Use of Spirulina platensis micro and nanoparticles for the removal synthetic dyes from aqueous solutions by biosorption

In this research, micro and nanoparticles of Spirulina platensis dead biomass were obtained, characterized and employed to removal FD&C red no. 40 and acid blue 9 synthetic dyes from aqueous solutions. The effects of particle size (micro and nano) and biosorbent dosage (from 50 to 750 mg) were studied. Pseudo-first order, pseudo-second order and Elovich models were used to evaluate the biosorption kinetics. The biosorption nature was verified using energy dispersive X-ray spectroscopy (EDS). The best results for both dyes were found using 250 mg of nanoparticles, in these conditions, the biosorption capacities were 295 mg g^?1 and 1450 mg g^?1, and the percentages of dye removal were 15.0 and 72.5% for the FD&C red no. 40 and acid blue 9, respectively. Pseudo-first order model was the more adequate to represent the biosorption of both dyes onto microparticles, and Elovich model was more appropriate to the biosorption onto nanoparticles. The EDS results suggested that the dyes biosorption onto microparticles occurred mainly by physical interactions, and for the nanoparticles, chemisorption was dominant.     

Biosorption of Basic Blue 7 by fungal cells immobilized on the green-type biomatrix of Phragmites australis spongy tissue

Biosorption is an effective alternative method for the control of water pollution caused by different pollutants such as synthetic dyes and metals. A new and efficient biomass system was developed from the passively immobilized fungal cells. The spongy tissue of Phragmites australis was considered as the carrier for the immobilization of Neurospora sitophila cells employed for the biosorption of Basic Blue 7. This plant tissue was used for the first time as a carrier for fungal cells. The biosorption was examined through batch- and continuous-mode operations. The biosorption process conformed well to the Langmuir model. Maximum monolayer biosorption capacity of the biosorbent was recorded as 154.756 mg g^?1. Kinetic findings showed a very good compliance with the pseudo-second-order model. The negative values of ΔG° indicated a spontaneous nature of the biosorption process and a positive value of ΔH° (14.69 kJ mol^?1) concluded favorable decolorization at high temperature. The scanning electron microscopy analysis showed that a porous, rippled, and rough surface of biomass system was covered with BB7 molecular cloud. IR results revealed that functional groups like –OH, –NH, and C?O participated to the decolorization. Breakthrough and exhausted points were found as 360 and 570 minutes, respectively. The biomass system was successfully applied to the treatment of real wastewater.     

Copper biosorption on Lyngbya putealis: Application of response surface methodology (RSM)

The potential use of biosorbent prepared from an indigenously isolated cyanobacterium, Lyngbya putealis, for the removal of copper from aqueous solution has been investigated under optimized conditions in this study. Batch mode experiments were performed to determine the adsorption equilibrium and kinetic behavior of copper in aqueous solution allowing the computation of kinetic parameters and maximum metal adsorption capacity. Influences of other parameters like initial metal ion concentration (10-100 mg l⁻¹), pH (2-8) and biosorbent dose (0.1-1.0 g/100 ml) on copper adsorption were also examined, using Box-Behnken design matrix. Very high regression coefficient between the variables and the response (R² = 0.9533) indicates excellent evaluation of experimental data by second order polynomial regression model. The response surface method indicated that 40-50 mg l⁻¹ initial copper concentration, 6.0-6.5 pH and biosorbent dose of 0.6-0.8 g/100 ml were optimal for biosorption of copper by biosorbent prepared from L. putealis. On the basis of experimental results and model parameters, it can be inferred that the biosorbent which has quite high biosorption capacity can be utilized for the removal of copper from aqueous solution.     

Biosorption of Basic Orange using dried A. filiculoides

In order to understand the biosorption of Basic Organic (BO) textile dye on dried Azolla filiculoides (A. filiculoides), batch experiments were conducted under various conditions. The results show that biosorption of BO on dried A. filiculoides was dependent on the initial solution pH, biosorbent dosage, contact time and the initial BO concentration. Using the Langmuir equation, the biosorption capacity (q_m) for BO was 833 mg/g at 303 K. The kinetic study suggested that the mechanism of biosorption was due to ion-exchange physisorption via the intra-particle diffusion and chemisorption on the external surface of dried A. filiculoides. Different techniques were used to characterize dried A. filiculoides and indicated that the biomass had a high cation exchange capacity (93.6 mmol/100 g), a large specific surface area (80.35–422.89 m²/g) and contained various functional groups which may play an important role in the physisorption and chemisorption of BO on the surface of A. filiculoides. The results showed that the removal ratio of BO reached 79.3% from wastewater containing 100 mg/L BO, indicating that the biomass could be used as a potential biosorbent for the removal of BO from industrial wastewater.     

