Bed Column Reactor Research Articles

Investigation of Remazol Brilliant Blue R removal in batch and fixed bed column reactor systems by MnOx: Non-linear isotherm and kinetic modelling

Remazol Brilliant Blue R (RBBR) is a dye frequently used in the textile industry. Discharging industrial effluents containing dye residues could pose a risk to biological systems. In the present study, the removal of RBBR from aqueous solutions was tested using MnOx in both batch and continuous systems. The effects of various parameters, including the solution’s initial pH, the amount of MnOx, the initial RBBR concentration, and temperature on RBBR removal by MnOx, were investigated. The optimum pH and MnOx amount at an initial RBBR concentration of 50 mg/L and 30°C were pH 7 and 0.3 g/L, respectively, resulting in an RBBR removal efficiency of 94.43 %. The adsorption capacity was found to be 227.06 mg/g at an initial RBBR concentration of 100 mg/L, pH 7, and 30°C. The adsorption process best fit the non-linear Langmuir isotherm and Elovich kinetic models, with the least error distributions and it was characterized as exothermic and spontaneous. The activation energy value was calculated to be 92.06 kJ/mol. In the fixed bed column reactor, the equilibrium uptake (qe) was 196.30 mg at an RBBR concentration of 200 mg/L and a flow rate of 3.70 mL/min. The results imply that MnOx shows great promise for wastewater treatment contaminated with dyes.

Efficient removal of cationic dye using ZIF-8 based sodium alginate composite beads: Performance evaluation in batch and column systems

The environmental and health risks associated with dye contamination in water sources are alarming. Recently, researchers have been focusing on developing an innovative and susceptible solution using composite beads that effectively combat this issue. In this paper, beads were synthesized using a sodium alginate (SA) and zeolitic imidazolate framework-8 (ZIF-8) through a simple dipping process. Several characterization tests were performed including XRD, FTIR, BET, TGA, and SEM-EDX. The SEM images confirmed that SA effectively coated the cubical structure of the ZIF-8, ensuring optimal performance. The efficiency of the resulting SA@ZIF-8 composite beads was tested on both synthetic malachite green dye and real industrial wastewater samples using batch and fixed bed column reactors. The findings revealed that maximum adsorption of 95.5% was achieved at pH 6 in 120 min of reaction time. FTIR and SEM analysis also confirmed the adsorption of MG dye onto the beads. The Freundlich isotherm model (R2 > 0.99) has a better fit than the Langmuir (R2 > 0.96) for describing the adsorption process. The PSO model predicted the kinetics of the system, whereas the intraparticle diffusion study supported the system's mechanistic analysis. Furthermore, the study also investigated the efficacy of the beads in treating real wastewater effluent samples collected from the dye industry. Overall, using sodium alginate-coated ZIF-8 beads was found to have many advantages over powdered ZIF-8, including higher selectivity, stability, reusability, and practicality, making them a promising alternative for adsorption applications. Therefore, these composite beads have the potential for the removal of the dye from wastewater, which could be widely applied in various industries.

Peptide‐based Organocatalyst on Stage: Functionalizing Mesoporous Silica by Tetrazine‐Norbornene Ligation

AbstractOrganocatalysis via the enamine mechanism developed to one of the most relevant tools in carbonyl chemistry and is widely used in asymmetric organic synthesis. In this work, a strategy is presented to conveniently immobilize a peptide‐based catalyst on silica supports for use in continuous flow catalysis reactions. A set of different porous silica supports is investigated spanning from mesoporous silica particles with defined pore sizes suitable for packed bed column reactors to silica monoliths with hierarchical meso‐macropore spaces. While the silica supports are functionalized with norbornene entities, the peptide‐based organocatalyst is modified with a tetrazine moiety, enabling the immobilization via inverse electron‐demand Diels‐Alder (IEDDA) reaction. The ligation results in catalyst loadings up to 0.2 mmol g‐1, without compromising the mesopore network. The catalytic activity of the materials is proven by the asymmetric C−C coupling reaction of n‐butanal to ß‐nitrostyrene proceeding in high yield and enantioselectivity in both batch and continuous flow setups.

