Efficient removal of anionic and cationic dyes from aqueous systems using spent Yerba Mate “Ilex paraguariensis”

Effective Removal of Cd(II) from Aqueous Solutions Using Theobroma cacao Agro-Industrial Waste

Theobroma cacao agro-industrial waste (WTC) has been characterized and tested as an effective biosorbent to remove Cd(II) from aqueous media. At the optimum pH of 5.0, a maximum adsorption capacity of q_e,max = 58.5 mg g^-1 was determined. The structural and morphological characterization have been conducted by FTIR, SEM/EDX, and TGA measurements. The SEM/EDX results confirmed that the metals are adsorbed on the surface. C-O-C, OH, CH, NH, and C=O functional groups were identified by FTIR. TGA results were consistent with the presence of hemicellulose. Biosorption kinetics were rapid during the first 30 min and then reached equilibrium. The corresponding experimental data were well fitted to pseudo-first and -second order models, the latter being the best. The biosorption isotherm data were also well fitted to Temkin, Langmuir, and Freundlich models, showing that several sorption mechanisms may be involved in the Cd(II) biosorption process, which was characterized as exothermic (ΔH⁰ < 0), feasible, and spontaneous (ΔG⁰ < 0). In binary (Cd-Pb and Cd-Cu) and ternary (Cd-Pb-Cu) systems, Cu(II) and particularly Pb(II) co-cations exert strong antagonistic effects. Using HNO₃, effective good regeneration of WTC was obtained to efficiently remove Cd(II) up to three times.

Efficient Lead Pb(II) Removal with Chemically Modified Nostoc commune Biomass

A new biosorbent based on Nostoc commune (NC) cyanobacteria, chemically modified with NaOH (NCM), has been prepared, characterized and tested as an effective biomass to remove Pb(II) in aqueous media. The adsorption capacity of NCM was determined to be qe = 384.6 mg g−1. It is higher than several other biosorbents reported in the literature. Structural and morphological characterization were performed by FTIR, SEM/EDX and point zero of charge pH (pHPZC) measurements. NCM biosorbent showed more porous surfaces than those NC with heterogeneous plates including functional adsorption groups such as OH, C = O, COO−, COH or NH. Optimal Pb(II) adsorption occurred at pH 4.5 and 5.5 with a biomass dose of 0.5 g L−1. The experimental data of the adsorption process were well fitted with the Freundlich-isotherm model and pseudo-2nd order kinetics, which indicated that Pb(II) adsorption was a chemisorption process on heterogeneous surfaces of NCM. According to the thermodynamic parameters, this process was exothermic (∆H0 < 0), feasible and spontaneous (∆G0 < 0). NCM can be regenerated and efficiently reused up to 4 times (%D > 92%). NCM was also tested to remove Pb (%R~98%) and Ca (%R~64%) from real wastewater.

La3+’s Effect on the Surface (101) of Anatase for Methylene Blue Dye Removal, a DFT Study

Density functional theory (DFT) is a widely used method for studying matter at the quantum level. In this study, the surface (101) of TiO2 (anatase phase) was considered to develop DFT calculations and explain the effect of lanthanum ion (La3+) on the electronic properties, adsorption capacity, and photocatalytic activity of this semiconductor. Due to the presence of the La3+ ion, the bandgap energy value of La/TiO2 (2.98 eV) was lower than that obtained for TiO2 (3.21 eV). TDOS analysis demonstrated the presence of hybrid levels in La/TiO2 composed mainly of O2p and La5d orbitals. The chemical nature of the La-O bond was estimated from PDOS analysis, Bader charge analysis, and ELF function, resulting in a polar covalent type, due to the combination of covalent and ionic bonds. In general, the adsorption of the methylene blue (MB) molecule on the surface (101) of La/TiO2 was energetically more favorable than on the surface (101) of TiO2. The thermodynamic stability of doping TiO2 with lanthanum was deduced from the negative heat-segmentation values obtained. The evidence from this theoretical study supports the experimental results reported in the literature and suggests that the semiconductor La/TiO2 is a potential catalyst for applications that require sunlight.

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 (R²: 0.98, AdjR²: 0.98, and RMSE: 8.97) and Dubinin-Radushkevich (R²: 0.99, AdjR²: 0.98, and RMSE: 6.84), respectively, based on the statistical tests of coefficient of determination (R²), adjusted coefficient of determination (AdjR²), 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.

