scholarly journals Highly Efficient Magnetic Phosphoric Acid Modified Defatted Chlorella Vulgaris Algae ( MDCV/Fe3O4) as a Novel Biosorbent for Methylene Blue Removal

2021 ◽  
Author(s):  
Zeinab Salehi ◽  
Sahar Naziri
Keyword(s):  
Methylene Blue ◽  
Phosphoric Acid ◽  
Chlorella Vulgaris ◽  
Contact Time ◽  
High Efficiency ◽  
Low Cost ◽  
Lipid Extraction ◽  
Precipitation Method ◽  
Acid Modification ◽  
Biosorption Capacity

Abstract Background:A novel biosorbent based on defatted Chlorella vulgaris (DCV) as a by-product of the biofuel industry was considered as an economical and inexpensive biosorbent in the form of magnetic modified defatted Chlorella vulgaris (MDCV/Fe3O4) for methylene blue (MB) removal. The lipid extraction was performed on raw Chlorella vulgaris (RCV). Phosphoric acid was selected as a DCV modifier. During acid modification, the variables affecting the biosorption capacity and the residual algae such as temperature (30-70 ), the contact time of DCV with acid (3-9 hr), the concentration of acid (2-6 mol/L), and the ratio of acid volume to DCV (30-70 mL/g) were investigated and optimized using Minitab-18 software. The modified defatted Chlorella vulgaris (MDCV) was prepared by acidification of DCV under optimal conditions. MDCV/ was prepared using the co-precipitation method for easy and low-cost separation of biosorbent. The XRD, FTIR, SEM, EDS, BET, and VSM analyses were performed to identify the structures and characteristics of RCV, DCV, MDCV, and MDCV/. Some experimentsere designed using Minitab-18 software to investigate the effects of temperature (5-45 ), contact time (30-90 min), biosorbent dosage (15-45 mg), initial concentration of MB (20-100 mg/L), and pH (5-9) on the biosorption capacity of MDCV/. The kinetic, isothermal and thermodynamic parameters were investigated on MDCV/.Results:The specific surface area of MDCV/ was 25.20 . RCV, DCV, and MDCV/ had a crystalline structure and MDCV had an amorphous structure. The data were most consistent with Pseudo-second-order and Freundlich models. The maximum biosorption capacity of MDCV/ was calculated in the amount of 32.44‌ mg/g. According to the positive values of and negative values of (-46.56 kJ/mol) and (-0.17 kJ/mol.K), the biosorption of MB on MDCV/ was non-spontaneous, exothermic with a decrease in irregularity.Conclusions:In this study, MDCV/ was applied as the MB biosorbent. Modifications such as lipid extraction, phosphoric acid modification and magnetization improved this biosorbent in its biosorption capacity and separation. Data were optimized in the acid modification and MB biosorption steps. Comparison of the characteristics of MDCV/ with unmodified species confirmed its high efficiency. Kinetic, isothermal and thermodynamic studies were also performed.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

scholarly journals Methylene Blue Adsorption from aqueous solution by low cost vine-wood biomass

2021 ◽  
Author(s):  
Rachida Souidi ◽  
yasmina khane ◽  
Lahcen Belarbi ◽  
Smain Bousalem
Keyword(s):  
Methylene Blue ◽  
Sulfuric Acid ◽  
Contact Time ◽  
Adsorption Process ◽  
Low Cost ◽  
Sulfuric Acid Concentration ◽  
Analytical Techniques ◽  
Batch Adsorption ◽  
Adsorbent Dosage ◽  
Adsorption Desorption

Abstract In this work, the sawdust of vine wood (VW) was treated with sulfuric acid and used to adsorb methylene blue (MB) from aqueous solutions via a batch adsorption process. The characteristics of the adsorbent were determined by various analytical techniques such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) and Brunauer−Emmett−Teller (BET) N2 adsorption−desorption isotherms. The effects of various experimental parameters including sulfuric acid concentration, particle size of the adsorbent, pH of the solution, contact time, initial concentration, adsorbent dosage and temperature on adsorption of MB by activating sawdust were systematically investigated. The experimental results showed that the adsorption efficiency was increased with contact time and adsorbent dosage. The maximum removal efficiency was found after 180 min of solid/liquid contact with adsorbent doses of 1 g/l for sawdust. The isotherm and kinetic experimental data for MB adsorption on VW sawdust were best-fitted by Langmuir models and Pseudo-second-order, respectively. The calculated values of the entropy (ΔS°), enthalpy (ΔH°) and Gibbs energy (ΔG°) indicated that the adsorption process was exothermic in nature. These results suggest that the activated sawdust can be employed as a low-cost and environmentally friendly adsorbent for the treatment of wastewaters containing dyes.

scholarly journals Optimization of Methylene Blue Adsorption on Agricultural Solid Waste Using Box–Behnken Design (BBD) Combined with Response Surface Methodology (RSM) Modeling

