A Hepatic Sinusoids-Based Microreactor for Photocatalytic Degradation of Methylene Blue by Titanium Dioxide

Author(s):  
Mahmoud A. Shouman ◽  
Ahmed H. El-Shazly ◽  
Mohamed S. Salem ◽  
Mohamed R. Elmarghany ◽  
Essam M. Abo-Zahhad ◽  
...  

Abstract Microreactor technology is considered a state of art technology that gained great attention from researchers due to the high effectiveness and the small residence time compared with other regular reactors. Great research work has been established to involve microreators in a variety of applications, including fuel production, food and chemical industries, medical applications. In the present study, a hepatic sinusoids-based microreactor is experimentally tested in Methylene blue degradation using titanium dioxide (TiO2) photocatalyst activated with ultraviolet lamp of wavelength 365 nm. Purification of water using photocatalysis is considered a promising technology that attract the industrial community. Different operating conditions are investigated including; flow rate, Methylene blue concentration, and TiO2 concentration. 3 different dye concentrations are used (10 ppm, 20 ppm, and 30 ppm) with 3 different photocatalyst concentrations (100 ppm, 300 ppm, and 500 ppm). The flow rate has a span from 0.25 ml/min to 1 ml/min. Experiments are conducted to determine best operating conditions. Results show that the microreactor system can be effectively used in dye degradation with a very small residence time. A degradation of over 95% was reached at a TiO2 concentration of 300 ppm and a flow rate of 0.25 ml/min for all tested dye concentrations.

2017 ◽  
Vol 15 (1) ◽  
pp. 129-138 ◽  
Author(s):  
Seied Mahdi Pourmortazavi ◽  
Mehdi Rahimi-Nasrabadi ◽  
Mohammad Reza Ganjali ◽  
Meisam Sadeghpour Karimi ◽  
Parviz Norouzi ◽  
...  

AbstractRegarding the importance of nanoparticles in today’s world, and in the light of the fact that their preparation can be a rather difficult task, we focused on the applicability of a simplistic direct precipitation approach for the preparation of praseodymium tungstate nanoparticles. To maximize the effectiveness of the method, a Taguchi robust design approach was applied to optimize the reaction in terms of the operating conditions influencing its outcome and the results were monitored by characterization of the Pr2(WO4)3 nanoparticles. Among the four parameters studied we found the dimensions of the produced nanoparticles to be determined by the concentrations of Pr3+ and WO43− solutions and the reaction temperature, while the flow rate of adding the cation solutions to the anion solution was found to leave very negligible effects on the product characteristics. To confirm the effect of the optimizations on the outcomes of the reaction, SEM, TEM, EDX, XRD, FT-IR and UV-Vis structural and morphological characterizations of the products were performed, the results of which were in agreement with those statistically predicted in the optimization procedure. Furthermore, as-synthesized praseodymium tungstate nanoparticles under ultraviolet light exhibited an efficient photocatalyst property in the photocatalytic degradation of methylene blue.


2020 ◽  
Vol 4 (3) ◽  
pp. 148-153
Author(s):  
Moses Titus Yilleng ◽  
Moses Sunday ◽  
Doctor Stephen

Titanium dioxide has proven to be one of the most promising heterogeneous catalyst. This work explores the photocatalytic activity of modified titanium dioxide. Nitrogen was incorporated into mesoporous TiO2 using Sol-gel method. The N-TiO2 was characterized using X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) thermogravimetric analysis (TGA), and U-Vis diffuse reflectance spectroscopy (DRS). 1%wtN-TiO2 expresses the highest photoactivity in UV light compared to 3%wtN-TiO2 and 5%wt N-TiO2 respectively. The photodegradation efficiency of the catalyst follows the following trend 1%wtN-TiO2 >3%wtN-TiO2 >5%wtN-TiO2>PURE-TiO2. The results obtained from the kinetics investigation shows the following trends 1%wtN-TiO2 is 0.049 s-1, 3%wtN-TiO2 is 0.0289 s-1, 5%wtN-TiO2 is 0.0143 s-1, and the PURE-TiO2 is 0.0118 s-1. The consistency in the rate constant values of the phodegradation of methylene blue; it clearly showed that the reaction follows a pseudo-first order kinetics.


2021 ◽  
Vol 21 (4) ◽  
pp. 2511-2519
Author(s):  
Muhammad Ali Bhatti ◽  
Aqeel Ahmed Shah ◽  
Khalida Faryal Almaani ◽  
Aneela Tahira ◽  
Ali Dad Chandio ◽  
...  

In this research work, we have produced a composite material consisting titanium dioxide (TiO2) and zinc oxide (ZnO) nanostructures via precipitation method. Scanning electron microscopy (SEM) study has shown the mixture of nanostructures consisting nanorods and nano flower. Energy dispersive spectroscopy (EDS) study has confirmed the presence of Ti, Zn and O as main elements in the composite. X-ray diffraction (XRD) study has revealed that the successful presence of TiO2 and ZnO in the composite. The composite material exhibits small optical energy band gap which led to reduction of the charge recombination rate of electron–hole pairs. The band gap for the composite TiO2/ZnO samples namely 1, 2, 3 and 4 is 3.18, 3.00, 2.97 and 2.83 eV respectively. Small optical bandgap gives less relaxation time for the recombination of electron and hole pairs, thus favorable photodegradation is found. The degradation efficiency for the TiO2/ZnO samples for methylene blue in order of 55.03%, 75.7%, 85.14% and 90.08% is found for the samples 1, 2, 3 and 4 respectively. The proposed study of titanium dioxide addition into ZnO is facile and inexpensive for the development of efficient photocatalysts. This can be capitalized at large scale for the energy and


2003 ◽  
Vol 767 ◽  
Author(s):  
Ara Philipossian ◽  
Erin Mitchell

AbstractThe residence time distribution of slurry in the pad-wafer interface was experimentally determined and used to calculate the slurry utilization efficiency (η) of the CMP process. Slurry utilization efficiency represents the percentage of slurry that actually participates in the polish by entering the region bounded between the wafer and the pad. Results show that η ranges from 2 to 22 percent, depending on operating conditions such as applied wafer pressure, relative pad wafer velocity, slurry flow rate and pad surface texture (i.e. type of pad grooving).


