Conditions In Batch Reactor Research Articles

Carbon Dioxide Sequestration in Alkaline Top Soil Using Alkaline Wastes

Due to growing concern about climate change and global warming, new ways must be developed to reduce CO2 emissions in atmosphere. Incinerator ash produced in municipal treatment facilities and marble-dust produced during marble cutting process are alkaline wastes. This paper examines the carbon mineral sequestration potential of mixing alkaline wastes in two soil samples in accelerated carbonation conditions. Six different percentages of alkaline wastes in 20g sample were used. Batch reactor conditions were maintained at 40°C, relative humidity 60-70% and CO2 flow-rate of 10 litres-a-minute. Optimum water content was found by carrying out experiments on a sample with 7 different water-to-solid ratio (0, 0.2, 0.4, 0.6, 0.8, 1 and 1.2). The particle-size effect was gauged by taking soil samples sieved through standard sieve sizes of BSS25 and BSS50. It was concluded that low water-to-solids ratio is better for carbonation, although some minimum amount of water is necessary for reaction. The optimum water-to-solids ratio for incinerator ash comes to be 0.4. Marble dust was found to be inefficient to capture CO2 due to lower pH and due to lump formation. As expected, carbonation was higher for samples with less particle size and higher surface area.

Synthesis and application of FeIII, NiII and MnII complexes anchored to HMS as efficient catalysts for cycloalkane oxyfunctionalization

Methoxysilane Schiff-base pentacoordinate metal complexes, i.e. Fe[Sal(PMeO-Si)DPTA], Ni[Sal(PMeO-Si)DPTA] and Mn[Sal(PMeO-Si)DPTA], were synthesized and single site covalently anchored into the uniform porous texture of HMS (2–10nm size) via condensation process. The correspondent supported catalysts (4.a, 4.b and 4.c, respectively) were characterized by FT-IR, SEM/EDS, XRD, TG, EPR and AAS analysis. In the catalytic tests, they showed high efficiency in the selective oxidation of cyclohexane using molecular O2 (overall conversion 40.7% with Cat. 4.a, 29.5% with Cat. 4.b and 26.2% with Cat. 4.c) under relatively mild condition in batch reactor. The Cat. 4.a system (HMS/3.a) exhibits highest TONs ca. 4.2×103 with good selectivity ca. 70% (48% ketone selectivity). The reaction mechanism involves free radicals, as it was proved by the addition of PPh3. Finally, these supported catalysts could be reuse up to several catalytic cycles.

Aldol condensation of furfural and acetone on zeolites

Zeolites of different structural types were used as catalysts for aldol condensation of furfural and acetone in batch reaction conditions at T=20–100°C and time 0–24h. To establish a relation between physico-chemical and catalytic properties of microporous materials, the samples were characterized by SEM, N2 adsorption, FTIR and TGA. It was found that the acidic solids possessed appreciable activity in the reaction and resulted in a formation of products of aldehyde–ketone interaction. Nevertheless, furfural conversion decreased rapidly due to coke formation inside zeolite pores. Simultaneously with a general route of the reaction observed for basic catalysts, dimerization of the condensation product on acidic sites occurred. It was supposed that catalytic behavior of zeolites considerably affected by their both structural and textural properties. Experiments with re-used samples showed that zeolites totally restored their activity and selectivity after calcination at 530°C.

The characteristic and comparison of denitrification potential in granular sequence batch reactor under different mixing conditions

The aim of the present work was to characterize and compare the denitrification potential of aerobic granular sludge under four different mixing conditions in lab-scale granular sequence batch reactor (GSBR). Batch experimental results showed that the specific denitrification rate (SDR) reached 0.68 and 0.11kgNOx–N/m3d with and without mixing, respectively. The lowest SDR of 0.091kgNOx–N/m3d was achieved under intermittent aeration condition, which mainly resulted from the high dissolved oxygen (DO) concentration and poor mixing in denitrification process. The SDR and NOx–N removal efficiency was improved to 0.7kgNOx–N/m3d and 97% under mixing condition by introducing gaseous nitrogen to reactor during 60min denitrification process. It was found that the mixture under recycling supernatant liquid condition did not benefit for the stability of granules due to the sludge floating problem in denitrification process. The mechanical stir had little impact on granules under oxic/anoxic combined with mixing by mechanical stir in anoxic phase operational strategy. When the total nitrogen (TN) and chemical oxygen demand (COD) were kept at 55 and 320mg/L in the influent, the SDR, nitrogen removal efficiency and rate reached approximately 0.64kgNOx–N/m3d, 97.7% and 0.255kgN/m3d in 50days continuous operation.