2021 ◽  
Vol 12 (4) ◽  
pp. 4567-4583
Keyword(s):  
Methylene Blue ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Contact Time ◽  
Organic Dyes ◽  
Low Cost ◽  
Sem Analysis ◽  
Solution Ph ◽  
Box Behnken Design ◽  
Mb Adsorption

Tunics corm saffron (TCS) is a low-cost adsorbent that removes methylene blue (MB) from an aqueous solution. The TCS was characterized using FTIR and SEM analysis. The influence of MB adsorption variables such as TCS dose (0.4–2.4 g L−1), contact time (0–120 min), MB dye concentration (100–500 mg L−1) was optimized Box–Behnken design (BBD) combined with response surface methodology (RSM) modeling. All three variables among the main parameters significantly affected the removal efficiency by applying the quadratic regression analysis. The results showed that the predicted values for MB adsorption were close to the experimental values and were in good agreement. Besides, the r2 value (r2=0.970) indicates that the regression can predict response for the adsorption process in the studied range. The optimum BBD-RSM for MB removal of 89.48 % was recorded at a TCS dose of 1.78 g L−1, contact time of 56 min, MB dye concentration of 176 mg L–1 at solution pH of 5.4 temperature 21 °C. Excellent regeneration of TCS to remove MB in sixth consecutive adsorption-desorption cycles. This work highlights that TCS offers tremendous potential as a low-cost for organic dyes removal from wastewaters.

Synthesis and Characterization of Attapulgite Clay Coated Ag/AgBr/TiO2 Visible Light Photocatalyst

2010 ◽  
Vol 178 ◽  
pp. 285-290 ◽  
Author(s):  
Xu Gu ◽  
Jin Long Jiang ◽  
Dong Li
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
High Efficiency ◽  
Catalyst Activity ◽  
Precipitation Method ◽  
High Dispersion ◽  
X Ray Diffraction ◽  
Visible Light Photocatalyst ◽  
Vis Spectroscopy ◽  
Attapulgite Clay

Attapulgite clay coated Ag/AgBr/TiO2 visible light photocatalyst was prepared by an impregnation-deposition-precipitation method. The catalyst was characterized via powder X-ray diffraction (XRD), TEM, UV-Vis spectroscopy, and EMAX, and their photocatalytic activity was examined by degradation of methylene blue in water under sunlight. The results showed that the catalyst exhibited high efficiency for the degradation of methylene blue and the catalyst activity maintained effectively after successive cyclic experiments under sunlight, attributed to adsorption of dye on attapulgite clay and high dispersion of AgBr and TiO2 nano-sized particles on the surface of attapulgite clay.

scholarly journals Study of the Digestate as an Innovative and Low-Cost Adsorbent for the Removal of Dyes in Wastewater

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 852
Author(s):  
Sicong Yao ◽  
Massimiliano Fabbricino ◽  
Marco Race ◽  
Alberto Ferraro ◽  
Ludovico Pontoni ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Removal Rate ◽  
Low Cost ◽  
Second Order ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Diffusion Kinetic ◽  
Pseudo Second Order

Digestate, as an urban solid waste, was considered as an innovative adsorbent for colorant polluted wastewater. Batch adsorption experiments were carried out using digestate as an adsorbent material to remove various dyes belonging to different categories. The removal rate and adsorption capacity of dyes were evaluated and the dose of digestate, contact time, and initial dye concentration were studied. The maximum removal rate was approximately 96% for Methylene Blue. The equilibrium time for the Methylene Blue was 4 h, while for other dyes, a longer contact time was required to reach the equilibrium. The suspicion of colloidal matter release into the solution from solid fraction of the digestate led to the investigation of the consequence of a washing step of the digestate adsorbent upstream the adsorption experiment. Washed and not washed adsorbents were tested and the differences between them in terms of dye removal were compared. Moreover, experimental data were fitted by pseudo-first order, pseudo-second order, and intra-partial diffusion kinetic models as well as Langmuir, Freundlich, and Sips isotherm models. The results from fitted models showed that the adsorption of various dyes onto the digestate was mostly well fitted by the Langmuir isotherm and pseudo-second-order kinetic model.

scholarly journals Effectiveness of Alkali-Acid Treatment in Enhancement the Adsorption Capacity for Rice Straw: The Removal of Methylene Blue Dye

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Nady A. Fathy ◽  
Ola I. El-Shafey ◽  
Laila B. Khalil
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Rice Straw ◽  
Acid Treatment ◽  
Low Cost ◽  
Second Order ◽  
Isotherm Models ◽  
Blue Dye ◽  
Acid Modification ◽  
Pseudo Second Order