Modelling of fixed bed and slurry bubble column reactors for Fischer–Tropsch synthesis

Abstract An extensive review of slurry bubble column reactor and fixed bed reactor steady state models for Fischer–Tropsch synthesis is presented in this work. Material, energy and momentum balance equations are presented here along with the relevant findings of each study for modelling purposes. For fixed bed reactor models, one-dimensional and two-dimensional models can be differentiated, with the latter being better at predicting hot spots and thermal runaways, although the computational effort required solving them is also higher. Fixed bed reactors can also be classified as pseudo-homogeneous or heterogeneous models, the former considering that all phases are in thermal and chemical equilibrium, and the latter having different profiles for the catalyst particles, generally including a pellet model. For slurry bubble column reactors, single-class and double-class bubble models can be differentiated. The double-class bubble models represent better churn-turbulent regimes at the expense of a higher computational effort.

Adsorption of As and Pb by Stone Powder/Chitosan/Maghemite Composite Beads (SCM Beads): Kinetics and Column Study

Adsorption kinetics of As and Pb onto composite beads synthesized with stone powder, chitosan, and maghemite (SCM beads) with weight ratio of 1:1:0.5 were investigated in batch mode. Several kinetic models such as pseudo-first order kinetic model (PFOKM), pseudo-second order kinetic model (PSOKM), two compartment first order kinetic model (TCFOKM), and modified two compartment first order kinetic model (MTCFOKM) were utilized to analyze the kinetics. Although the beads had low specific surface area and pore volume, MTCFOKM, one of two compartment models, could predict the most accurately because the As and Pb were adsorbed onto at least two kinds of adsorption sites such as functional groups in chitosan and Fe in maghemite. In MTCFOKM, both the fast adsorption fraction (f1’) and the fast adsorption constant (k1’) for Pb were higher than those for As. Therefore, the equilibrium time (teq) for Pb adsorption was shorter than that for As adsorption, indicating that Pb adsorption was more affinitive than As adsorption onto SCM beads (especially maghemite). Column study with a bed column reactor packed with the SCM beads was also conducted. For column study, the effect of flow rate and pore volume on removal efficiency of As and Pb was also investigated. Three models such as the Thomas, Adams-Bohart (A-B), and Yoon-Nelson (Y-N) models were used to fit the column experimental data to analyze the breakthrough curves and the saturation time. Both Thomas and Y-N models were most appropriate. Conclusively, the SCM beads are suitable for adsorption treatment of As and Pb from contaminated groundwater and are particularly effective in Pb removal.

Clarification of apple, grape and pear juices by co-immobilized amylase, pectinase and cellulase

In this study, the use of co-immobilized amylase, pectinase and cellulase enzymes for clarification of apple, grape and pear juices were investigated. Four different co-immobilization method was applied and the highest activity was observed for co-immobilized enzymes onto silica gel. The effect of the enzyme units used in the co-immobilization, reaction temperature and time on turbidity and reducing sugar concentration were optimized by Response Surface Methodology (RSM) via Design Expert Software 8.0.7.1. applying 3-factor Box-Behnken design. Co-immobilized samples were reacted with the substrate solution in batch type and feedback packed bed column reactors and according to turbidity and reducing sugar concentration values, batch reactor efficiency was found to be higher. Finally, freshly squeezed apple, pear and grape juices were interacted with co-immobilized enzymes in the batch reactor system, and turbidity and reducing sugar concentrations were monitored over time. Changes were also observed in antioxidant activities depending on the enzyme treatment.

