scholarly journals Evaluation of adsortive potential of coconut mesocarp in the removal of reactive red dye 195 in aqueous effluents

2020 ◽  
Vol 25 (4) ◽  
Author(s):  
Antonio do Nascimento Dantas Filho ◽  
Edna Maria Mendes Aroucha ◽  
Ricardo Henrique de Lima Leite ◽  
Francisco Klebson Gomes dos Santos
Keyword(s):  
Textile Industry ◽  
High Efficiency ◽  
Agricultural Waste ◽  
Zero Point ◽  
Maximum Adsorption Capacity ◽  
Toxic Substances ◽  
Balance Study ◽  
Aqueous Effluents ◽  
Elovich Equation ◽  
Coconut Mesocarp

ABSTRACT The textile industry produces dye-rich effluents that when released in hydric bodies hamper the penetration of sunlight, impairing photosynthetic processes. Besides that, dyes have been indicated as potentially toxic substances. In general, the processes of removing of these contaminants have been much studied, with the technique of adsorption standing out for its high efficiency, in addition to operational advantages and the possibility of reuse agricultural waste as adsorbents, benefiting the environment and reducing costs. The present work had as objective to study the performance of coconut mesocarp utilized as adsorbent in the bleaching process of synthetic effluent containing 25 g.L-1 of reactive red 195 dye. The adsorbent were characterized by granulometry, thermogravimetric analysis and zero point charge. Kinetic and balance study was realized, applying kinetic models and adsorption isotherms. The adsorbent exhibited removal efficiency of 89.92 % in 120 min. The maximum adsorption capacity was 24.04 g.g-1 at 30 °C. The kinetic study showed that the data was better adjusted by an Elovich equation, indicating slow chemisorption. The thermodynamic study exhibited that the adsorption process is exothermic and spontaneous for all the temperatures evaluated.

scholarly journals Functionalized Porous Nanoscale Fe3O4 Particles Supported Biochar From Peanut Shell For Pb(II) Ions Removal From Landscape Wastewater

2021 ◽  
Author(s):  
Xiaojun Jin ◽  
Renrong Liu ◽  
Huifang Wang ◽  
Li Han ◽  
Muqing Qiu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
High Efficiency ◽  
Adsorption Process ◽  
Low Cost ◽  
Agricultural Waste ◽  
Maximum Adsorption Capacity ◽  
Complexation Reaction ◽  
Order Kinetic ◽  
Peanut Shell ◽  
Adsorption Mechanisms

Abstract The large amounts of heavy metal from landscape wastewater have become serious problems of environmental pollution and risks for human health. It affects the growth of plant and aquatic, and leads to the destruction of landscape. Therefore, the development of efficient novel adsorbent is a very important for treatment of heavy metal. A low-cost and easily obtained agricultural waste (Peanut Shell) was modified by nanoscale Fe3O4 particles. Then, the functionalized porous nanoscale Fe3O4 particles supported biochar from peanut shell (PS-Fe3O4) for removal of Pb(II) ions from aqueous solution was investigated. The characterization of PS-Fe3O4 composites showed that PS from peanut shell was successfully coated with porous nanoscale Fe3O4 particles. The pseudo second-order kinetic model and Langmuir model were more fitted for describing the adsorption process of Pb(II) ions in solution. The maximum adsorption capacity of Pb(II) ions removal in solution by PS-Fe3O4 composites could reach 188.68 mg/g. The adsorption process of Pb(II) ions removal by PS-Fe3O4 composites was a spontaneous and endothermic process. The adsorption mechanisms of Pb(II) ions by PS-Fe3O4 composites were mainly controlled by the chemical adsorption process. They included Fe-O coordination reaction, co-precipitation, complexation reaction and ion exchange. PS-Fe3O4 composites were thought as a low-cost, good regeneration performance and high efficiency adsorption material for removal of Pb(II) ions in solution.

scholarly journals Kinetics and Equilibrium Study of Cadmium Ion Sorption onto Date Pits — An Agricultural Waste

