scholarly journals Mechanisms of halosulfuron methyl pesticide biosorption onto neem seeds powder

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atta ul Haq ◽  
Muhammad Saeed ◽  
Muhammad Usman ◽  
Ameer Fawad Zahoor ◽  
Muhammad Naveed Anjum ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Sorption Kinetics ◽  
Point Of Zero Charge ◽  
Neem Seed ◽  
Solution Ph ◽  
Chemical Surface ◽  
Operation Conditions ◽  
Zero Charge ◽  
Pseudo Second Order ◽  
Kinetics Of

AbstractThe current investigation was designed to remove halosulfuron methyl from aqueous media by means of neem seed powder (NSP) in batch modes. Characterizations of NSP were carried out by using EDX, SEM, FTIR, point of zero charge and surface analysis. Optimum operation conditions were scrutinized by studying the influence of different factors like solution pH, dose of NSP, contact time, initial halosulfuron methyl concentration and temperature. Result indicates the dependency of the removal of halosulfuron methyl on solution pH and maximal removal (54%) was achieved in acidic medium (i.e. pH 3.0). To identify the chemical surface of NSP, point of zero charge of NSP was determined and was found to be 6.5 which imply that the surface of NSP is positively charged below pH 6.6 and favored the anionic sorption. Kinetics of halosulfuron methyl were demonstrated well by pseudo second order due to highest R2 (0.99) owing to the nearness between experimental and calculated sorption capacities. Isotherm results imply that Langmuir was found to the principal model to explain the removal of halosulfuron methyl and maximum monolayer sorption capacity was determined to be 200 mg g−1. Thermodynamic parameters like ΔH°, ΔG° and ΔS° were calculated from van’t Hoff plot and were found negative which suggest that removal of halosulfuron methyl is exothermic and spontaneous at low temperature. These outcomes insinuate that neem seed power may be a valuable, inexpensive and ecofriendly biosorbent for the removal of pesticides.

scholarly journals Adsorption studies of Mo and Vonto ferrihydrite

2008 ◽  
Vol 72 (1) ◽  
pp. 385-388 ◽  
Author(s):  
L. Brinza ◽  
L. G. Benning ◽  
P. J. Statham
Keyword(s):  
Binary System ◽  
Binding Sites ◽  
Point Of Zero Charge ◽  
High Uptake ◽  
Adsorption Efficiency ◽  
Adsorption Studies ◽  
Ph Values ◽  
Zero Charge ◽  
Kinetics Of

AbstractIn this paper, the kinetics of Mo and V (100 μM) uptake on ferrihydrite (FHY) were evaluated in batch, mono-sorbate systems at pH between 4 and 9, and in bi-sorbate systems in the presence of P (100 μM) at pH 7. In the Mo and V single-sorbate experiments, 100% adsorption was observed at pH values below 6 and 8, respectively. Above the point of zero charge (PZC = 7.97) of FHY, the adsorption efficiency for Mo dropped dramatically (20% at pH 8) while V showed high uptake efficiencies even at pH 9 (60% efficiency). The results from the bi-sorbate experiments (Mo-P and V-P) showed that at pH 7, P out-competed (97%) Mo for binding sites on FHY, while in the V-P binary system only ∼44% of the binding sites are occupied by P with the remaining sites being occupied by V.

Application of the intra-particle diffusion model for activated carbon fibers in an aqueous medium

2012 ◽  
Vol 1373 ◽  
Author(s):  
Teresa Ramírez-Rodríguez ◽  
Fray de Landa Castillo-Alvarado
Keyword(s):  
Activated Carbon ◽  
Diffusion Model ◽  
Carbon Fibers ◽  
Aqueous Media ◽  
Particle Diffusion ◽  
Activated Carbon Fibers ◽  
Kinetics Of Adsorption ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Kinetics Of

ABSTRACTThe intra-particle diffusion model (IPD), proposed by Weber and Morris has been applied to the analysis of the kinetics of adsorption on activated carbon fibers with phosphate groups in the removal of cadmium ions in aqueous media. It is evident that the removal of cadmium ion kinetic model of pseudo-second order provides a better fit than the model of pseudo-first order and the intra-particle diffusion model provides the best to the sample compared activating solution: grams fibers of 1:3.