Analysis of Continuous Bioadsorptive Removal of Cadmium in the Light of Circular Economy and Sustainability

The presented study is an experimentation on bioadsorption of cadmium on lentil husk (LH) stacked in fixed bed column reactor. Here the concept of circular economy is integrated to demonstrate its compliance with biological adsorption. In addition sustainability evaluation of the work has been done with respect to environmental, economical and executional procedure. As regard to experimentation adsorption capacity, percentage adsorption and breakthrough time all found to be dependent on the variation of design parameters. Sorbate (cadmium) concentration in treated effluents was inversely proportional to bed height and directly related to flow rate owing to prolonged interaction with metal binding sites. Adsorption capacity (164.25 mg g−1) peaked up at highest feed concentration due to formation of concentration gradient, overcoming the resistance offered during transfer of solute. Desorption was fruitful (up to ~96%) and the fixed bed regained its performing capacity successively. Industrial effluents were reclaimed with high accuracy for considerable duration.

Removal of boron by a modified resin in fixed bed column: Breakthrough curve analysis using dynamic adsorption models and artificial neural network model

Continuous removal of toxic element boron from aqueous solution was investigated with new phenolic hydroxyl modified resin (T-resin) using a fixed bed column reactor operated under various flow rates, bed height and influent concentrations. The breakthrough time, exhaustion time and uptake capacity of the column bed increased with increasing column bed height, whereas decreased with increasing influent flow rate. The breakthrough time and exhaustion time decreased, but uptake capacity increased with increasing influent concentration, and actual uptake capacity was obtained as 6.52 mg/g at a concentration of 7.64 mg/L. The three conventional models of bed depth service time (BDST), Thomas and Yoon-Nelson were used to appropriately predict the whole breakthrough behavior of the column and to estimate the characteristic model parameters for boron removal. However, artificial neural network (ANN) model was more accurate than the conventional models with the least relative error and the highest correlation coefficients. By the relative importance of the operational parameters obtained from ANN model, the sequence is as follows: total effluent time > initial concentration > flow rate > column height. The adsorption capacity of boron was changed between 5.24 and 1.74 mg/g during the five time regeneration. From the life factor calculation, it is suggested that the column bed could avoid the breakthrough time of t = 0 for 6.8 cycles, whereas, the uptake capacity would be zero after 7.8 cycles.

Immobilization of Halomonas halodurans and Bacillus halodurans in packed bed bioreactor for continuous removal of phenolic impurities in waste water

Phenol is an organic contaminant widely distributed in wastewater. Biodegradation is one of the suitable methods used to remove phenol from the wastewater. In this study, the bacterial laccase and pectinase were analyzed and phenol degradation potential was studied. A total of six bacterial strains were selected and their phenol degrading potentials were studied. Laccase and pectinase producers were screened on substrate agar plates and several strains produced these enzymes in submerged fermentation. Among these enzyme producing strains, strain PD8 and PD22 exhibited potent phenol degrading ability than other strains. These two bacterial strains (Halomonas halodurans PD8 and Bacillus halodurans PD22) exhibited maximum growth in phenol-supplemented culture medium. These two organisms grown well at wide pH values (pH 3.0 and 10.0), survive well between 20 °C and 50 °C, and showed growth between 1 and 10% sodium chloride concentration. The lyophilized enzyme from PD8 and PD22 were immobilized with alginate beads cross liked with divalent cations. At 1% alginate, the binding efficiency was 40.2 ± 2.9% and it improved up to 2.0% concentration (67.5 ± 4.2%) and further increase on alginate concentration affected binding efficiency. Phenol degradation was maximum within 10 h of treatment in the immobilized packed bed column reactor (83.1 ± 3.2%) and colour removal efficiency was maximum at 12 h treatment (82.1 ± 3.9%). After four successive experimental trials more than 40% efficiency was achieved.

Deacidification of palm oil mill effluent using anion exchange resin

This paper described the method to deacidify Palm oil mill effluent (POME) by substituting FFA contents to anion from exchange resins (Dowex Marathon A and Lewatit MP500). The deacidification was conducted in a fixed bed column reactor using two different effluents, collected from factory fat pit and cooling pond. Furthermore, the acid values were evaluated to calculate the quantity of FFA content. After deacidification, the acid values of POME from the two sources were lower than 1 mgKOH/g oil and with a brighter color.