Debaryomyces hansenii F39A as biosorbent for textile dye removal

Many industries generate a considerable amount of wastewater containing toxic and recalcitrant dyes. The main objective of this research was to examine the biosorption capacity of Reactive Blue 19 and Reactive Red 141 by the Antarctic yeast Debaryomyces hansenii F39A biomass. Some variables, including pH, dye concentration, amount of adsorbent and contact time, were studied. The equilibrium sorption capacity of the biomass increased with increasing initial dye concentration up to 350mg/l. Experimental isotherms fit the Langmuir model and the maximum uptake capacity (q_max) for the selected dyes was in the range of 0.0676-0.169mmol/g biomass. At an initial dye concentration of 100mg/l, 2g/l biomass loading and 20±1°C, D. hansenii F39A adsorbed around 90% of Reactive Red 141 and 50% of Reactive Blue 19 at pH 6.0. When biomass loading was increased (6g/l), the uptake reached up to 90% for Reactive Blue 19. The dye uptake process followed a pseudo-second-order kinetics for each dye system. As seen throughout this research study, D. hansenii has the potential to efficiently and effectively remove dyes in a biosorption process and may be an alternative to other costly materials.

Biosorption of Congo Red from Aqueous Solutions Based on Self-Immobilized Mycelial Pellets: Kinetics, Isotherms, and Thermodynamic Studies

In the current study, Aspergillus fumigatus and Pseudomonas putida were co-cultured to obtain self-immobilized mycelial pellets to evaluate the decolorization efficiency of Congo red (CR). The obtained co-culture exhibited the highest decolorization efficiency of 99.22% compared to monoculture of A. fumigatus (89.20%) and P. putida (55.04%). The morphology and surface properties of the mycelial pellets were characterized by SEM, FTIR, BET, and XPS. The adsorption kinetics and isotherms were well described by pseudo-second-order and Langmuir models. The findings revealed that the removal efficiency of the mycelial pellet for CR was significantly influenced by physicochemical parameters. Thermodynamic result showed that the biosorption process was endothermic. The maximum adsorption capacity can be obtained from the Langmuir model, which is 316.46 mg/g, it suggests that mycelial pellet was an efficient biosorbent to remove CR from aqueous solution. This study indicates that the mycelial pellet can develop a sustainable approach to eliminate CR from the wastewater.

Microwave assist sorption of crystal violet and Congo red dyes onto amphoteric sorbent based on upcycled Sepia shells

A new sorbent based on Sepia shells (cuttlefish bones) has been synthesized (SSBC) and tested for the sorption of cationic dye (crystal violet, CV) and an anionic dye (congo red, CR). SSBC was produced by reaction of sepia shells powder with urea in the presence of formaldehyde. In the first part of the work, the sorbent was characterized using scanning electron microscopy, energy dispersive X-ray analysis, Fourier-transform infra-red spectrometry and titration (for determining pH_PZC). In a second step, sorption properties were tested on the two dyes through the study of pH effect, sorbent dosage, temperature and ionic strength; the sorption isotherms and uptake kinetics were analyzed at the optimum pH: Langmuir equation fits isotherm profiles while the kinetic profile can be described by the pseudo-second order rate equation. Maximum sorption capacities reach up to 0.536 mmol g^-1 for CV and 0.359 mmol g^-1 for CR, at pH 10.6 and 2.4, respectively. The comparison of sorption properties at different temperatures shows that the sorption is endothermic. Processing to the sorption under microwave irradiation (microwaved enforced sorption, MES) increases mass transfer and a contact time as low as 1 min is sufficient under optimized conditions (exposure time and power) reaching the equilibrium, while 2-3 h were necessary for "simple" sorption. Dye desorption was successfully tested using 0.5 M solutions of NaOH and HCl for the removal of CR and CV, respectively. The sorbent can be re-used for a minimum of four cycles of sorption/desorption. Finally, the sorbent was successfully tested on spiked tap water and real industrial wastewater.

A low-cost and eco-friendly biosorbent material for effective synthetic dye removal from aquatic environment: characterization, optimization, kinetic, isotherm and thermodynamic studies

