scholarly journals Photocatalytic Degradation of Trifluralin in Aqueous Solutions by UV/S2O82− and UV/ZnO Processes: A Comparison of Removal Efficiency and Cost Estimation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fatemeh Sadeghi ◽  
Abdolmajid Fadaei ◽  
Fazel Mohammadi-Moghadam ◽  
Sara Hemati ◽  
Gashtasb Mardani

Trifluralin is one of the most widely used herbicides, being accounted as the cause of cancer in human. In the present research, the UV/S2O82− and ZnO/UV processes’ efficiency in the removal of trifluralin was investigated. A lab scale equipped with a UV lamp was applied. The parameters were studied, including initial trifluralin concentration (0.4–1.2 mg/L), contact time (20–60 min), S2O82− concentration (20–60 μM), and ZnO concentration (50–150 mg/L). The remained trifluralin concentration was measured by HPLC. This study proved the trifluralin removal of 92.90 ± 1.6% and 87.91 ± 19.22% for UV/S2O82− and UV/ZnO processes in the best operation conditions (contact time of 60 min, the persulfate concentration of 40 μM, and the ZnO concentration of 100 mg/L). The optimal trifluraline concentrations were 1.2 mg/L and 0.6 mg/L for UV/S2O82− and UV/ZnO processes, respectively. In both processes, the removal efficiency of trifluralin increased significantly with increasing contact time. The findings exhibited that both processes UV/S2O82− and UV/ZnO followed the zero-order kinetic. The electrical energy consumed of UV/S2O82 and UV/ZnO was about 43.95 and 20.41 Kwh/kg, respectively. The results show that UV/S2O82− and ZnO/UV processes were appropriate as the effective treatment method for trifluralin removal. Therefore, it is proposed to study the performance of these processes as an environmentally friendly practice in full scale with real wastewater.

Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.


2021 ◽  
Vol 52 (2) ◽  
pp. 336-347
Author(s):  
I. N. Abd ◽  
M. J. Mohammed-Ridha

Cladophora and Spirulina algae biomass have been used for the removal of Tetracycline (TC) antibiotic from aqueous solution. Different operation conditions were varied in batch process, such as initial antibiotic concentration, different biomass dosage and type, contact time, agitation speed, and initial pH. The result showed that the maximum removal efficiencies by using 1.25 g/100 ml Cladophora and 0.5 g/100 ml Spirulina algae biomass were 95% and 94% respectively. At the optimum experimental condition of temperature 25°C, initial TC concentration 50 mg/l, contact time 2.5hr, agitation speed 200 rpm and pH 6.5. The characterization of Cladophora and Spirulina biomass by Fourier transform infrared (FTIR) indicates that the presence of functional groups of different components such as the Hydroxyl group (-OH), amides(N-H stretch) were responsible of surface adsorption processes. The isothermal study has been applied using Freundlich, Temkin, and Langmuir models. The data best fitted with the Langmuir model. Finally, The pseudo-second-order kinetic model was best fitted the kinetic data with a high coefficient of determination (R2< 0.97 and 0.99) when used Cladophora and Spirulina algae biomass, respectively. The study showed that both Cladophora and Spirulina algae were promising and economical biomass that could be used for a large scale bioreactor.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ruhollah Kasraei ◽  
Mohammad Malakootian ◽  
Maryam Mohamadi

AbstractThe aim of this research was to investigate ciprofloxacin (CIP) removal efficiency from aqueous solutions by using Fe3O4 nanoparticles @Trioctylmethylammonium thiosalicylat Ionic liquid (Fe3O4 NP@ TOMATS IL) as a new magnetic nanoadsorbent. The adsorbent was characterized by field emission scanning electron microscope-energy dispersive spectroscopy (FESEM-EDS), mapping, Fourier transform infrared spectroscopy (FT-IR), the Brunauer–Emmett–Teller (BET), X-ray powder diffraction (XRD). The effects of solution pH, adsorbent dose, contact time, initial CIP concentration, and temperature on CIP removal were also investigated. In optimal conditions such as pH = 5.6, CIP concentration = 30 mg/L, adsorbent dose = 0.15 g, temperature = 30 °C, contact time = 90 min, the removal efficiency in synthetic and real wastewater were obtained 87 and 73%, respectively. Batch experiments were carried out to study the sorption Kinetics, thermodynamics, and equilibrium isotherms of CIP with magnetic nanoadsorbent. The results show that all of the above factors influence CIP removal. The Langmuir adsorption isotherm fits the adsorption process well, with the pseudo second-order model describing the adsorption kinetics accurately. The thermodynamic parameters indicate that adsorption is mainly physical adsorption. Recycling experiments revealed that the behavior of adsorbent is maintained after recycling for four times.