Adsorptive column studies for removal of Reactive Blue 4 dye using dry cells of Rhizopus oryzae (MTCC 262)

The biosorption potential of dry biomass of Rhizopus oryzae (MTCC 262) in removing a textile dye Reactive Blue 4 from dye contaminated wastewater using up-flow packed-bed column reactor has been studied. The impact of operating parameters like flow rate of dye solution, bed height of column and concentration of dye in the feed solution on the removal potential has also been studied. The Adam-Bohart Model, Yoon-Nelson Model and Thomas model are used for the analysis of experimental data. Dye removal of 71.81% is obtained using dry biomass at flow rate of 2 mL min-1of dye solution, bed height of 15 cm and influent dye concentration of 200 mg L-1. Adsorbed dye can be successfully recovered from dry R.oryzae (MTCC 262) biomass of packed bed column reactor by running 1 (N) NaOH solution. Results demonstratesignificant reduction in Reactive Blue 4 concentration after the biosorption process.

Modelling for removal of Cr(VI) and Pb(II) using sago bark (Metroxylon sagu) by fixed-bed column method

Industries commonly produced a large scale of wastewater that consisted of hazardous materials such heavy metals. Recently, one of popular methods for wastewater treatment was adsorption system using biosorbent. Sago bark (Metroxylon sagu) was a solid waste remained from sago starch industry. It contained various functional group such as carbonyl and hydroxyl groups that could be utilized to resolve wastewater containing metal ions. Removal of Cr(VI) and Pb(II) using sago bark (Metroxylon sagu) have been investigated by a fixed bed column reactor. The effect of flow rate (2, 4, 6 mL/min) and bed depth (3, 6, 9 cm) was examined in order to observe column performance (15x1 cm id). The result revealed that the lower flow rate and the higher bed depth delayed the breakthrough time and exhaustion time. Thus, the optimum conditions were achieved at 2 mL/min of flow rate and 9 cm of bed depth for both metal ions. The equation of Thomas, BDST and Yoon-Nelson models was carried out to evaluate the breakthrough curve. The repeatability and regeneration of sago bark were analyzed by HNO3 0.01 M within 3 cycles. It means that sago bark has a promising ability to remove Cr(VI) and Pb(II) ions in solution.

Effective removal of Cd2+, Zn2+ by immobilizing the non-absorbent active catalyst by packed bed column reactor for industrial wastewater treatment

Cadmium and zinc are leading heavy metal pollutants causing serious health problems when discharged into the aquatic environments. The present investigation focused on the bioaccumulation of Cd2+ and Zn2+depending on the sorption process by Bacillus amyloliquefaciens HM28. The selected bacterium was multi-metal (Zn2+, Pb2+, Cd2+, Cu2+ and Li+) and antibiotic (cefotaxime, ampicilin, nalidixic acid, ceftazidime, penicillin and kanamycin) resistance was resolved. The identified strain showed maximum resistance onCd2+ (2575 ppm) and Zn2+ (1300 ppm). The sorption of Cd2+ and Zn2+ by a dried bacterium was investigated. Biosorption of Cd2+ was maximum (98.4 ± 5.2%) at 100 mg/L concentration and maximum Zn2+ (98.3 ± 1.5%) was detected in the medium containing 150 mg/L metal ion. Bioremoval was maximum after 30 min contact time with dried biomass and the absorption rate improved. The optimum Cd2+ and Zn2+ bioremoval yield of 93 ± 4.4% and 89.8 ± 4.3% were observed, at pH 7.0 and 7.5, respectively. Despite the significant reduction in growth rate, heavy metals increased nitro-blue tetrazolium reduction from 11 ± 1.3 to 67 ± 3.3%. Dehydrogenase activity elevated due to heavy metal stress. Bacterial biomass was immobilized in a glass column (20 cm × 2 cm). Biosorption of Cd2+ and Zn2+ ions were performed in a packed bed column. The breakthrough time of Cd2+ was 210 min at 1 mL/min flow rate and it decreased 94 min at 5 mL/min flow rate, whereas 240 min at 1 mL/min, and 90 min at 5 mL/min, respectively. The absorption capacity was 4.87 ± 0.8 to 5.43 ± 0.5 mg/g for Cd2+ and 3.85 ± 0.3 to 4.53 ± 0.4 mg/g for Zn2+. The present findings revealed the potential of B. amyloliquefaciens HM28 biomass in Cd2+ and Zn2+ biosorption, with feasibility in the bioremediation of Cd2+ and Zn2+ contaminated water.

