Batch Mode Research Articles

Adsorption Behavior of Methylene Blue Onto Activated Coconut Shells: Kinetic, Thermodynamic, Mechanism and Regeneration of the Adsorbent.

Adsorption techniques are widely used to remove some classes of pollutants from waters, especially those which are not easily biodegradable. The removal of Methylene blue (MB), as a pollutant, from waste waters of textile, paper, printing and other industries has been addressed by the researchers. The aim of this study is to eliminate MB by Activated Coconut Shells (ACS) produced at low cost by adsorption in batch mode. The ACS was characterized by the FTIR spectroscopy and point of zero charge (pHpzc: 5.06). Some examined factors were found to have significant impacts on the MB uptake of ACS like the initial dye concentration Co (40-120mg/L), solution pH (2-8), ACS dose (1-12g/L), agitation speed (50-500 r/min), particles size (1.0-1.2mm) and temperature (298-333K). The best capacity was found at pH 6 with an adsorbent dose 8g/L, an agitation speed 200 r/min and a contact time of 60 min. Modeling Kinetics and Isotherms shows that the pseudo-second-order kinetic model with R 2 (0.935 -0.998) and Langmuir adsorption isotherm model provide better fitness to the experimental data with the maximum adsorption capacity of 30.30mg/g at 25°C. The separation factor RL (0.933-0.541) in the concentration range studied (10-120mg/L) shows a favorable adsorption. The isotherms at different temperatures have been used for the determination of the free energy ΔG° (198-9.72kJ/mol); enthalpy ΔH° (82.082kJ/mol) and entropy ΔSo (245.689J/K mol) to predict the nature of MB adsorption process. The positive values of (ΔGo) and (ΔHo) indicate a non-spontaneous and endothermic MB adsorption with a chemisorption. The adsorbent elaborated from Coconut Shells was found to efficient and suitable for the removal of MB dye from aqueous solutions, due to its availability, low cost preparation and good uptake capacity.

Investigation of the agricultural reuse potential of urban wastewater and other resources derived by using membrane bioreactor technology within the circular economy framework

The European Union, as delineated in Regulation (EU) 2020/741, sets forth minimum criteria for the reuse of wastewater. Directive 86/278/CEE sets the regulations for the reuse of sewage sludge in agriculture. This study aimed to investigate the treated water derived from a pilot plant situated in Granada, Spain, that utilizes membrane bioreactor technology to process real urban wastewater with the quality standards necessary for agricultural reuse. Additionally, the study evaluated the utilization potential of other resources generated during wastewater treatment, including biogas and biostabilized sludge. The pilot plant incorporated a membrane bioreactor featuring four ultrafiltration membranes operating continuously alongside a sludge treatment line operating in batch mode. The pilot plant operated during four cycles, each with distinct hydraulic retention times (6 h and 12 h) and variable mixed liquor-suspended solids concentrations (ranging from 2688 mg L−1 to 7542 mg L−1). During these cycles, the plant was doped with increasing concentrations of emerging contamination compounds (diclofenac, ibuprofen, and erythromycin) to test their effect on the resources derived from the treatment. Subsequently, a tertiary treatment involving an advanced oxidation process was applied to the different water lines, which left the wastewater treatment plant for a period of 30 min and utilized varying concentrations of oxidant. The results indicate that the effluent obtained meets the required quality standards for agricultural use. Therefore, there is potential to use this waste as a resource, which is in line with the principles of the circular economy. Furthermore, the other resources generated during the treatment process, such as the biogas produced during the digestion process and the biostabilized sludge, have the potential to be used as resources according to the circular economy indicators.