Competitive biosorption of Acid Blue 25 and Acid Red 337 onto unmodified and CDAB-modified biomass of Aspergillus oryzae

The performance of unmodified and cetyldimethylethyl ammonium bromide (CDAB) modified nonviable Aspergillus oryzae for removal of Acid Blue 25 (AB 25) and Acid Red 337 (AR 337) was investigated in single and binary systems. In single system, the biosorption capacities of CDAB-modified biosorbent reached 160.36 and 280.39 mg g⁻¹ for AB 25 and AR 337, respectively, which were 1.52 and 1.66 times higher than that of unmodified biosorbent. In binary system, the biosorption capacities of unmodified and CDAB-modified biosorbents for both dyes decreased significantly compared to that in single system. Relative competitiveness analysis demonstrated that there existed critical initial concentration ratio which determined the predominance of dyes during biosorption process. The biosorption of AB 25 was found to be in dominant position at initial concentration ratio of [AB 25]/[AR 337] above 0.63. Kinetic analysis indicated that intraparticle diffusion was the limiting step for biosorption of two dyes onto biosorbents.     

Biosorption of Nickel(II) from aqueous solution by the fungal mat of Trametes versicolor (rainbow) biomass: equilibrium, kinetics, and thermodynamic studies

This study investigates the equilibrium, kinetics and thermodynamics of Nickel(II) biosorption from aqueous solution by the fungal mat of Trametes versicolor (rainbow) biomass. The optimum biosorption conditions like pH, contact time, biomass dosage, initial metal ion concentration and temperaturewere determined in the batch method. The biosorbent was characterized by FTIR, SEM and BET surface area analysis. The experimental data were analyzed in terms of pseudo-first-order, pseudo-secondorder and intraparticle diffusion kinetic models, further it was observed that the biosorption process of Ni(II) ions closely followed pseudo-second-order kinetics. The equilibrium data of Ni(II) ions at 303, 313, and 323 K were fitted to the Langmuir and Freundlich isotherm models. Langmuir isotherm provided a better fit to the equilibrium data andthe maximum monolayer biosorption capacity of the T. versicolor(rainbow) biomass for Ni(II) was 212.5 mg/g at pH 4.0. The calculated thermodynamic parameters, ΔG^○, ΔH^○, and ΔS^○, demonstrated that the biosorption of Ni(II) ions onto the T. versicolor (rainbow) biomass was feasible, spontaneous and endothermic at 303 ～ 323 K. The performance of the proposed fungal biosorbent was also compared with that of many other reported sorbents for Nickel(II) removal and it was observed that the proposed biosorbent is effective in terms of its high sorption capacity.     

Senna auriculata L. flower petal biomass: An alternative green biosorbent for the removal of fluoride from aqueous solutions

Fluoride contamination in groundwater is a major concern in many parts of India and all over the world. Researches paying attention for the removal of fluoride through the application of biosorbents prepared from different parts of plants are finding greater scope and importance. The present research work focuses on Senna auriculata L., flower petal biomass as biosorbent, and evaluated its feasibility for fluoride ion elimination from aqueous solutions. Batch experiments were conducted to remove fluoride under different experimental conditions have been optimized for the maximum removal of fluoride; 80% removal was observed at pH: 6, sorbent dosage: 0.25 g/100 mL, time of agitation: 90 min, and initial concentration of the fluoride ions: 5 mg/L. Characterization studies of the biosorbent revealed its favorability towards the sorption of fluoride. In the isothermal modeling studies, Langmuir isotherm model was obeyed by the biosorption process with R² value of 0.98 and from a kinetic perspective, the biosorption of fluoride onto the biosorbent observed the pseudo-second-order reaction with R² value of 0.98. The developed biosorbent has been applied to real field fluoride-contaminated water samples and found to be successful.     