2003 ◽  
Vol 21 (3) ◽  
pp. 245-260 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Leema Al-Makhadmeh
Keyword(s):  
Activated Carbons ◽  
Agricultural Waste ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Cadmium Ion ◽  
Activation Temperature ◽  
Cadmium Ions ◽  
Equilibrium Study ◽  
Ion Sorption ◽  
Date Pits

Activated carbons derived from date pits obtained as a surplus agricultural solid waste and natural date pits were used for the adsorption of cadmium ions from water. The effect of contact time, pH, temperature, cadmium ion concentration, sorbent dose, salinity, as well as the activation temperature on the removal of cadmium ions by date pits was studied. The maximum adsorption capacity of date pits for cadmium ions was obtained using the linear Langmuir isotherm model and used as a basis for comparative purposes. Three sorption kinetic models were used for explaining the probable mechanisms of cadmium ion uptake. The kinetic data for the adsorption process obeyed a second-order rate equation.

scholarly journals Phenol adsorption from wastewater using cashew nut shells as adsorbent

2018 ◽  
Vol 7 (3) ◽  
pp. 966
Author(s):  
Kartik Kulkarni ◽  
Varsha Sudheer ◽  
C R Girish
Keyword(s):  
Agricultural Waste ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Multilayer Adsorption ◽  
Phenol Adsorption ◽  
Cashew Nut ◽  
Experimental Parameters ◽  
Order Kinetic Model

The potential of agricultural waste cashew nut shells as an adsorbent for removing phenol from wastewater is presented in this paper. The adsorbent was treated with 3M sulphuric acid in order to improve the properties. The experimental parameters such as adsorbent dosage, concentration and temperature were optimized with response surface methodology (RSM). The isotherm data were tested with different isotherm models and it obeyed Freundlich Isotherm showing the multilayer adsorption. The kinetic data satisfied pseudo-first order kinetic model. The maximum adsorption capacity was calculated to be 35.08 mg/g proving the capability of cashew nut shells for removing phenol from wastewater.  

Finishing System Based on Ultrasonic Computerized Processes for Textiles

2014 ◽  
Vol 658 ◽  
pp. 666-671
Author(s):  
Florin Pantilimonescu ◽  
Lucian Constantin Hanganu ◽  
Mihaita Peptanariu ◽  
Stefan Grigoras ◽  
Irina Ionescu ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Textile Industry ◽  
Residual Water ◽  
Toxic Substances ◽  
Environment Pollution ◽  
Chemical Substances ◽  
Textile Materials ◽  
Transfer Processes ◽  
Active Chemical ◽  
High Work

During conventional finishing textile processes it is necessary a big consumption both of water and energy. This aspectsare is imposed by the development process of thermo and mass transfer of finishing agents into the textile structure materials applied in dentistry (fibers, yarns, fabric, nonwovens). The intensification of transfer processes into the textile materials is realized in conventional finishing textile industry (washing, cleaning, and coloring) by using high work temperature. The negative result of this intervention and the presence of chemical substances without degradation mean the environment pollution by the pour out residual water with a great quantity of toxic substances. The recently laboratory scientific research showed that the use of ultrasonic systems in finishing textile materials contributes both to the acceleration of thermo and mass transfer and to the decreasing of active chemical substances. In this way the paper presents a finishing system based on ultrasonic processes which is composed by modules and specific hardware components.

scholarly journals Potential of Araucaria angustifolia bark as adsorbent to remove Gentian Violet dye from aqueous effluents

2018 ◽  
Vol 78 (8) ◽  
pp. 1693-1703 ◽  
Author(s):  
Jordana Georgin ◽  
Fernanda Caroline Drumm ◽  
Patrícia Grassi ◽  
Dison Franco ◽  
Daniel Allasia ◽  
...  
Keyword(s):  
Gentian Violet ◽  
Low Cost ◽  
Fixed Bed ◽  
Amorphous Structure ◽  
Maximum Adsorption Capacity ◽  
Araucaria Angustifolia ◽  
Wood Processing ◽  
Fixed Bed Adsorption ◽  
Aqueous Effluents ◽  
Equilibrium Data

