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Conventional physico-chemical treatment of industrial wastewater containing compounds such as phenol encounters difficulties due to low substrate level, additional use of chemicals, and generation of hazardous by products along with increased process cost. Biological treatment appears to be a solution for treatment of such industrial wastewater. In the present study an aerobic sequential batch reactor (SBR) has been used for treatment of synthetic wastewater containing phenol. The effects of increasing phenol concentrations on the sludge characteristic have been also investigated. It was observed that, activity of activated sludge for acclimatization of phenol decreases at concentrations above 2000 mg L−1. It may be attributed to toxicity of phenol to active biomass at higher concentrations. Kinetics of phenol degradation has also been studied using Haldane model.

Wet peroxide oxidation (WPO) of oilfield sludge was performed in a batch reactor. Effect of reaction parameters such as residence time, reaction temperature, HE (H2O2 excess) and initial concentration of oilfield sludge were investigated. The experimental results showed that WPO can effectively remove the organic compounds of the oilfield sludge, the residence time and reaction temperature are the main factors for COD removal of oilfield sludge. The initial concentration of the oilfield sludge and HE are also important. When the reaction temperature is 340 °C, initial concentration of the oilfield sludge is 4000 mg/L, the residence time is 9 min and the COD removal oilfield sludge could reach 88.68%. The COD removal increases with the rise of reaction temperature and residence time. The preliminary study of mechanism on the oilfield sludge by WPO is carried out. The result indicates that the oilfield sludge by WPO can be explained by free radical mechanism.

Abstract Oil palm frond and empty fruit bunch (EFB), which were abundant biomass resources found in Indonesia, were hydrothermally-treated using two different types of reactor, e.g. batch and semi-flow reactor. The objective of this research was to make a comparison of product resulted from both types of treatment. Based on the experimental results, it was found that liquefaction of biomass material occurred more effectively in semi-flow reactor. Semi-flow reactor facilitated a higher recovery of several sugar compounds such as xylooligosaccharides and arabinose. On the hand, residual solids from batch treatment had higher theoretical calorific values (18.81 and 18.00 MJ/kg) than those from semi-flow (15.40 and 17.41 MJ/kg, for frond and EFB respectively). [ABSTRACT FROM AUTHOR]

This paper presents a model of a batch stirred tank reactor with spherical catalyst particles as microreactors. The model involves three regions: an array of porous enzyme-loaded microreactors where enzyme reaction as well as mass transfer by diffusion take place, a diffusion limiting region surrounding the particles and a convective region where the substrate is of uniform concentration. The microbioreactors are mathematically modeled by a two-compartment model based on reaction-diffusion equations containing a nonlinear term related to the Michaelis-Menten enzyme kinetics. The influence of the physical and kinetic parameters of the microbioreactors on the transient effectiveness of the bioreactor system is numerically investigated in a wide range of model parameters. The numerical simulation was carried out using the finite difference technique. The simulation results show non-monotonic effect of the initial substrate concentration and nonlinear effects of the internal and external diffusion limitations as well as adsorption capacity of the microreactors on the transient effectiveness. [ABSTRACT FROM AUTHOR]

In this work, the parametric sensitivity of the production process of o-nitroaniline, from ammonia and onitrobenzene, was studied with the aim of determining its safe operating conditions. The industrial batch operation data, related to the accident occurred at the Monsanto plant located in Sauget, Illinois, United States, were analyzed. For the conditions of that day, using the mass and energy balances, the variation of the reactor temperature was modeled. Additionally, local-sensitivity temperature coefficients were calculated with respect to the amount of o-nitrobenzene fed to the reactor for different initial operating temperatures. Thus, safe operating conditions were determined according to different initial operating conditions. Finally, it was explained how the combination of two factors in the operational conditions (reactor load and failure in the service fluid) were the factors that promoted the rupture of the reactor. [ABSTRACT FROM AUTHOR]