2021 ◽  
Vol 68 (4) ◽  
pp. 791-803
Author(s):  
Lei Yao ◽  
Chao Hong ◽  
Hani Dashtifard ◽  
Hossein Esmaeili

This study aimed to determine the best adsorbent among Moringa oleifera-derived activated carbon (AC), eggshell-derived CaO nanoparticles and CaO/Fe3O4 for sodium (Na+) removal from aqueous media. In the first step, the appropriate adsorbent for sodium adsorption was determined among the three adsorbents, which the results showed that the AC had the highest sorption efficiency. Then, response surface methodology (RSM) was used to evaluate the impact of different factors on the Na+ ion sorption efficiency using the AC. The highest removal efficiency was obtained to be 95.91% at optimum conditions such as pH of 11, contact time of 45 min, temperature of 25 °C, sodium ion concentration of 900 mg/L, and adsorbent dosage of 5 g/L. Also, the best conditions using the genetic algorithm was obtained at contact time of 94.97 min, adsorbent dosage of 3.52 g/L, Na+ ion concentration of 939.92 mg/L and pH value of 10.92. Moreover, the maximum sorption capacity using the Langmuir model was obtained to be 249.67 mg/g, which was a significant value. Besides, the equilibrium and kinetic studies indicated that the experimental data of sodium adsorption process were fitted well with the Langmuir isotherm model and the pseudo-second-order kinetic model, respectively. Furthermore, the thermodynamic study indicated that the sorption process was endothermic. Generally, among the three adsorbents used, activated carbon with a high removal efficiency and significant sorption capacity can be considered as a promising adsorbent for the removal of sodium from wastewater on an industrial scale.


2017 ◽  
Vol 76 (11) ◽  
pp. 3114-3125 ◽  
Author(s):  
Doga Aktas ◽  
Nadir Dizge ◽  
H. Cengiz Yatmaz ◽  
Yasemin Caliskan ◽  
Yasin Ozay ◽  
...  

Abstract Adsorption and advanced oxidation processes are being extensively used for treatment of wastewater containing dye chemicals. In this study, the adsorption and Fenton behavior of iron rich Terra Rosa soil was investigated for the treatment of aqueous anthraquinone dye (Reactive Blue 19 (RB19)) solutions. The impact of pH, initial dye concentration, soil loading rate, contact time and temperature was systematically investigated for adsorption process. A maximum removal efficiency of dye (86.6%) was obtained at pH 2, soil loading of 10 g/L, initial dye concentration of 25 mg/L, and contact time of 120 min. Pseudo-first-order, pseudo-second-order, Elovich, and Weber–Morris kinetic models were applied to describe the adsorption mechanism and sorption kinetic followed a pseudo-second-order kinetic model. Moreover, Langmuir, Freundlich and Temkin isotherm models were used to investigate the isothermal mechanism and equilibrium data were well represented by the Langmuir equation. The maximum adsorption capacity of soil was found as 4.11 mg/g using Langmuir adsorption isotherm. The effect of soil loading and hydrogen peroxide (H2O2) dosage was solely tested for Fenton oxidation process. The highest removal efficiency of dye (89.4%) was obtained at pH 2, H2O2 dosage of 10 mM, soil loading of 5 g/L, initial dye concentration of 50 mg/L, and contact time of 60 min. Thermodynamic studies showed that when the adsorption dosage of dye was 25 mg/L at 293–313 K, adsorption enthalpy (ΔH) and entropy (ΔS) were negative and adsorption free energy (ΔG) was positive. This result indicated that the adsorption was exothermic. Morphological characteristics of the soil were evaluated by X-ray fluorescence (XRF), scanning electron microscopy (SEM), and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy before and after the adsorption and oxidation process.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1161
Author(s):  
Somayeh Rahdar ◽  
Abbas Rahdar ◽  
Mostafa Sattari ◽  
Laleh Divband Hafshejani ◽  
Athanasia K. Tolkou ◽  
...  

