Removal of hydrocarbons from synthetic road runoff through adsorptive filters

2015 ◽  
Vol 72 (5) ◽  
pp. 802-809 ◽  
Author(s):  
Andreas Vesting ◽  
Eva Heinz ◽  
Brigitte Helmreich ◽  
Marc Wichern

Compact filter systems, which are installed to significantly reduce the load of pollutants from road runoff, are very promising treatments for urban runoff. The objective of this research was to evaluate the effectiveness of activated carbon, activated lignite, zero valent iron, exfoliated graphite, amorphous ferric hydroxide, and activated alumina at removing petrol hydrocarbons from synthetic road runoff. Therefore, the kinetics and the equilibrium adsorption of petrol hydrocarbons onto these adsorbents were investigated using column adsorption experiments at levels ranging from 100 to 42 g L−1. Of the tested adsorbents, exfoliated graphite is the most effective with a maximum adsorption capacity for petrol hydrocarbons of 3,850 mg g−1. The experimental equilibrium data are fitted to the Freundlich and Langmuir models.

Author(s):  
Ulker Asli GULER

Nanoscale zero valent iron (nzvi) and functional pumice modified nanoscale zero valent iron (P-nzvi) were successfully synthesized and used for the removal of tetracycline (TC). These materials were characterized by SEM, TEM, XRD, FTIR, BET. Different factors such as the mass ratio, dosage of adsorbent, ph, initial TC concentration and temperature were investigated. Based on these results; a possible removal mechanism was proposed including TC adsorption and TC reduction via oxidation of Fe0 to Fe3+. In addition, isotherm and thermodynamic parameters were applied to the equilibrium data. The maximum adsorption capacity of TC by nzvi and P-nzvi was 105.46 mg/g and 115.13 mg/g, respectively. Adsorption and reduction kinetics were examined for the TC removal process. The pseudo-second-order model and pseudo-first-order model was observed for adsorption and reduction process, respectively. Finally, more than 90% of TC from aqueous solutions was removed by nzvi and P-nzvi.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yige Guo ◽  
Bin Chen ◽  
Ying Zhao ◽  
Tianxue Yang

AbstractAntibiotics are emerging pollutants and increasingly present in aquaculture and industrial wastewater. Due to their impact on the environment and health, their removal has recently become a significant concern. In this investigation, we synthesized nano zero-valent iron-loaded magnetic mesoporous silica (Fe-MCM-41-A) via precipitation and applied the adsorption of oxytetracycline (OTC) from an aqueous solution. The effects of competing ions such as Na+, Ca2+ and Cu2+ on the adsorption process under different pH conditions were studied in depth to providing a theoretical basis for the application of nanomaterials. The characterization of the obtained material through transmission electron microscopy demonstrates that the adsorbent possesses hexagonal channels, which facilitate mass transfer during adsorption. The loaded zero-valent iron made the magnetic, and was thus separated under an applied magnetic field. The adsorption of OTC onto Fe-MCM-41-A is rapid and obeys the pseudo-second-order kinetic model, and the maximum adsorption capacity of OTC is 625.90 mg g−1. The reaction between OTC and Fe-MCM-41-A was inner complexation and was less affected by the Na+. The effect of Ca2+ on the adsorption was small under acidic and neutral conditions. However, the promotion effect of Ca2+ increased by the increase of pH. Cu2+ decreased the removal efficiencies continuously and the inhibitory effects decrease varied with the increase of pH. We propose that surface complexing, ion-exchange, cationic π-bonding, hydrogen bonding, and hydrophobicity are responsible for the adsorption of OTC onto Fe-MCM-41-A.