A novel biosorbent was prepared by the surface modification of Zostera marina L. bioresidues and used for the removal of model synthetic dye, methylene blue from aqueous medium in this study. Taguchi design of experiment (DoE) methodology was employed to investigate the influence of significant operational parameters (reaction time, pH of medium and dye concentration) on the biosorption process and to develop a mathematical model for the estimation of biosorption potential of biosorbent. The percentage contribution of each of these process variables on the dye biosorption was found to be 9.03%, 1.95% and 88.84%, respectively. The dye biosorption capacity under the obtained optimum environmental conditions (reaction time of 120 min, pH of 8 and dye concentration of 15 mg L^-1) was estimated to be 140.154 mg g^-1 (R²: 99.83). This value was very close to the experimentally obtained dye removal performance value (140.299 mg g^-1). These findings indicated the high ability of Taguchi DoE technique in the optimization and simulation of dye biosorption system. The kinetic and equilibrium modeling studies showed that the pseudo-second-order and Langmuir models were the best models for the elucidation of dye removal behavior of biosorbent. Besides, the performance of dye decontamination system was evaluated using the pseudo-second-order kinetic parameters. The thermodynamic analyses displayed that the dye biosorption was a feasible, spontaneous and exothermic process. For large scale dye purification applications, a single-stage batch biosorption system was also designed using the mathematical modeling data. All these results revealed that Z. marina L. bioresidues could be used as a promising alternative biosorbent material for the effective and eco-friendly dye biosorption systems.

Microwave-accelerated sorption of cationic dyes onto green marine algal biomass

Monolithic algal green powder (MAGP) was fabricated based on the marine green macroalga Enteromorpha flexuosa. It was scrutinized by using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared (FT-IR), point of zero charge (PH_PZC), and Brunauer-Emmett-Teller (BET) surface area. The ability of Enteromorpha flexuosa to capture both crystal violet (CV) and methylene blue (MB) from aqueous solutions was evaluated. The influence of variable conditional parameters on CV dye and MB dye batch sorption was investigated. Results showed that percentage removal of 90.3% and 93.4% were obtained under optimum conditions of variables for CV and MB, respectively. Effect of microwave radiation on dye sorption was also appraised. Processing the sorption under microwave irradiation (microwave-enforced sorption, MES) increases mass transfer and a contact time as low as 1 min is sufficient under optimized conditions (exposure time and power) reaching the equilibrium. The reusability of MAGP sorbent was achieved for four cycles of sorption/desorption by using 0.5 M HCl. The ability of MAGP for cationic dyes removal from spiked tap water and petrochemical plant discharge wastewater samples was successfully registered. Ultimately, the displayed data showed a superior and excellent ability of algal powder to be exploited as a green, harmless, and effective sorbent for cationic dye removal.

Taguchi DoE methodology for modeling of synthetic dye biosorption from aqueous effluents: parametric and phenomenological studies

Biosorption technology has been acknowledged as one of the most successful treatment approaches for colored industrial effluents. The problems such as its high manufacturing cost and poor regeneration capability in the use of activated carbon as a biosorbent have prompted the environmental scientists to develop alternative biosorbent materials. In this context, as a sustainable green generation alternative biosorbent source, the discarded seed biomass from pepper (Capsicum annuum L.) processing industry was explored for the biotreatment of colored aqueous effluents in this study. To test the wastewater cleaning ability of biosorbent, Basic red 46 was selected as a typical model synthetic dye. Taguchi DoE methodology was employed to study the effect of important operational parameters, contact time, pH and synthetic dye concentration, on the biosorption process and to develop a mathematical model for the estimation of biosorption potential of biosorbent. The percentage contribution of each of these process variables on the dye biosorption was found to be 19.31%, 41.39%, and 38.74%, respectively. The biosorption capacity under the optimum environmental conditions, contact time of 360 min, pH of 8 and dye concentration of 30 mg L^-1, was estimated to be 92.878 mg g^-1 (R²: 99.45). This value was very close to the experimentally obtained dye removal performance value (92.095 mg g^-1). These findings indicated the high ability of Taguchi DoE technique in the optimization and simulation of dye biosorption system. The kinetic and equilibrium modeling studies showed that the pseudo-second-order and Langmuir models were the best models for the elucidation of dye removal behavior of biosorbent. The thermodynamic studies displayed that the dye biosorption was a feasible, spontaneous and exothermic process. This parametric and phenomenological survey revealed that the discarded pepper seed biomass can be introduced as a potential and efficient biosorbent for the bioremediation of colored industrial effluents.

WITHDRAWN: An integrated approach towards sustainable wastewater treatment and biofuel production: A phytotechnological study on defatted residual seed biomass of Datura stramonium L

Available online 1 March 2019. This article has been withdrawn at the request of the editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

WITHDRAWN: A combinatorial bioinnovative approach integrating synthetic dye bioremediation and bioenergy production using waste pepper seed biomass