In this scientific study, the hydrolysis reaction was carried out in a batch reactor to test which order of the reaction is, the rate constant at different temperatures and also, activation energy, and frequency factor. For this purpose, this hydrolysis reaction was experimentally performed the time-dependent NaOH consumption in a batch reactor in the different temperature range (283 K-313 K). The results show that hydrolysis of the ethyl acetate is a forward one-way second order reaction. The analysis of the experimental data showed that the activation energy is 29.775 kJ mol-1 and frequency factor 27038. [ABSTRACT FROM AUTHOR]

Abstract Structured lipids (SL) are chemically or enzymatically modified oils and fats with respect to their original fatty acid composition or position in acylglycerols. These compounds present improved functional or nutraceutical properties. The present work aimed at the enzymatic synthesis of SL, MLM-type dietary triacylglycerols, that is, those with medium chain fatty acids (M) at the sn -1 and sn -3 positions, and long chain fatty acids (L), in the internal position of the triacylglycerol. Grapeseed oil was selected based on its composition rich in unsaturated fatty acids, principally linoleic acid. This oil was submitted to batch acidolysis with medium chain fatty acids (caprylic or capric) in solvent-free media. Reactions were catalyzed by different immobilized commercial lipases, namely: Lipozyme TL IM® (Thermomyces lanuginosa lipase), Lipozyme RM IM® (Rhizomucor miehei lipase) and Novozym 435® (Candida antarctica lipase B). The incorporation degree (ID) ranged from 23.62 ± 1.34 to 34.53 ± 0.05 mol%, after 24 h reaction at 45 °C, using a molar ratio (MR) fatty acid:oil of 2:1. The best results were obtained using capric acid and Lipozyme RM IM® lipase (34.53 ± 0.05 mol%). In the experimental design, the influence of MR and temperature on ID were evaluated. ID increased with MR and T and was fitted to a saddle-like surface. Highlights • Enzymatic acidolysis reactions in batch reactors employing medium chain fatty acids. • Structured lipids (MLM-type dietary triacylglycerols), from grapeseed oil. • Incorporation degree of fatty acid: ranged from 23.62 ± 1.34 to 34.53 ± 0.05%. • Best results: capric acid and Lipozyme RM IM lipase. • Only linear molar ratio had a significant influence on the incorporation degree. [ABSTRACT FROM AUTHOR]

Nanophotocatalytic ozonation (PCO) of textile dyeing wastewater with Cu-ZnO nanocatalyst was studied in a laboratory scale recirculating photocatalytic ozonation batch reactor. A bench scale reactor was fabricated to suit the integration of ozonation and nano photocatalytic treatment. After optimizing the reaction parameters such as Ozone dosage, Catalyst dosage, pH for nano PCO with Copper doped zinc oxide (Cu-ZnO) nanocatalyst and Amaranth dye as a model pollutant, the efficiency of the PCO reactor was investigated with respect to ozone dosage (0.24g/h-0.57g/h), liquid volume (1000 mL-5000 mL), recycle rate (6 L/h- 39L/h). Based on the optimized parameters, the mineralization of the Amaranth dye resulted in 85.6% removal. Ozone dose was found to have a significant impact on the process efficiency. Wastewater from textile dyeing industry showed 95% degradation measured by Chemical Oxygen Demand removal and 80% mineralization by reduction of Total Organic Carbon. Biodegradability of the treated wastewater increased to 0.42 implying that the further treatment could be progressed by biological method. This study on recirculating batch reactor shows that this treatment could be scaled up for industrial sector. [ABSTRACT FROM AUTHOR]

The aqueous extract of Adiantum capillus-veneris L was used as a reducing agent in the batch method for the synthesis of silver nanoparticles (AgNPs). For improving AgNP synthesis, the concentrations of metal ions solution and leaf extract were optimized in 24 h. Using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-Vis spectroscopy, AgNPs were characterized. In the UV-Vis spectrum, the peak was observed at 453 nm, indicating the surface plasmon resonance (SPR) of AgNPs. The purity and crystalline nature of AgNPs were confirmed based on the XRD assessment. In addition, specific functional groups, which led to silver nitrate reduction in AgNP formation, were examined using FTIR. According to TEM, the average particle size was 18.4 nm in AgNPs. Antibacterial activity assays with Escherichia coli and Staphylococcus aureus demonstrated that AgNPs reduced bacterial growth and produced well-defined inhibition zones. [ABSTRACT FROM AUTHOR]