Abstract Araucaria angustifolia bark (AA-bark), a waste generated in wood processing, was evaluated as a potential adsorbent to remove Gentian Violet (GV) dye from aqueous solutions. The AA-bark presented an amorphous structure with irregular surface and was composed mainly of lignin and holocellulose. These characteristics indicated that the adsorbent contains available sites to accommodate the dye molecules. The GV adsorption on AA-bark was favored at pH 8.0 with adsorbent dosage of 0.80 g L−1. Pseudo-nth order model was adequate to represent the adsorption kinetics of GV on AA-bark. A fast adsorption rate was verified, with the equilibrium being attained within 30 min. Equilibrium data were well represented by the Langmuir model. The maximum adsorption capacity was 305.3 mg g−1. Adsorption was spontaneous, favorable and endothermic. AA-bark was able to treat a simulated dye house effluent, reaching color removal values of 80%. An excellent performance was found in fixed bed experiments, where the length of the mass transfer zone was only 5.38 cm and the breakthrough time was 138.5 h. AA-bark can be regenerated two times using HNO3 0.5 mol L−1. AA-bark can be used as a low-cost material to treat colored effluents in batch and fixed bed adsorption systems.

scholarly journals Synergistic effect of carboxyl and sulfate groups for effective removal of radioactive strontium ion in a Zr-metal-organic framework

2021 ◽  
Author(s):  
Lin Ren ◽  
Xudong Zhao ◽  
Baosheng Liu ◽  
Hongliang Huang
Keyword(s):  
Adsorption Capacity ◽  
High Efficiency ◽  
Metal Organic Framework ◽  
Maximum Adsorption Capacity ◽  
Potential Candidate ◽  
Dual Groups ◽  
Metal Organic ◽  
Strontium Ion ◽  
Rapid Adsorption ◽  
Organic Framework

Abstract Rapid removal of radioactive strontium from nuclear wastewater is of great significance for environment safety and human health. This work reported the effective adsorption of strontium ion in a stable dual-group metal-organic framework, Zr6(OH)14(BDC-(COOH)2)4(SO4)0.75 (Zr-BDC-COOH-SO4), which contains strontium-chelating groups (-COOH and SO4) and strongly ionizable group (-COOH). Zr-BDC-COOH-SO4 exhibits very rapid adsorption kinetics (<5 min) and a maximum adsorption capacity of 67.5 mg g−1. The adsorption behaviors can be well evaluated by pseudo-second-order model and Langmuir isotherm model. Further investigations indicate that the adsorption of Sr2+ in Zr-BDC-COOH-SO4 would not be interfered by solution pH and adsorption temperature obviously. Feasible regeneration of the adsorbent was also demonstrated through a simple elution method. Mechanism investigation suggests that free -COOH contributes to the rapid adsorption based on electrostatic interaction while introduction of -SO4 can enhance the adsorption capacity largely. Thus, these results suggest that Zr-BDC-COOH-SO4 might be a potential candidate for Sr2+ removal and introducing dual groups is an effective strategy for designing high-efficiency adsorbents.

scholarly journals Mecanismos de acción de las rizobacterias promotoras del crecimiento vegetal.

2011 ◽  
Vol 12 (2) ◽  
pp. 159 ◽  
Author(s):  
Mauricio Camelo R. ◽  
Sulma Paola Vera M. ◽  
Ruth Rebeca Bonilla B.
Keyword(s):  
Plant Growth ◽  
High Efficiency ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting Bacteria ◽  
Toxic Substances ◽  
Pests And Diseases ◽  
Modern Agriculture ◽  
Plant Growth Promoting ◽  
Production Cycles ◽  
Growth Promoting