A combinatorial study integrating synthetic dye bioremediation and biodiesel production using discarded pepper seed biomass was performed for a cleaner and more sustainable environment/energy in the present work. The vegetal oil was extracted from the pepper seed biomass and the defatted residual biomass was mainly investigated as a sustainable green generation alternative biosorbent source for the treatment of colored aqueous effluents. To test the wastewater cleaning ability of biosorbent, basic red 46 was selected as a common harmful model synthetic dye. The kinetic, equilibrium and thermodynamic modeling studies were performed to elucidate the dye biosorption behavior of biosorbent. Besides, the performance of dye bioremediation system was evaluated using the kinetic modeling parameters, and for large scale dye purification applications, a single-stage batch bioreactor system was designed using the mathematical modeling data. The operating conditions significantly affected the biosorption process. The pseudo-second-order and Freundlich models provided the best fit to the kinetic and isotherm data, respectively. The thermodynamic studies showed that the dye biosorption was a feasible and spontaneous process. The maximum dye biosorption capacity of biosorbent based on Langmuir model was predicted as 82.019 mg g-1. As compared many other biosorbents reported in literature for the same contaminant, this high value revealed a great potential of biosorbent for the dye removal from aqueous medium. Thus, the present study showed that the discarded pepper seed biomass could be employed as a highly efficient as well as cost-effective material for both dye bioremediation and biodiesel production in a sustainable manner.

Bioremediation potential of waste biomaterials originating from coastal Zostera marina L. meadows for polluted aqueous media with industrial effluents

The studies on novel and efficient biosorbent materials for the promotion of environmental and economic sustainability have been become an up-to-date attempt by scientists for the removal of synthetic dyes from industrial effluents. The biosorbents prepared from biomass based resources are emerging as an alternative promising material for the environmental clean-up because of their low-cost, renewability, eco-friendly, easy availability and so forth characteristics. Hence, for the first time, the biosorption performance of abundantly available natural biowastes originating from coastal Zostera marina L. meadows was explored for the biotreatment of colored industrial effluents in the present study. The biosorption properties of biosorbent for methylene blue as a representative synthetic industrial dye were investigated by means of the operational parameters optimization, kinetic, isotherm, thermodynamic and characterization studies. The operating conditions significantly affected the biosorption process and the optimal values were determined as pH of 8, biosorbent dosage of 10 mg, dye concentration of 15 mg L^-1 and contact time of 120 min. Elovich and Freundlich models provided the best fit to the kinetic and isotherm data compared with other applied models, respectively. The negative change in free energy (-10.682 to -8.466 kJ mol^-1) indicated a thermodynamically feasible and spontaneous process. The characterization analysis showed that the biosorbent has appropriate chemical and physical properties for the dye biosorption. Thus, the present study displayed that the waste materials originating from coastal Z. marina L. meadows can be applied as a highly efficient as well as cost-effective green generation biosorbent for the clean-up of colored aquatic media.

Qualitative analysis of acid washed black cumin seeds for decolorization of water through removal of highly intense dye methylene blue

Dyes in water change the colour, taste and odour of water, are highly visible, and can be toxic and cancerous for the coloured water consumption human beings. Basic dyes particularly, methylene blue, MB has high colour intensity, shows intense colour even at low concentration, and are very toxic due to their complex structure. Instead of adsorption, removal of MB from water using various traditional treatment methods is costly and less effective. The use of bioadsorbent provides easy and low cost technique for removal of MB. For searching the adequate technique of dye removal, adsorption efficiency and mechanism of bioadsorbent can be analyzed. To this, MB removal efficiency of seeds of medicinal plant, black cumin seeds were analyzed. The data are supplied in the article.

Wastewater treatment for Amoxicillin removal using magnetic adsorbent synthesized by ultrasound process

In this study, the effect of magnetic adsorbent prepared from Olive kernel (MA-OK) was studied in the Amoxicillin (AMX) removal. The synthesized adsorbent, under a sonochemical method, were characterized using Field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and X-ray diffraction (XRD). The absorption functions in the batch experiments were studied using the expected parameters for the maximum absorption capacities (q_m) such as pH, contact time, the dosage adsorbent, and the initial concentration of AMX. The residual amount of AMX were recorded after injection into the HPLC. The proportion of the mobile phase was methanol to water (40:60) at a flow rate of 1 ml/min. Adsorption experimental results indicated that the removal efficiency reaches its maximum using 0.5 g/L of the adsorbent, concentration of AMX (200 mg/L) at contact time of 90 min and pH of 6. The kinetics of the reaction and the adsorption isotherm could be well described by the pseudo-second order equation and the Langmuir adsorption isotherm with a regression coefficient of 0.9981 and 0.9979, respectively. The maximum adsorption capacity obtained from the Langmuir model was to be 238.1 mg/g. The ionic strength of the solution has no significant effect on increasing the AMX removal efficiency. Eventually, application of this adsorbent was successfully performed for removing AMX from aqueous and hospital wastewater solutions.