The effectiveness of alkali-acid modification in enhancement the adsorption capacity of rice straw (RS) for removing a basic dye was studied. The obtained adsorbents were characterized by slurry pH, pHPZC, iodine number, methylene blue number, FTIR, and SEM analyses. Adsorption of methylene blue (MB) was described by the Langmuir, Freundlich, Tempkin, and Redlich-Peterson isotherm models. Effects of contact time, initial concentration of MB dye, pH of solution, adsorbent dose, salt concentration of NaCl, and desorbing agents on the removal of MB were reported. Kinetic studies were analyzed using the pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models and were found to follow closely the pseudo-second-order model. Equilibrium data were best represented by the Langmuir and Redlich-Peterson isotherms. The adsorption capacities were varied between 32.6 and 131.5 mg/g for untreated and treated RS samples with NaOH-1M citric acid (ARS-1C), respectively. Adsorption behavior of the ARS-1C sample was experimented in a binary mixture containing methylene blue (basic) and reactive blue 19 (acidic) dyes which showed its ability to remove MB higher than RB19. Overall, the results indicate that the alkali-acid treatment proved to be potential modification for producing effective low-cost adsorbents for the removal of the basic dyes from wastewater.

scholarly journals Fe3O4-NPs/Orange-Peel composite as magnetic heterogeneous Fenton-like catalyst towards high-efficiency degradation of methyl orange

2021 ◽  
Author(s):  
Qiang Zhao ◽  
Congcong Zhang ◽  
Xiaoqiang Tong ◽  
Yunling Zou ◽  
Yan Li ◽  
...  
Keyword(s):  
Methyl Orange ◽  
High Efficiency ◽  
Low Cost ◽  
Orange Peel ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Heterogeneous Fenton ◽  
Fe3o4 Nps ◽  
Degradation Ratio ◽  
Co Precipitation

Abstract Fe3O4-NPs/orange-peel (MOP) composite was prepared via one-step in-situ co-precipitation method as magnetic heterogeneous Fenton-like catalyst. The properties of MOP were characterized by SEM, TEM, BET, XRD, FT-IR, TGA and XPS technologies. Its Fenton-like catalytic responses towards removal of methyl orange (MO) were investigated, in which the effects of initial dye concentration, pH, temperature and H2O2 dosage were studied. The MO degradation ratio up to 98.0% was obtained within 20 min in optimized conditions. The catalyst also shows excellent catalytic stability exhibiting nearly 90% degradation ratio in 10th cycle within 20 min, whereas pure Fe3O4-NPs showing only 62.5% in this stage. Due to the stabilization of complexing orange peel hydroxyl to Fe oxide in the composite and its magnetic separation property, Fe3O4-NPs/orange-peel composite exhibits excellent Fenton-like catalytic performance which offers great prospects for low-cost and high-efficiency organic dye wastewater treatment.

scholarly journals High-efficiency adsorption and regeneration of methylene blue and aniline onto activated carbon from waste edible fungus residue and its possible mechanism

RSC Advances ◽  
2020 ◽  
Vol 10 (24) ◽  
pp. 14262-14273 ◽  
Author(s):  
Hongyan Li ◽  
Lianxin Liu ◽  
Jianguo Cui ◽  
Jiali Cui ◽  
Fang Wang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Zinc Chloride ◽  
High Efficiency ◽  
Low Cost ◽  
Activation Method ◽  
Impregnation Ratio ◽  
Edible Fungus

Edible fungus residue as an efficient and low-cost precursor was used to produce Edible Fungus residue Activated Carbon (EFAC) using the zinc chloride activation method at a 1 : 2 impregnation ratio and 600 °C activation for 3 hours.

scholarly journals Repeated Utilization of Ionic Liquid to Extract Lipid from Algal Biomass

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Weizheng Zhou ◽  
Zhongming Wang ◽  
Md. Asraful Alam ◽  
Jingliang Xu ◽  
Shunni Zhu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
High Efficiency ◽  
Volume Fraction ◽  
Morphological Changes ◽  
Low Cost ◽  
Lipid Extraction ◽  
Reaction System ◽  
Dry Weight ◽  
Solvent System

In this work, different kinds of ionic liquids and reaction conditions for the extraction of lipid from microalgae biomass were optimized and repeated use of ionic liquids for microalgal lipid extraction was evaluated. Morphological changes of microalgae cells were compared in terms of pre- and post-treatment to understand the mechanisms of ionic liquid treatment. Ionic liquid [BMIM][MeSO4] showed the best lipid extraction efficiency at 70°C and with reaction time of 2 hours. The ratios (ILs : methanol) of 1 : 7 and 1 : 3 were the optimum ratios to complete the extraction of the lipids from microalgae. The initial 50% volume fraction of [BMIM][MeSO4] was 16.04% of dry weight, which showed the highest five average extraction rates. The loss of ionic liquid in the reaction system and the increase in water content of ionic liquids were considered as the main reasons for the decrease in the extraction rate. It is suggested that the potential of lipid extraction in this IL-methanol co-solvent system is promising due to the high efficiency, low cost, safety, environmental protection, and other characteristics.

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