Interactions of Cd2+, Co2+ and MoO42− Ions with Crushed Concrete Fines

Construction and demolition activities generate approximately two thirds of the world’s waste, with concrete-based demolition material accounting for the largest proportion. Primary aggregates are recovered and reused, although the cement-rich fine fraction is underutilised. In this study, single metal batch sorption experiments confirmed that crushed concrete fines (CCF) are an effective sorbent for the maximum exclusion of 45.2 mg g−1 Cd2+, 38.4 mg g−1 Co2+ and 56.0 mg g−1 MoO42− ions from aqueous media. The principal mechanisms of sorption were determined, by scanning electron microscopy of the metal-laden CCF, to be co-precipitation with Ca2+ ions released from the cement to form solubility limiting phases. The removal of Co2+ and MoO42− ions followed a zero-order reaction and that of Cd2+ was best described by a pseudo-second-order model. The Langmuir model provided the most appropriate description of the steady state immobilisation of Cd2+ and Co2+, whereas the removal of MoO42− conformed to the Freundlich isotherm. Long equilibration times (>120 h), loose floc formation and high pH are likely to limit the use of CCF in many conventional wastewater treatment applications; although, these properties could be usefully exploited in reactive barriers for the management of contaminated soils, sediments and groundwater.

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Adsorptive removal of PPCPs by biomorphic HAP templated from cotton

Water Science & Technology ◽

10.2166/wst.2016.209 ◽

2016 ◽

Vol 74 (1) ◽

pp. 276-286 ◽

Cited By ~ 6

Author(s):

Bin Huang ◽

Dan Xiong ◽

Tingting Zhao ◽

Huan He ◽

Xuejun Pan

Keyword(s):

Adsorption Mechanism ◽

Adsorption Process ◽

Freundlich Isotherm ◽

Kinetic Studies ◽

Precipitation Method ◽

Adsorptive Removal ◽

Transmission Electron ◽

Initial Ph ◽

Pseudo Second Order ◽

Co Precipitation

Biomorphic nano-hydroxyapatite (HAP) was fabricated by a co-precipitation method using cotton as bio-templates and employed in adsorptive removal of ofloxacin (OFL) and triclosan (TCS) that are two representative pharmaceuticals and personal care products (PPCPs). The surface area and porosity, crystal phase, functional group, morphology and micro-structure of the synthesized HAP were characterized by Brunauer–Emmett–Teller isotherm, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron macroscopic and transmission electron microscopy. The effects of initial pH, ionic strength, initial concentration, contact time and temperature on the removal of PPCPs were studied in a batch experiment. The adsorption of OFL and TCS was rapid and almost accomplished within 50 min. Kinetic studies indicated that the adsorption process of OFL and TCS followed the pseudo-first-order and pseudo-second-order models, respectively. The Freundlich isotherm described the OFL adsorption process well but the adsorption of TCS fitted the Langmuir isotherm better. Thermodynamics and isotherm parameters suggested that both OFL and TCS adsorption were feasible and spontaneous. Hydrogen bond and Lewis acid–base reaction may be the dominating adsorption mechanism of OFL and TCS, respectively. Compared to other adsorbents, biomorphic HAP is environmentally friendly and has the advantages of high adsorption capacity, exhibiting potential application for PPCPs removal.

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

10.21203/rs.3.rs-345643/v1 ◽

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.

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Smectitic clays enriched with ferric ions for the rapid removal of anionic dyes in aqueous media

Clay Minerals ◽

10.1180/clm.2020.6 ◽

2020 ◽

Vol 55 (1) ◽

pp. 12-23 ◽

Cited By ~ 1

Author(s):

Itamar A. Rodrigues ◽

Juan C. Villalba ◽

Maria J. Santos ◽

Fábio L. Melquiades ◽

Fauze J. Anaissi

Keyword(s):

Aqueous Media ◽

Freundlich Isotherm ◽

Order Kinetic ◽

Ferric Ions ◽

Anionic Dyes ◽

Brilliant Blue Fcf ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Rapid Removal ◽

