scholarly journals Removal of ciprofloxacin from aqueous solution by electro-activated persulfate oxidation using aluminum electrodes

2019 ◽  
Vol 80 (3) ◽  
pp. 587-596
Author(s):  
Mohammad Malakootian ◽  
Mohammad Ahmadian

Abstract The aim of this study was to determine the removal of ciprofloxacin (CIP) by the electro-persulfate (EC-PS) process using aluminum (Al) electrodes. The effects of variables including pH, contact time, PS concentration, initial CIP concentration and current density on the removal efficiency of CIP were studied. In order to determine the mechanisms of the EC-PS process, the radical scavenger tests, as well as energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FT-IR) were performed on the sludge. The results showed that the PS process alone had no effect on the CIP removal, and the EC process alone could remove 25% of CIP after 160 min. However, the EC-PS process under the optimum conditions: pH of 7, time of 40 min, current density of 2.75 mA/cm2, CIP concentration of 20 mg/L, and PS concentration of 0.84 mM removed 90% of CIP. The effect of the EC-PS process on the actual hospital wastewater was 81% in optimal conditions. The kinetic study also showed that the second-order kinetic model was the most consistent. The oxidation process during the initial contact was dominant in the EC-PS process and, over time, the EC process was dominant for CIP removal.

2021 ◽  
Author(s):  
Majid Mohadesi ◽  
Ashkan Gouran ◽  
Kiarash Seifi

Abstract This study investigated the removal of an organic drug called ibuprofen from the wastewater containing this drug. Iron oxide supported on modified Iranian clinoptilolite was used as the photocatalyst in the presence of the light of a solar lamp. XRD, SEM, EDAX and FT-IR analyses were performed to detect the prepared photocatalyst. The results of photocatalytic identification analyses proved the suitable loading of iron oxide supported on modified Iranian clinoptilolite. This study investigated the effect of initial concentration of ibuprofen (5–25 mg/L), photocatalyst concentration (100–300 mg/L), and process time (10–240 min) on the removal from ibuprofen from wastewater containing this drug. The experiments were performed in a setup in the presence of a solar lamp with a flux of 300 W/m2. The results indicated that with the initial ibuprofen concentration of 25 mg/L, photocatalyst concentration of 300 mg/L, and time of 210 min, the highest percentage of ibuprofen removal was 99.80%. Kinetic modeling was then performed using the Langmuir-Hinshelwood model, and a quasi-first-order kinetic model showed a good agreement with the results obtained. Finally, the recovery of the photocatalyst was investigated and the results showed that under optimal conditions about 91% of ibuprofen was removed after five re-uses of the photocatalyst.


2016 ◽  
pp. 39-48
Author(s):  
Pathompong Vibhatabandhu ◽  
Sarawut Srithongouthai

Biosorptionis an effective process for removal and recovery of heavy metal ions from aqueous solutions. In the present study, batch adsorption experiments were carried out for the removal of copper (Cu II) from aqueous solutions using cuttlebone powder (<100 μm)as a bio-adsorbent. The effects of initial pH, adsorbent dosage, initial concentration, and contact time on adsorption efficiency and capacity were studied to evaluate the optimum conditions for copper removal.The results found optimal conditions at initial pH of 5.0, 10 g L-1cuttlebone, 500 mg L-1initial concentration of Cu II in solution, and 150 min of equilibrium time.The Langmuir isotherm and pseudo-second order kinetic model were fitted to the experimental adsorption data. The maxi-mum adsorption capacity calculated from theLangmuir isotherm was 54.05 mg g-1. This result shows that cuttlebone is an effective bio-adsorbent, constituting a promising, efficient, low-cost, and eco-friendly technology bio-sorbent for reducing copper pollution during wastewater treatment.


2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.


2012 ◽  
Vol 11 (02) ◽  
pp. 1250019 ◽  
Author(s):  
RAJESH KUMAR ◽  
S. K. JAIN

This study was carried out to evaluate the environmental application of functionalized carbon nanotubes through the experimental removal of strontium (II) from water. The aim was to find the optimal condition for the removal of strontium from water under different conditions such as initial concentration of strontium, contact time and neutral pH. The functionalized multi wall carbon nanotubes (f-MWCNT) were characterized by FT-IR and scanning electron microscopy (SEM). The adsorption isotherms were correlated to Freundlich and Langmuir models and it was found that the adsorption data could be fitted better by Langmuir model than Freundlich one. The kinetic data shows that the adsorption describes well with the pseudo-second order kinetic model. Functionalized MWCNT can be used as good adsorbent for the removal of the strontium ions from polluted water according to results.


2011 ◽  
Vol 413 ◽  
pp. 148-153 ◽  
Author(s):  
Xue Na Hu ◽  
Ya Han ◽  
Jia Yan Li ◽  
Jun Yan Wu ◽  
Jian Rong Chen ◽  
...  

Thiol-functionalized MCM-48 (SH-MCM-48) was synthesized by co-condensation method, with co-templates of cetyltrimethylammonium bromide (CTAB) and nonionic poly (ethylene oxide)–poly (propylene oxide)–poly (ethylene oxide) triblock copolymer (Pluronic P123). The resulting material was characterized by XRD and FT-IR spectrum. The potential of SH-MCM-48 for adsorption Zn (II) from aqueous solution was examined. Batch adsorption studies were carried out to investigate the effect of experimental parameters including pH, metal ions concentration and adsorption time. The maximum adsorption capacities of Zn (II) onto SH-MCM-48 were 30.12, 34.01 and 38.02 mg g-1 at the temperature of 303, 313 and 323K, respectively. The adsorption kinetics data were found to follow the pseudo-second-order kinetic model, and adsorption isotherms were fitted well with Langmuir and Freundlich models. Moreover, the adsorption thermodynamic parameters (△G0, △H0 and △S0) were measured, and indicated that the adsorption was an exothermic and spontaneous process.


