Alternative treatments to improve the potential of rice husk as adsorbent for methylene blue

2016 ◽  
Vol 75 (2) ◽  
pp. 296-305 ◽  
Author(s):  
Dison S. P. Franco ◽  
Eduardo H. Tanabe ◽  
Daniel A. Bertuol ◽  
Glaydson S. dos Reis ◽  
Éder C. Lima ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Rice Husk ◽  
Aqueous Media ◽  
Surface Characteristics ◽  
Organic Fraction ◽  
Alternative Treatments ◽  
Adsorption Sites ◽  
Adsorption Capacities ◽  
Endothermic Process ◽  
Mb Adsorption

Alternative treatments, such as, NaOH, ultrasound assisted (UA) and supercritical CO2 (SCO2), were performed to improve the potential of rice husk as adsorbent to remove methylene blue (MB) from aqueous media. All the treatments improved the surface characteristics of rice husk, exposing its organic fraction and/or providing more adsorption sites. The Langmuir and Hill models were able to explain the MB adsorption for all adsorbents in all studied temperatures. The experimental and modeled parameters demonstrated that the MB adsorption was favored by the temperature increase and by the use of NaOH-rice husk. The maximum adsorption capacities for the MB solutions (ranging from 10 to 100 mg L−1), estimated from the Langmuir model at 328 K, were in the following order: NaOH rice-husk (65.0 mg g−1) > UA-rice husk (58.7 mg g−1) > SCO2-rice husk (56.4 mg g−1) > raw rice husk (52.2 mg g−1). The adsorption was a spontaneous, favorable and endothermic process. In general, this work demonstrated that NaOH, UA and SCO2 treatments are alternatives to improve the potential of rice husk as adsorbent.

scholarly journals Uptake of Methylene Blue from Aqueous Solution by Pectin–Chitosan Binary Composites

2020 ◽  
Vol 4 (3) ◽  
pp. 95
Author(s):  
Dexu Kong ◽  
Lee D. Wilson
Keyword(s):  
Methylene Blue ◽  
Aqueous Media ◽  
Dye Adsorption ◽  
Adsorption Properties ◽  
Point Of Zero Charge ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Adsorption Sites ◽  
Biopolymer Composites

To address the need to develop improved hybrid biopolymer composites, we report on the preparation of composites that contain chitosan and pectin biopolymers with tunable adsorption properties. Binary biopolymer composites were prepared at variable pectin–chitosan composition in a solvent directed synthesis, dimethyl sulfoxide (DMSO) versus water. The materials were characterized using complementary methods (infrared spectroscopy, thermal gravimetric analysis, pH at the point-of-zero charge, and dye-based adsorption isotherms). Pectin and chitosan composites prepared in DMSO yielded a covalent biopolymer framework (CBF), whereas a polyelectrolyte complex (PEC) was formed in water. The materials characterization provided support that cross-linking occurs between amine groups of chitosan and the –COOH groups of pectin. CBF-based composites had a greater uptake of methylene blue (MB) dye over the PEC-based composites. Composites prepared in DMSO were inferred to have secondary adsorption sites for enhanced MB uptake, as evidenced by a monolayer uptake capacity that exceeded the pectin–chitosan PECs by 1.5-fold. This work provides insight on the role of solvent-dependent cross-linking of pectin and chitosan biopolymers. Sonication-assisted reactions in DMSO favor CBFs, while cross-linking in water yields PECs. Herein, composites with tunable structures and variable physicochemical properties are demonstrated by their unique dye adsorption properties in aqueous media.

scholarly journals Comparative Study on the Adsorption Capacities of the Three Black Phosphorus-Based Materials for Methylene Blue in Water

2020 ◽  
Vol 12 (20) ◽  
pp. 8335
Author(s):  
Juanhong Wang ◽  
Zhaocheng Zhang ◽  
Dongyang He ◽  
Hao Yang ◽  
Dexin Jin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Black Phosphorus ◽  
Adsorption Effect ◽  
Adsorption Sites ◽  
Surface Areas ◽  
Adsorption Behaviors ◽  
Adsorption Capacities ◽  
Reduced Graphene ◽  
Black Phosphorene