Thermal runaway is a hazardous problem frequently occurring in the chemical productions. An effective way to avoid accidents caused by thermal runaway is preliminary hazard analysis which can help determine the comparatively safe operating condition in the design phase. In this paper, a series of batch reactor thermal runaway scenarios based on esterification of isopropyl propionate has been studied and according to mixing law the optimal inhibitor injection location has been confirmed. The reactor model is established by computational fluid dynamics (CFD) technology and verified by RC1e test. The effect of cooling temperature, cooling velocity and stirring speed are investigated in detail. Based on the failure status analyses, the appropriate location of temperature probe was then determined by the divergence (DIV) criterion. Finally, the inhibitory mixing performances were evaluated by a global mixing criterion. The results indicated the mixing time and inhibitory region were greatly influenced by the injection location. [ABSTRACT FROM AUTHOR]

[Display omitted] • PBR reactor proved to be much more adequate for this kinetic study than BTR. • The relation between residence time (PBR) and reaction time (BTR) is very high. • All the obtained Arrenhius parameters are under kinetic compensation effect. • None of the LHHW kinetic models fitted the data. • The true mechanism have to take in account fructose isomers and DMSO co-catalyst effect. 5-hydroxymethyl-2-furfural (HMF) is an important furanic compound that can be obtained from renewable raw materials. HMF has wide application in the industry, acting as an intermediate in the production of fine chemicals, polymer, biofuels, and pharmaceuticals. In this research, HMF was obtained from the catalytic fructose dehydration. Purolite® SGC650H, a gel-type strongly acidic resin, was applied as a catalyst using dimethylsulfoxide (DMSO) as a solvent. All experiments were carried out in a batch reactor (BTR) and a continuous packed bed reactor (PBR). The reactor performance data showed that increase in temperature resulted in higher HMF yield. In contrast, the higher the fructose concentration, the lower the HMF conversion. The HMF production rates in the PBR were higher because of the concentration of the catalyst. The rate constants were calculated by means of a pseudo-first-order reaction model, and the Arrhenius kinetic parameters obtained changed with regards to the reactants concentrations. The kinetic parameters displayed linear correlation in the Cremer-Constable diagram, which means that the system was under a kinetic compensation effect (KCE); therefore, the model was not suitable to represent the reaction. Langmuir-Hinshelwood (LHHW) models for rate equation were also tested. However all of them failed to adjust to the data, and thus a rate law was not determined. Due to the observed KCE, it was believed that there is at least a set of parallel dehydration reactions initiated from the different fructose isomers which has an influence on kinetic parameters. [ABSTRACT FROM AUTHOR]

In this study, the photocatalytic activities were investigated for the treatment of Reactive Green 12 (RG 12) solution under UV and visible irradiation using Cu doped TiO 2 , and TiO 2 impregnated on (1) cellulose and (2) UV-C activated polyester catalysts. The obtained results revealed that TiO 2 impregnated on UV-C activated polyester showed promising performances compared to the other synthesized catalysts. Moreover, the dispersion of active sites on UV-C pretreated polyester was optimized and tested for RG 12 removal in the binary mixture, the presence of Direct Red 89 (DR 89) dye had an inhibiting effect on the rate of RG 12 discoloration process because of the competitive effect between dyes molecules toward the available active sites. The role and contribution of reactive oxidizing species (ROS): OH, O 2 − and h + was also examined with the two catalysts under different light sources; it was found that the superoxide radical anion played the key role in RG 12 photocatalytic degradation for both TiO 2 supported catalysts. Nevertheless, the behavior of O 2 − radicals was found to be changed from promoting effect to inhibitory effect when changing light from UV to Visible. [ABSTRACT FROM AUTHOR]

