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

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.

Application of Central Composite Design to the Photo Fenton Degradation of Methyl Orange Azo Dye Using Fe-Activated Carbon Catalyst

Photo-fenton oxidation technique is one of the emerging oxidation processes explored in treatment of organic pollutants in aqueous solutions. This research is focused on utilization of Fe(II) loaded activated carbon and H2O2(aq) in a photofenton process to generate hydroxyl radicals that mineralize methyl orange dyes. Samples of activated carbon were treated with Fe(NO3)2(aq) and characterized using SEM, pHZPC, specific surface area and boehm’s titration. The degradation of methyl orange by the iron loaded activated carbon (Fe-Ac), via photo-Fenton process, was investigated in lab-scale defined by experimental design. Central composite design (CCD) was used to evaluate the effects of the five independent variables considered for the optimization of the oxidative process: time, FeAc dose, methyl orange concentration, pH and H2O2 concentrations. In the optimization, the correlation coefficients (R2 ) for the quadratic model was 0.9941. Optimum reaction conditions were obtained at pH = 3, catalyst dose = 0.1 mg/100ml, H2O2 = 0.62ml, methyl orange concentration = 5mg/l and time = 30 minutes.

Electrospun 3,5-dithienylvinyleneBODIPY embedded polystyrene nanofibers for the photocatalytic degradation of azo dyes in industrial wastewaters

The potential utility of electrospun polystyrene (PS) nanofibers embedded with 2,6-diiodo-8-phenyl-1,7-dimethyl-3,5-di-2-thienylvinyleneBODIPY for the photocatalytic degradation of azo dyes is investigated. A comparison of the singlet oxygen quantum yield of the [Formula: see text]-extended BODIPY dye in solution and in the PS nanofibers demonstrates that its photosensitizer properties are retained when it is embedded in the solid phase. The photocatalytic degradation properties of the PS nanofibers for Methyl Orange and Orange G were determined by using a Thorlabs 625 nm light emitting diode. The rate of photodegradation increases with the Orange G and Methyl Orange concentration and follows pseudo-first order kinetics at pH 6.7.

Photocatalytic and Photoelectrocatalytic Degradation of Methyl Orange Using Graphite/PbTiO3 Composite

Synthesis of graphite/PbTiO3 composite as a catalyst in photodegradation and photoelectrodegradation process of methyl orange have been conducted. The purposes of this research are to study the effect of radiation time, composition of composite, voltage and pH of solution for methyl orange degradation. Photodegradation process of methyl orange was carried out for 5; 10; 15; 20; 25 and 30 min. Ratio of graphite : PbTiO3 (w/w) were varied at 1:3; 1:2; 1:1; 2:1 and 3:1. Meanwhile, the applied voltages were 7.5; 10 and 12.5 V and the photoelectrodegradation was conducted under pH condition of 3; 7; and 11, respectively. The result showed that optimum composition of graphite/PbTiO3 in the methyl orange photodegradation was obtained at 1:1 ratio for 30 min with degradation up to 90.43% ± 0.062. The degradation reaction follows first order reaction with a rate constant of 0.0688 min-1. The optimum voltage is 10 V, in which it reduced the methyl orange concentration up to 92.65% ± 0 with a rate constant 0.0941 min-1 for first order reaction. The optimum pH is pH = 11, that provide methyl orange reduction up to 95.28% ± 0.082.