Time Required

AbstractSodium smectite clays were enriched with ferric ions (Argel-Fe and Volclay-Fe) to convert the surface charge of the clays from negative to positive and to use the clays in the discolouration of a synthetic effluent composed of seven anionic dyes (mixed from tartrazine, Brilliant Blue FCF and amaranth). The iron content increased from 5.99% to 11.02% for Argel-Fe and from 5.39% to 10.54% for Volclay-Fe. The efficiency of the discolouration of the anion dye mixture was evaluated by measuring the absorbance of the mixture at 562 nm, where the band with the greatest intensity was found. The contact time required for the system to reach equilibrium was ~5 min for both adsorbents. The kinetic adsorption data supported a pseudo-second-order kinetic model. The experimental data support the dual-site Langmuir–Freundlich isotherm model. The maximum adsorption capacities were 88.68 mg g–1 for Argel-Fe and 392.21 mg g–1 for Volclay-Fe. The enrichment of clays with Fe(III) added functionality to the clays and generated adsorbents with rapid adsorption abilities and high discolouration capacities.

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Adsorption of methyl orange from aqueous solution using chitosan/diatomite composite

Water Science & Technology ◽

10.2166/wst.2017.034 ◽

2017 ◽

Vol 75 (7) ◽

pp. 1633-1642 ◽

Cited By ~ 12

Author(s):

Peng Zhao ◽

Runhu Zhang ◽

Jianglin Wang

Keyword(s):

Aqueous Solution ◽

Methyl Orange ◽

Removal Rate ◽

Ph Effect ◽

Aqueous Media ◽

Freundlich Isotherm ◽

Electron Microscopy Analysis ◽

Equilibrium Data ◽

Pseudo Second Order ◽

Adsorption And Desorption Performance

A novel chitosan/diatomite composite was prepared by a simple mixture in the mass ratio to remove methyl orange (MO) from aqueous media in this study. The composite adsorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy analysis. The parameters to influence the adsorption of MO were studied under such conditions as kinetics, adsorption isotherm, pH effect, and thermodynamics. The results revealed that adsorption of MO was initially rapid and the equilibrium time was reached after 40 min. The optimal value of the pH was 5.0 for better adsorption. The equilibrium data were well fitted to the Langmuir isotherm compared to the Freundlich isotherm, and exhibited the highest capacity and a removal rate of 88.37% under an initial dye concentration of 50 mg/L. The kinetic data were well described by the pseudo-second order model. The thermodynamic calculations revealed that the sorption was viable, spontaneous, and exothermic under the conditions studied. In addition, the chitosan/diatomite composite had good adsorption and desorption performance with respect to reusability after six cycles. These results showed that the chitosan/diatomite could be considered as a potential adsorbent for the removal of MO in aqueous solution.

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Removal of Pb(II) by Pellicle-Like Biofilm-Producing Methylobacterium hispanicum EM2 Strain from Aqueous Media

Water ◽

10.3390/w11102081 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2081 ◽

Cited By ~ 1

Author(s):

Sun-Wook Jeong ◽

Hyo Kim ◽

Jung Yang ◽

Yong Choi

Keyword(s):

Aqueous Media ◽

Freundlich Isotherm ◽

Infrared Analysis ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Multilayer Adsorption ◽

Drinking Water Contamination ◽

Equilibrium Data ◽

Order Kinetic Model ◽

Pseudo Second Order

As concerns are increasing about drinking water contamination with heavy metals, we investigated the possible use of a pellicle (floating biofilm)-like biofilm-producing microorganism as a biosorbent for the treatment of Pb(II) in aqueous solutions. The bacterial pellicle-producing Methylobacterium hispanicum EM2 strain (EM2) was newly isolated from mine tailing soil, and we investigated its use as a biosorbent for treating a Pb(II)-contaminated aqueous solution. The EM2 strain was strongly resistant to Pb(II) up to a concentration of 800 mg/L, and achieved remarkable adsorption performance (adsorption rate and maximum adsorption capacity of 96% ± 3.2% and 79.84 mg/g, respectively) under optimal conditions (pH, biomass content, contact time, and initial Pb(II) concentration of 7.1 g/L, 60 min, and 10 mg/L, respectively). The adsorption of Pb(II) was characterized by scanning electron microscopy-energy dispersive x-ray spectroscopy and Fourier-transform infrared analysis. The equilibrium data matched the Freundlich isotherm model well, indicating the occurrence of multilayer adsorption of Pb(II) onto the heterogeneous surface of the EM2 strain, which was also consistent with the pseudo-second-order kinetic model (R2 = 0.98). The high Pb(II) removal efficiency was also confirmed by conducting an adsorption experiment using Pb(II)-contaminated industrial wastewater.