Performance of durian shell waste as high capacity biosorbent for Cr(VI) removal from synthetic wastewater

The capability of durian shell waste biomass as a novel and potential biosorbent for Cr(VI) removal from synthetic wastewater was studied. The adsorption study was performed in batch mode at different temperatures and pH. Langmuir and Freundlich isotherm models fit the equilibrium data very well (R² > 0.99). The maximum biosorption capacity of durian shell was 117 mg/g. On modeling its kinetic experimental data, the pseudo-first order prevails over the pseudo-second order model. Thermodynamically, the characteristic of Cr-biosorption process onto durian shell surface was spontaneous, irreversible and endothermic.     

Biosorption characteristics of Aspergillus fumigatus for the decolorization of triphenylmethane dye acid violet 49

This study focuses on the possible use of Aspergillus fumigatus to remove acid violet 49 dye (AV49) from aqueous solution. In batch biosorption experiments, the highest biosorption efficiency was achieved at pH 3.0, with biosorbent dosage of 3.0 gL^?1 within about 30 min at 40 °C. The Langmuir and Freundlich models were able to describe the biosorption equilibrium of AV49 onto fungal biomass with maximum dye uptake capacity 136.98 mg g^?1. Biosorption followed a pseudo-second-order kinetic model with high correlation coefficients (R ²?>?0.99), and the biosorption rate constants increased with increasing temperature. Thermodynamic parameters indicated that the biosorption process was favorable, spontaneous, and endothermic in nature, with insignificant entropy changes. Fourier transform infrared spectroscopy strongly supported the presence of several functional groups responsible for dye–biosorbent interaction. Fungal biomass was regenerated with 0.1 M sodium hydroxide and could be reused a number of times without significant loss of biosorption activity. The effective decolorization of AV49 in simulated conditions indicated the potential use of biomass for the removal of color contaminants from wastewater.     

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

Abstract

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.     

Bioremediation potential of a widespread industrial biowaste as renewable and sustainable biosorbent for synthetic dye pollution

In this study, a model synthetic azo dye (Basic red 46) bioremoval by Carpinus betulus sawdust as inexpensive, eco-friendly, and sustainable biosorbent from aqueous solution was examined in a batch biosorption system. The effective environmental parameters on the biosorption process, such as the value of pH, amount of biosorbent, initial dye concentration and contact time were optimized using classical test design. The possible dye-biosorbent interaction was determined by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The equilibrium, thermodynamic, and kinetic studies for the biosorption of Basic red 46 onto the sawdust biomass were performed. In addition, a single-stage batch dye biosorption system was also designed. The dye biosorption yield of biosorbent was significantly influenced by the change of operating variables. The experimental data were best described by the Freundlich isotherm model and both the pseudo-first-order kinetic and the pseudo-second-order kinetic models. Thermodynamic research indicated that the biosorption of dye was feasible and spontaneous. Based on the Langmuir isotherm model, the biosorbent was found to have a maximum biosorption potential higher than many other biosorbents in the literature (264.915?mg g^?1). Thus, this investigation presents a novel green option for the assessment of waste sawdust biomass as a cheap and effective biosorbent material.     

Biosorption of Food Green 3 by a novel green generation composite biosorbent from aqueous environment

A green type composite biosorbent composed of pine, oak, hornbeam, and fir sawdust biomasses modified with cetyltrimethylammonium bromide (CTAB) was first used for biosorption of an unsafe synthetic food dye, Food Green 3 from liquid medium in this study. Batch studies were carried by observing the effects of pH, dye concentration, biosorbent amount, and contact time. The equilibrium data were analyzed using Freundlich, Langmuir, and Dubinin–Radushkevich equations. Freundlich model gave a better conformity than other equations. The maximum dye removal potential of biosorbent was found to be 36.6 mg/g based on Langmuir isotherm. The pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models were applied to clarify the process kinetics of biosorption. The mechanism studies suggested the biosorption process obeying Elovich kinetics and involving pore diffusion. The estimated values of biosorption free energy from Dubinin–Radushkevich isotherm (E value <8 kJ/mol) and thermodynamic studies (0 < ΔG° < ?20 kJ/mol) implied a spontaneous, feasible, and physical process. Hence, this investigation suggested that the CTAB modified mix sawdust biomass could be a promising biosorbent for biosorption of such problematic dyes from impacted media.     