FOTODEGRADASI METHYL ORANGE DALAM REAKTOR FIXED BED BATU APUNG-SEMEN

Abstrak Tujuan penelitian ini adalah untuk mengetahui karakteristik batu apung dan semen yang digunakan sebagai bed dalam reaktor fixed bed dan efektivitasnya dalam mendegradasi methyl orange akibat pengaruh pH larutan dan sinar dalam sistem reaksi. Bed yang digunakan adalah batu apung berukuran kecil dengan perekatan semen dalam cetakan stainless steel berukuran 5x16x16 cm. Fotodegradasi methyl orange dijalankan pada pH larutan 7 dan diberikan sinar 2 buah lampu UV Sankyo Denky FT10T8BLB FL10BLB 10 W 325 nm selama 1, 2, 3, 4, 5, 6 dan 7 jam. Methyl orange disirkulasi pada temperatur kamar dari tangki penampungan menuju reaktor fixed bed menggunakan pompa dengan debit sebesar 6,89 mL/detik. Batu apung dan semen yang digunakan sebagai bed dianalisis bentuk dan unsur yang dikandungnya dengan menggunakan SEM EDX. Konsentrasi methyl orange sebelum dan setelah proses fotodegradasi diukur dengan menggunakan spektrofotometer UV Visibel Shimadzu 1240. Hasil penelitian menunjukkan bahwa batu apung memiliki bentuk yang tidak beraturan dengan kandungan unsur tertinggi berupa Si sedangkan semen yang digunakan sebagai perekat memiliki bentuk seperti butiran yang homogen dengan kandungan unsur tertinggi Ca. Fotodegradasi methyl orange berjalan optimum pada pH 3 untuk waktu penyinaran 7 jam sebesar 40,37%. Degradasi methyl orange berlangsung efektif dengan adanya sinar dibandingkan tanpa penyinaran. Reaksi fotodegradasi methyl orange mengikuti kinetika reaksi orde satu semu dengan nilai k sebesar 0,0378 jam-1. Kata kunci : batu apung-semen, fotodegradasi, methyl orange, reaktor fixed bed Abstract The objectives of this research were to know the characterization of pumice stone and cement used in fixed bed reactor. The fixed bed used was made from pumice stone with a gluing cement in 5x16x16 cm stainless steel mold. Methyl orange photodegradation were carried out with pH 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,and 14 and irradiated by 2 lamps of UV Sankyo Denky FT10T8BLB FL10BLB 10 W 325 nm for 1, 2, 3, 4, 5, 6 and 7 hours. Methyl orange was circulated at room temperature from its reservoir to fixed bed reactor by a pump with 6.89 mL/s. Pumice stone and cement were analyzed by SEM EDX to know its characterization. Methyl orange concentration before and after photodegradation were measured by UV Visible Spectrophotometer Shimadzu 1240. The result showed that pumice stone has irreguler shape with the highest material is Si and cement has homogeneous granule with the highest material is Ca. The best fotodegradation of methyl orange with UV irradiation at pH 3. Methyl orange photodegradation follows pseudo first order kinetics with reaction constant 0,0378 hour-1. Keywords : fixed bed reactor, methyl orange, pumice stone-cement, photodegradation

OPTIMASI FOTODEGRADASI METIL ORANYE MENGGUNAKAN FOTOKATALIS TiO2/Al2O3 MONTMORILONIT

Abstrak: Dispersi TiO2 ke dalam montmorilonit terpilar aluminium (PILM) telah sukses dilakukan. Fotokatalis dibuat dengan menginterkalasikan Al13 ke dalam montmorilonit alam kemudian dikalsinasi pada temperatur 500oC. Dispersi TiO2 ke dalam montmorilonit terpilar aluminium (PILM) dilakukan dengan menggunakan metode impregnasi dengan konsentrasi teoritis 0,4%, 0,8% 1% dan 3%. Fotodegradasi metil oranye optimum diperoleh pada Ti/PILM 1%, pH 10, konsentrasi metil oranye 1,5 M dan konsentrasi katalis 1 gram/liter dengan laju konstanta orde satu sebesar 21,77x10-3 per menit.Kata kunci : Metil Oranye, Montmorilonit,Optimasi, Fotokatalis, TiO2Abstract: Dispersion of TiO2 on montmorillonite pillared aluminium has been done successfully. The photocatalyst were prepared by intercalation of Al13 onto natural montmorillonite and then calcined at 500oC. Titania dispersion onto aluminium pillared montmorillonite was carried out by impregnation method at the theoritic concentration of 0.4%, 0.8%, 1% and 3% titania. Photodegradation optimum of methyl orange was found to be at Ti/PILM 1%, pH 10, methyl orange concentration 1.5 M and concentration of photocatalyst 1 gram/litre. The photodegradation follows first order reaction with constan rate of 21.77x10-3 per minutes.Key Word: Methyl Orange, Montmorillonite, Optimation, Photocatalyst, TiO2

