scholarly journals Detoxification of As(III) in Aqueous Media by Using Photo-Fenton Method

2021 ◽  

<p>In this paper, photo-Fenton method has been systematically examined to oxidize the toxic and mobile As(III) in the solution by •OH radicals resulted from the reactions between Fe2+ and H2O2 under UV light, to form the less toxic and insoluble As(V). The effects of various experimental parameters including initial Fe2+ and H2O2 concentrations, working pH, and contact time were studied through a batch experiment. The concentration of As(V) resulted from the photo-oxidation was determined by visible spectrophotometry method based on the formation of arsenate molybdate solution. The results of the research attributed noticeably that the As(III) could be oxidized through photo-Fenton process to form As(V) that was assigned by a considerable decline in the concentration. The maximal oxidation of As(III) with 10 mg L-1 of the concentration in 50 mL of the aqueous solution, that was about 85%, can be reached in the presence of Fe2+ 10-2 mole L-1, H2O2 5. 10-2 mole L-1 at the working pH 3 and within 3 h of the reaction time. It has been also detected that for reaching the permissible level (lower than 0.01 mg L-1 ), three stages of the photo-Fenton process were required.</p>

2019 ◽  
Vol 21 (2) ◽  
pp. 180-186 ◽  

<p>Photo-Fenton for decreasing concentration of Pb(II) ions in the aqueous solution is systematically studied. The photo-Fenton process was carried out by batch technique, under UV light. The influences of process operating parameters were evaluated. The results of the research demonstrated that by photo-Fenton process, the concentration of Pb(II) ions in the aqueous solution can be decreased, that may be through oxidation mechanism by OH radicals. The decrease is found to be controlled by Fe2+ and H2O2 concentrations, as well as by the pH and the irradiation time. For 20 mg/L of Pb(II) in the 100 mL solution, the optimum condition of the oxidation is obtained to be 10 mmole/L of Fe2+, 200 mmole/L of H2O2, pH 3, and 90 min of the reaction time. It is also confirmed that the oxidation of Pb (II) by OH radical has formed the undissolved PbO2, that is less toxic and easier to be handled.</p>


2011 ◽  
Vol 8 (2) ◽  
pp. 803-808 ◽  
Author(s):  
U. V. Ladhe ◽  
S. K. Wankhede ◽  
V. T. Patil ◽  
P. R. Patil

Adsorptions of Erichrome Black T dye in aqueous solution on cotton stem activated carbon have been studied as a function of contact time, concentration and pH. Effect of various experimental parameters has been investigated at 39±1°C under batch adsorption technique. The result shows that cotton stem activated carbon adsorbs dye to a sufficient extent. The physicochemical characterization and chemical kinetics was also examined for the same dye. The overall result shows that it can be fruitfully used for the removal of dye from wastewaters.


2015 ◽  
Vol 798 ◽  
pp. 390-394
Author(s):  
Saptono Hadi ◽  
Budi Hastuti ◽  
Nurina Tulus Setiawati

Research on the application of chitosan derived from oyster (Anadara inflata) shell as adsorbent for heavy metal Cu (II) has been conducted. Optimum conditions for adsorption, including pH, reaction time, and mass of adsorbent were investigated. Adsorption capability of Cu (II) by chitosan under those optimum conditions was subsequently evaluated by determining their adsorption isotherms and interaction mechanism. The results showed that the optimum condition for adsorption were pH 8, contact time 60 min, and mass of adsorbent 300 mg. Under those optimum conditions, chitosan has a high percentage removal of Cu (II) from aqueous solution, up to 70%. The adsorption process was well described as Langmuir isotherm and it is assumed that the interaction between Cu (II) and chitosan was based on chemical mechanism.


2019 ◽  
Vol 31 (6) ◽  
pp. 1343-1348
Author(s):  
K.V. SATHASIVAM ◽  
N.K. FULORIA ◽  
S. FULORIA ◽  
P.J. DARSHENEE ◽  
R. XAVIER ◽  
...  