<p>La dinámica poblacional de la especie humana ha llevado a que la explotación de los recursos naturales, en búsqueda de suplir las necesidades alimenticias de los miles de millones de personas que habitan el planeta. Esta necesidad ha llevado a la utilización de materiales de alta eficiencia en la agricultura, variedades vegetales resistentes a plagas y enfermedades con ciclos de producción más cortos, agroquímicos que surten las necesidades nutricionales y provean protección frente factores bióticos adversos (plagas y enfermedades). Sin embargo, estas estrategias utilizadas en la agricultura moderna han generado impactos ambientales negativos que aún no comprendemos. La contaminación de aguas freáticas, eutrofización, aumento de gases de invernadero y acumulación de sustancias toxicas en la cadena trófica, son algunos de los graves problemas que se presentan por el uso indiscriminado de agroquímicos. Como alternativa a la utilización de estas sustancias, se ha propuesto el uso de bacterias rizosféricas que tienen reconocida acción sobre el crecimiento y desarrollo vegetal (PGPR, por sus siglas en ingles). Estas bacterias son capaces de estimular el desarrollo de las plantas de manera directa e indirecta y poseen una serie de mecanismos complejos que interactúan entre sí para establecer relaciones benéficas, especialmente con las raíces de las plantas objetivo. El estudio y entendimiento de las PGPR han sido temas de gran importancia en muchas investigaciones a nivel mundial, por esta razón esta revisión tiene por objetivo hacer una revisión parcial para dar a conocer los mecanismos que poseen las rizobacterias promotoras del crecimiento vegetal en el desarrollo de las plantas, así como el papel que desempeñan en el ciclaje de nutrientes.</p><p> </p><p><strong>Mechanisms of action of plant growth promoting rhizobacteria.</strong></p><p>The population dynamics of the human race has led to the exploitation of natural resources in search of a way to meet the nutritional needs of the billions of people inhabiting the planet. This need has led to the use of high-efficiency materials in agriculture, plant varieties with shorter production cycles that are also resistant to pests and diseases, and chemicals that provide protection against biotic factors (pests and disease), additionally the nutrients required to grow plants. However, the strategies used in modern agriculture have led to negative environmental impacts that we have yet to fully understand. Groundwater contamination, eutrophication, increased greenhouse gases, and the accumulation of toxic substances in the food chain are some of the serious problems that have arisen worldwide due to the indiscriminate use of agrochemicals. As an alternative to the use of these substances, the use of rhizopheric bacteria has been proposed owing to its known action as plant growth- promoting bacteria (PGPB). These bacteria are able to stimulate plant growth directly and indirectly and have several complex mechanisms that interact with each other to establish beneficial relationships, especially with the roots of target plants. The study and understanding of PGPR have been the subjects of great importance in many studies at a global level. This review, therefore, aims to better understand the mechanisms of plant growth-promoting rhizobacteria on plant development and their role in nutrient cycling.</p>

scholarly journals Polyacrylonitrile/Crown Ether Composite Nanofibres With High Efficiency for Adsorbing Li(I): Experiments and Theoretical Calculations

2021 ◽  
Vol 9 ◽  
Author(s):  
Tao Ding ◽  
Qian Wu ◽  
Mianping Zheng ◽  
Zhen Nie ◽  
Min Li ◽  
...  
Keyword(s):  
Crown Ether ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
High Efficiency ◽  
Theoretical Calculations ◽  
Salt Lakes ◽  
Maximum Adsorption Capacity ◽  
Chemical Grafting ◽  
Epoxy Groups

Lithium, as the lightest alkali metal, is widely used in military and new energy applications. With the rapid growth in demand for lithium resources, it has become necessary to improve the effectiveness of extraction thereof. By using chemical grafting and electrospinning techniques, nanofibres containing crown ether were developed for adsorbing Li(I) from the brine in salt lakes, so as to selectively adsorb Li(I) on the premise of retaining specific vacancies of epoxy groups in crown ether. In lithium-containing solution, the adsorbing materials can reach adsorption equilibrium within three hours, and the maximum adsorption capacity is 4.8 mg g−1. The adsorption mechanisms of the adsorbing materials for Li(I) were revealed by combining Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) with density functional theory (DFT) calculation. The results indicated that in crown ether, O in epoxy groups was coordinated with Li(I) to form Li–O and four O atoms in the epoxy groups were used as electron donors. After coordination, two O atoms protruded from the plane and formed a tetrahedral structure with Li(I), realising the specific capture of Li(I). By desorbing fibres that adsorbed Li(I) with 0.5-M HCl, the adsorption capacity only decreased by 10.4% after five cycles, proving ability to regenerate such materials. The nanofibres containing crown ether synthesised by chemical grafting and electrospinning have the potential to be used in extracting lithium resources from the brine in salt lakes.