A STUDY OF THE ADSORPTION OF DYES FROM THEIR AQUEOUS SOLUTIONS BY MORUPULE COAL 1

The adsorption of methyl orange (MO) from its solution by steam activated coal from Morupule colliery was investigated spectrophotometrically using the batch technique, through kinetics and thermodynamics’ study, and found to be reversible at all temperatures used. This was to check whether the coal could be used to purify dye-polluted water from dying and printing textile industry. The effects of varying methyl orange concentration, solution pH and temperature were investigated. The adsorption rate and the adsorption capacity increased with increasing initial concentration, with decreasing solution pH and with increasing temperature. The adsorption capacity was generally low probably due to the low coal surface area (10 m2g-1). The increase in rate and capacity with increasing temperature is believed to be increased surface area due to the swelling of coal which accompanies its heating. The adsorption kinetics fitted the Lagergren pseudo second order model best indicating overall third order or dual simultaneous pseudo first order processes. Results from the thermodynamic study fitted Freundlich model best indicating heterogeneity of the surface of the coal sample.

Preparation and Photocatalytic Performance Study of La-WO3 Co-Doping TiO2

Butyl titanate as titanium source, anhydrous ethanol as solvent, glacial acetic acid as inhibitor, La-WO3/TiO2, La/TiO2, WO3/TiO2and pure TiO2 photocatalysts were prepared through sol-gel method; At the same time, both of which were characterized by infrared spectrometer and uv-vis spectrophotometer; With methyl orange as simulated target degradation material, heat treatment temperature、different dopants, etc. on photocatalytic performance influences of TiO2were studied by spectrophotometer. Experimental results show that doping can improve obviously the photocatalytic activity of TiO2. When calcination temperature is 500 ℃, dosage of catalyst is 0.25 g, pH is 1, and methyl orange concentration is 10 mg/L, La-WO3/TiO2 photocatalytic effect is best, and degradation rate is 46.18%.

Preparation and Photocatalytic Performance Study of Na+/K+-WO3 by Ultrasonic Micro Method

With n-butanol/CTAB/cyclohexane as micro emulsion system, sodium tungstate and hydrochloric acid as raw material, alkali metals (Na+, K+) nitrate as dopant, pure WO3、Na+-WO3, K+-WO3 and Na+/K+-WO3 powders were prepared by ultrasonic micro-emulsion method; And performances of samples were analyzed by visible spectrophotometer. Photocatalytic activity study show that alkali metal sodium ion and potassium ion doped, photocatalytic activities of WO3 are improved markedly; When doping amount is 1.0%, catalyst amount is 2g/L, methyl orange concentration is 20mg/L, degradation time is 80 min, Na+-WO3 powder has the best photocatalytic degradation performance at 460nm, and the degradation rate is as high as 65%.

Polymer-Titania Composites for Photocatalysis of Organics in Aqueous Environments

Microcomposites composed of titanium dioxide nanoparticles embedded within cross-linked, thermally responsive microgels of poly(N-isopropylacrylamide) were prepared. These microcomposites showed rapid sedimentation, which is useful for gravity separation of the titania nanoparticles in applications such as environmental remediation. To investigate the degradation kinetics using these microcomposites in aqueous suspensions, methyl orange was employed as a model contaminant. The decline in the methyl orange concentration was monitored using UV-Vis spectroscopy. Degradation of methyl orange was also measured using only nanoparticles TiO2 (DegussaTM P25) for comparison with the microcomposites. Experiments were performed at different pH conditions that spanned acidic, neutral, and basic conditions to gain insight into the interplay of TiO2 surface charge, ionization of the polyelctrolyte chains in the microcomposites, and ionization of the methyl orange.