Present study was intended to explore the biosorption of Cu(II) and Pb(II) ions in aqueous solution using activated carbon biosynthesized from macro-algae Kappaphycus alvarezii under different experimental parameters. Activated carbon was produced via zinc chloride chemical activation method. The effect of parameters such as pH, temperature over biosorption, amount of adsorbents, initial Cu(II) and Pb(II) aqueous concentration, and contact time were studies. The pH 4.0 for adsorption of Cu(II) and Pb(II), and metal ions uptake contact time of 60 min were considered as optimum. Equilibrium data of biosorption were analyzed by models of Langmuir and Freundlich isotherm at different initial Cu(II) and Pb(II) aqueous solutions concentration. Fruendlich adsorption isotherm model fitted well into biosorption data with a regression value of 0.9986. Thermodynamic parameters such as change in change of enthalpy (ΔHº), change of entropy (ΔSº) and Gibbs free energy (ΔGº) were also determined.


2017 ◽  
Vol 726 ◽  
pp. 365-369
Author(s):  
Xia Kong ◽  
Ya Wei Hu ◽  
Wei Pan

Abstract. ZnO nanoparticles with different morphology were synthesized through a one-step and low temperature hydrothermal method with different reaction time. The prepared ZnO nanoparticles have been used as photocatalysts for the degradation of methylene blue (MB) aqueous solution under UV irradiation to study the relationship between the morphology and photocatalytic performance. The phase, crystallographic structure and morphology of synthesised ZnO nanoparticles were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The photocatalytic activity of ZnO nanoparticles were carried out by UV-visible spectroscopy (UV-vis). SEM results showed that different particle sizes and morphologies of flower-like, elliptical-shape and rod-shapes were obtained at 60 °C for 1 h, 4 h, 8 h and 12 h, which promoted photodegradation of methylene blue (MB) aqueous solution under UV light irradiation. Especially, elliptical-shape ZnOnanoparticles with reaction time of 4 h were most efficient, and the degradation rate was up to 98.2% after 20 min UV irradiation.


Author(s):  
Fahimeh Moghadam ◽  
Asma Ghasemi Pourafshar

Background and Aim: Undoubtedly, controlling the maximum entry of heavy metals into the food is one of the measures which should be taken into account in order to maintain the food consumers' health and achieve the food safety. The sensitivity and importance of this issue are doubled due to the irreparable, acute and chronic complications of heavy metals which are classified according to the effects on the nervous system until the carcinogenesis in the human body. On the other hand, this issue is significantly important since these metals differently enter to crops such as tea, water, and rice and generally the food and beverage that are widely consumed. Therefore, the aim of this study is to remove heavy lead metal from aqueous solution by Fenton method. This study is an experimental study. The samples are synthesized in a collection of laboratories at the Faculty of Health, and the pH parameters, contact time and lead elimination rate and the optimal Fenton ratio are investigated. Results are analyzed using SPSS software and Charts are plotted by excel. The results showed that the best pH for removal of lead 5 and its best concentration is 30 mg/ L, and the optimal Fenton ratio is 1 to 5, as well as the best contact time for removal of lead from aqueous media for 10 minutes. The present study showed that the pH factor, contact time, Fenton concentration and lead in all four were effective in removing lead from aquatic solution.


2019 ◽  
Vol 268 ◽  
pp. 01005 ◽  
Author(s):  
Maria Patrichia Oliva ◽  
Clinton Corral ◽  
Michael Jesoro ◽  
John Raymond Barajas

Lack of stringent policies requiring water treatment facilities to combat occurrence of residual antibiotics in effluents critically impairs the resiliency of low-income communities to drug-resistant pathogens. In an attempt to mitigate the effects of residual drugs in aqueous media, we investigate the extent to which rice husk ash (RHA) functionalized by Moringaoleifera protein (MOP) sequestrates amoxicillin in solution. A semi-factorial design was implemented to evaluate the influence of initial amoxicillin concentration, initial MOP functionalized RHA dosage, and contact time on the removal on amoxicillin in water. Results of our experiments have shown that MOP functionalization enhanced RHA by doubling its rate to sequestrate amoxicillin molecules in solution. This strongly indicated that MOP adhered on the surface of RHA significantly improved its capacity to remove amoxicillin contamination in aqueous solution. Statistical analysis employed further supported our results by implying a significant difference between the performance of MOP-functionalized and bare RHA. In conclusion, our results strongly suggest that MOP functionalization can be a potential practical solution to alleviate the vulnerability of communities to emerging antibiotic pollution.


