scholarly journals A Semi-Pilot Photocatalytic Rotating Reactor (RFR) with Supported TiO2 /Ag Catalysts for Water Treatment

2017 ◽  
Author(s):  
Carlos Montalvo ◽  
Claudia Aguilar ◽  
Roberto Alcocer ◽  
Miguel Ramirez
Keyword(s):  
Reaction Time ◽  
Optimal Parameter ◽  
Pilot Scale ◽  
Silver Particles ◽  
Commercial Titanium ◽  
Low Concentrations ◽  
Maximum Reaction ◽  
Conversion Rates ◽  
Total Contact Area ◽  
Ag Catalysts

A four stage semi-pilot scale RFR reactor with ceramic disks as support for TiO2 modified with silver particles was developed for the removal of organic pollutants. The design presented in this article is an adaptation of the rotating biological reactors (RBR) and its coupling with the modified catalyst provides additional advantages to designs where a catalyst in suspension is used. The optimal parameter of rotation was 54 rpm and the submerged surface of the disks offer a total contact area of 387 M2. The modified solid showed a decrease in the value of its bandgap compared to commercial titanium. The system has a semi-automatic operation with a maximum reaction time of 50 h. Photo-activity tests show high conversion rates at low concentrations. The results conform to the Langmuir heterogeneous catalysis model.

scholarly journals A Novel Sucrose Isomerase Producing Isomaltulose from Raoultella terrigena

2021 ◽  
Vol 11 (12) ◽  
pp. 5521
Author(s):  
Li Liu ◽  
Shuhuai Yu ◽  
Wei Zhao
Keyword(s):  
Ph Value ◽  
Wild Type ◽  
Michaelis Constant ◽  
Wild Type Enzyme ◽  
Maximum Reaction Rate ◽  
E Coli ◽  
Maximum Reaction ◽  
Conversion Rates ◽  
Raoultella Terrigena ◽  
Sucrose Isomerase

Isomaltulose is widely used in the food industry as a substitute for sucrose owing to its good processing characteristics and physicochemical properties, which is usually synthesized by sucrose isomerase (SIase) with sucrose as substrate. In this study, a gene pal-2 from Raoultella terrigena was predicted to produce SIase, which was subcloned into pET-28a (+) and transformed to the E. coli system. The purified recombinant SIase Pal-2 was characterized in detail. The enzyme is a monomeric protein with a molecular weight of approximately 70 kDa, showing an optimal temperature of 40 °C and optimal pH value of 5.5. The Michaelis constant (Km) and maximum reaction rate (Vmax) are 62.9 mmol/L and 286.4 U/mg, respectively. The conversion rate of isomaltulose reached the maximum of 81.7% after 6 h with 400 g/L sucrose as the substrate and 25 U/mg sucrose of SIase. Moreover, eight site-directed variants were designed and generated. Compared with the wild-type enzyme, the enzyme activities of two mutants N498P and Q275R were increased by 89.2% and 42.2%, respectively, and the isomaltulose conversion rates of three mutants (Y246L, H287R, and H481P) were improved to 89.1%, 90.7%, and 92.4%, respectively. The work identified a novel SIase from the Raoultella genus and its mutants showed a potential to be used for the production of isomaltulose in the industry.

scholarly journals New analytical methodology for studies of treatment procedures of landfill leachates - experiences from a pilot plant study

2019 ◽  
pp. 273-275
Author(s):  
Lennart Mårtensson ◽  
Staffan Bergström ◽  
Britt-Marie Svensson ◽  
Lennart Mathiasson
Keyword(s):  
Organic Compounds ◽  
Pilot Scale ◽  
Chemical Oxidation ◽  
Landfill Leachates ◽  
Analytical Methodology ◽  
Msw Landfill ◽  
Analytical Protocol ◽  
Low Concentrations ◽  
Before And After ◽  
Treatment Procedures

In this study we have in pilot scale tested different methods for treatment of leachate from amunicipal solid waste (MSW) landfill, Only to focus on sum parameters, nutrients and metalswhen designing treatment methodology for landfill leachate is not enough, it is also importantto measure the content of toxic organic compounds in low concentrations, However, it is notpractical to analyse all substances in the leachate and for making evaluation of treatmentsfeasible our own analytical protocol was created, The efficiency of tested treatmentprocedures was evaluated by measuring changes in concentrations of a number of chosenparameters and organic compounds before and after treatment The treatment methods testedthat showed the highest efficiency towards organic pollutants in leachate were ozonetreatment and chemical oxidation with Fenton's reagent However, more natural basedmethods like filtering the leachate through a bed with peat mixed with carbon containingbottom-ash showed promising results.