Impact of Organic Carbon on the Biodegradation of Estrone in Mixed Culture Systems

The effects of organic carbon concentrations and loading on the degradation of estrone (E1) were examined under various conditions in batch reactors and membrane-coupled bioreactors (MBRs). Experiments examined effects on individual microorganisms (substrate competition and growth) and on the whole community (selection). Substrate competition with organic carbon (competitive inhibition and catabolic repression) was not a factor in E1 degradation (P = 0.19 and 0.29 for two different analyses). Conversely, addition of organic carbon increased E1 degradation rates, attributable to biomass growth in feast-famine reactors over a five-day period (P = 0.016). Subsequently, however, community dynamics controlled E1 degradation rates, with other organisms outcompeting E1 degraders. More moderate but sustained increases in E1 degradation rates were observed under starvation conditions. Low influent organic carbon strength was detrimental to E1 degradation in MBRs, where organic carbon concentration and loading were decoupled (P = 0.018). These results point to the importance of multiple substrate utilizers in E1 degradation. They also suggest that while initial growth of biomass depends on the presence of sufficient organic carbon, further enrichment under starvation conditions may improve E1 degradation capability via the growth and/or stimulation of multiple substrate utilizers rather than heterotrophs characterized by an r-strategist growth regime.

Denitrification of drinking water using Saccharum spontaneum L. as a natural organic solid substrate

Research Article| September 04 2013 Denitrification of drinking water using Saccharum spontaneum L. as a natural organic solid substrate Euclides M. Deago; Euclides M. Deago 1Centro de Investigaciones Hidráulicas e Hidrotécnicas, Universidad Tecnológica de Panamá, 0819-07289 El Dorado, Avda Domingo Díaz, Panama City, Panama2Departamento de Ingeniería Hidráulica y Ambiental, Pontificia Universidad Católica de Chile, Avda Vicuña Mackenna 4860, P-690441 Macul, Santiago, Chile E-mail: euclides.deago@utp.ac.pa Search for other works by this author on: This Site PubMed Google Scholar Gonzalo E. Pizarro Gonzalo E. Pizarro 2Departamento de Ingeniería Hidráulica y Ambiental, Pontificia Universidad Católica de Chile, Avda Vicuña Mackenna 4860, P-690441 Macul, Santiago, Chile Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2013) 62 (7): 477–486. https://doi.org/10.2166/aqua.2013.115 Article history Received: October 25 2012 Accepted: July 18 2013 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Cite Icon Cite Permissions Search Site Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsThis Journal Search Advanced Search Citation Euclides M. Deago, Gonzalo E. Pizarro; Denitrification of drinking water using Saccharum spontaneum L. as a natural organic solid substrate. Journal of Water Supply: Research and Technology-Aqua 1 November 2013; 62 (7): 477–486. doi: https://doi.org/10.2166/aqua.2013.115 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex There is a global concern regarding the increasing pollution of natural water bodies by nitrate as a result of anthropogenic activities. To address this situation, natural organic solid substrates (NOSS) have been investigated as carbon sources in denitrification. Despite advances in this field, a lack of knowledge about the kinetics involved in the denitrification processes using NOSS still exists. For this reason, we have studied denitrification using Saccharum spontaneum L. (S. spontaneum) as NOSS to better understand these kinetic processes. This paper presents experimental results obtained for the release of organic carbon from S. spontaneum, and for its use by denitrifying bacteria. Laboratory tests were developed under anoxic conditions in batch reactors. Our results showed that the kinetics of release of organic carbon from the S. spontaneum was first order (0.08 d−1). Furthermore, the maximum rate of utilization of substrate (5.61 mg N-NO3− mgVSS−1 day−1) and the denitrification rate (327 mg N-NO3−L−1 d−1) were high (VSS = volatile suspended solids). We demonstrated that it is possible to obtain high yields of denitrification using organic carbon released from S. spontaneum. This study improves the knowledge on the use of NOSS, as alternative sources of carbon for denitrification. denitrification, drinking water, kinetic, natural organic solid substrates, Saccharum spontaneum L. This content is only available as a PDF. © IWA Publishing 2013 Supplementary data APPENDIX A-B- pdf file You do not currently have access to this content.