Chlorate Removal by Calcined Mg/Fe/Ce Layered Double Hydroxides

2015 ◽  
Vol 737 ◽  
pp. 537-540
Author(s):  
Yan Wei Guo ◽  
Hua Zhang ◽  
Zhi Liang Zhu
Keyword(s):  
Polluted Water ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Langmuir Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Kinetics Of

A novel Mg/Fe/Ce layered double hydroxide (LDHs) and its calcined product (CLDH) were synthesized and CLDH was used as adsorbents for the removal of chlorate ions. Results showed that the initial solution pH was an important factor influencing the chlorate adsorption. The adsorption behavior of chlorate followed the Langmuir adsorption isotherm with a maximum adsorption capacity of 18.2 mg/g. The adsorption kinetics of chlorate on CLDH can be described by the pseudo-second-order kinetic model. It was concluded that the CLDH material is a potential adsorbent for the purification of polluted water with chlorate.

scholarly journals Itaconic acid-modified layered double hydroxide as a ‎novel adsorbent for effective removal of Congo red from aqueous solutions

2021 ◽  
Author(s):  
Mohammad Dinari ◽  
Shirin Shabani
Keyword(s):  
Layered Double Hydroxide ◽  
Itaconic Acid ◽  
Congo Red ◽  
Aqueous Media ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Solution Ph ◽  
Pseudo Second Order ◽  
Double Hydroxide

Abstract Herein, we report the synthesis of Cu-Ca-Al/NO3-based layered double hydroxide through co-precipitation methodology. The prepared layered double hydroxide was then modified with itaconic acid. The physicochemical properties of the prepared materials were studied using Fourier transform-infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric analysis, and nitrogen adsorption/desorption technique. The prepared materials were then applied as novel adsorbents for the removal of Congo red as a model of an anionic dye from aqueous media. To reach maximum adsorption, the effect of parameters including sample solution pH, adsorbent amount, contact time, and initial concentration of Congo red on the adsorption process was investigated. Kinetic studies were also conducted to study the mechanism of adsorption. In this regard, the kinetic models of pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion were studied. The results showed that the adsorption of Congo red onto Cu-Ca-Al-LDH and LDH-ITA adsorbents followed the pseudo-second-order kinetic model. To evaluate the equilibrium adsorption data, different isotherms including Langmuir, Freundlich, and Dubinin-Radushkevich were also applied. The data revealed that the Freundlich isotherm provided the best fit with the equilibrium data of both adsorbents. Maximum adsorption capacities of 81 and 84 mg g− 1 were obtained using Cu-Ca-Al-LDH and LDH-ITA adsorbents, respectively.

scholarly journals Use of sweet ‘Pêra’ peel as an adsorbent in the treatment of textile effluents

2019 ◽  
Vol 23 (9) ◽  
pp. 716-722
Author(s):  
Ketyla K. R. do Nascimento ◽  
Fernando F. Vieira ◽  
Marcello M. de Almeida ◽  
Josué da S. Buriti ◽  
Aldre J. M. Barros ◽  
...  
Keyword(s):  
Contact Time ◽  
Exponential Model ◽  
Point Of Zero Charge ◽  
Infrared Analysis ◽  
Hydroxyl Groups ◽  
Solution Ph ◽  
Initial Concentration ◽  
Zero Charge ◽  
Adsorbed Quantity ◽  
Air Circulation

ABSTRACT The disposal of industrial wastewater into aquatic bodies without proper treatment can cause severe damage to the environment and human health. The objective of this study was to perform the drying of the sweet orange (Citrus sinensis L. Osbeck) peel cultivar Pêra and evaluate the viability of its use as biosorbent in the removal of a direct dye. Drying was carried out in an oven with air circulation at temperatures of 60 and 80 ºC. The mathematical models of Page, Henderson and Pabis, Logarithmic, Midilli and Two-term exponential were fitted to the moisture data as a function of time. The material was characterized by scanning electron microscopy, point of zero charge, and infrared spectroscopy. In the adsorption study, a complete 24 factorial design was used to analyze the influence of mass, initial concentration, solution pH and contact time on adsorbed quantity (qt) and removal percentage of the dye (R%). In the drying, the two-term exponential model fitted best to the experimental data. The characterization of the material indicated that the adsorbent has zero charge point of 3.5 and porous structure, and the infrared analysis indicated the presence of carboxylic and hydroxyl groups. In the adsorption, the adsorbed quantity of the dye increased under conditions of lower pH and biosorbent mass and higher initial concentration and contact time. The removal percentage of dye increases with higher biosorbent mass. The biosorbent used is a promising waste for the adsorption of the burgundy-16 dye.