SAINTIFIK ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 104-115
Author(s):  
Agusriyadin Agusriyadin

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.


Author(s):  
Yanchang Zhang ◽  
Lin Zhao ◽  
Yongkui Yang ◽  
Peizhe Sun

Biochar (BC)-supported nanoscale zero-valent iron (nZVI-BC) was investigated as a heterogeneous Fenton-like activator to degrade the antibiotic ornidazole (ONZ). The characterization of nZVI-BC indicated that BC could enhance the adsorption of ONZ and reduce the aggregation of nZVI. Thus, nZVI-BC had a higher removal efficiency (80.1%) than nZVI and BC. The effects of parameters such as the nZVI/BC mass ratio, pH, H2O2 concentration, nZVI-BC dose, and temperature were systematically investigated, and the removal of ONZ followed a pseudo-second-order kinetic model. Finally, possible pathways of ONZ in the oxidation process were proposed. The removal mechanism included the adsorption of ONZ onto the surface of nZVI-BC, the generation of •OH by the reaction of nZVI with H2O2, and the oxidation of ONZ. Recycling experiments indicated that the nZVI-BC/H2O2 system is a promising alternative for the treatment of wastewater containing ONZ.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Li

Using straw and urea as raw materials, biochar (BC) and g-C3N4 were prepared by oxygen-free pyrolysis at 300°C and 550°C. BC/g-C3N4 was prepared by loading different amounts of g-C3N4 onto the surface of biochar and characterized by SEM and FT-IR. The adsorption effect on methylene blue (MB) was investigated from the aspects of dosage and pH. The studies of adsorption equilibrium isotherms and the kinetic and the thermodynamic parameters on the BC/g-C3N4 adsorbents are discussed. The results showed that BC/g-C3N4 0.16 g/L with a doping ratio of 1 : 3 was added to the MB solution with an initial concentration of 50 mg/L and pH=11. The adsorption rate and adsorption amount were 96.72% and 302.25 mg/g, respectively. The adsorption process included surface adsorption and intraparticle diffusion, which conformed to the pseudo-second-order kinetic model and Langmuir-Freundlich model. Thermodynamic parameters (ΔG0<0, ΔH0>0, and ΔS0>0) showed that the adsorption reaction is spontaneous, which positively correlated with temperature.


2011 ◽  
Vol 8 (s1) ◽  
pp. S19-S26 ◽  
Author(s):  
M. Montazerozohori ◽  
S. Nezami ◽  
S. Mojahedi

Anatase titanium dioxide catalyzed photodegradation of tolonium chloride at various bufferic pH of 2, 7, 9 and 12 in aqueous solution is presented. The effect of some physicochemical parameters such as initial concentration of dye, catalyst amount and reaction time on photocatalytic degradation has been investigated in a photo-reactor cell containing high pressure mercury lamp to obtain the optimum conditions in each bufferic pH at constant temperature. A complete spectrophotometric kinetic study of tolonium chloride under high pressure irradiation at buffer media was performed. The photocatalytic degradation observed rate constants (kobs) were found to be 2.90×10-3, 3.30×10-3, 3.20×10-3and 5.20×10-3min-1for buffer pH of 2-12 respectively. It was found that a pseudo-first-order kinetic model based on Langmuir-Hinshelwood one is usable to photodegradation of this compound at all considered buffer pH. In addition to these, the Langmuir-Hinshelwood rate constants, krfor the titled compound at various pH are reported.


2020 ◽  
Vol 14 (3) ◽  
pp. 316-326 ◽  
Author(s):  
Josephraj Jegan ◽  
Saravanan Praveen ◽  
Thillainayagam Bhagavathi Pushpa ◽  
Ravindran Gokulan

In the present study, bioremediation of Basic Violet 03 is examined using biochar derived from agricultural wastes. The pyrolytic studies revealed that ideal temperature for maximum yield of biochar derived from Coconut Shell (CSB), Ground nut Shell (GnSB) and Rice Husk (RHB) was obtained as 400 °C, 350 °C and 300 °C respectively. Further from the batch mode of operations, it was concluded that the optimum conditions of biochar dose, pH, temperature and initial concentration are 4 g/L, 8, 40 °C and 75 mg/L with a maximum uptake of 15.79 mg/g, 17.28 mg/g, and 12.64 mg/g for CSB, GnSB and RHB. The adsorption isotherm studies concluded that the three-parameter Sips model was obtained to be the best fit with a maximum correlation coefficient (R2) of 0.9937, 0.9935 and 0.9965. The pseudo second order kinetic model was found to well represent the experimental kinetic data. The characterization results of biochar through SEM, EDX and FTIR revealed that there was a strong binding capacity of adsorbent was observed before and after adsorption process. The promising results concluded that biochar derived from agricultural wastes can potentially be utilized for the removal of cationic dyes.


Sign in / Sign up

Export Citation Format

Share Document