Biosorption of Acid Black 172 and Congo Red from aqueous solution by nonviable Penicillium YW 01: Kinetic study, equilibrium isotherm and artificial neural network modeling

The main objective of this work was to investigate the biosorption performance of nonviable Penicillium YW 01 biomass for removal of Acid Black 172 metal-complex dye (AB) and Congo Red (CR) in solutions. Maximum biosorption capacities of 225.38 and 411.53 mg g⁻¹ under initial dye concentration of 800 mg L⁻¹, pH 3.0 and 40 °C conditions were observed for AB and CR, respectively. Biosorption data were successfully described with Langmuir isotherm and the pseudo-second-order kinetic model. The Weber-Morris model analysis indicated that intraparticle diffusion was the limiting step for biosorption of AB and CR onto biosorbent. Analysis based on the artificial neural network and genetic algorithms hybrid model indicated that initial dye concentration and temperature appeared to be the most influential parameters for biosorption process of AB and CR onto biosorbent, respectively. Characterization of the biosorbent and possible dye-biosorbent interaction were confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy.     

Removal of Acid Blue25 from aqueous solutions using Bengal gram fruit shell (BGFS) biomass

The feasibility for the removal of Acid Blue25 (AB25) by Bengal gram fruit shell (BGFS), an agricultural by-product, has been investigated as an alternative for high-cost adsorbents. The impact of various experimental parameters such as dose, different dye concentration, solution pH, and temperature on the removal of Acid Blue25 (AB25) has been studied under the batch mode of operation. pH is a significant impact on the sorption of AB25 onto BGFS. The maximum removal of AB25 was achieved at a pH of 2 (83.84%). The optimum dose of biosorbent was selected as 200 mg for the removal of AB25 onto BGFS. Kinetic studies reveal that equilibrium reached within 180 minutes. Biosorption kinetics has been described by Lagergren equation and biosorption isotherms by classical Langmuir and Freundlich models. Equilibrium data were found to fit well with the Langmuir and Freundlich models, and the maximum monolayer biosorption capacity was 29.41 mg g^?1 of AB25 onto BGFS. The kinetic studies indicated that the pseudo-second-order (PSO) model fitted the experimental data well. In addition, thermodynamic parameters have been calculated. The biosorption process was spontaneous and exothermic in nature with negative values of ΔG° (?1.6031 to ?0.1089 kJ mol^?1) and ΔH° (?16.7920 kJ mol^?1). The negative ΔG° indicates the feasibility of physical biosorption process. The results indicate that BGFS could be used as an eco-friendly and cost-effective biosorbent for the removal of AB25 from aqueous solution.     

Biosorption kinetics and isotherm studies of Acid Red 57 by dried Cephalosporium aphidicola cells from aqueous solutions

Equilibrium, kinetics and thermodynamic studies on the removal of Acid Red 57 (AR57) by biosorption onto dried Cephalosporium aphidicola (C. aphidicola) cells have been investigated in a batch system with respect to pH, contact time and temperature. The results showed that the equilibrium time was attained within 40 min and the maximum biosorption capacity of AR57 dye onto C. aphidicola cells was 2.08 × 10⁻⁴ mol g⁻¹ or 109.41 mg g⁻¹ obtained after contact with 0.4 g dm⁻³ biosorbent concentration, pH₀ of 1 and at a temperature of 20 °C. The pseudo-second-order kinetic model was observed to provide the best correlation of the experimental data among the kinetic models studied. Biosorption isotherm models were developed and the Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models were conformed well to the experimental data. The changes of free energy, enthalpy and entropy of biosorption were also evaluated for the biosorption of AR57 dye onto C. aphidicola cells.     

Nickel(II) biosorption by <Emphasis Type="Italic">Rhodotorula glutinis</Emphasis>