2018 ◽  
Vol 78 (8) ◽  
pp. 1693-1703 ◽  
Author(s):  
Jordana Georgin ◽  
Fernanda Caroline Drumm ◽  
Patrícia Grassi ◽  
Dison Franco ◽  
Daniel Allasia ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Bayram Kizilkaya ◽  
A. Adem Tekınay

Removal of lead (II) from aqueous solutions was studied by using pretreated fish bones as natural, cost-effective, waste sorbents. The effect of pH, contact time, temperature, and metal concentration on the adsorption capacities of the adsorbent was investigated. The maximum adsorption capacity for Pb (II) was found to be 323 mg/g at optimum conditions. The experiments showed that when pH increased, an increase in the adsorbed amount of metal of the fish bones was observed. The kinetic results of adsorption obeyed a pseudo second-order model. Freundlich and Langmuir isotherm models were applied to experimental equilibrium data of Pb (II) adsorption and the value ofRLfor Pb (II) was found to be 0.906. The thermodynamic parameters related to the adsorption process such asEa,ΔG°,ΔH°, andΔS° were calculated andEa,ΔH°, andΔS° were found to be 7.06, 46.01 kJ mol−1, and 0.141 kJ mol−1K−1for Pb (III), respectively.ΔH° values (46.01 kJmol−1) showed that the adsorption mechanism was endothermic. Weber-Morris and Urano-Tachikawa diffusion models were also applied to the experimental equilibrium data. The fish bones were effectively used as sorbent for the removal of Pb (II) ions from aqueous solutions.


2013 ◽  
Vol 316-317 ◽  
pp. 653-656
Author(s):  
Bai Jie Niu ◽  
Wen Ming Ding ◽  
Dan Dang

As an effective adsorbent, granular activated alumina (GAA) has been widely used in defluoridation. In order to reduce cost and operate environment-friendly, the adsorbent should be regenerated. In this paper, column experiment was done to characterize the fluoride removal properties and to develop an optimal method to regenerate fluoride-rich modified activated alumina (MGAA). The MGAA can be regenerated by utilizing sodium hydroxide solution desorption, deionized water washing and ferric sulfate reactivation and then used for futher defluoride operation. The influence of the concentration of desorption agent (NaOH solution) and desorbing time on desorption rate and the adsorption capacity of regenerated MGAA were studied. The optimal desorption condition was: 1% NaOH solution for desorption agent, desorbing time in 1.5h.In addition, when the regenerated MGAA was used again for column adsorption test, its adsorption capacity reached 94% of that of original sorbent in 1mg/L outlet fluoride concentration.


2015 ◽  
Vol 16 (1) ◽  
pp. 115-127 ◽  
Author(s):  
P. Dhanasekaran ◽  
P. M. Satya Sai ◽  
C. Anand Babu ◽  
R. Krishna Prabhu ◽  
K. K. Rajan

Arsenic is a toxic element found naturally in groundwater. Due to its carcinogenicity, risk for heart diseases and diabetes, arsenic needs to be removed from groundwater for potable application. ‘Anjili’ tree sawdust was chemically modified with ferric hydroxide and activated alumina (SFAA) and used as an adsorbent for the removal of arsenic from groundwater. The adsorbent was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) to study the pore structure and surface functional groups. Effect of contact time, initial concentration, pH, particle size and temperature was studied. Arsenic adsorbed by SFAA followed Freundlich adsorption isotherm. Maximum sorption of arsenic by SFAA adsorbent occurred at pH 6.5. Arsenic sorption kinetics followed a pseudo-second-order model. The maximum sorption capacity at 303 K was found to be 54.32 mg/g for As(III) and 77.60 mg/g for As(V). Interference of other ions on the adsorption was in the order of PO43− > SO42− > HCO3− > NO3−.


2021 ◽  
Vol 43 (4) ◽  
pp. 436-436
Author(s):  
Nida Shams Jalbani Nida Shams Jalbani ◽  
Amber R Solangi Amber R Solangi ◽  
Shahabuddin Memon Shahabuddin Memon ◽  
Ranjhan Junejo Ranjhan Junejo ◽  
Asif Ali Bhatti Asif Ali Bhatti