Dyes are known as one of the most dangerous industrial pollutants which can cause skin diseases, allergy, and provoke cancer and mutation in humans. Therefore, one of the important environmental issues is the effective removal of dyes from industrial wastewater. In the current work, BaFe12O19/CoFe2O4@polyethylene glycol (abbreviated as BFO/CFO@PEG) nanocomposite was synthesized and evaluated regarding its capacity for adsorptive removal of a model dye Acid Blue 92 (denoted as AB92) from aqueous solutions. The characteristics of the prepared nanocomposite was determined by tests such as X-ray diffraction (XRD), scanning electron microscope (SEM), vibration sample magnetization (VSM), and Fourier transform infrared spectroscopy (FTIR). The effects of conditional parameters including pH (2–12), initial concentration of dye (20–100 mg/L), adsorbent dosage (0.02–0.1 g/L) and contact time (0-180 min) on the adsorption of dye were investigated and then optimized. The results indicated that with the increase of the adsorbent dosage from 0.02 to 0.1 g/L, the removal efficiency increased from 74.1% to 78.6%, and the adsorbed amount decreased from 148.25 to 31.44 mg/g. The maximum removal efficiency (77.54%) and adsorption capacity (31.02 mg/g) were observed at pH 2. Therefore, the general optimization conditions revealed that the maximum adsorption efficiency of dye was obtained in condition of initial concentration of 20 mg/L, contact time of 1 h and pH of solution equal 2. The adsorption isotherm and kinetic data were evaluated using a series of models. The pseudo-second order kinetic model and Freundlich isotherm model show the best fitting with experimental data with R2∼0.999.


2019 ◽  
Vol 6 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Dariush Naghipour ◽  
Abdoliman Amouei ◽  
Kamran Taher Ghasemi ◽  
Kamran Taghavi

Background: Metoprolol (MTP) with its low biodegradability is one of the most dominant micropollutant in the effluent of wastewater treatment plants. The aim of this study was to investigate the removal of metoprolol from aqueous solutions by the activated carbon prepared from pine cones. Methods: The pine cones were activated using thermal activation method. Characteristics of the adsorbent were determined using Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). In this study, the influent of different parameters such as pH, contact time, initial concentrations of metoprolol, adsorbent dose, temperature, adsorption isotherms, and kinetics were investigated. Results: The maximum removal efficiency of MTP (89.2%) was obtained at pH=8.5, adsorbent dose=1.5 g, contact time=60 min, and initial concentration=50 mg/L. By increasing the adsorbent dose, the removal efficiency also increased, but the adsorption capacity decreased, however, by increasing the initial concentration, the removal efficiency decreased, but the adsorption capacity increased. The isotherm experimental data for metoprolol was best fitted using the Langmuir model, and kinetic data were better described by pseudo-second-order kinetic model. The thermodynamic study indicated that the adsorption of MTP by the adsorbent was feasible, spontaneous, and endothermic. Conclusion: MTP removal by the activated carbon prepared from pine cones showed that this natural adsorbent is appropriate for removal of metoprolol from aqueous solutions regarding cost, efficiency, and production method.


