scholarly journals Performance Evaluation of Small Sized Powdered Ferric Hydroxide as Arsenic Adsorbent

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 957 ◽  
Author(s):  
Muhammad Usman ◽  
Ioannis Katsoyiannis ◽  
Manassis Mitrakas ◽  
Anastasios Zouboulis ◽  
Mathias Ernst
Keyword(s):  
Adsorption Capacity ◽  
Tap Water ◽  
Ferric Hydroxide ◽  
Equilibrium Concentration ◽  
Arsenic Species ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Water Matrix ◽  
The Impact

The small sized powdered ferric oxy-hydroxide, termed Dust Ferric Hydroxide (DFH), was applied in batch adsorption experiments to remove arsenic species from water. The DFH was characterized in terms of zero point charge, zeta potential, surface charge density, particle size and moisture content. Batch adsorption isotherm experiments indicated that the Freundlich model described the isothermal adsorption behavior of arsenic species notably well. The results indicated that the adsorption capacity of DFH in deionized ultrapure water, applying a residual equilibrium concentration of 10 µg/L at the equilibrium pH value of 7.9 ± 0.1, with a contact time of 96 h (i.e., Q10), was 6.9 and 3.5 µg/mg for As(V) and As(III), respectively, whereas the measured adsorption capacity of the conventionally used Granular Ferric Hydroxide (GFH), under similar conditions, was found to be 2.1 and 1.4 µg/mg for As(V) and As(III), respectively. Furthermore, the adsorption of arsenic species onto DFH in a Hamburg tap water matrix, as well as in an NSF challenge water matrix, was found to be significantly lower. The lowest recorded adsorption capacity at the same equilibrium concentration was 3.2 µg As(V)/mg and 1.1 µg As(III)/mg for the NSF water. Batch adsorption kinetics experiments were also conducted to study the impact of a water matrix on the behavior of removal kinetics for As(V) and As(III) species by DFH, and the respective data were best fitted to the second order kinetic model. The outcomes of this study confirm that the small sized iron oxide-based material, being a by-product of the production process of GFH adsorbent, has significant potential to be used for the adsorptive removal of arsenic species from water, especially when this material can be combined with the subsequent application of low-pressure membrane filtration/separation in a hybrid water treatment process.

scholarly journals Selective adsorption of cationic dye utilizing poly(methacrylic acid-co-ethylene dimethacrylate) monolith from wastewater

2021 ◽  
Author(s):  
Bessy D’Cruz ◽  
Mohamed O. Amin ◽  
Metwally Madkour ◽  
Entesar Al-Hetlani ◽  
Keyword(s):  
Adsorption Capacity ◽  
Methacrylic Acid ◽  
Selective Adsorption ◽  
Tap Water ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Adsorption Efficiency ◽  
Ethylene Dimethacrylate ◽  
The Impact ◽  
Competing Ions

In this study, poly(methacrylic acid-co-ethylene dimethacrylate (poly(MAA-co-EDMA)) monolith was prepared for the selective adsorption of acidic dye, namely methylene blue (MB), from wastewater. The fabrication of the monolith was carried out by photoinitiation polymerization by irradiating a mixture of methacrylic acid (MAA), ethylene dimethacrylate (EDMA), porogenic solvents and an initiator. Batch adsorption assays were performed to examine the impact of monolith dosage and initial dye concentration on the adsorption capacity and efficiency of the monolith towards MB dye molecules. This adsorption kinetic study revealed that MB adsorption on the monolith followed pseudo-second-order model and equilibrium adsorption behavior was best modeled by Langmuir adsorption isotherm indicating a monolayer adsorption with a maximum adsorption capacity of 50.00 mg g-1. Owing to the presence of negative binding sites on the monolith surface, cationic MB molecules are selectively adsorbed from MB/methyl orange (MO) mixture with an adsorption efficiency of 99.54% at equilibrium time. Moreover, the MB adsorbed monolith was regenerated up to four cycles and the percentage removal efficiency of MB on the monolith dropped to 67.64 % after the fourth cycle. Finally, the monolith effectively adsorbed MB from the tap water in presence of competing ions and the maximum adsorptive capacity obtained was 47.62 mg g-1 with 84.5% adsorption efficiency. Hence, poly(MAA-co- EDMA) monolith is an adequate sorbent for the treatment of cationic dyes in the presence of other dyes and competing ions from wastewater.