In current study, the diphenylaminomethylcalix[4]arene (3) was synthesized and immobilized onto silica surface to prepare a selective, regenerable and stable resin-4. The synthesized resin-4 has been characterized by FT-IR spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and Brunauer-Emmett-Teller (BET) techniques. To check the adsorption capacity of resin-4, the batch and column adsorption methodology were applied and it has observed that the resin-4 was selectively removed Hg2+ ions under the optimized parameters. The maximum adsorption capacity was obtained at pH 9 using 25 mg/L of resin-4. Under the optimal conditions, different equilibrium, kinetic and thermodynamic models were applied to experimental data. The results show that adsorption mechanism is chemical in nature following Langmuir model with good correlation coefficient (R2=0.999) and having 712.098 (mmol/g) adsorption capacity. The energy of calculated from D-R model suggests the ion exchange nature of the adsorption phenomenon. Dynamic adsorption experiments were conducted using Thomas model. The maximum solid phase concentration (qo) was 7.5 and rate constant was found to be 0.176 with (R2=0.938) for Hg2+ ions. The kinetic study describes that the adsorption mechanism follows pseudo second order (R2=0.999). The thermodynamic parameters such as ∆H (0.032 KJ/mol) and ∆S (0.127 KJ/mol /K) and ∆G (-5.747,-6.306, -7.027 KJ/mol) shows that the adsorption of Hg2+ ion is endothermic and spontaneous. The reusability of resin-4 was also checked and it has observed that the after 15 cycle only 1.2 % adsorption reduces. Moreover, the resin-4 was applied on real wastewater samples obtained from local industrial zone of Karachi, Sindh-Pakistan.


2021 ◽  
Author(s):  
Estefanía Martinis ◽  
Juliano Denardin ◽  
Raul Calderón Raul Calderón ◽  
Cristóbal Flores ◽  
Karen Manquián-Cerda ◽  
...  

Abstract A novel hybrid nanomaterial, nanoscale zero-valent iron (nZVI)-grafted imogolite nanotubes (Imo), was synthesized via a fast and straightforward chemical procedure. The as-obtained nanomaterial (Imo-nZVI) was characterized using transmission electron microscopy (TEM), electrophoretic mobility (EM) and vibrating sample magnetometry (VSM). The prepared Imo-nZVI was superparamagnetic at room temperature and could be easily separated by an external magnetic field. Sorption batch experiments were performed in single- and multicomponent system and showed that Hg2+ and Pb2+ could be quantitatively adsorbed at pH 4.0 with maximum adsorption capacities of 62.3 and 73.8 mg·g− 1, respectively. It was observed that the functional groups in Imo-nZVI interact preferentially with analytes according to Misono Softness parameter. The higher performance of Imo-nZVI compared with Imo and nZVI is related to the increased adsorption sites in the functionalized nanomaterial. The sorption equilibrium data obeyed the Langmuir model, while kinetic studies demonstrated that the sorption processes of Hg2+ and Pb2+ followed the pseudo-second-order model. This study suggests that the Imo-nZVI composite can be used as a promising sorbent and provides a simple and fast separation method for the removal of Hg and Pb ions from contaminated water.


2019 ◽  
Vol 19 (11) ◽  
pp. 7035-7043 ◽  
Author(s):  
Tong Ouyang ◽  
Jidan Tang ◽  
Fang Liu ◽  
Chang-Tang Chang

The objective of this paper is to study the removal of Cr(VI) in aqueous solution by using a new graphene oxide-coated rice husk biochar composite (GO-RHB). GO-RHB is a synthetic material having a porous structure with lots of oxygen-containing functional groups and a large surface area that provide effective adsorption sites. Experiments showed that GO-RHB had higher adsorption capacity under acidic than under alkaline conditions. At pH of 2, GO-RHB has the maximum adsorption capacity(48.8 mg g−1). Equilibrium data obtained by fitting with the Langmuir and Freundlich models indicate that the reaction process was monolayer adsorption. The adsorption of Cr(VI) followed the pseudo-second-order kinetic model that illustrates chemical adsorption. Intraparticlediffusion studies further revealed that film diffusion was taking place. Moreover, the results of thermodynamics showed that the adsorption process was endothermic and spontaneous in nature. The removal mechanism of Cr(VI) was also explained in detail. The prepared adsorbent is highly efficient and might be useful than many other conventional adsorbent used for the removal of Cr(VI) from wastewater.


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