Antibiotics are among the most successful group of pharmaceuticals used for human and veterinary therapy. However, large amounts of antibiotics are released into municipal wastewater due to incomplete metabolism in humans or due to disposal of unused antibiotics. Anaerobic treatment systems increasingly used for removal of antibiotics from wastewater. Today, anaerobic treatment systems commonly used for wastewater containing medium and high degree of organic matters. This study was carried out for the treatment of synthetic wastewater containing different antibiotic group in batch reactor for removal of COD. The treatment process was monitored based on the statistical optimisation data of the batch reactor studies. In the Full factorial tests, 27 different tests are established by considering the variables such as (i) different antibiotic groups (fluconazole, cefamycin and tetracycline); (ii) different initial antibiotic concentrations (25, 50, 75 mg/L) and (iii) a type of co-substrate (propionic acid, glucose, propionic acid-butyric acid-acetic acid mixture). As a result of the statistical study is significant type of antibiotics, antibiotic concentration and type of cosubstrate have a significant effect statistically on the COD removal (p<0.05). The maximum COD removal for the fluconazole (experiment 19) was 98,87%. [ABSTRACT FROM AUTHOR]

Fe-impregnated 13X (Fe-13X) catalysts were prepared for catalytic wet peroxide oxidation (CWPO) of methyl orange (MO) solution in batch and continuous fixed bed reactors. A systematical study was carried out to investigate the influence of the main operating parameters on the batch reactor performance. The kinetic curves were analyzed by using a pseudo-first-order kinetic equation over the 30-70 ° C temperature range. In addition, the effects of catalysts filling amount and feed flow rate on the catalytic performance of Fe-13X catalysts in a fixed bed reactor were studied. The experimental results showed that the Fe-13X catalysts achieved the highest activity (100% MO conversion and 74.5% chemical oxygen demand (COD) elimination ratio, respectively) at 25 min with trace mount of Fe leaching concentration (<2.1 mg/L) at the optimized reaction conditions (namely 1.0 g/L catalyst concentration, pH 2.0, 17.6 mM H2O2, 70 ° C) in a batch reactor. Kinetic studies showed that two different reaction regions existed, and an activation energy of 51.9 kJ/mol for the second region was found. Under the optimal operating conditions found (namely, catalysts filling amount of 3.5 g, feed flow rate of 4 mL/min), the Fe-13X catalysts displayed high MO conversion (99.4%) and COD elimination ratio (77.1%) after continuously ran for 200 min in a fixed bed reactor. [ABSTRACT FROM AUTHOR]

Industrial waste polypropylene (PP) homopolymer and residual fuel oil (RFO) were pyrolyzed together in presence of catalyst ZSM-5 under the atmospheric pressure with different mixing ratios of the feedstocks. The experiments were carried out in a batch reactor at two different temperatures of 500 °C and 600 °C with the blended mixture (PP/RFO) to catalyst (ZSM-5) ratio of 4:1. The effects of blending ratios between the two feedstocks and temperature with respect to the yield of the products oil, gas, and residual coke were determined. The optimum blending ratio of PP and RFO with respect the higher quantity yield of liquid product was found to be 1:1 at 500 °C. The percentages of liquid fuel, gas, and coke were observed to be 74.8%, 10.2%, and 15% at 500 °C. [ABSTRACT FROM AUTHOR]

In view of the scale up of a batch reactor for super absorbent polymer (SAP), a dynamic mathematical model of a commercial scale batch reactor was developed with mass balance, energy balance, and complex polymerization kinetics. The kinetic parameters of the polymerization were estimated on the basis of the established mathematical model and reference data. Simulation results were validated with less than 10% marginal error compared with reference data. A case study was executed in terms of dynamic simulation for eight different initial concentrations of initiator and monomer to analyze the influence of initial concentration and predict the operation condition for desired product. The results were compared with various reference data, and good agreement was achieved. From the results, we argue that the methodology and results from this study can be used for the scale up of a polymerization batch reactor from the early stage of design. [ABSTRACT FROM AUTHOR]