Effects of tall fescue biochar on the adsorption behavior of desethyl-atrazine in different types of soil

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3575-3595
Author(s):  
Wanting Li ◽  
Ruifeng Shan ◽  
Yuna Fan ◽  
Xiaoyin Sun
Keyword(s):  
Tall Fescue ◽  
Adsorption Process ◽  
Exothermic Reaction ◽  
Equilibrium Concentration ◽  
Black Soil ◽  
Adsorption Behavior ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.

scholarly journals Removal of Cu(II) from Aqueous Solutions Using Amine-Doped Polyacrylonitrile Fibers

2020 ◽  
Vol 10 (5) ◽  
pp. 1738
Author(s):  
Kay Thwe Aung ◽  
Seung-Hee Hong ◽  
Seong-Jik Park ◽  
Chang-Gu Lee
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Equilibrium Studies ◽  
Naoh Solution ◽  
Surface Modified ◽  
Pan Fibers

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.

Adsorption of Ni(II) by a thermo-sensitive colloid: methylcellulose/calcium alginate beads

2019 ◽  
Vol 68 (7) ◽  
pp. 495-508
Author(s):  
Zhongmin Li ◽  
Wanwan Wu ◽  
Wenyan Jiang ◽  
Guangtao Wei ◽  
Yunshang Li ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Adsorption Process ◽  
Alginate Beads ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Calcium Alginate Beads ◽  
Lower Temperature ◽  
Kinetics And Isotherms

Abstract The adsorption of Ni(II) by a thermo-sensitive adsorbent of methylcellulose/calcium alginate beads (CAMCBs) was studied using batch adsorption tests to determine the adsorption process and properties, the effects of adsorbent dosage, initial concentration, adsorption time and temperature. The adsorption process was further investigated using kinetics, isotherms and thermodynamic methods. The kinetics and isotherms studies showed the adsorption of Ni(II) on CAMCBs was fitted by the pseudo-second-order kinetic model and Langmuir isothermal adsorption model, respectively. The thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic at lower temperature, and the entropy of the adsorption process was negative. In the study of regeneration, it was confirmed that under the temperature of 60 °C, the desorption agent of CaCl2 with concentration of 3 g·L−1 was more conducive to the desorption of Ni(II) from CAMCBs. Both adsorption capacity and mechanical strength of the used CAMCBs could be basically recovered to the level of fresh CAMCBs after desorption. The prepared CAMCBs had a good property of adsorption of Ni(II) and an excellent regeneration performance.

scholarly journals Adsorption of Basic and Acidic Dyes onto Agricultural Wastes

2016 ◽  
Vol 70 ◽  
pp. 12-26 ◽  
Author(s):  
Nnaemeka John Okorocha ◽  
J. Josphine Okoji ◽  
Charles Osuji
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Thermodynamic Quantities ◽  
Order Kinetic ◽  
Dyes Adsorption ◽  
Adsorbent Dose

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22.96mg/g and 7.77mg/g for the adsorption of CV and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0obtained for both dyes indicate the spontaneous nature of the adsorption process while the positive values of ΔH0and ΔS0obtained indicated the endothermic nature and increased randomness during the adsorption process respectively for the adsorption of CV and CR onto ALP. Based on the results obtained such as good adsorption capacity, rapid kinetics, and its low cost, ALP appears to be a promising adsorbent material for the removal of CV and CR dye stuff from aqueous media.

scholarly journals Sheet-like Skeleton Carbon Derived from Shaddock Peels with Hierarchically Porous Structures for Ultra-Fast Removal of Methylene Blue

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2554
Author(s):  
Panlong Dong ◽  
Hailin Liu ◽  
Shengrui Xu ◽  
Changpo Chen ◽  
Suling Feng ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Hierarchically Porous ◽  
Column Adsorption

To remove the pollutant methylene blue (MB) from water, a sheet-like skeleton carbon derived from shaddock peels (SPACs) was prepared by NaOH activation followed by a calcination procedure under nitrogen protection in this study. Characterization results demonstrated that the as-prepared SPACs displayed a hierarchically porous structure assembled with a thin sheet-like carbon layer, and the surface area of SPAC-8 (activated by 8 g NaOH) was up to 782.2 m2/g. The as-prepared carbon material presented an ultra-fast and efficient adsorption capacity towards MB due to its macro-mesoporous structure, high surface area, and abundant functional groups. SPAC-8 showed ultrafast and efficient removal capacity for MB dye. Adsorption equilibrium was reached within 1 min with a removal efficiency of 99.6% at an initial concentration of 100 mg/g under batch adsorption model conditions. The maximum adsorption capacity for MB was up to 432.5 mg/g. A pseudo-second-order kinetic model and a Langmuir isotherm model described the adsorption process well, which suggested that adsorption rate depended on chemisorption and the adsorption process was controlled by a monolayer adsorption, respectively. Furthermore, column adsorption experiments showed that 96.58% of MB was removed after passing through a SPAC-8 packed column with a flow rate of 20 mL/min, initial concentration of 50 mg/L, and adsorbent dosage of 5 mg. The as-prepared adsorbent displays potential value in practical applications for dye removal due to its ultrafast and efficient adsorption capacity.