Modeling and Optimization of Carbon Dioxide Removal in Packed Bed Column Reactor

Global warming due to greenhouse gases has become a serious global issue. Extensive efforts are being made to fighting this phenomenon through carbon capture as carbon dioxide (CO2) is its major contributor. This study focused on CO2 capture in packed bed column reactor using Poly-(D) glucosamine under the various process parameters such as temperature, feed flow rate and mass of the adsorbent. Statistical design of experiments was carried out in order to analysis the effect process parameters on the capacity of CO2 capture in packed bed column. The obtained results show that feed flow rate has the significant affect compared to others. The maximum of 956 mg of CO2 is captured under the following operating conditions; temperature of 40oC, feed flow rate of 30 ml/min and 0.25 g of the Poly-(D) glucosamine. The ability of Poly-(D) glucosamine to capture the CO2 in packed bed column is confirmed.

A Comparative Study of Swarm Intelligence-Based Optimization Algorithms in WSN

Global warming due to greenhouse gases has become a serious global issue. Extensive efforts are being made to fighting this phenomenon through carbon capture as carbon dioxide (CO2) is its major contributor. This study focused on CO2 capture in packed bed column reactor using Poly-(D) glucosamine under the various process parameters such as temperature, feed flow rate and mass of the adsorbent. Statistical design of experiments was carried out in order to analysis the effect process parameters on the capacity of CO2 capture in packed bed column. The obtained results show that feed flow rate has the significant affect compared to others. The maximum of 956 mg of CO2 is captured under the following operating conditions; temperature of 40oC, feed flow rate of 30 ml/min and 0.25 g of the Poly-(D) glucosamine. The ability of Poly-(D) glucosamine to capture the CO2 in packed bed column is confirmed.

Hydrodynamics and phenol adsorption studies in continuous counter current liquid-solid settling column

Adsorption is a cost-efficient and a well-established method to treat a large volume of wastewater. Most of the adsorption studies have been carried out in batch and continuous (packed and fluidized bed column) reactors. In most of the continuous operations, a solid adsorbent is held in batch mode and the liquid phase is continuous. In a counter-current liquid-solid adsorber, both the liquid and solid phase will be continuous. In this study, synthetic wastewater containing phenol of 200 ppm is treated in a counter-current liquid-solid adsorber using activated carbon as the adsorbent. The adsorption kinetics and the effect of size and mass of adsorbent were studied in batch operation. Thermodynamic properties including Gibbs' free energy, standard enthalpy and entropy change were calculated and the feasibility of the process is confirmed. In the continuous counter-current liquid-solid settling column, the effects of liquid flow rate, particle size and solid flow rate on hydrodynamics and mass transfer have been studied. From the range of flow rates studied in this work, liquid flowrate of 10 lph and solids (of diameter 0.5 mm) flow rate of 24 g/s gave the maximum phenol removal. An empirical equation has been proposed to predict the mass transfer coefficient for the range of continuous process.