Fabrication of mango-leaf biowaste mediated green magnetite (Fe3O4@MBE NPs) and modified EDTA/Fe3O4@MBE NCs for enhanced heavy metals sequestration: Characterisation, simulation modelling, mechanism, cost-effectiveness and electroplating wastewater performance

This work reports biogenic green fabricated novel magnetite nanoparticles (Fe3O4@MBE NPs) coated with mango-leaf biowaste extract and modified disodium ethylenediamine tetra-acetate (EDTA) functionalised nanocomposite (EDTA/Fe3O4@MBE NCs). Several approaches were used to characterise them, and their applicability as nanoadsorbents was exhaustively investigated in batch mode sequestration of Cd(II), Ni(II), and Zn(II) from synthetic solutions. The Brunauer Emmett and Teller’s surface areas of Fe3O4@MBE and EDTA/Fe3O4@MBE was determined to be 47.73 and 43.95 m2/g, respectively, with average porous diameters of 10.36 and 7.44 nm, revealing mesoporosity. EDTA/Fe3O4@MBE NCs exhibit soft ferromagnetism with a saturation magnetisation of 40.67 emu/g. Further, EDTA modification creates carboxyl and amino sites, improving adsorption performance. Adsorption was pH dependent, with optimal sequestration at 40 mg/L divalent metal ions, 0.5 g/L nanoadsorbent dosage, and 75 min of reaction duration at 27 °C. Among the simulation models employed, the Langmuir isotherm, pseudo second order kinetic, and Elovich kinetic were the best fitted and offered the highest capability to explain the adsorption process. The Langmuir monolayer adsorption capacity (qmax) of 147.06, 129.87, and 117.65 mg/g for Cd(II), Ni(II), and Zn(II) by EDTA/Fe3O4@MBE, respectively, were significantly higher than Fe3O4@MBE (120.48, 102.04, and 95.24 mg/g). The best-suited kinetics precisely describe chemisorption as the primary rate-limiting phase in divalent metal ions adsorption. Thermodynamics approved the endothermic nature and feasibility of divalent metals adsorption, with modest improvement in efficacy at higher temperatures. The ability of EDTA/Fe3O4@MBE to form stable surface complexes with divalent metals enhances adsorption even in the presence of other co-existing ionic species. EDTA/Fe3O4@MBE NCs magnetic separability, improved sequestration upto five recycles, and regenerability of ≥89.07 % demonstrate its cost-effectiveness in heavy metals sequestration. Finally, practicality study confirmed that EDTA/Fe3O4@MBE nanoadsorbent provides a practical and economically efficient option for heavy metals sequestration from electroplating wastewater; thus, it contributed towards UN-2030, SDG No-6.

MMO-induced batch and pilot-scale electro-oxidation treatment of municipal wastewater.

The present research aimed to explore the durability of MMO electrodes through electro-oxidation (EO) in purifying secondary treated actual sewage wastewater using batch and pilot-scale setups. The main aim is to inactivate bacteria in sewage treatment plants before they are released into the environment, thus contaminating water and soil. Process parameters such as current density (j), NaCl dose (n), and treatment time (t) were optimized using response surface methodology in a lab-scale EO reactor under batch conditions. The results showed that optimization of current density at 5.90mA/cm2 and NaCl concentration at 1.31g/L led to 93.90% of bacterial inactivation (Q1) within 8min of treatment and 0.48 kWh/m3 energy consumption (Q2). Biological analysis was conducted to validate bacterial cell destruction and count coliform bacteria in the EO-treated sewage wastewater. XRD, cyclic voltammetry studies, and FE-SEM/EDS analysis were done to confirm the MMO anode's durability and stability after 100 recycles. The study prioritized bacterial inactivation along with organic matter degradation. Besides that, a small pilot-scale study on the actual sewage wastewater with a volume of 10-50 L was done in batch mode under previously optimized conditions to analyze the efficacy of the MMO anodes in terms of bacterial inactivation.