The present study reports the feasibility of using Rhodotorula glutinis biomass as an alternative low-cost biosorbent to remove Ni(II) ions from aqueous solutions. Acetone-pretreated R. glutinis cells showed higher Ni(II) biosorption capacity than untreated cells at pH values ranging from 3 to 7.5, with an optimum pH of 7.5. The effects of other relevant environmental parameters, such as initial Ni(II) concentration, shaking contact time and temperature, on Ni(II) biosorption onto acetone-pretreated R. glutinis were evaluated. Significant enhancement of Ni(II) biosorption capacity was observed by increasing initial metal concentration and temperature. Kinetic studies showed that the kinetic data were best described by a pseudo-second-order kinetic model. Among the two-, three-, and four-parameter isotherm models tested, the Fritz-Schluender model exhibited the best fit to experimental data. Thermodynamic parameters (activation energy, and changes in activation enthalpy, activation entropy, and free energy of activation) revealed that the biosorption of Ni(II) ions onto acetone-pretreated R. glutinis biomass is an endothermic and non-spontaneous process, involving chemical sorption with weak interactions between the biosorbent and Ni(II) ions. The high sorption capacity (44.45 mg g⁻¹ at 25°C, and 63.53 mg g⁻¹ at 70°C) exhibited by acetone-pretreated R. glutinis biomass places this biosorbent among the best adsorbents currently available for removal of Ni(II) ions from aqueous effluents.     

两种大型真菌子实体对Cd2+的生物吸附特性

对两种多孔菌科大型真菌槐栓菌(Trametes robiniophila)和木蹄层孔菌(Fomes fomentarius)子实体生物吸附Cd²⁺的影响因素(包括吸附剂用量、初始pH、吸附时间、初始Cd²⁺浓度)和吸附特性进行分析。结果表明,槐栓菌和木蹄层孔菌对低浓度的Cd²⁺(10 mg/L)吸附的最适pH为6;Cd²⁺的去除率随吸附剂用量和吸附时间的增加而增大,槐栓菌和木蹄层孔菌均在吸附剂用量为2g/L时达到吸附平衡,槐栓菌在吸附时间为30 min时达到吸附平衡,而木蹄层孔菌在吸附时间为60 min时达到吸附平衡;槐栓菌和木蹄层孔菌对10 mg/L Cd²⁺的最大去除率分别为98%和94%。Langmuir等温吸附平衡模型比Freundlich等温吸附平衡模型能更好的拟合两种大型真菌对Cd²⁺的吸附过程;槐栓菌和木蹄层孔菌对10 mg/L Cd²⁺的最大吸附量分别为17.40 mg/g和8.91 mg/g。对实验数据进行动力学模型拟合可知,两种大型真菌对Cd²⁺的生物吸附过程均符合准二阶动力学模型。槐栓菌和木蹄层孔菌生物吸附低浓度Cd²⁺的化学反应机理可能为离子交换。     

Biosorption of food dyes onto Spirulina platensis nanoparticles: equilibrium isotherm and thermodynamic analysis

The biosorption of food dyes FD&C red no. 40 and acid blue 9 onto Spirulina platensis nanoparticles was studied at different conditions of pH and temperature. Four isotherm models were used to evaluate the biosorption equilibrium and the thermodynamic parameters were estimated. Infra red analysis (FT-IR) and energy dispersive X-ray spectroscopy (EDS) were used to verify the biosorption behavior. The maximum biosorption capacities of FD&C red no. 40 and acid blue 9 were found at pH 4 and 298 K, and the values were 468.7 mg g⁻¹ and 1619.4 mg g⁻¹, respectively. The Sips model was more adequate to fit the equilibrium experimental data (R² > 0.99 and ARE < 5%). Thermodynamic study showed that the biosorption was exothermic, spontaneous and favorable. FT-IR and EDS analysis suggested that at pH 4 and 298 K, the biosorption of both dyes onto nanoparticles occurred by chemisorption.     

Application of Arthrospira (Spirulina) platensis biomass for silver removal from aqueous solutions

The cyanobacterium Arthrospira (Spirulina) platensis was used to study the process of silver biosorption. Effects of various parameters such as contact time, dosage of biosorbent, initial pH, temperature, and initial concentration of Ag(I) were investigated for a batch adsorption system. The optimal biosorption conditions were determined as pH 5.0, biosorbent dosage of 0.4 g, and initial silver concentration of 30 mg/L. Equilibrium adsorption data were analyzed by the Langmuir and Freundlich models – however, the Freundlich model provided a better fit to the experimental data. The kinetic data fit the pseudo-second-order model well, with a correlation coefficient of 0.99. The analysis of thermodynamic parameters (ΔG°, ΔH° and ΔS°) revealed that the adsorption process of silver ion by spirulina biomass was exothermic and spontaneous (ΔG° < 0), and exothermic (ΔH° < 0) process. The biosorption capacity of biomass A. platensis serves as a basis for the development of green technology for environmental remediation.