biosorption onto ZMLC the dye can be desorbed effectively by using mineral base KOH solution. Consequently, the ZMLC is said to be a promising biosorbent to remediate gentian violet-contaminated water as well as wastewater.

Fibrous chitosan/cellulose composite as an efficient adsorbent for Co(Ⅱ) removal

With the rapid development of industries, the heavy metal-containing wastewater has become one of the most serious environmental problems. Adsorption is a key approach in treating heavy metal-containing wastewater. The performance of adsorbents is determined by the effective exposure of its adsorptive sites, which determines its adsorption capacity. In this study, fibrous chitosan/cellulose composite was prepared using the wet-spinning method to increase its specific surface area, thus enhancing the adsorption capacity. The as-prepared fibrous composite showed a homogeneous fiber structure (diameter: 88 ± 16 μm) and high specific surface area (2.5 m2 g−1). Furthermore, the adsorption capacity towards Co(Ⅱ) was greatly enhanced, more than three times higher than that of the pure chitosan beads (diameter: 2–3 mm). The maximum adsorption capacity was calculated to be 23.6 ± 2.5 mg-Co(Ⅱ) per g-chitosan by the Langmuir isotherm model, an order of magnitude higher than that of pure chitosan beads. In addition, the adsorption kinetic behavior of chitosan/cellulose fibers on Co(Ⅱ) followed the pseudo second-order kinetic model. The optimal pH for Co(Ⅱ) removal was approximately 6.0. Furthermore, FT-IR and XPS analyses indicated the amino groups played a dominant role, with the aid of hydroxyl groups, in the coordination and adsorptive removal of Co(II). Possible interaction configurations were also proposed in this study. In conclusion, the proposed physical modification of chitosan greatly improved its adsorption capacity and mechanical strength, making it a promising biosorbent for Co(II) removal.

Mussel-inspired polydopamine decorated pomelo peel as a durable biosorbent for adsorption of cationic dyes

In this work, an eco-firendly biosorbent was simply fabricated via self-polymerization of polydopamine on the porous pomelo peel. The composition and morphology of the obtained polydopamine modified pomelo peel (PP-PDA) were confirmed by Fourier transform infrared, emission scanning electron microscopy and Brunauer−Emmett−Teller surface area measurements, respectively. Next, the adsorption capacity of the PP-PDA towards various anionic and cationic dyes was investigated. Interestingly, the PP-PDA exhibited high adsorption capacity towards cationic dyes with the maximum adsorption capacities of 434.78 mg/g for methylene blue, 208.33 mg/g for neutral red and 143.88 mg/g for malachite green, respectively. Due to this adsorption feature, the PP-PDA can achieve selective adsorption of cationic dyes from mixtures. Meanwhile, the adsorption kinetics and adsorption isotherms of the PP-PDA towards cationic dyes obeyed pseudo-second-order kinetic and Langmuir isotherm model, respectively. Additionally, the results presented that the adsorption capacity of the PP-PDA increased with the increment of pH value of the aqueous solution, however, its adsorption capacity decreased with increasing of the salt concentration. Most importantly, the fabricated PP-PDA could be easily regenerated, its adsorption capacity could be maintained well even after twenty cycles. Therefore, the as-prepared PP-PDA can be employed as a promising biosorbent for dye-contaminated wastewater of treatment.

Terbium Excitation Spectroscopy as a Detection Method for Chromatographic Separation of Lanthanide-Binding Biomolecules.

Studies of biosorption and bioaccumulation of heavy metals deal mostly with challenging, inhomogeneous, and complex materials. Therefore, most reports describe only application studies, while fundamental research is limited to indirect methods and speculations on the binding mechanisms. In this study, we describe a method for detecting and isolating heavy metal-binding biomolecules directly from crude extracts. The underlying principle is terbium sensitization and fluorescence excitation spectroscopy used offline after a chromatographic run. Compounds interacting with metal ions inevitably change the coordination sphere of terbium, which is reflected in the excitation spectrum leading to metal-specific luminescence. Main advantages of our approach include simple, fast, and inexpensive experiment design, nondestructive measurements, and detection limits far below 1 mg. Here, we have applied our method for three promising biosorbents (green algae, moss, and cyanobacterium) and obtained first information on the character of active compounds isolated from each species.