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Sustainable adsorption method for the remediation of malachite green dye using nutraceutical industrial fenugreek seed spent

Biomass Conversion and Biorefinery ◽

10.1007/s13399-021-01827-w ◽

2021 ◽

Author(s):

Syed Noeman Taqui ◽

Mohan C. S. ◽

Bibi Ahmadi Khatoon ◽

Manzoore Elahi M. Soudagar ◽

T. M. Yunus Khan ◽

...

Keyword(s):

Malachite Green ◽

Low Cost ◽

Aqueous Media ◽

Freundlich Isotherm ◽

Study Data ◽

Isotherm Model ◽

Adsorption Method ◽

Fenugreek Seed ◽

Malachite Green Dye ◽

Pseudo Second Order

AbstractNutraceutical industrial fenugreek seed spent (NIFGS), a relatively low-cost material abundantly available with nearly negligible toxicity for the bioremediation of malachite green (MG) dye from aqueous media, is reported. Studies on the various parameters affecting the adsorption capacity of NIFGS were carried out to evaluate the kinetics and the equilibrium thermodynamics. All the experiments were designed at about pH 7. The adsorption isotherm model proposed by Langmuir fits better than the Freundlich isotherm model. Kinetic study data confirms the viability of pseudo-second-order model. Calculated thermodynamic factors suggest that the adsorption phenomenon is endothermic, almost instantaneous, and physical in nature.

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Facile Co-precipitation Synthesis of Nanosized MnFe2O4 for Effective Removal of Zn(II) Ions From Aqueous Media

10.21203/rs.3.rs-174931/v1 ◽

2021 ◽

Author(s):

Ahmed Alharbi ◽

Ahmad A. Alluhaybi ◽

Salwa AlReshaidan ◽

Hany M. Youssef

Keyword(s):

Aqueous Media ◽

Precipitation Method ◽

Maximum Adsorption Capacity ◽

Sem Image ◽

Effective Removal ◽

Initial Ph ◽

Pseudo Second Order ◽

Ft Ir ◽

Co Precipitation ◽

Average Size

Abstract In this work, the spinel nanosized MnFe2O4 (18.14 nm) was facilely synthesized through the co-precipitation method to study the removal of Zn(II) ions from aqueous media. The fabricated MnFe2O4 sample was characterized using VSM, XRD, HR-TEM, EDS, FE-SEM, and FT-IR analyses. The principal XRD peaks, which are ascribed to (4 4 0), (3 3 3), (4 2 2), (4 0 0), (2 2 2), (3 1 1), (2 2 0), and (1 1 1) crystal planes, prove the cubic assembly of nanosized manganese ferrite as shown from JCPDS No. 74-2403. The EDS pattern confirmed that the % Wt of Mn, Fe, and O is 24.12, 48.04, and 28.15, respectively. The FE-SEM image confirmed the cubic nature of the surface of MnFe2O4 nanoparticles which have an average size of 110 nm. The saturation magnetization was 65 emu/g. The impacts of initial pH, concentration of Zn(II) ions, contact time, and temperature on the uptake of Zn(II) ions were accurately investigated. The removal of Zn(II) ions is spontaneous, exothermic, and followed the pseudo-second-order model and the Langmuir isotherm. The maximum adsorption capacity equals 330.03 mg/g.

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Adsorption of Congo Red Dye from Aqueous Solutions by Montmorillonite as a Low-cost Adsorbent

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2016-0203 ◽

2017 ◽

Vol 16 (1) ◽

Cited By ~ 6

Author(s):

Yusef Omidi Khaniabadi ◽

Hassan Basiri ◽

Heshmatollah Nourmoradi ◽

Mohammad Javad Mohammadi ◽

Ahmad Reza Yari ◽

...