scholarly journals Highly Selective Synthesis of Chlorophenols under Microwave Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Yawen Xiong ◽  
Hongdong Duan ◽  
Xia Meng ◽  
Zhaoyun Ding ◽  
Weichun Feng
Keyword(s):  
Reaction Mechanism ◽  
Reaction Time ◽  
Hydrochloric Acid ◽  
Microwave Irradiation ◽  
High Efficiency ◽  
Selective Synthesis ◽  
Conversion Rates ◽  
Electron Donating Groups ◽  
Electron Transfers ◽  
Excellent Selectivity

Oxychlorination of various phenols is finished in 60 minutes with high efficiency and perfect selectivity under microwave irradiation. These reactions adopt copper(II) chloride (CuCl2) as the catalyst and hydrochloric acid as chlorine source instead of expensive and toxic ones. Oxychlorination of phenols substituted with electron donating groups (methyl, methoxyl, isopropyl, etc.) atortho-andmeta-positions is accomplished with higher conversion rates, lower reaction time, and excellent selectivity. A proposed reaction mechanism is deduced; one electron transfers from CuCl2to phenol followed by the formation of tautomeric radical that can be rapidly captured by chlorine atom and converts intopara-substituted product.

scholarly journals Study of production 500 kg/batch polyaluminum chloride from aluminum hydrate

2021 ◽  
Vol 882 (1) ◽  
pp. 012014
Author(s):  
H E Mamby ◽  
K N Hidayat ◽  
A Wahyudi
Keyword(s):  
Reaction Time ◽  
Acid Concentration ◽  
Raw Materials ◽  
Pilot Scale ◽  
Suspended Solid ◽  
Total Acid ◽  
Hydrated Alumina ◽  
Polyaluminum Chloride ◽  
Aluminum Ions ◽  
Materials Used

Abstract Polyaluminum chloride (PAC) is commonly used as a chemical in the water treatment industry, deodorant and paper-making. The PAC is a complex inorganic substance between hydroxyl and aluminum ions that gradually takes place chlorination with its general formula of Alx(OH)yCl3x-y. It has the ability to coagulate suspended solid or dispersed colloid within water perform easily precipitated flock. The raw materials used for manufacturing liquid PAC consists of hydrated alumina (Al(OH)3), hydrochloric acid (HCl), sulfuric acid (H2SO4) and calcium carbonate (CaCO3). A pilot-scale experiment with a capacity of 500 kg/batch feed was conducted by reacting Al(OH)3 with HCl and H2SO4, then neutralized using CaCO3 to obtain liquid PAC and gypsum as a by-product. The variation of acid concentration as reactant and reaction time were conducted to determine its effect on the composition of PAC and the amount of gypsum produced. The optimum experiment produced liquid PAC with the highest Al2O3 composition of 11.96% and the lowest Cl− ion of 10.87% at 2 hours reaction time with a total acid concentration of 37.74%.

Pressurized Pilot-Scale Test Facility for Catalytic Combustion of Simulated Gasified Biomass: First Test Results

2001 ◽  
Author(s):  
J. Jacoby ◽  
T. Strasser ◽  
T. Fransson ◽  
P. Thevenin ◽  
S. Järås
Keyword(s):  
Catalytic Combustion ◽  
Thermal Protection ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Test Facility ◽  
Conversion Rates ◽  
First Results ◽  
Scale Test ◽  
Fuel Source ◽  
Pilot Scale Test

Gasified biomass has become an attractive fuel source for the production of electricity for various processes due to its potential to reduce the net CO2 emission. The overall aim is to combine biomass as a fuel source with high temperature catalytic combustion in order to lower emissions of nitrogen oxides, carbon monoxide and hydrocarbons. This paper presents the design of a pressurized test facility for testing various catalytic materials under varying operating conditions and arrangements in the combustor. Instrumentation of the rig is described. Catalyst development and preparations are being described as well as the first results from the pilot-scale test facility. Different catalyst configurations and compositions have been tested. It was shown that a Pd / LaAl11O18 catalyst is able to ignite the synthetic gasified biomass and that high conversion rates of H2 can be achieved with this type of catalyst. By applying a layer of barium stabilized alumina, thermal protection of the catalyst is achieved, hence limiting the maximum catalyst temperature.

scholarly journals Biodiesel Production through Catalytic Microwave In-situ Transesterification of Micro-algae (Chlorella sp.)