scholarly journals Controlled biosynthesis of gold nanoparticles with Coffea arabica using factorial design

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Wanderson Juvencio Keijok ◽  
Rayssa Helena Arruda Pereira ◽  
Luis Alberto Contreras Alvarez ◽  
Adilson Ribeiro Prado ◽  
André Romero da Silva ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Factorial Design ◽  
Textile Industry ◽  
Coffea Arabica ◽  
Metallic Nanoparticles ◽  
High Efficiency ◽  
Antimicrobial Properties ◽  
Control Mechanisms ◽  
Solar Panels ◽  
Aromatic Molecules

Abstract Green synthesis of metallic nanoparticles has become incredibly popular, mainly by minimizing problems of environmental contamination and by being able to reduce, stabilize and potentially functionalize nanomaterials. Such compounds have possible applications in various areas, e.g., pharmaceuticals (drug delivery systems, cosmetics), textile industry (clothing with antimicrobial properties), diagnostic medicine (imaging, high efficiency biosensors), energy (solar panels), bioremediation, among others. However, the lack of reproducibility and information on the control mechanisms during synthesis have made the application of green-synthesized nanoparticles unfeasible. Thus, this study proposed the investigation of the main mechanisms affecting synthesis control, using factorial design for the preparation of gold nanoparticles with extract of Coffea arabica. We obtained stable (Zeta Potential, UV-vis and DLS), monodisperse, and quasi-spherical (TEM) nanoparticles, which presented adsorbed aromatic molecules (FTIR and RAMAN) and defined crystal structure (XRD), proving that the plant extract acted as a reducing agent, as well as a stabilizer and functionalizer for the synthesized nanostructures. The factorial design employed here to obtain gold nanoparticles with Coffea arabica extract allowed for a controlled and reproducible synthesis, enabling new possibilities for the application in several fields.

scholarly journals Chitosan Hydrogel Beads Supported with Ceria for Boron Removal

2019 ◽  
Vol 20 (7) ◽  
pp. 1567 ◽  
Author(s):  
Joanna Kluczka ◽  
Gabriela Dudek ◽  
Alicja Kazek-Kęsik ◽  
Małgorzata Gnus
Keyword(s):  
Aqueous Solutions ◽  
Boric Acid ◽  
Inductively Coupled Plasma ◽  
High Efficiency ◽  
Optical Emission ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Chitosan Hydrogel ◽  
Chitosan Beads

In this study, a chitosan hydrogel supported with ceria (labelled Ce-CTS) was prepared by an encapsulation technique and used for the efficient removal of excess B(III) from aqueous solutions. The functionalisation of chitosan with Ce(IV) and the improvement in the adsorptive behaviour of the hydrogel were determined by SEM-EDS, FTIR, XRD, and inductively coupled plasma optical emission spectrometer (ICP-OES) analyses and discussed. The results demonstrate that Ce-CTS removes boric acid from aqueous solutions more efficiently than either cerium dioxide hydrate or raw chitosan beads, the precursors of the Ce-CTS biosorbent. The maximum adsorption capacity of 13.5 ± 0.9 mg/g was achieved at pH 7 after 24 h. The equilibrium data of boron adsorption on Ce-CTS fitted the Freundlich isotherm model, while the kinetic data followed the Elovich pseudo-second-order model, which indicated that the process was non-homogeneous. The dominant mechanism of removal was the reaction between boric acid molecules and hydroxyl groups bound to the ceria chelated by chitosan active centres. Due to its high efficiency in removing boron, good regeneration capacity and convenient form, Ce-CTS may be considered a promising biosorbent in water purification.

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