scholarly journals Rice Straw Biochar and Magnetic Rice Straw Biochar for Safranin O Adsorption from Aqueous Solution

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 186
Author(s):  
Do Thi My Phuong ◽  
Nguyen Xuan Loc
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Rice Straw ◽  
Batch Adsorption ◽  
Particle Diffusion ◽  
Order Kinetic ◽  
Magnetic Biochar ◽  
Intra Particle Diffusion ◽  
Rice Straw Biochar ◽  
Safranin O

This study investigates the adsorption of Safranin O (SO) from aqueous solution by both biochar and magnetic biochar derived from rice straw. Rice straw biochar (RSB) was made by pyrolysis in a furnace at 500 °C, using a heating rate of 10 °C·min−1 for 2 h in an oxygen-limited environment, whilst the magnetic rice straw biochar (MRSB) was produced via the chemical precipitation of Fe2+ and Fe3+. The physicochemical properties of the synthesized biochars were characterized using SEM, SEM- EDX, XRD, FTIR techniques, and N2 adsorption (77 K) and pHpzc measurements. Batch adsorption experiments were used to explore the effect of pH, biochar dosage, kinetics, and isotherms on the adsorption of SO. Experimental data of RSB and MRSB fit well into both Langmuir and Freundlich isotherm models, and were also well-explained by the Lagergren pseudo-second-order kinetic model. The maximum SO adsorption capacity of MRSB was found to be 41.59 mg/g, while for RSB the figure was 31.06 mg/g. The intra-particle diffusion model indicated that the intra-particle diffusion may not be the only rate-limiting step. The collective physical and chemical forces account for the adsorption mechanism of SO molecules by both RSB and MRSB adsorbents. The obtained results demonstrated that the magnetic biochar can partially enhance the SO adsorption capacity of its precursor biochar and also be easily separated from the solution by using an external magnet.

The Influence of Biochar on Adsorption Behaviour of Triazine Herbicides in Different Soil Types

2021 ◽  
Author(s):  
Nadežda Stojanov ◽  
Tijana Zeremski ◽  
Snežana Maletić ◽  
Milorad Živanov ◽  
Jelena Tričković
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Single Point ◽  
Organic Matter Content ◽  
Equilibrium Concentration ◽  
Soil Types ◽  
Batch Adsorption ◽  
Triazine Herbicides ◽  
Point Distribution ◽  
Adsorption Sites

<p>Biochar is promising material used to enhance organic matter content in soil and to mitigate climate change through carbon sequestration. In addition to that, biochar increases crop yield by means of improving soil capacity for water- and nutrient-holding capacity, and due to its adsorption capacity, it decreases mobility and bioavailability of organic pollutants and heavy metals. Biochar (BC) is a carbon-rich and porous material produced by pyrolysis of biomass under oxygen-limited conditions. The unwanted spread of pesticides to the environment and their leaching into the groundwater is of great concern. The aim of this work is to investigate the potential of BC to improve the adsorption capacity for two triazine herbicides in three different soil types with various organic matter (OC) content. Triazine herbicides (terbuthylazine and atrazine) were chosen as the most widely used pesticides in recent decades. The main difference among between three different soils types used in the study is in their OM content, which was 0.48%, 2.34% and 4.12%, respectively for Soil1, Soil2, and Soil3. The BC used in this work is commercially available compost-activated biochar produced by pyrolysis of beechwood chips at 700 <sup>o</sup>C. A batch adsorption experiments were conducted to investigate herbicide adsorption in soil without BC and with the amendment of BC (0, 1, 5, and 10%). The concentration of herbicides in the aqueous phase at equilibrium (which is achieved after 72 h) was determined by GC-MS. The adsorption isotherms were well described with the Freundlich model (R<sup>2</sup> values range from 0.714 to 0.998). Values of Freundlich exponent <em>n</em> were less than 1 (from 0.314 to 0.897), which indicates that the isotherms are of L-type. This shows that with the increase of compound concentration relative adsorption decreases because of the saturation of adsorption sites. Single-point distribution coefficients (<em>K<sub>d</sub></em>) were calculated at selected equilibrium concentration (<em>c<sub>e</sub></em>= 100 µg dm<sup>–3</sup>). <em>K<sub>d</sub></em> values increased with an increase of BC content, especially for 5% and 10% of BC amendment. <em>K<sub>d</sub></em> values of atrazine in Soil1 were in the range 1.91–14.55, in Soil2 from 4.76–15.65, and in Soil3 from 4.79–20.11, while <em>K<sub>d</sub></em> values of terbuthylazine ranged from 1.14–30.92 in Soil1, from 14.13–50.74 in Soil2, and from 12.65–47.03 in Soil3. In unamended Soil1 the adsorption of both herbicides was lower in comparison to unamended Soil2 and Soil3, which is in accordance with the well-known fact that the OC content of soil primarily affects the adsorption of pesticides. The adsorption capacity of Soil 2 and Soil 3 was not significantly different. It is observed that the adsorption of terbuthylazine is higher in all soil types, which is in accordance with its lower solubility and higher affinity for OM in comparison to atrazine. It is shown that sorption capacity of soil for pesticides could be improved by adding biochar into the soil, thus reducing herbicide mobility into the environment. Further studies will be conducted by column experiments to investigate more realistic environmental scenarios.</p>