Biodiesel Yield Assessment in Continuous-Flow Reactors Using Batch Reactor Conditions

Fatty acid methyl esters derived from renewable sources such as vegetable oils has gained importance nowadays as an alternative fuel for diesel engines. The present study is aimed to produce biodiesel from non-edible oil (Karanja oil of Indian origin) both in batch and continuous reactors. The purpose of the study is the comparison of Karanja biodiesel production with different reactor types under variable reaction characteristics. Therefore, two types of continuous reactors were used: helical tube reactor and reactive distillation (RD) column. Experiments were carried out to obtain suitable operating parameters in batch- and continuous-flow reactors. For batch reactor, suitable operating conditions obtained are: 7:1 methanol-to-oil molar ratio, 0.8% (by weight of oil) catalyst (KOH), 65°C reaction temperature, and 1-h reaction time, at which the maximum yield obtained is 96%. In continuous helical tube reactor, maximum yield of 92.6% was obtained at 6.6 mL/min of flow rate at the same operating conditions of batch reactor. In continuous RD column, maximum yield of biodiesel 96.6% was obtained at the same operating conditions except methanol-to-oil molar ratio (5:1) because of recycling of methanol into the column. The residence times in the helical tube reactor and RD column were 4 and 8 min, respectively, as compared to 1 h in the batch reactor for almost the same yield.

Comparison of non-agitated and agitated batch, thermophilic anaerobic digestion of sugarbeet tailings

Sugar beet tailings were anaerobically digested at non-agitated and agitated conditions in identical thermophilic batch reactors. The average methane yield in the agitated digester was only 74% of that in the non-agitated digester. Ninety percent of the ultimate methane yield was produced in approximately 5days in the non-agitated digester whereas it took 12days in agitated digester. Even upon using an active inoculum from non-agitated digester the methane rate and yield was low in the agitated digester. On the other hand when the poorly performing inoculum from the agitated digester was transferred to the non-agitated digester, its activity was immediately enhanced. The non-agitated digester harbored a diverse microbial community with phylotypes Methanoculleus and Methanosarcina being dominant methanogens. Methanosaeta was the only methanogen detected in the agitated digester. It also contained a hydrogen-producing bacterial phylotype Petrotoga in high proportion which was not detected in the other digester.

Tethering of Dinuclear Complexes to SBA‐15 and Their Application in CO2 Hydrogenation

AbstractTwo bimetallic cryptates (containing Cu and Co), which have previously been shown to react with and activate atmospheric CO2, were tethered to modified mesoporous SiO2 and their activities in promoting the CO2+H2 reaction has been analysed. The cryptates were tethered to C3H6Cl‐modified SBA‐15 through a condensation reaction between surface alkyl chlorides and 2° amines of the ligands, which released HCl and formed 3° amine linkages. The materials were characterised using BET, thermogravimetric analysis, FTIR and elemental analysis and their activities in promoting the CO2+H2 reaction was tested under batch reactor conditions. Co ions appear to selectively populate the medal sites of the tethered ligands whereas Cu ions appear to deposit on the surface as Cu(BF4)2 salts. The composite materials generate CO and CH4 from the CO2+H2 mixtures. Co‐containing catalysts are more effective than their Cu analogues in promoting the reaction.

Effect of the initial total solids concentration and initial pH on the bio-hydrogen production from cafeteria food waste

In this paper, the influence of the initial pH and the total solids (TS) concentration on hydrogen production from the organic fraction of cafeteria food waste at mesophilic conditions in batch reactors was determined. It was found that the yield and specific hydrogen production rate were influenced by the initial pH and the initial total solids concentration. The highest hydrogen production rate, 2.90 mmolH2/d, was obtained at 90 gTS/L and a pH of 5.5. Under this condition, the TS and chemical oxygen demand (COD) removal were the lowest (10% as TS and 14% as COD). However, considering the specific values, the highest specific degradation rate (192.2 mLH2/gVSremoved/d) was obtained with the lowest TS concentration and an initial pH of 7.0. It was found that the influence of the TS concentration on hydrogen production was more significant than that of the initial pH for this type of residues.

Featuring Functional Component Groups of Sustainable Solid Waste Material on Carbon Dioxide Capture

The abundant biomass from palm oils can be converted into valuable product via pyrolysis process. In this research, the pyrolysis of sustainable oil palm solid waste, empty fruit bunch (EFB), was performed using a static batch reactor in a tubular furnace. The bio-solid waste material obtained was treated with hydrophobic solution (methyl ester) and then impregnated with bio-oil substrate obtained from the pyrolysis. The modified bio-solid waste material was then tested for carbon dioxide capture. SEM results indicated presence uniform and sticky-like material on the surface when further treated with bio-oil substrate. Though, TGA results indicated that addition of hydrophobic solution and bio-oil reduced the thermal stability of the EFB bio-solid. At higher temperature of 150 – 3500C bio-oil impregnated sample indicated little amount of volatile components with carbon residue of 85.39%. The FTIR results of the hydrphobic impregnated bio-solid waste indicated a unique broad peak among all the samples at 620.05cm-1which shows the presence of bending stretch carbon dioxide. This shows that bio-oil modified bio-solid char obtained from EFB has the capabity of capturing CO2.