Enhancement of Succinic Acid Production by Actinobacillus succinogenes in an Electro-Bioreactor

This work examines the electrochemically enhanced production of succinic acid using the bacterium Actinobacillus succinogenes. The principal objective is to enhance the metabolic potential of glucose and CO2 utilization via the C4 pathway in order to synthesize succinic acid. We report on the development of an electro-bioreactor system to increase succinic acid production in a power-2-X approach. The use of activated carbon fibers as electrode surfaces and contact areas allows A. succinogenes to self-initiate biofilm formation. The integration of an electrical potential into the system shifts the redox balance from NAD+ to NADH, increasing the efficiency of metabolic processes. Mediators such as neutral red facilitate electron transfer within the system and optimize the redox reactions that are crucial for increased succinic acid production. Furthermore, the role of carbon nanotubes (CNTs) in electron transfer was investigated. The electro-bioreactor system developed here was operated in batch mode for 48 h and showed improvements in succinic acid yield and concentration. In particular, a run with 100 µM neutral red and a voltage of −600 mV achieved a yield of 0.7 gsuccinate·gglucose−1. In the absence of neutral red, a higher yield of 0.72 gsuccinate·gglucose−1 was achieved, which represents an increase of 14% compared to the control. When a potential of −600 mV was used in conjunction with 500 µg∙L−1 CNTs, a 21% increase in succinate concentration was observed after 48 h. An increase of 33% was achieved in the same batch by increasing the stirring speed. These results underscore the potential of the electro-bioreactor system to markedly enhance succinic acid production.

Distributed learning with compressed gradient differences*

Training large machine learning models requires a distributed computing approach, with communication of the model updates being the bottleneck. For this reason, several methods based on the compression of updates were recently proposed using sparsification or quantization. However, none of the prior methods are able to learn the gradients, which renders them incapable of converging to the true optimum in the batch mode. In this work we propose a new method – DIANA – which resolves this issue via compression of gradient differences. We provide theory in the strongly convex and nonconvex settings that shows improved convergence rates, and use it to obtain the first convergence rate for the previously proposed method TernGrad. Finally, we provide theory to support non-smooth regularizers.

Enhancing anaerobic digestion of food waste for biogas production: Impact of graphene nanoparticles and multiwalled nanotubes on direct interspecies electron transfer mechanism

The present research investigated the effect of two carbonaceous materials, multiwalled carbon nanotubes (MWCNTs), and graphene nanoparticles (GNPs), on biogas yield from food waste (FW) in an anaerobic digestion system for 30 days. Lab scale investigations were conducted in batch mode in 250 mL glass reactor bottles and the findings were compared to the control reactor. The performance of the experimental procedure was assessed in terms of biogas output and organic matter reduction. The addition of 100 mg/L multiwalled carbon nanotubes and 100 mg/L GNPs increased the cumulative biogas production (33.55 % and 81.16 %, respectively) while decreasing the total solid content (about 25.95 % and 24.95 %, respectively). However, increasing the concentration of both carbon nanomaterials from 100 mg/L to 500 mg/L reduced the total biogas production compared to the control, which can be attributed to cytotoxic effects. A microbial diversity study was performed using 16S amplicon sequencing to understand the changes occurring in the microbial ecology. The predominant phyla found during diversity analysis were Firmicutes, Proteobacteria, Actinobacteriota, and Bacteroidota. Finally, addition of carbonaceous nanomaterials to the anaerobic reactors favours organic matter degradation through the DIET mechanism. It improves the biogas production kinetics and productivity during the anaerobic digestion of FW up to a certain dose.

Enhanced degradation of micropollutants using In situ electrogenerated sulfate radical at high flux

The degradation of micropollutants via in situ-generated reactive species from coexisting substances in water is a promising approach for advanced water treatment. However, treatment efficiency and practical applications are hindered by limited operation conditions and prohibitive costs, respectively. Herein, we report an upgraded electrochemical filtration system that is chemical-free and made efficient by achieving in situ SO4•– generation at enhanced flux and in complicated water matrices. The ion transport was enhanced by coupled electric and flow fields, providing an outstanding performance in removing micropollutants. At the optimized conditions, the proposed system degraded 90.5% of bisphenol A (BPA) in 40 min and its degradation kinetics was 14.7 times that of the batch mode, and the treatment efficiency of the proposed system was 2.5 times more efficient than our previous design because of the enhanced flux. Quenching experiments indicate that indirect oxidation by SO4•– and •OH as well as direct electron transfer play critical roles during the BPA degradation. Importantly, the proposed system does not need any added chemicals and uses only the ubiquitous SO42− and electricity. From an environmental point of view, its energy conservation and the lack of additional chemicals ensure its applicability for purifying micropollutants.