2020 ◽  
Vol 9 (1) ◽  
pp. 113-117
Author(s):  
Mahfud Mahfud ◽  
Ummu Kalsum ◽  
Viqhi Ashwie
Keyword(s):  
Reaction Time ◽  
Microwave Power ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
In Situ Transesterification ◽  
Chlorella Sp ◽  
Low Concentrations ◽  
Face Centered ◽  
Hexane Solution

Aim of this research are to study and develop research related to the potential of Chlorella sp. into biodiesel with the help of microwaves in-situ transesterification by characterizing parameters such as microwave power (300; 450; 600 W) and reaction time (10; 30; 50 minutes) with catalyst concentration of KOH and molar ratio of microalga : methanol are 2% and 1:12 respectively and optimized by response surface methodology with Face Centered Central Composite Design (FCCCD). The study was carried out by dissolving the catalyst into methanol according to the variable which was then put into a reactor containing microalgae powder in the microwave and turned on according to the predetermined variable. After the reaction process is complete, the mixture is filtered and resuspended with methanol for 10 minutes to remove the remaining FAME and then the obtained filtrate is cooled. Water is added to the filtrate solution to facilitate the separation of hydrophilic components before being separated and pushed apart until 3 layers are formed. Amount of FAMEs in the first layer formed were extracted with n-hexane solution and washed with water and the FAME product obtained was then distilled to remove the remaining n hexane and then weighed. The results indicated that yield increased with increasing reaction time and microwave power with the best conditions of 50 minutes each and 440.53 watts with the highest yield reaching 35.72% (dry basis) through using of KOH catalysts with low concentrations, 2%.©2020. CBIORE-IJRED. All rights reserved

scholarly journals Efficient Physisorption of Candida Antarctica Lipase B on Polypropylene Beads and Application for Polyester Synthesis

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 369 ◽  
Author(s):  
Simone Weinberger ◽  
Alessandro Pellis ◽  
James Comerford ◽  
Thomas Farmer ◽  
Georg Guebitz
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Candida Antarctica ◽  
Candida Antarctica Lipase B ◽  
Novozym 435 ◽  
Polymerization Process ◽  
Candida Antarctica Lipase ◽  
Reaction Products ◽  
Lipase B ◽  
Conversion Rates

In the present work, Candida antarctica lipase B (CaLB) was adsorbed onto polypropylene beads using different reaction conditions, in order to investigate their influence on the immobilization process and the enzyme activity of the preparations in polymerization reactions. In general, lower salt concentrations were more favorable for the binding of enzyme to the carrier. Polymerisation of dimethyl adipate (DMA) and 1,4-butanediol (BDO) was investigated in thin-film systems at 70 °C and at both atmosphere pressure (1000 mbar) and 70 mbar. Conversion rates and molecular masses of the reaction products were compared with reactions catalyzed by CaLB in its commercially available form, known as Novozym 435 (CaLB immobilized on macroporous acrylic resin). The best results according to molecular weight and monomer conversion after 24 h reaction time were obtained with CaLB immobilized in 0.1 M Na2HPO4\NaH2PO4 buffer at pH 8, producing polyesters with 4 kDa at conversion rates of 96% under low pressure conditions. The stability of this preparation was studied in a simulated continuous polymerization process at 70 °C, 70 mbar for 4 h reaction time. The data of this continuous polymerizations show that the preparation produces lower molecular weights at lower conversion rates, but is comparable to the commercial enzyme concerning stability for 10 cycles. However, after 24 h reaction time, using our optimum preparation, higher molecular weight polyesters (4 kDa versus 3.1 kDa) were obtained when compared to Novozym 435.