Keyword(s):

Aqueous Solutions ◽

Congo Red ◽

Low Cost ◽

Aqueous Media ◽

Freundlich Isotherm ◽

Second Order ◽

Isotherm Models ◽

Order Kinetic ◽

Effective Option ◽

Pseudo Second Order

AbstractIn this study, the sorption of Congo red (CR), as a toxic dye, from aqueous media was investigated using montmorillonite (MMT) as a low-cost adsorbent. The influence of several factors such as contact time, pH, adsorbent dosage, dye content, and ionic strength was investigated on the dye removal. MMT was characterized by Fourier transformed infrared (FTIR) spectroscopy and X-ray diffractometer (XRD). Different kinetic and isotherm models including pseudo-first and pseudo-second order kinetic and Langmuir and Freundlich were applied to analyze experimental data, respectively. The results showed that the data were well fitted by pseudo-second-order kinetic and Freundlich isotherm models. The optimum conditions for the sorption of CR were achieved over 40 min and at pH=2. According to the results of the present study, MMT can be used as a low-cost, eco-friendly and effective option for the adsorption of CR from aqueous solutions.

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Natural clays as effective sorbents of anthropogenic pollutants

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/885/1/012060 ◽

2021 ◽

Vol 885 (1) ◽

pp. 012060

Author(s):

S V Badmaeva ◽

S Ts Khankhasaeva ◽

M V Ukhinova

Keyword(s):

Aqueous Media ◽

Dye Adsorption ◽

Methyl Green ◽

Anthropogenic Pollutants ◽

Pseudo Second Order ◽

Natural Clays ◽

Kinetics Of ◽

Adsorptive Properties ◽

Effective Sorbent ◽

Good Agreement

Abstract In this work, the adsorptive properties the Tuldon deposit were studied using the example of the adsorption of the basic dye “Methyl Green” from aqueous solutions. It has been established that the kinetic regularities of the dye adsorption on clay are consistent with the model of the kinetics of the pseudo-second order, characteristic of chemisorption. The isotherm of the dye adsorption is in good agreement with the Langmuir model. The results of the study allow us to conclude that the clay of the Tuldon deposit can be an effective sorbent for removing basic dyes from aqueous media.

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Adsorption and Photocatalytic Mineralization of Bromophenol Blue Dye with TiO2 Modified with Clinoptilolite/Activated Carbon

Catalysts ◽

10.3390/catal11010007 ◽

2020 ◽

Vol 11 (1) ◽

pp. 7

Author(s):

Emmanuel Kweinor Tetteh ◽

Sudesh Rathilal

Keyword(s):

Activated Carbon ◽

Photocatalytic Degradation ◽

Oxygen Demand ◽

Freundlich Isotherm ◽

Reaction Rate Constant ◽

Coefficient Of Determination ◽

Bromophenol Blue ◽

Blue Dye ◽

Order Kinetic ◽

Co Precipitation

This study presents a hybridized photocatalyst with adsorbate as a promising nanocomposite for photoremediation of wastewater. Photocatalytic degradation of bromophenol blue (BPB) in aqueous solution under UV-irradiation of wavelength 400 nm was carried out with TiO2 doped with activated carbon (A) and clinoptilolite (Z) via the co-precipitation technique. The physiochemical properties of the nanocomposite (A–TiO2 and Z–TiO2) and TiO2 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. Results of the nanocomposite (A–TiO2 and Z–TiO2) efficiency was compared to that with the TiO2, which demonstrated their adsorption and synergistic effect for the removal of chemical oxygen demand (COD) and color from the wastewater. At an optimal load of 4 g, the photocatalytic degradation activity (Z–TiO2 > A–TiO2 > TiO2) was found favorably by the second-order kinetic model. Consequently, the Langmuir adsorption isotherms favored the nanocomposites (Z–TiO2 > A–TiO2), whereas that of the TiO2 fitted very well on the Freundlich isotherm approach. Z–TiO2 evidently exhibited a high photocatalytic efficacy of decomposition over 80% of BPB (COD) at reaction rate constant (k) and coefficient of determination (R2) values of 5.63 × 10−4 min−1 and 0.989, respectively.

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