scholarly journals Mass-transfer processes in the adsorption of crystal violet by activated carbon derived from pomegranate peels: Kinetics and thermodynamic studies

2020 ◽  
Vol 15 ◽  
pp. 155892502091984
Author(s):  
Moussa Abbas ◽  
Zahia Harrache ◽  
Mohamed Trari
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Crystal Violet ◽  
Agitation Speed ◽  
Second Order ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Solution Ph ◽  
Pseudo Second Order ◽  
Adsorbent Dose

This study investigates the potential use of activated carbon, prepared from pomegranate peels, as an adsorbent activated using H3PO4 and its ability to remove crystal violet from an aqueous solution. The adsorbent was characterized by the Brunauer–Emmett–Teller method (specific surface area: 51.0674 m2 g−1) and point of zero charge (pHPZC = 5.2). However, some examined factors were found to have significant impacts on the adsorption capacity of activated carbon derived from pomegranate peels such as the initial dye concentration (5–15 mg L−1), solution pH (2–14), adsorbent dose (1–8 g L−1), agitation speed (100–700 r/min), and temperature (298–338 K). The best adsorption capacity was found at pH 11 with an adsorbent dose of 1 g L−1, an agitation speed at 400 r/min, and a contact time of 45 min. The adsorption mechanism of crystal violet onto activated carbon derived from pomegranate peels was studied using the pseudo-first-order, pseudo-second-order, Elovich, and Webber–Morris diffusion models. The adsorption kinetics were found to rather follow a pseudo-second order kinetic model with a determination coefficient ( R2) of 0.999. The equilibrium adsorption data for crystal violet adsorbed onto activated carbon derived from pomegranate peels were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation with qmax capacities of 23.26 and 76.92 mg g−1 at 27°C and 32°C, respectively. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters like the free energy, enthalpy, and entropy to predict the nature of adsorption process. The negative values Δ G0 (−5.221 to −1.571 kJ mol−1) and Δ H0 (−86.141 kJ mol−1) indicate that the overall adsorption is spontaneous and exothermic with a physisorption process. The adsorbent derived from pomegranate peels was found to be very effective and suitable for the removal of reactive dyes from aqueous solutions, due to its availability, low-cost preparation, and good adsorption capacity.

Interaction Influence of Contact Time and pH on Cobalt Retention by Carbon Nanotubes Bearing Various Loads of TiO2 and Fe3O4

2021 ◽  
Vol 17 ◽  
Author(s):  
Ismail Fasfous ◽  
Amjad El-Sheikh ◽  
Anas Awad ◽  
Yahya El-Degs ◽  
Jamal Dawoud
Keyword(s):  
Carbon Nanotubes ◽  
Removal Rate ◽  
Cost Effective ◽  
Research Area ◽  
Second Order ◽  
Nano Materials ◽  
Solution Ph ◽  
Retention Capacity ◽  
Pseudo Second Order ◽  
Kinetics Of

Background: Nano-materials have facilitated remarkable advances in the remediation of many environmental problems. A few studies have tackled the removal of Co(II) from aqueous solutions using nano-materials. Herein, we recently studied the retention kinetics of cobalt species on carbon nanotubes (CNT) bearing different amounts of TiO2 and Fe3O4 nano-materials individually. c Method: CNT and their TiO2/Fe3O4-modified nano-material forms were well characterized. Cobalt retention by these adsorbents was investigated at different influencing factors: Co(II) content, solution pH, and time. The kinetic data were fitted with pseudo-first-order, pseudo-second-order rate models and intra-particle diffusion models for better elucidation of the mechanism of Co retention. Results: XRD evidenced the formation of TiO2 and Fe3O4. High loads of both oxides were needed for higher and faster Co retention by CNT. Co retention capacity increased with increasing the solution pH. The pseudo-second-order model presented the kinetics of Co retention at 30 oC, and 48% of available capacity was attained within the first hour of interaction by CNT-TiO2 and with a moderate S/L ratio of 0.5 g/L. Co retention was increased with the amount of oxide to reach a maximum value of 16. 40 mg/g (90.2% TiO2) and 13.60 mg/g (48.2% Fe3O4). The Jovanović equilibrium model predicted the maximum retention values as the nearest to the experimental ones. Conclusion: The potential of CNT-Fe3O4 /TiO2 nano-materials has been successfully demonstrated for the removal of cobalt, which makes them highly attractive and cost-effective adsorbents for wastewater treatment. The reported retention and removal rate values were relatively better than those seen in the literature. Loading different active oxides by CNT is an interesting research area as selective adsorbents can be fabricated with affordable experimental costs.