• High Triclosan concentration inhibits the nitrification in biological processes. • Triclosan deteriorates biomass characteristics increasing irreversible fouling. • MBR is a suitable technology for triclosan and caffeine removal. Alternative processes need to be designed for the treatment of industrial effluents containing pharmaceutical and personal care products to improve their quality, permit the reuse of water for industrial applications and meet the standards set by environmental regulations prior to discharge. This type of effluent is a major source of water pollution since conventional activated sludge-based treatments are not effective in removing micropollutants. Carbamazepine, caffeine and triclosan are important trace contaminants commonly found in wastewater treatment plants, and were selected as target compounds to be treated in a cyclic anoxic/aerobic membrane bioreactor. This study aims to evaluate the biomass' characteristics and activity, and its influence over membrane fouling when treating the aforementioned compounds. Caffeine is known to be partially biodegraded whereas triclosan can inhibit microorganism's activity. In order to evaluate this effect, complimentary batch experiments were set up to determine whether triclosan might inhibit nitrification. Low ammonia removal efficiencies were observed in both experimental systems, therefore suggesting that nitrification was being inhibited probably due to the presence of triclosan. The ultrafiltration membrane bioreactor process demonstrated to be an efficient and appropriate technology for chemical oxygen demand removal, achieving an average of 97%, for caffeine reaching up to 93.7 ± 9.7 removal efficiencies, and 89.7 ± 8.3% for triclosan. For carbamazepine the removal was lower (36.2 ± 6.8%) due to its recalcitrance. Furthermore, biomass filterability indicators displayed high sludge deterioration increasing substantially the fouling. [ABSTRACT FROM AUTHOR]

Abstract: We report on the electrochemical generation of ferrate species in a batch reactor at neutral conditions (pH ∼7) using boron‐doped diamond (BDD) electrodes and Fe (III) salts for applications in drinking water treatment. The impact of several relevant variables, including current density (5–55 mA cm−2), pH (5–8), and type and concentration of the dissolved iron salts on the production of ferrates were examined. In addition, linear sweep voltammetry (LSV) studies were conducted using buffered electrolytes with and without the presence of iron (III) to decouple the parasitic oxygen evolution reaction. The LSV measurements in the presence of iron (III) and with a neutral electrolyte exhibit oxidation peaks centered ∼2.0 V (versus SHE), indicating the production of ferrates at this pH. The rate of ferrate generation is not strongly affected by the pH condition (≤ 20 %); however, current density and the source of iron were found to have a higher impact on the production rate of ferrates. The efficacy of the process was higher using FeCl3 instead of other sources of iron such as Fe2O3 and FeO(OH). The batch reactor results were successfully interpreted by a simple model that considered the kinetics of the ferrate generation and degradation reactions. [ABSTRACT FROM AUTHOR]

Coming out from the growth kinetics, the Gompertz model has been developed and considered as the best one for simulating the biogas production from anaerobic digestion. However, the model has failed to describe the starting point of the process, and no-sense of lag phase constant has been pointed out. Thus, the goal of this study is to develop a new kinetic model of biogas production with meaningful constants that can alternate the Gompertz model. The kinetic constants of the model were determined by applying the least squares fitting method for experimental data. The experimental data were taken from running seven batch reactors of co-digestion of vegetable, sludge and horse manure under 37oC, pH of 6.7, and total solids of 2.5%. The result of the high coefficient of determination (0.9611-0.9906) demonstrated that the new biogas production kinetic model was feasible to simulate the biogas generation process. This finding has opened a new choice that can deal with simulation of the biogas production. Moreover, co-digestion of vegetable, horse manure, and sludge was also evaluated under strong attention. The biogas potential was in the range of 183-648 Nml/g-VS with the best carbon-tonitrogen ratio of 16. Vegetable waste played a major role in producing the biogas yield while horse manure and sludge contributed to balancing nutrient of the digestion process. Also, the strong correlation between carbon-to-nitrogen ratio and kinetic constants confirmed that the carbon-to-nitrogen ratio was the key factor that influenced biogas generation. [ABSTRACT FROM AUTHOR]

Graywater (GW) is the term given to all used water discharged from a house, except for toilet water. Among the different sources, laundry and kitchen sink are the main contributors to the total GW load of organic carbon and suspended solids; these sources can also be called dark GW, whereas bathtub and handbasins are the less polluted sources of GW known as light GW. The main aim of this study was to evaluate the effect of organic loading rate (OLR) (0.27, 0.49, and 0.82 COD kg/m³/d) and retention time (RT) (8, 16, and 24 h) on sand filters. The performance of coarse and fine sand filter was monitored by monitoring the reduction in biochemical oxygen demand (BOD), chemical oxygen demand (COD), oil and grease (O&G), and turbidity. The experimental results showed that increase in OLR and RT increase the removal efficiency. The maximum removal efficiency was observed in BOD was 78%, COD was 77%, O&G was 75%, and turbidity was 81% at 24 h RT and OLR 0.82 kg/m³/d. [ABSTRACT FROM AUTHOR]