2007 ◽  
pp. 835-843 ◽  
Author(s):  
Kamilla Hansen ◽  
Henrik R. Andersen ◽  
Tobias Hey ◽  
Anna Ledin

The removal efficiency by photolysis and advanced oxidation (AOP) of some estrogeniccompounds was investigated in tap water and biologically treated sewage. The compoundsinvestigated included parabens, industrial phenols, sunscreen chemicals and steroid estrogens.Treatment experiments were performed using a UV lamp optimized for photochemicaltreatment in a flow through set-up. The effect of different concentrations of H2O2 anddifference between tap water and treated sewage was investigated for all compounds.The treatment effectiveness is evaluated based on the Electrical Energy per Order (EEO) (unitkWh/111e3), which is defined as the electrical energy consumed per unit volume of water treatedrequired for 90 % removal of the investigated compound.It was found that the removal efficiency was better in tap water than in wastewater which isdue to the shadow effect from the inorganic and organic substance in the wastewater. Further,it was found that the removal of all the compounds was dependent of the UV dose for bothtreatment methods. The energy required for 90% removal of the compounds was between 28kWh/111e3 ± 2.9 (butylparaben) and 1.2 kWh/ 111e3 (estrone) for the UY treatment. The AOPresults in a more unifom1 value of EEO, which is between 8. 7 kWh/m3 (bisphenol A andbenzophenone-7) and 1.8 kWh/m3 ( I 7a-ethynyl estradiol).The removal at different concentration of H2O2 was investigated and it was found thatremoval effectiveness increased with concentration until 60 mg/L, but decreased at I 00 mg/L,which may be caused by H2O2 scavenging the HO'-radicals.


2010 ◽  
Vol 7 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Reza Shokoohi ◽  
Vahid Vatanpoor ◽  
Mansuor Zarrabi ◽  
Akram Vatani

Adsorption process by activated carbon is widely used for removal of dyes. Because of economical limits, activated carbon derived from low cost materials seem to be economical. The aim of this work is preparation of activated carbon from poplar wood and investigation of its ability to removal of (AR18) dye. In this work, we prepared the activated carbon by chemical activation method in electric furnace. In addition we have investigated effect of various parameters such as pH, contact time, dye concentration and adsorbent dosage on dye removal. Langmuir and Freundlich isotherm models have been investigated. Pseudo-first order, pseudo-second order and modified pseudo-first order kinetic models have been used for experimental data. The results showed that removal efficiency was increased with increasing of adsorbent dosage, contact time and decreasing of pH, but with increasing of dye concentration, the removal efficiency was decreased. Adsorption isotherm models showed that Langmuir isotherm model was best fitted onto collected data (r2>0.978). In addition, kinetic models showed that sorption of AR18 onto activated carbon prepared from poplar wood follows the pseudo-first order model (r2>0.9758).


2017 ◽  
Vol 4 (1) ◽  
pp. 6021-6021
Author(s):  
Mohammad Reza Samarghandi ◽  
Ali Poormohammadi ◽  
Samane Shanesaz ◽  
Kazem Godini

The current study aimed at comparing the performances of activated carbon and graphene in the removal of reactive red 198. The experiments were conducted in a batch reactor and the effects of some operational parameters including initial dye concentration, pH, contact time, and different doses of activated carbon and graphene on the removal efficiency of dye were investigated. The results showed that the adsorption efficiency was affected by initial dye concentration. In general, with increasing contact time up to 180 minutes, the removal efficiency increased significantly. The removal efficiency of reactive red 198 increased with increasing contact time, and after 60 minutes of contact time, adsorption phase reached the equilibrium. When activated carbon was used, the maximum removal efficiency happened at pH 3. At this pH value, reactive red 198 was removed completely (100%) after 120 minutes, whereas the minimum efficiency was observed at pH 10. A similar trend was also observed for graphene as an adsorbent. Moreover, the removal efficiency of the dye by both adsorbents increased with the increase of the adsorbent dosage. The experimental data showed that the adsorption of reactive red198 on both active carbon and graphene fitted well into the second-order kinetic model. Active carbon and graphene fitted well Langmuir 1 model. According to the results, graphene acts as suitable adsorbent and can be applied in treating several industrial effluents and contaminated water in greater scales. The main upside of grapheme, in comparison with activated carbon, is that it reaches the equilibrium in a shorter time. Further, grapheme adsorbed the dye nearly completely (98% to 100%).


Sign in / Sign up

Export Citation Format

Share Document