Author(s):  
Bianca Azanfire ◽  
Dumitru Bulgariu ◽  
Lăcrămioara Nemeş ◽  
Laura Bulgariu

The removal of Pb(II) ions is an important issue for the treatment of industrial wastewater, due to its serious consequences on environment and human health. In this study a local clay material was tested as adsorbent for the retention of Pb(II) ions from aqueous solution. The proposed method can be considered low-cost, mainly due to the high availability of clay material in this region, and the high removal percent of Pb(II) ions (> 99%) allows us to say that this method has a high efficiency. Therefore, the finding of the optimal values of the most important experimental parameters which affects the efficiency of Pb(II) ions adsorption on clay adsorbent, represent the next important step in highlighting the practical applicability of this process. The most important experimental parameters, including initial solution pH,adsorbent dose, initial Pb(II) ions concentration, contact time and temperature, were analyzed in batch systems. The obtained experimental results indicates that the efficiency of adsorptionprocess is highest at initial solution pH of 7.0, 4.0 g adsorbent/L, 5 min of contact time and high temperature (50 C). Under these conditions, the removal percent of Pb(II) ions is over 99 % over the initial concentration range between 20 and 310 mg Pb(II)/L. The results of this study suggest that this clay material is an excellent adsorbent for Pb(II) ions removal and broadens the potential applicability of these materials in environmental remediation.


2018 ◽  
Vol 78 (12) ◽  
pp. 2469-2480
Author(s):  
Avat Ghasemi ◽  
Mahmoud Reza Sohrabi ◽  
Fereshteh Motiee

Abstract A new sawdust/magnetite nanoparticles/polyethyleneimine (SD/MNP/PEI) nanocomposite was synthesized by grafting polyethyleneimine (PEI) to magnetic sawdust. Features of SD/MNP/PEI were characterized using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). SD/MNP/PEI was used as an adsorbent for the removal of lead (Pb (II)) from aqueous solution. The effects of independent variables including pH of solution, adsorbent dose and contact time were performed and adsorption isotherms were obtained. Experimental results show that priority effective variables were pH and the amount of nanocomposite, and it was found that the sorption capacity increases with the increasing phase contact time. The adsorption process followed the Langmuir adsorption isotherm. Although SD and SD/MNP do not show a high affinity for the adsorption of Pb (II) in aqueous media, polyethyleneimine cross-linked on SD/MNP showed 40 and 66% increases, respectively, in the adsorption of Pb (II) compared to the SD and SD/MNP. It was found that SD/MNP/PEI removes more efficiently lead ions from aqueous solutions than the SD, SD/MNP. Desorption of the lead from the SD/MNP/PEI was conducted. It was proved that SD/MNP/PEI has excellent properties and can be used as a sorbent of multi-use.


2012 ◽  
Vol 9 (2) ◽  
pp. 621-630 ◽  
Author(s):  
Farah Kanwal ◽  
Muhammad Imran ◽  
Liviu Mitu ◽  
Zeeshan Rashid ◽  
Huma Razzaq ◽  
...  

This study is concerned with the development of some synthetic polymers, copolymers and their sulfonated derivatives as adsorbents. The effectiveness of these adsorbents in removing Cr(III) from aqueous solution was evaluated by batch technique. The influence of different experimental parameters on removal process such as solution pH, contact time, adsorbent dose, Cr(III) concentration and temperature were evaluated. Adsorption equilibrium was achieved in 20 to 30 min. at pH > 5. The Langmuir, Freundlich and Temkin adsorption isotherms were used to elucidate the observed sorption phenomena. The maximum Cr(III)37.8 mg/gram of PS(polystyrene) and 37.2 mg/g of SAN (styrene/acrylonitrile copolymer) was removed as evaluated from Langmuir isotherm while the heat of sorption was in the range 0.21–7.65 kJ/mol as evaluated from Temkin isotherm. It can be concluded that PS developed in this study exhibited considerable adsorption potential for application in removal of Cr(III) from aqueous media as compared to its copolymers and other derivatives used in this study.


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