Static Formation and Dissociation of Methane+Methylcyclohexane Hydrate for Gas Hydrate Production and Regasification

AbstractThe formation and decomposition of methane+methylcyclohexane (MCH) hydrate in a static batch reactor, which was also designed as a high‐pressure microwave reactor, were investigated. The addition of 300 ppm sodium dodecyl sulfate (SDS) provides continuous formation of CH4+MCH hydrate under static conditions. Increasing the initial pressure within the narrow range of 2.7 to 4.6 MPa at 274 K enhances the formation rate by even several times. The gas storage capacity can be largely improved with partial coexisting of sI CH4 hydrate. Unlike a stirred formation, an increase of nonaqueous MCH inhibits the static formation of sH hydrate. The following regasification by 2.45 GHz microwave heating indicates that the dissociation is rate‐controlled by the parallel connection of efficient internal heating and conventional external heating. The multiphase convection characterized by osmotic dehydration and driven by intensified regasification is considered as the dominant mechanism affecting the quiescent dissociation.

Production of extremely pure diacylglycerol from soybean oil by lipase-catalyzed glycerolysis

Research work was objectively targeted to synthesize highly pure diacylglycerol (DAG) with glycerolysis of soybean oil in a solvent medium of t-butanol. Three commercial immobilized lipases (Lipozyme RM IM, Lipozyme TL IM and Novozym 435) were screened, and Novozym 435 was the best out of three candidates. Batch reaction conditions of the enzymatic glycerolysis, the substrate mass ratio, the reaction temperature and the substrate concentration, were studied. The optimal reaction conditions were achieved as 6.23:1 mass ratio of soybean oil to glycerol, 40% (w/v) of substrate concentration in t-butanol and reaction temperature of 50 °C. A two-stage molecular distillation was employed for purification of DAG from reaction products. Scale-up was attempted based on the optimized reaction conditions, 98.7% (24 h) for the conversion rate of soybean oil, 48.5% of DAG in the glycerolysis products and 96.1% for the content of DAG in the final products were taken in account as the results.

Firmicutes with iron dependent hydrogenase drive hydrogen production in anaerobic bioreactor using distillery wastewater

Distillery wastewater rich in organics is an inexpensive renewable resource for making first generation biofuel. Distillery wastewaters are mostly treated via the biomethanation route; however, in this study the conditions in sequential batch reactor (SBR) are being set to develop and analyze the microbial community that opted for hydrogen production. An optimum performance condition for a bioreactor was achieved after 40 days of operation, which gave substrate degradation rate of 0.72 kg/m 3-day with volumetric hydrogen production of 0.32 mol H 2/m 3-day. Study proposes that the dominant Delftia sp., a hydrogen oxidizing bacterium has been replaced during hydrogen production mode with dominant Anaerofilum sp., an anaerobic Firmicute and the iron dependent hydrogenases dominated as functional gene for hydrogen production. Future studies are required where process-engineering interventions could be applied to improve the hydrogen driving biochemical process.

Continuous Flow Synthesis of Fullerene Derivatives

Various fullerene-based electron acceptor materials for organic photovoltaic applications were prepared via [3+2] and [4+2] cycloadditions using a continuous flow approach. The 1,3-dipolar cycloaddition of the tosylhydrazone precursor and the Diels-Alder cycloaddition of indene to either C(60) or C(70) under conventional batch reaction conditions were translated to the continuous flow process. By varying the residence time, temperature, and equivalents of cycloaddition reagent, significant improvements in yields and reaction times were achieved over conventional batch processes.

Digestion of cattle manure under mesophilic and thermophilic conditions: characterization of organic matter applying thermal analysis and 1H NMR

Digestion of cattle manure collected from a livestock farm together with bedding material (straw) has been studied under mesophilic and thermophilic conditions in batch reactors. The digestion was carried out for a prolonged period with the aim of evaluating the changes undergone by the organic matter. The mesophilic digestion carried out revealed a greater capacity to produce gas and transform organic matter, while a higher conversion rate, but a lower gas yield, was obtained under thermophilic conditions. Degradation of the organic matter was evaluated by means of thermal analysis and (1)H NMR. Stabilisation through anaerobic digestion (either mesophilic or thermophilic) resulted in an increase in the quality of the organic matter, as characterised by an enrichment in thermostable compounds, and an accumulation of long chain aliphatic materials. The experiments performed demonstrated the transformation of organic matter into complex materials under anaerobic conditions with an accumulation of aliphatic components under both types of conditions tested. Degradation through mesophilic digestion, in comparison to the thermophilic process, resulted in a greater destruction of straw particles.