An electrocoagulation technique using a 3.5 L reactor, with aluminum electrodes in a monopolar arrangement with polarity switch at each 10 s was used to separate oil from synthetic oily water similar in oil concentration to produced water from offshore platforms. Up to 98% of oil removal was achieved after 20 min of processing. Processing time dependence of the oil removal and pH was measured and successfully adjusted to exponential models, indicating a pseudo first order behavior. Statistical analysis was used to prove that electrical conductivity and total solids depend significantly on the concentration of electrolyte (NaCl) in the medium. Oil removal depends mostly on the distance between the electrodes but is proportional to electrolyte concentration when initial pH is 8. Electrocoagulation with polarity switch maximizes the lifetime of the electrodes. The process reduced oil concentration to a value below that stipulated by law, proving it can be an efficient technology to minimize the offshore drilling impact in the environment. [ABSTRACT FROM AUTHOR]

Conventional Display Technologies are being challenged by the emergence of Micro LED Display Technology. AIXTRON identifies the increased MOCVD requirements Micro LED applications are bringing and how these can be addressed. We present progress on improvements to MOCVD processing of red, green and blue Micro LEDs based on Planetary technology. [ABSTRACT FROM AUTHOR]

The industrial production of biodiesel requires mathematical models that adjust to real conditions. The present study is a proposal for the design and validation of a mathematical model for the oil transesterification reaction, representing a promising alternative that contributes to making the biodiesel production process more efficient. This proposal centers on the presentation of analytical models capable of simulating the real batch reactor scenarios in which the transesterification process is carried out. The objective of this study was to design a dynamic model for the batch reactor system, using reaction kinetics and the heat and mass balance, as well as demonstrating the different approaches, such as Takagi–Sugeno modeling and the linear approach. Furthermore, the physical and kinetic parameters were considered a time variant variable. The Takagi–Sugeno (TS) model is presented as a convex combination of linear models through the nonlinearities represented below, a combination which enables the testing of both the simplicity versus complexity of the nonlinear systems and their functionality, via the application of an estimator. The linearization of the nonlinear model was undertaken as a simple representation of the system. The different models were simulated and the results compared with those reported in the literature in order to confirm their applicability. Finally, an experimental validation is presented in order to demonstrate the utility of the models which could be used in processes for optimizing control in the production of biodiesel. [ABSTRACT FROM AUTHOR]

Reactive red-195 synthetic solution of dye was investigated over different operational parameters in simple electrochemical cell for decolourisation. Effect of operational parameters such as variation in applied electrical potential, electrolyte concentration, dye concentration, inter electrode distance (S), cathode material, H2O2 dose and electrolysis time were analysed separately in batch process using iron electrodes. Potential of 20 volts is optimised and applied to successive experiments, considering colour removal efficiency and energy consumption. 100% colour removal was achieved in 4 min for H2O2 dose of 6.0ml/L and 2.5gm/L of NaCl respectively. Similarly increase in gap between electrodes to 4.0 cm and concentration of dye to 100 mg/L, process required 18 min to achieve 100% colour removal. Fe-Al and Fe-Steel combination gave good results at initial, but Fe-Fe and Fe-Al gave 100% colour removal at earliest, compared to Fe-Steel. Electrochemical process may prove efficient in such treatments. [ABSTRACT FROM AUTHOR]

The direct esterification of benzoic acid with a series of aliphatic alcohols was performed in a continuous flow microwave (MW) reactor. In the first stage, the reactivity of the alcohols towards benzoic acid was mapped in a batch MW reactor. Then, the different esterifications were optimized in the continuous reactor. All parameters including the temperature could be controlled.ᅟ [ABSTRACT FROM AUTHOR]