Parametric and adsorption kinetic studies of methylene blue removal from simulated textile water using durian (Durio zibethinus murray) skin

2015 ◽  
Vol 72 (6) ◽  
pp. 896-907 ◽  
Author(s):  
S. M. Anisuzzaman ◽  
Collin G. Joseph ◽  
D. Krishnaiah ◽  
A. Bono ◽  
L. C. Ooi
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Durio Zibethinus

In this study, durian (Durio zibethinus Murray) skin was examined for its ability to remove methylene blue (MB) dye from simulated textile wastewater. Adsorption equilibrium and kinetics of MB removal from aqueous solutions at different parametric conditions such as different initial concentrations (2–10 mg/L), biosorbent dosages (0.3–0.7 g) and pH solution (4–9) onto durian skin were studied using batch adsorption. The amount of MB adsorbed increased from 3.45 to 17.31 mg/g with the increase in initial concentration of MB dye; whereas biosorbent dosage increased from 1.08 to 2.47 mg/g. Maximum dye adsorption capacity of the durian skin was found to increase from 3.78 to 6.40 mg/g, with increasing solution pH. Equilibrium isotherm data were analyzed according to Langmuir and Freundlich isotherm models. The sorption equilibrium was best described by the Freundlich isotherm model with maximum adsorption capacity of 7.23 mg/g and this was due to the heterogeneous nature of the durian skin surface. Kinetic studies indicated that the sorption of MB dye tended to follow the pseudo second-order kinetic model with promising correlation of 0.9836 < R2 < 0.9918.

scholarly journals Comparative Removal of Lead and Nickel Ions onto Nanofibrous Sheet of Activated Polyacrylonitrile in Batch Adsorption and Application of Conventional Kinetic and Isotherm Models

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Muhammad Tahir Amin ◽  
Abdulrahman Ali Alazba ◽  
Muhammad Shafiq
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Optimum Dose ◽  
Infrared Spectrometry ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorption Data

We investigated the adsorption of lead (Pb2+) and nickel (Ni2+) ions by electrospun membranes of polyacrylonitrile (PAN) nanofiber activated with NaHCO3 (PANmod). Analysis by Fourier-transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDX) validated the functionalization of PAN nanofibers with NaHCO3, and the successful agglomeration of Pb2+ and Ni2+ onto PANmod. After a rapid uptake of the heavy metal ions (15 min), the equilibrium contact time was attained (60 min) following a linear increase of both adsorption capacity and removal efficiency. PANmod showed a better affinity for Ni2+ than Pb2+. The adsorption on PANmod was best described by the pseudo-second-order kinetic model for both studied models, supporting chemisorption. By varying the solution pH from 2.0 to 9.0, we found that the adsorption capacity followed an increasing trend, reaching a maximum at the pH of 7.0. Despite increasing adsorption capacities, the removal efficiency of both heavy metal ions exhibited a decreasing trend with increase in initial concentrations. The amount of PANmod directly affects the removal efficiency, with 0.7 and 0.2 g being the optimum dose for maximum uptake of Pb2+ and Ni2+, respectively. The Langmuir model fitted well the Pb2+ adsorption data suggesting monolayer adsorption, and the Freundlich model perfectly fitted the Ni2+ adsorption data, indicating heterogeneous adsorption. The estimated values of the mean free energy of adsorption in the D–R isotherm indicated a physical adsorption of both heavy metal ions into the surface of the PANmod.

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