scholarly journals Host (dealumination Y zeolite)-guest (substituted heteropolyacid) nanocomposites as an efficient catalyst in the removal of methyl orange

Author(s):  
Maryam Moosavifar ◽  
Fariba Mavadat ◽  
Armen Avanes

Abstract Substituted polyoxometal encapsulated into Y zeolite was synthesized with two ratios: H5PMo10W1Ti1O40.XH2O/Y (hereafter designated as SPY-1011, the numbers show the amount of Mo, W, Ti, respectively) and H5PMo1W10Ti1O40.XH2O/Y (hereafter designated as SPY-1101) was synthesized using the template synthesis method. The nanocomposite materials were characterized by XRD, FT-IR, UV-Vis, FESEM, and EDS techniques. The photocatalytic activity of systems was investigated within the photodegradation of methyl orange. The W, Mo, and Ti content of the catalyst was evaluated by the ICP method. The results showed that the photocatalyst performance depends on catalyst loading, pH effect, methyl orange concentration, the type, and the number of substituted species. The chemical oxygen demand (COD) experiment indicated mineralisation of the methyl orange with 83% after 120 min irradiation. The absences of hydrazine during degradation confirmed by the amperometric experiment, in turn, showed methyl orange converted to simple inorganic materials. Photocatalytic degradation of methyl orange follows a pseudo-first-order kinetic.

2007 ◽  
Vol 336-338 ◽  
pp. 1983-1985 ◽  
Author(s):  
Xiu Yan Li ◽  
Ling Ke Zeng ◽  
Ping An Liu ◽  
Hui Wang ◽  
An Ze Shui

The photocatalyst of nanometer ZnO powder was prepared by precipitation method with ZnSO4⋅7H2O and Na2CO3 as raw materials. Laboratory experiments with methyl orange (MO) as the model pollutant have been carried out to evaluate the photocatalytic activity of nanometer ZnO photocatalyst. A high-pressure mercury lamp was used as the energy source for the photocatalytic experiments. The effects of process parameters such as catalyst loading, initial methyl orange concentration, pH and electrolyte on the photodegradation have been investigated.


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Emmanuel Kweinor Tetteh ◽  
Sudesh Rathilal

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.


Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract


2018 ◽  
Vol 31 ◽  
pp. 03002 ◽  
Author(s):  
Hadiyanto Hadiyanto

Tofu industries produce waste water containing high organic contents and suspendid solid which is harmful if directly discharged to the environment. This waste can lead to disruption of water quality and lowering the environmental carrying capacity of waters around the tofu industries. Besides, the tofu waste water still contains high nitrogen contents which can be used for microalgae growth. This study was aimed to reduce the pollution load (chemical oxygen demand-COD) of tofue wastewater by using ozone treatments and to utilize nutrients in treated tofu waste water as medium growth of microalgae. The result showed that the reduction of COD by implementation of ozone treatment followed first order kinetic. Under variation of waste concentrations between 10-40%, the degradation rate constant was in the range of 0.00237-0.0149 min-1. The microalgae was able to grow in the tofue waste medium by the growth rate constants of 0.15-0.29 day-1. This study concluded that tofu waste was highly potent for microalgae growth.


2013 ◽  
Vol 750-752 ◽  
pp. 1397-1400 ◽  
Author(s):  
Li Mei Duan ◽  
Jing Hai Liu ◽  
Xiu Ting Xu ◽  
Ling Xu ◽  
Zong Rui Liu

Applying one-step solvothermal synthesis method, different CdS/TiO2 nanocomposite materials are obtained by changing the ratio of sulfur and titanium sources. The composite structure and morphology are determined by XRD and TEM. Taking the degradation of methyl orange solution as a model reaction, the photocatalytic activity of CdS/TiO2 composite materials is investigated. The results show that the amount of CdS in composite photocatalyst has great effects on the degradation efficiency of methyl orange under the irradiation of sunlight, and the lower pH of reaction system is also needed to sustain the high degradation efficiency for methyl orange.


2018 ◽  
Vol 78 (10) ◽  
pp. 2131-2140 ◽  
Author(s):  
Oscar M. Rodríguez-Narváez ◽  
Oracio Serrano-Torres ◽  
Kazimierz Wrobel ◽  
Enric Brillas ◽  
Juan M. Peralta-Hernandez

Abstract This paper reports the degradation of a solution of 0.314 mM diclofenac (DCF), while using 5–15 mM Oxone as oxidizing agent with the catalytic action of 0.05–0.2 mM Co2+. The best performance was obtained for 10 mM Oxone and 0.2 mM Co2+, achieving the total DCF abatement and 77% removal of chemical oxygen demand after 30 min. Oxidizing of sulfate () and hydroxyl (•OH) radicals was formed by the Co2+/Oxone system. Oxone was firstly oxidized to persulfate ion that was then quickly converted into the above free radicals. For Oxone contents ≥10 mM, the decay of DCF concentration followed a second-order kinetic reaction, but the apparent rate constant changed with the Co2+ concentration used. High-performance liquid chromatography (HPLC) analysis of treated solutions showed the formation of some intermediates, whereas oxalic acid was identified as the prevalent final short-linear carboxylic acid by ion-exclusion HPLC.


2017 ◽  
Vol 14 (3) ◽  
pp. 582-587
Author(s):  
Baghdad Science Journal

In this work, the photocatalytic degradation of indigo carmine (IC) using zinc oxide suspension was studied. The effect of influential parameters such as initial indigo carmine concentration and catalyst loading were studied with the effect of Vis irradiation in the presence of reused ZnO was also investigated. The increased in initial dye concentration decreased the photodegradation and the increased catalyst loading increased the degradation percentage and the reused-ZnO exhibits lower photocatalytic activity than the ZnO catalyst. It has been found that the photocatalytic degradation of indigo carmine obeyed the pseudo-first-order kinetic reaction in presence of zinc oxide. This was found from plotting the relationship between ln (C0/Ct) and irradiation the rate constant of the process.UV- spectrophotometer was used to study the indigo carmine photodegradation.


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.


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