Decolorization of Reactive Red 195 by a mixed culture in an alternating anaerobic–aerobic Sequencing Batch Reactor

The mono-azo dye Reactive Red 195 (RR 195) is a widely used color compound in the textile industry. As many other colors, it is persistent and difficult to be removed from water with conventional processes. The present study investigates biological decolorization of RR 195 under alternate anaerobic–aerobic conditions in a laboratory scale Sequencing Batch Reactor (SBR) containing a mixed culture and fed with a biodegradable carbon source. Different values of the Sludge Retention Time (SRT), Hydraulic Retention Time (HRT), influent color and organic carbon loadings were adopted during the experimental activity and their effects on color and Chemical Oxygen Demand (COD) removal efficiencies and process kinetics determined. The optimal operating conditions were found to be: 800 mg l −1 influent COD, 50 d SRT and a 24 h-cycle. Under these conditions, the maximum color efficiency of 97% was achieved for a 40 mg l −1 RR 195 in the feed. Some inhibition was present at influent color loadings above 40 mg l −1, which was confirmed by the application of the Haldane model.

Performance and kinetic evaluation of phenol biodegradation by mixed microbial culture in a batch reactor

Mixed microbial culture collected from effluent treatment plant of a coke oven industry has been studied for its phenol biodegrading potential under aerobic condition in a batch reactor. The result showed that, after acclimatization, the culture could biodegrade up to 700 mg/l of phenol. The results showed that specific growth rate of microorganisms and specific substrate degradation rate increased up to 300 mg/l of initial phenol concentration and then started decreasing. The biodegradation kinetics is fitted to different substrate inhibition models by MATLAB 7.1©. Among all models, Haldane model was best fitted (Root Mean Square Error = 0.0067) for phenol degradation. The different biodegradation constants (Ks, Ki, Sm, mmax, YX/S, kd) estimated using these models showed good potential of the mixed microbial culture in phenol biodegradation. Key words: Mixed culture, phenol biodegradation, kinetics, inhibition model.

Investigations into the biodegradation of microcystin-LR in wastewaters

Microcystins are potent hepatotoxins that can be produced by cyanobacteria. These organisms can proliferate in wastewaters due to a number of factors including high concentrations of nutrients for growth. As treated wastewaters are now being considered as supplementary drinking water sources, in addition to their frequent use for irrigated agriculture, it is imperative that these wastewaters are free of toxins such as microcystins. This study investigated the potential for biodegradation of microcystin-LR (MCLR) in wastewaters through a biological sand filtration experiment and in static batch reactor experiments. MCLR was effectively removed at a range of concentrations and at various temperatures, with degradation attributed to the action of microorganisms indigenous to the wastewaters. No hepatotoxic by-products were detected following the degradation of MCLR as determined by a protein phosphatase inhibition assay. Using TaqMan polymerase chain reaction, the first gene involved in bacterial degradation of MCLR ( mlrA) was detected and the responsible bacteria shown to increase with the amount of MCLR being degraded. This finding suggested that the degradation of MCLR was dependent upon the abundance of MCLR-degrading organisms present within the wastewater, and that MCLR may provide bacteria with a significant carbon source for proliferation; in turn increasing MCLR removal.

Pressurized Hot Water Extraction of anthocyanins from red onion: A study on extraction and degradation rates

Pressurized Hot Water Extraction (PHWE) is a quick, efficient and environmentally friendly technique for extractions. However, when using PHWE to extract thermally unstable analytes, extraction and degradation effects occur at the same time, and thereby compete. At first, the extraction effect dominates, but degradation effects soon take over. In this paper, extraction and degradation rates of anthocyanins from red onion were studied with experiments in a static batch reactor at 110 °C. A total extraction curve was calculated with data from the actual extraction and degradation curves, showing that more anthocyanins, 21–36% depending on the species, could be extracted if no degradation occurred, but then longer extraction times would be required than those needed to reach the peak level in the apparent extraction curves. The results give information about the different kinetic processes competing during an extraction procedure.