Dye effluent has attracted considerable attention from worldwide researchers due to its harm and toxicity in recent years; as a result, the treatment for dye has become one of the focuses in the environmental field. Adsorption has been widely applied in water treatment owing to its various advantages. However, the adsorption behaviors of the new materials, such as the 2D black phosphorus (BP), for pollution were urgently revealed and improved. In this work, BP, black phosphorene (BPR), and sulfonated BPR (BPRS) were prepared by the vapor phase deposition method, liquid-phase exfoliating method, and modification with sulfonation, respectively. The three BP-based materials were characterized and used as adsorbents for the removal of methylene blue (MB) in water. The results showed that the specific surface areas (SSAs) of BP, BPR, and BPRS were only 6.78, 6.92, and 7.72 m2·g−1, respectively. However, the maximum adsorption capacities of BP, BPR, and BPRS for MB could reach up to 84.03, 91.74, and 140.85 mg·g−1, which were higher than other reported materials with large SSAs such as graphene (GP), nanosheet/magnetite, and reduced graphene oxide (rGO). In the process of BP adsorbing MB, wrinkles were generated, and the wrinkles would further induce adsorption. BPR had fewer layers (3–5), more wrinkles, and stronger adsorption capacity (91.74 mg·g−1). The interactions between the BP-based materials and MB might cause the BP-based materials to deform, i.e., to form wrinkles, thereby creating new adsorption sites between layers, and then further inducing adsorption. Although the wrinkles had a certain promotion effect, the adsorption capacity was limited, so the sulfonic acid functional group was introduced to modify BPR to increase its adsorption sites and promote the adsorption effect. These findings could provide a new viewpoint and insight on the adsorption behavior and potential application of the BP-based materials.

Preparation of Coal-Based Activated Carbon and its Application for Methylene Blue Removal

2012 ◽  
Vol 253-255 ◽  
pp. 988-992
Author(s):  
Guo Zhuo Gong ◽  
Qiang Xie ◽  
Wen Fen Yang ◽  
Xin Yao
Keyword(s):  
Methylene Blue ◽  
Orthogonal Experiment ◽  
Preparation Condition ◽  
Raw Material ◽  
Activation Temperature ◽  
Surface Areas ◽  
Preparation Conditions ◽  
Adsorption Capacities ◽  
Acid Washing ◽  
Mb Adsorption

In accordance with an orthogonal experiment design, a series of ACs for methylene blue (MB) removal had been prepared in the presence of small amounts of KOH in raw material combined with delicate acid washing after carbonization and before steam activation. ACs were characterized, and their adsorption capacities for MB were determined as well. It was found that it was feasible to regulate and optimize pore structure in coal-based ACs by tuning preparation conditions concisely and properly, and the MB adsorption capacities were linearly correlated with their specific surface areas. Based on statistic analysis, it was revealed that among the four process variables studied for the sorbent prepared in this work, the activation temperature was found to be the most significant one for the MB adsorption capacity, the next ones were the activation time, the flow rate of water vapor and the amount of KOH, and an optimized preparation condition was figured out.

scholarly journals Silica Pillared Montmorillonites as Possible Adsorbents of Antibiotics from Water Media

2018 ◽  
Vol 8 (8) ◽  
pp. 1403 ◽  
Author(s):  
Maria Roca Jalil ◽  
Florencia Toschi ◽  
Miria Baschini ◽  
Karim Sapag
Keyword(s):  
Complex Formation ◽  
Aqueous Media ◽  
Pillared Clays ◽  
Raw Material ◽  
Van Der Waals Interactions ◽  
Adsorption Mechanisms ◽  
Adsorption Sites ◽  
Adsorption Capacities ◽  
Inner Sphere ◽  
Sphere Complex

In this work, three silica pillared clays (Si-PILC) were synthetized, characterized, and evaluated as possible adsorbents of ciprofloxacin (CPX) and tetracycline (TC) form alkaline aqueous media. The pillared clays obtained showed significant increases in their specific surface areas (SBET) and micropore volumes (Vμp) regarding the raw material, resulting in microporosity percentages higher than 57% in all materials. The studies of CPX and TC removal using pillared clays were compared with the natural clay and showed that the Si-PILC adsorption capacities have a strong relationship with their porous structures. The highest adsorption capacities were obtained for CPX on Si-PILC due to the lower molecular size of CPX respect to the TC molecule, favoring the interaction between the CPX− and the pillars adsorption sites. Tetracycline adsorption on silica pillared clays evidenced that for this molecule the porous structure limits the interaction between the TCH− and the pillars, decreasing their adsorption capacities. However, the results obtained for both antibiotics suggested that their negative species interact with adsorption sites on the pillared structure by adsorption mechanisms that involve inner-sphere complex formation as well as van der Waals interactions. The adsorption mechanism proposed for the anionic species on Si-PILC could be considered mainly as negative cooperative phenomena where firstly there is a hydrophobic effect followed by other interactions, such as der Waals or inner-sphere complex formation.