Functionalized Zea Mays Cob (FZMC) as low-cost agrowaste for effective adsorption of malachite green dyes data set

This dataset article presents the effective adsorption of Malachite Green (MG) dyes onto FZMC as low-cost agro-waste. The physicochemical parameters data of the FZMC (1329 m2/g surface area; 12% moisture content; 0.9% loss of mass on ignition; 0.386 g/cm3 bulk density) showed its suitability for sorption. Favorable adsorption of MG dye in a batch technique was achieved at pH 8, 120 min contact time through 100 – 600 ppm concentrations. With R2>0.98, the Pseudo second-order model best represented kinetic data. The mechanism was better represented by the intraparticle diffusion model. Equilibrium data were best described by Freundlich and confirmed by Halsey isotherm with R2>0.97 and physisorption nature of the d-R isotherm model (E (J/mol) <8 kJ/mol). Qmax of FZMC (64.52 mg/g) surpassed those previously reported. Surface chemistry and morphology were determined by FTIR and SEM. The dataset revealed FZMC as a promising biosorbent for the treatment of industrial wastewater.

Synthesis and characterization of a novel activated carbon using nonliving lichen cetraria islandica (L.) ach. and its application in water remediation: Equilibrium, kinetic and thermodynamic studies of malachite green removal from aqueous media

Although lichens are natural and cheap sources, there is no study in the literature about the production of activated carbon from lichen species. In this study, a novel activated carbon (ACCI) from non-living lichen Cetraria islandica (L.) Ach. (LCI) was produced, and physicochemical and morphological characterizations of the LCI and ACCI were examined with the help of Brauner-Emmett-Teller surface area (BET), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) techniques. The BET surface area, Barrett-Joyner-Helenda (BJH) adsorption total volume of pores and BJH adsorption average pore diameter of the ACCI were determined as 394.417 m2.g − 1, 0.1216 cm3.g − 1 and 12.768 Å (1.28 nm), respectively, while these values for non-living LCI were 1.103 m2.g − 1, 0.0044 cm3. g − 1 and 140.18 Å (14.02 nm), respectively. To investigate and compare the biosorption properties of the LCI and ACCI in wastewater treatment, batch mode biosorption experiments were carried out, and the effect of various parameters on malachite green (MG) dye removal from aqueous media were studied. The experimental data were fitted with 4 different kinetic models (pseudo first-order (PFO), pseudo second-order (PSO), Elovich model (EM) and intra-particle diffusion (IDM)) and 3 different isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich (D-R)). The biosorption of MG onto both the LCI and ACCI follows well the PSO kinetics. The rate constants k2 for the LCI and ACCI were found as 0.0125–0.0157 g.mg−1.min−1 and 0.00612–0.00979 g.mg−1.min−1, respectively (298–318 K). The equilibrium time was 80 min for the ACCI, and the maximum biosorption capacity and the removal efficiency (%) for the ACCI were found as 666.22 mg.g − 1 and 93.46%, respectively. The biosorption mechanism of MG onto both the LCI and ACCI was physical biosorption. This result was confirmed by the activation energies (9.095 kJ.mol−1 for LCI and 18.450 kJ.mol−1 for ACCI), the d-R mean energies (6.8041–7.4536 kJ.mol−1 for LCI and 7.3323–8.0582 kJ.mol−1 for ACCI in the temperature range 298–318 K), and FTIR, XRD, TGA and SEM/EDX results. The enthalpy change (ΔH0) values for the LCI and ACCI were found to be in the range of 8.7987–17.2582 kJ.mol−1 and 20.4899–29.2728 kJ.mol−1, respectively (20–70 mg.L − 1 initial MG concentrations). This indicated the endothermic behaviour of the biosorption.The novelty of this study is that besides obtained and characterized the activated carbon (ACCI) from the non-living LCI for the first time, the comparisons and discussions on the biosorption capability of the ACCI and LCI for the removal of MG dye from aqueous media are included in this paper.All results showed that the synthesized ACCI is an effective, cheap and promising biosorbent for the cleaning treatment of MG dye from wastewaters.