Sorption Kinetics of Pro-Oxidant-Loaded PE Plastic Bags in Aqueous Media

2015 ◽  
Vol 1125 ◽  
pp. 240-244 ◽  
Author(s):  
Giselle Lou D. Leuterio ◽  
Bryan B. Pajarito
Keyword(s):  
Water Immersion ◽  
Aqueous Media ◽  
Sorption Kinetics ◽  
Deionized Water ◽  
Alkaline Solutions ◽  
Maximum Weight ◽  
Transparent Films ◽  
Highest Weight ◽  
Plastic Bags ◽  
Kinetics Of

Sorption studies in aqueous media of pro-oxidant-loaded polyethylene (PE) films from commercial plastic bags are conducted. A total of 6 types of plastic bags are tested at three levels of thickness and two levels of color (transparent and opaque white). PE films are immersed in deionized water, acidic, and alkaline solutions at 60 °C. Sorption curves show that once the maximum uptake is reached, the weight change of PE films started to decline. The films showing the highest weight uptake and loss are observed in opaque films in alkaline solution. Analysis of variance (ANOVA) shows that during water immersion, both maximum weight uptake and loss are affected by colorant additive, with opaque films yielding the highest weight uptake and loss. During acid immersion, transparent films have significantly higher weight uptake than opaque films. The weight uptake during acid immersion is only affected by film thickness, with the thickest films showing the lowest weight uptake. Similar to results in water immersion, thickness is found to be insignificant to weight uptake and loss of PE films during alkali immersion. Meanwhile, colorant additive is significant to both weight uptake and loss for all films immersed in different solutions.

scholarly journals Removal of cadmium and lead from aqueous solutions using iron phosphate-modified pollen microspheres as adsorbents

2021 ◽  
Vol 60 (1) ◽  
pp. 365-376
Author(s):  
Xiaoxing Zhang ◽  
Hui Liu ◽  
Jin Yang ◽  
Li Zhang ◽  
Binxia Cao ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Mechanism ◽  
Iron Phosphate ◽  
Sorption Kinetics ◽  
Order Model ◽  
Solution Ph ◽  
Adsorption Capacities ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order ◽  
Cadmium And Lead

Abstract Iron phosphate-modified pollen microspheres (pollen@FePO4) were prepared and applied as sorbents for the removal of heavy metals (Cd2+ and Pb2+) from the aqueous solution. Batch sorption studies were conducted to investigate the effects of solution pH, contact time, sorbent dosage, and metal concentration on the adsorption process. The sorption of Cd2+ and Pb2+ ions on pollen@FePO4 corresponds to the pseudo-second-order model and Langmuir isotherm, which is similar to the unmodified pollen. At pH 5.92, pollen@FePO4 offers maximum adsorption capacities of 4.623 and 61.35 mg·g−1 for Cd2+ and Pb2+, respectively. The faster sorption kinetics and higher adsorption capacities of Cd2+ and Pb2+ ions onto pollen@FePO4 than pollen indicates that it might be a promising material for the removal of heavy metal ions in aqueous solutions. The possible adsorption mechanism involves electrostatic and chemisorption for Cd2+ and mainly complexion for Pb2+.

scholarly journals Use of Garlic Processing By-Products to Remove Pollutants from Aqueous Media

2021 ◽  
Vol 12 (4) ◽  
pp. 4518-4528
Keyword(s):  
Activated Carbons ◽  
Aqueous Media ◽  
Order Model ◽  
Chemical Reagents ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Sorption Parameters ◽  
Kinetics Of ◽  
By Products ◽  
Sorption Characteristics

The paper summarized the literature data on using ground peels, outer leaves, and garlic roots (Allium sativum L.) as sorption materials to remove various metal ions, dyes, and antibiotics from aqueous media. This paper provides brief information on the amount of waste generated from processing garlic, its chemical composition, and ways of reuse. It gives the adsorption processes parameters and the values of sorption parameters for the studied pollutants. It was shown that garlic residue sorption characteristics for various pollutants could be increased by chemical modification with various chemical reagents. It was determined that the Langmuir model more accurately describes the pollutant’s adsorption isotherms in most cases, and the kinetics of the process more accurately describes the pseudo-second-order model. It was shown that garlic peels and steam are good precursors for activated carbons production.

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