Integrated production of prebiotic xylooligosaccharides and high value cellulose from oil palm biomass

Oil palm empty fruit bunch (OPEFB) fibre, which is the byproduct of fruits being stripped from the fresh fruit bunch in palm oil mill, was evaluated in terms of the production of xylooligosaccharides (XOs) and the solid residue was treated for cellulose recovery. Chemoenzymatic hydrolysis that consists of chemical fractionation of OPEFB fibre to isolate xylan with further enzymatic hydrolysis to XOs in a packed bed column reactor (PBCR) was performed. An immobilised xylanase of Thermomyces lanuginosus at the concentration of 8.25 fungal xylanase unit wheat/mililitre (FXUW mL−1) was employed on a PBCR to hydrolyse the xylan at 55 °C and pH 5.5. The yields of XOs are composed of xylopentaose, xylotetraose, xylotriose and xylobiose, successfully produced from the OPEFB-xylan, shown in HPLC analysis with the total production of 8,776 mg/L and the immobilised xylanase can be recycled up to six enzymatic treatment cycles. The solid residue generated from the xylan extraction was further treated with mild concentration of bleaching agents of 20% (v/v) formic acid and 5% (v/v) hydrogen peroxide at 85 °C. The Fourier transform infrared spectroscopy (FTIR) analysis showed that the products obtained have the standard cellulose structure and functional group. Further analyses on the properties of the extracted cellulose in terms of crystallinity, thermal stability and morphology were conducted. The integrated process to produce XOs from OPEFB and recover cellulose from its byproduct is sustainable to extract fine chemicals from OPEFB.

Simultaneous fluoride and nitrate removal from drinking water using mixotrophic denitrification processes in a fixed bed column reactor

Simultaneous fluoride and nitrate removal from drinking water using mixotrophic denitrification processes in a fixed bed column reactor

Application of zirconium caged activated biochar alginate beads towards deionization of Cr(VI) laden water in a fixed bed column reactor

An investigation of dynamic fixed bed loaded with zirconium caged steam activated biochar alginate bead was performed towards deionization of Cr(VI) laden aqueous solution. Impact of process parametric factors which include bed height (5 to 30 cm), initial influent concentration (10 to 60 mg/L) and flow rate (1 to 4 mL/min) were studied at a constant pH of 3 ± 0.5 from a synthetic non-competitive Cr(VI) solution. As interpreted from the experimentations it was observed that with every increase in bed height, length of the breakthrough curve also increased. On the contrary to bed height, increase in metal concentration and flow rate with predefined bed height efficacy of the column decreased. The adsorbent bed was able to retain 499.5 mg of ions with an uptake of 116.805 mg/g from an optimum influent metal concentration of 50 mg/L at a flow rate of 1 mL/min. A removal of 93.54% was observed at this optimum condition. The process was evaluated with bed depth service time model, Thomas and Yoon-Nelson model which substantiated the findings. From desorption-adsorption cycle it was observed that the column retained its removal efficacy up to 7 cycles with a column regeneration percentage of 51.108%. This adsorbent was capable of removing Cr(VI) from a multi-ion synthetic waste water solution where the breakthrough curve showed similarity with 10 mg/L of synthetic single Cr(VI) ion solution. Thus, the prepared zirconium caged adsorbent could be used in a fixed bed column reactor towards remediating metal ions from contaminated aqueous solution.

Rice straw-based biochar beads for the removal of radioactive strontium from aqueous solution

Biochars from agricultural residues have recently attracted significant attention as adsorbents for purifying contaminated water and wastewater. In this study, the removal of strontium from aqueous solutions was investigated using rice straw-based biochar (RSBC) beads in both batch and continuous fixed-bed column systems. The RSBC beads had negatively charged surfaces and exhibited a large surface area (71.53m2/g) with high micro-porosity. The synthesized beads showed a maximum adsorption capacity of 175.95mg/g at an initial strontium concentration of 10g/L at 35°C and pH7. Furthermore, they showed a good selectivity toward strontium ions in the presence of competing ions such as Al3+, Mg2+, and K+. The effects of different operating conditions like flow rate and initial strontium concentration were investigated in the fixed–bed column reactor. The Thomas, Adams–Bohart, and Yoon–Nelson models were applied to the experimental data to predict the breakthrough curves using non-linear regression. Both the Thomas and the Yoon–Nelson models were appropriate for describing entire breakthrough curves under different operating conditions. Overall, RSBC beads demonstrate great potential as efficient adsorbents for the treatment of wastewater polluted with strontium in a continuous operation mode.