The use of insoluble matter of Moroccan oil shale for removal of dyes from aqueous solution

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methylene Blue ◽  
Oil Shale ◽  
Heating Temperature ◽  
Blue Dye ◽  
Adsorption Capacities ◽  
Experimental Parameters ◽  
Initial Ph ◽  
New Material ◽  
Activating Agent ◽  
Moderate Cost

The study aims to use an adsorbent natural based of Moroccan oil shale of Timahdit area (Y layer) in a physical-chemical adsorption process for treating industrial discharges colorful. The used adsorbent is the insoluble party of the sub-critical extraction of decarbonized oil shale of Timahdit. The tests performed on the methylene blue (MB), showed a strong elimination in the first 10 minutes. The influences of various experimental parameters were studied: mass ratio of adsorbent, time and temperature of thermal treatment, contact time, pH of MB and heating temperature of solution on the parameters of material were studied. The experimental results have shown that the adsorption of methylene blue dye by the adsorbent is more than 90% at initial pH a range 6-7 at room temperature for 30 minutes. The process is simple and the adsorbent produced is a new material with interesting adsorption capacities of moderate cost which does not require an activating agent and can be used as industrial adsorbent for the decontamination of effluents containing organic pollutants.

scholarly journals Investigation of Seeds and Peels of Citrullus colocynthis as Efficient Natural Adsorbent for Methylene Blue Dye

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1279
Author(s):  
Wafa Mohammed Alghamdi ◽  
Ines El Mannoubi
Keyword(s):  
Methylene Blue ◽  
Kinetic Model ◽  
Langmuir Isotherm ◽  
Order Kinetic ◽  
Citrullus Colocynthis ◽  
Natural Adsorbent ◽  
Spontaneous Process ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Mb Adsorption

Natural adsorbents as low-cost materials have been proved efficient for water remediation and have significant capacity for the removal of certain chemicals from wastewater. The present investigation aimed to use Citrullus colocynthis seeds (CCSs) and peels (CCPs) as an efficient natural adsorbent for methylene blue (MB) dye in an aqueous solution. The examined biosorbents were characterized using surface area analyzer (BET), scanning electron microscope (SEM), thermogravimetric analyzer (TGA) and Fourier transform infra-red (FT-IR) spectroscopy. Batch adsorption experiments were conducted to optimize the main factors influencing the biosorption process. The equilibrium data for the adsorption of MB by CCSs were best described by the Langmuir isotherm followed by the Freundlich adsorption isotherms, while the equilibrium data for MB adsorption by CCPs were well fitted by the Langmuir isotherm followed by the Temkin isotherm. Under optimum conditions, the maximum biosorption capacity and removal efficiency were 18.832 mg g−1 and 98.00% for MB-CCSs and 4.480 mg g−1 and 91.43% for MB-CCPs. Kinetic studies revealed that MB adsorption onto CCSs obeys pseudo-first order kinetic model (K1 = 0.0274 min−1), while MB adsorption onto CCPs follows the pseudo-second order kinetic model (K2 = 0.0177 g mg−1 min−1). Thermodynamic studies revealed that the MB biosorption by CCSs was endothermic and a spontaneous process in nature associated with a rise in randomness, but the MB adsorption by CCPs was exothermic and a spontaneous process only at room temperature with a decline in disorder. Based on the obtained results, CCSs and CCPSs can be utilized as efficient, natural biosorbents, and CCSs is promising since it showed the highest removal percentage and adsorption capacity of MB dye.

Preparation and Application of Titanate Nanotubes on Methylene Blue Degradation from Aqueous Media

2011 ◽  
Vol 117-119 ◽  
pp. 786-789 ◽  
Author(s):  
Wen Churng Lin ◽  
Wein Duo Yang ◽  
Zen Ja Chung ◽  
Hui Ju Chueng
Keyword(s):  
Methylene Blue ◽  
Surface Area ◽  
Uv Irradiation ◽  
Aqueous Media ◽  
Hydrothermal Process ◽  
Reaction Times ◽  
Titanate Nanotubes ◽  
Methylene Blue Degradation ◽  
Bet Analysis

Titanate nanotubes were synthesized at various hydrothermal temperatures and reaction times by the hydrothermal process and used as photocatalyst. BET analysis was conducted in order to find out the surface area of these as-prepared samples and it was found that the surface area increases with rise in temperature till 130 oC. Synthesized as-prepared titanate nanotubes were applied on methylene blue degradation from aqueous media by UV irradiation. It was observed that dye removes ~99% from the aqueous media at a titanate nanotubes dose of 2 g/L.

Ouricuri (Syagrus coronata) fiber: a novel biosorbent to remove methylene blue from aqueous solutions

2016 ◽  
Vol 75 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Lucas Meili ◽  
Társila Santos da Silva ◽  
Daniely Carlos Henrique ◽  
João Inácio Soletti ◽  
Sandra Helena Vieira de Carvalho ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Experimental Design ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Fiber Diameter ◽  
Aqueous Media ◽  
Process Efficiency ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Studies

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L−1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g−1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.

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