Green synthesis of magnesium oxide nanoparticles using extracts of two brown seaweeds for removal of acid black 1 dye from aqueous environments

Water pollution by synthetic dyes, particularly acid black 1, poses a significant environmental challenge. The present study has addressed this issue by synthesizing novel magnesium oxide (MgO) nanocomposites using extracts from Padina sanctae crucis (Psc) and Sargassum hystrix (Sh) algae via a sol-gel process. The primary objective was to evaluate the efficacy of these nanocomposites in removing acid black 1 dye from aqueous solutions. The synthesized materials were characterized using Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, thermal gravimetric analysis (TGA), and dynamic light scattering (DLS). The results show the successful synthesis of MgONPs and MgO@Sh and MgO@Psc NPs with approximate sizes of 45.64–65.64, 52.14–59.09 and 39.19–58.30 nm. Batch mode experiments were conducted to assess the influence of contact time, pH, and adsorbent dosage on dye removal efficiency. The results demonstrated that at pH 6, increasing the adsorbent dosage from 0.5 to 2 g/L enhanced the dye removal efficiency from 41.6% to 59.1% for MgO@Psc and from 43.4% to 64.1% for MgO@Sh. The Sips isotherm model and intra-particle diffusion kinetic model provided the best fit to the experimental data. The negative values of ΔG° indicated, which the adsorption process is more spontaneous at higher temperatures. This study highlights the potential of MgO@Psc and MgO@Sh nanocomposites as effective adsorbents for acid black 1 removal, offering a promising solution for water purification.

Kinetic-free sizing criterion for the thermally controlled scale-up of batch fine-chemical processes

A number of newly developed exothermic reactions of the fine-chemical industry can be safely tested at the industrial scale in an existing batch reactor since they cannot lead to dangerous reactor overpressures even under adiabatic conditions. However, when the process is scaled from a laboratory to an industrial reactor, the normal decrease of the heat transfer efficiency per unit volume can be so relevant that at the industrial scale the process cannot be thermally controlled, leading to a lower and less reproducible quality of the final product. In these cases, the industrial reactor must be equipped with an external heat transfer surface in addition to that provided by the reactor jacket only. The sizing of such an additional surface through conventional tools requires the knowledge of the heat release rate in the recommended temperature range and hence of the system kinetic behavior, which is often a missing information in the fine-chemical industry due to the fragmentation of the involved processes. In this work, a kinetic-free sizing criterion is presented for the temperature-controlled scale-up of intrinsically safe exothermic reactions carried out in the batch mode of operation, allowing for a simple and general estimation of the required heat transfer surface at the industrial scale from the analysis of the pseudo-adiabatic temperature trends measured during the original industrial batches. The proposed methodology has been validated using a set of process information about the final nitration step for the synthesis of an API as well as industrial-scale data collected during the scale-up of a water-in-oil emulsion polymerization for the synthesis of a polycationic thickener used in the cosmetic industry.

Characterization of <i>Adansonia Digitata</i> Seed Cake with a View to Identifying an Energy Recovery Strategy