2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Delia Teresa Sponza ◽  
Cansu Doğanx

The scope of this study, is  1-butanol production from CO2 with S. elongatus PCC 7942 culture. The yields of 1-butanolproduced/CO2utilized have been calculated. The maximum concentration of produced 1- butanol is 35.37 mg/L and 1-butanolproduced/CO2utilized efficiency is 92.4. The optimum operational conditions were  30°C temperature, 60 W intensity of light, pH= 7.1, 120 mV redox potential, 0.083 m3/sn flow rate with CO2 and 0.5 mg/l dissolved O2 concentration. Among the enzymes on the metabolic trail of the production of 1-butanol via using S. elongatus PCC 7942 cyanobacteria. At maximum yield; the measured concentrations are 0.016 µg/ml for hbd; 0.0022 µg/ml for Ter and 0.0048 µg/ml for AdhE2. The cost analyses necessary for 1-butanol production has been done and the cost of 1 litre 1-butanol has been determined as maximum 1.31 TL/L.


2003 ◽  
Vol 3 (5-6) ◽  
pp. 67-72
Author(s):  
S. Takizawa ◽  
T. Win

In order to evaluate effects of operational parameters on the removal efficiency of trichloroethylene and 1,1,1-trichloroethene from water, lab-scale experiments were conducted using a novel hollow-fibre gaspermeable membrane system, which has a very thin gas-permeable membrane held between microporous support membranes. The permeation rate of chlorinated hydrocarbons increased at higher temperature and water flow rate. On the other hand, the effects of the operational conditions in the permeate side were complex. When the permeate side was kept at low pressure without sweeping air (pervaporation), the removal efficiency of chlorinated hydrocarbon, as well as water permeation rate, was low probably due to lower level of membrane swelling on the permeate side. But when a very small amount of air was swept on the membrane (air perstripping) under a low pressure, it showed a higher efficiency than in any other conditions. Three factors affecting the permeation rate are: 1) reduction of diffusional boundary layer within the microporous support membrane, 2) air/vapour flow regime and short cutting, and 3) the extent of membrane swelling on the permeate side. A higher air flow, in general, reduces the diffusional boundary layer, but at the same time disrupts the flow regime, causes short cutting, and makes the membrane dryer. Due to these multiple effects on gas permeation, there is an optimum operational condition concerning the vacuum pressure and the air flow rate. Under the optimum operational condition, the residence time within the hollow-fibre membrane to achieve 99% removal of TCE was 5.25 minutes. The log (removal rate) was linearly correlated with the average hydraulic residence time within the membrane, and 1 mg/L of TCE can be reduced to 1 μg/L (99.9% removal).


2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1546
Author(s):  
Árpád Imre-Lucaci ◽  
Melinda Fogarasi ◽  
Florica Imre-Lucaci ◽  
Szabolcs Fogarasi

This paper presents a novel approach for the recovery of lead from waste cathode-ray tube (CRT) glass by applying a combined chemical-electrochemical process which allows the simultaneous recovery of Pb from waste CRT glass and electrochemical regeneration of the leaching agent. The optimal operating conditions were identified based on the influence of leaching agent concentration, recirculation flow rate and current density on the main technical performance indicators. The experimental results demonstrate that the process is the most efficient at 0.6 M acetic acid concentration, flow rate of 45 mL/min and current density of 4 mA/cm2. The mass balance data corresponding to the recycling of 10 kg/h waste CRT glass in the identified optimal operating conditions was used for the environmental assessment of the process. The General Effect Indices (GEIs), obtained through the Biwer Heinzle method for the input and output streams of the process, indicate that the developed recovery process not only achieve a complete recovery of lead but it is eco-friendly as well.


2020 ◽  
Vol 17 (4) ◽  
pp. 47-52
Author(s):  
Vibha Goswami ◽  
Renu Upadhyaya ◽  
Sumanta Kumar Meher

In this study, synthesised Azadirachta indica adsorbent was used for the removal of methylene blue dye using a packed bed column. The effect of feed flow rate, feed methylene blue dye concentration, and bed height of column on percentage removal of dye was studied. It was observed that the column bed exhausted rapidly at a higher flow rate and therefore, a breakthrough occurred faster. However, it was observed that bed exhaustion time increases on increasing the bed height from 2 to 10 inch at 10 mg/L feed dye concentration and feed flow rate of 40 ml/min. It was also found that the breakthrough curve is more dispersed and the percentage removal of dye increases on decreasing the feed methylene dye concentration from 150 to 10 mg/L. The percentage removal was found to be 96.89% at 20 ml/min of feed flow rate under 10 inch of bed height and 10 mg/L of feed dye concentration. The atomic absorption spectrophotometer and scanning electron microscope were used for estimating the effluent dye concentration from the column and morphological study, respectively.


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