The Preparation of Starch Sodium Octenyl Succinate and its Application as Surface Sizing Agent

2014 ◽  
Vol 936 ◽  
pp. 992-996 ◽  
Author(s):  
Chen Wei Tang ◽  
Zhao Li Liu ◽  
Ya Feng Cao ◽  
Feng Zhi Tan ◽  
Yuan Li
Keyword(s):  
Reaction Time ◽  
Solid Content ◽  
Degree Of Substitution ◽  
Reaction Conditions ◽  
Reaction Efficiency ◽  
Maximum Value ◽  
Maximum Reaction ◽  
Surface Sizing ◽  
Film Forming

The preparation of Starch sodium octenyl Succinate (SSOS) and its application as a surface sizing agent in papermaking was studied in this paper. The effect of different reaction conditions on esterification of starch was firstly discussed. Based on which, SSOS with different degree of substitution (DS) was obtained and its surface sizing performance was researched. The results showed that the optimal esterification conditions were as follows: When pH is 8.5, reaction emperature is 35°C, reaction time is 3h, the maximum reaction efficiency can be achieved. The study of surface sizing performance of SSOS showed that when solid content of SSOS was 0.8613 and its DS was 0.0381, the picking speed of paper was up to a maximum value. SSOS showed a good film-forming property when its concentration was 3%.

Study of the Silanization Process in CNFs: Time, Temperature, Silane Type and Concentration Influence

2009 ◽  
Vol 4 ◽  
pp. 33-43 ◽  
Author(s):  
Cristina Palencia ◽  
F. Rubio ◽  
Cesar Merino ◽  
Juan Rubio ◽  
J.L. Oteo
Keyword(s):  
Thermal Analysis ◽  
Reaction Time ◽  
Functional Group ◽  
Reaction Times ◽  
Coupling Agents ◽  
Temperature Reaction ◽  
Silane Coupling Agents ◽  
Influence Of Temperature ◽  
Low Concentrations ◽  
Silane Coupling

Functionalization of CNFs with silane coupling agents (SCAs) has been studied in this work. APS silane has been used in order to study the influence of temperature and reaction time on the silanization process. Thermal analysis and surface area measurements have revealed that reaction times higher than 1 min. and temperature reaction higher than 25°C do not increase the amount of adsorbed silane on CNFs surface. Silanization process carried with different SCAs (APS, AMO, DMO and GMO) has allowed the study of the concentration and silane structure influence. It has been observed that differences in SCA adsorption are related to the silane structure. Aminosilanes APS and AMO show a very similar behaviour because they have the same functional group. However, the diaminosilane DMO shows lower interaction with CNFs surface due to the length of the diamine chain, that avoid further silane adsorption on the coated CNFs surface. The epoxysilane GMO shows a similar behaviour to other SCAs at low concentrations, while for high silane concentrations epoxysilane GMO forms multilayers.

Removal of Toxic Arsenic and Antimony from Groundwater Spiro Tunnel Bulkhead in Park City Utah Using Colloidal Iron Hydroxide: Comparison with Reverse Osmosis

2009 ◽  
Vol 83-86 ◽  
pp. 553-562 ◽  
Author(s):  
Z. Pawlak ◽  
P.S. Cartwright ◽  
Adekunle Oloyede ◽  
E. Bayraktar
Keyword(s):  
Reverse Osmosis ◽  
Removal Rate ◽  
Iron Hydroxide ◽  
Pilot Scale ◽  
Arsenic Acid ◽  
Colloidal Iron ◽  
Low Concentrations ◽  
Silver Mine ◽  
Ph Range ◽  
Filtration Technology

Verification testing of two model technologies in pilot scale to remove arsenic and antimony based on reverse osmosis and chemical coagulation/filtration systems was conducted in Spiro Tunnel Water Filtration Plant located in Park City, Utah, US. The source water was groundwater in abandoned silver mine, naturally contaminated by 60-80 ppb of arsenic and antimony below 10 ppb. This water represents one of the sources of drinking water for Park City and constitutes about 44% of the water supply. The failure to remove antimony efficiently by coagulation/filtration (only 4.4% removal rate) under design conditions is discussed in terms of the chemistry differences between Sb (III, V) and As (III, V). Removal of Sb(V) at pH > 7, using coagulation/filtration technology, requires much higher (50 to 80 times) concentration of iron (III) than As. The stronger adsorption of arsenate over a wider pH range can be explained by the fact that arsenic acid is tri-protic, whereas antimonic acid is monoprotic. This difference in properties of As(V) and Sb(V) makes antimony (V) more difficult to be efficiently removed in low concentrations of iron hydroxide and alkaline pH waters, especially in concentration of Sb < 10 ppb.

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