Agri-food processing emits huge quantities of waste and is considered one of today's major environmental problems. There are many different options (anaerobic digestion, thermochemistry and feed production) that can be applied to the management and evaluation of waste treatment. The aim of the present study was to explore the appropriate recovery option for Adansonia digitata seed cake through its characterization. The physicochemical characteristics of <i>Adansonia digitata</i> seed cakes were determined in accordance with international standards. Anaerobic digestion was tested under thermophilic conditions in batch mode over 75 days. Results showed that dry matter content averaged 87.35 ± 0.03%, organic matter content averaged 95.03 ± 0.41%, carbon to nitrogen ratio averaged 19.75. Digestion of <i>Adansonia digitata</i> seed cakes proved highly productive, with a maximum percentage of 68.5% CH<sub>4</sub> for 185.57 liters of biogas, i.e. an average production of 2.47 liters per day for 1720 g DM. The methanogenic potential (BMP) of <i>Adansonia digitata</i> seed cake was 331.21 ml/g of organic matter introduced. <i>Adansonia digitata</i> oilcake had an average gross calorific value of 18.54MJ/Kg. These results are encouraging and mark the start of any study on the energy recovery of <i>Adansonia digitata</i> seed cake in biogas.

Biodecolorization of Azo Dye by Bacteria Alcaligenes faecalis Sub Sp. Phenolicus Isolated from a Bark-Beetle Tunnel Developed in Peltophorum Pterocarpum Plant

This study assessed the decolorization of reactive red 120 (RR120) by Alcaligenes faecalis subsp. phenolicus strain isolated from the bark borer insect (Indarbela tetraonis) tunnel developed in Peltophorum pterocarpum. The optimal parameters for the dye of decolorization 0.1 mg/L of dye were pH 7, temperature 35°C, fructose (0.4% w/v) as the carbon supply (0.4% w/v), peptone (0.2% w/v) as the nitrogen source (0.4% w/v), 12 hours of static conditions, and 0.3 ml of inoculums. Cell suspension, sodium alginate (3%, w/v), and PVA (5%, w/v) immobilized cell beads (10 beads 0.5 mm in size) were used in the batch continuous reactor for complete bio-decolorization of RR120. The batch reactor was subjected to 5 cycles of batches for 3 days of constant use. Under optimal conditions, the batch mode achieved more than 99% dye decolorization and fabric color removal in less than 48 hours of contact. When the control and dye-decolorized media were analyzed using UV spectroscopy, the absorbance of the control medium was higher than that of the decolorized media. GC-MS and FTIR analysis revealed the basic compounds and functional groups of the parent RR120 dye. This strain decolored 76.51% of AB 113, 96.8% of orange II, 98.47% of congo red, 98.3% of RR120, 97.92% of phenol red individual dyes, and 94.72% of the dye mixture at 12 hours. A. faecalis subsp. Phenolicus strains produced positive results in the qualitative analytical test of exopolysaccharides (EPS) and plant growth-promoting rhizobacteria (PGPR) production. The RR120 was decolorized in the presence of heavy metal ions by A. faecalis sub-sp. Phenolicus bacteria.

Development and integration of a continuous horizontal belt filter into drug production procedure

In the pharmaceutical industry, filtration is traditionally carried out in batch mode. However, with the spread of continuous technologies, there is an increasing demand for robust continuous filtration strategies suitable for processing suspensions produced in continuous crystallizers. Accordingly, this study aimed to investigate a lab-scale horizontal conveyor belt filtration approach for pharmaceutical separation purposes for the first time. The newly developed continuous horizontal belt filter (CHBF) was tested under different systems (microcrystalline cellulose (MCC)/water, lactose/ethanol and acetylsalicylic acid (ASA)/water) and diverse conditions. Filtration was robust using a well-defined unimodal particle size distribution MCC in water system, where the residual moisture content varied within narrow limits of 45–52% independently from the process conditions. Besides, the residual moisture content highly depended on the applied solvent and particle size. It could be reduced to below 2% by processing the suspensions of either a volatile solvent (lactose in ethanol) or an aqueous slurry of a large particle size ASA. Finally, the CHBF was connected to a mixed suspension mixed product removal (MSMPR) or a plug flow crystallizer (PFC). The residual moisture content of the CHBF-filtered ASA product and operation characteristics (onset of steady-state) were evaluated in both continuous crystallizer-filter systems. The MSMPR-CHBF system operated with a longer startup period. The size of the in situ-produced crystals was of a similar order magnitude in both systems, resulting in a similar residual moisture content (around 20%). Overall, the tested continuous filter was robust, did not modify the crystal morphology in the examined experimental range, and could be effectively integrated with continuous crystallizers.

Membrane compaction in batch reverse osmosis operation and its impact on specific energy consumption

Reverse osmosis (RO) membrane water permeability is measured under cyclic pressure loading conditions corresponding to batch and semi-batch operation modes. Due to the viscoelasticity of the membrane support layer, compaction effects carry forward across multiple pressurization cycles, with the intracycle behavior stabilizing after a large number of cycles. The average membrane permeability of semi-batch RO systems is lower than that of batch RO, since semi-batch RO spends a larger fraction of its cycle time at higher pressures. The instantaneous permeability in batch RO decreases during the cycle as pressure is increased, but at a lower rate than the steady-state permeability variation with applied pressure. Therefore, the batch permeability values are lower at low pressures and higher at high pressures than the corresponding steady-state values. Since more water is recovered in the initial low-pressure stages of a multi-stage RO system, compaction increases the specific energy consumption of batch RO more than that of staged systems. Other loss mechanisms such as channel and minor pressure losses and high-pressure motor+pump efficiency variation with load further result in batch RO becoming energetically inferior to two- or three-stage RO, especially for low-salinity, high recovery applications.

N/NiO-ornated graphitic fiber-engrained micro-carbon beads: Innovative packed bed type capacitive electrodes for microbial fuel cells

Nitrogen-doped nickel oxide-catalyzed carbon nanofiber-decorated micro-activated carbon beads (NiO-N-CNF/ACB) were synthesized through suspension polymerization and employed as capacitive fixed-packed bed electrodes in microbial fuel cell (MFC-) for wastewater treatment and byproduct electricity generation. The capacitive electrode was meticulously designed to manifest enhanced characteristics crucial for MFC applications. The large specific surface area of NiO-N-CNF/ACB offers advantages in terms of catalytic sites and stored charge produced by electrogenic bacteria to form an electrochemical double-layer on the electrode, thereby enhancing power generation. The incorporation of NiO, coupled with graphitic contents, biocompatibility, and the formation of three-dimensional structures, contributes to the excellent performance of the NiO-N-CNF/ACB electrodes. The NiO-N-CNF/ACB electrodes-based MFC operated in batch mode demonstrated an open-circuit potential of 0.8 V, an impressive maximum power density of 2900 mW/m3, and a noteworthy 74 % reduction in chemical oxygen demand. Additionally, the synthesized NiO-N-CNF/ACB exhibited a remarkable specific capacitance 754 F/g and a cumulative total charge of 255 C/g, surpassing the corresponding values for plain NiO-ACB and ACB. This study positions NiO-N-CNF/ACB as a promising capacitive packed bed electrode material, offering enhanced power generation, efficient wastewater treatment, and superior biofilm formation, thereby advancing the potential for sustainable and efficient MFC systems.

Application of Marine Mollusk Shells (Meretrix lusoria) as Low-Cost Biosorbent for Removing Cd2+ and Pb2+ Ions from Aqueous Solution: Kinetic and Equilibrium Study

The present work aims to evaluate the applicability of mollusk (Meretrix lusoria) shells as a biosorbent for toxic metal ions (Cd2+ and Pb2+) following the batch mode biosorption procedure. Some well-known analytical methods have been used to characterize the biosorbent such as a scanning electron microscope (SEM), an energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction. The mechanism of metal ion biosorption was examined using various analytical techniques. Therefore, an evaluation of operating factors such as contact time, pH, initial concentration of metal ions, biosorbent dose, and temperature was performed. The results obtained in this investigation indicated that the optimum conditions for the biosorption of Cd+2 and Pb+2 ions are as follows: pH = 6; contact times of 90 min; and the 20 mg/L of initial [M2+]. And a biosorbent dosage of 1.0 g/100 mL for each metal ion solution was also determined. The maximum removal efficiency results were 90.6% for Cd+2 and 91.5% for Pb+2 at pH 6.0. The biosorption isotherm was investigated using three forms of linear equilibrium (Freundlich, Langmuir, and Temkin models). Kinetic studies were also conducted to determine the equilibrium time for the biosorption of the studied metals utilizing the pseudo-second-order, pseudo-first-order, and intraparticle diffusion model. The data indicate that the biosorption kinetics of Cd2+ and Pb2+ follow the pseudo-second-order models. According to the present study, it can be identified that the shell of Meretrix lusoria is a suitable biosorbent for Cd2+ and Pb2+ ions and can contribute to their removal from environmentally polluted water.

Bentonite clay reinforced alginate grafted composite hydrogel with remarkable sorptive performance toward removal of methylene green

The rapid industrial progress in today's world has led to an alarming increase in water pollution caused by various contaminants such as synthetic dyes. To address this issue, a new hydrogel sorbent, BC-r-Na-Alg-g-p(NIPAm-co-AAc), was developed by combining bentonite clay, sodium alginate, and poly(N-isopropyl acrylamide-co-acrylic acid) through one-pot free radical polymerization at 60 °C. The developed sorbent was characterized using several analytical techniques including SEM, FTIR, TGA, UTM, and swelling studies. The swelling capacity of the sorbent was observed to increase remarkably with an increase in pH, reaching a maximum of 9664 % at pH 11. In batch mode sorption experiments, the sorbent's performance toward methylene green (MG) was investigated by analysing the effects of contact time, pH, temperature, and concentration. The experimental data were fitted to pseudo-second-order kinetic and Langmuir isotherm models, indicating chemisorption as the dominant interaction mode between the anionic sorbent and cationic MG. However, physisorption may also occur to a lesser extent, indicated by the significant R2 of the pseudo-first-order kinetic and Freundlich isotherm models. Additionally, the sorbent exhibited very little decrease (approximately 5 %) in sorptive performance for six sorption-desorption cycles. Overall, the facile fabrication, excellent swelling (9664 %), promising sorption performance (2573 mg.g−1), and good recyclability (6 cycles) make the developed sorbent a potential candidate for various industrial applications.

Quality by design for mRNA platform purification based on continuous oligo-dT chromatography

Oligo-deoxythymidine (Oligo-dT) ligand-based affinity chromatography is a robust method for purifying mRNA drug substances within the manufacturing process of mRNA-based products, including vaccines and therapeutics. However, the conventional batch mode of operation for oligo-dT chromatography has certain drawbacks that reduce this process’s productivity. Here, we report a new continuous oligo-dT chromatography process for the purification of in vitro transcribed mRNA, which reduces losses, improves the efficiency of oligo-dT resin use, and intensifies the chromatography process. Furthermore, the quality by design (QbD) framework was used to establish a design space for the newly developed method. The optimisation of process parameters, including salt type, salt concentration, load flow rate and mRNA load concentration both in batch and the continuous mode, achieved >90% yield (mRNA recovery) along with >95% mRNA integrity and >99% purity. The productivity of continuous chromatography was estimated to be 5.75-fold higher, and the operating cost was estimated 15% lower, when compared to batch chromatography. Furthermore, the QbD framework was further used to map the relationship between critical quality attributes (CQAs) and key performance indicators (KPIs) as a function of critical process parameters (CPPs) and critical material attributes (CMAs).

Environmental Sustainability of the Removal of Alpaca Fiber Dye Using a Thermally Modified Sludge from a Drinking Water Treatment Facility

In this work, the removal of dye using thermally modified sludge from a drinking water treatment facility (DWTS) was evaluated. This study gives value to the waste from the coagulation flocculation process (waste sludge) in order to remove an emerging organic agent (Bordeaux B). The sustainability of the process leads to a circular economy, which represents an important environmental contribution. The physicochemical characterization of the DWTS was carried out by standard methods. DRX and FTIR spectroscopy, SEM, and superficial specific area SBET N2 at 77 K were used. Thermal activation processes were carried out (200–600 °C) to obtain the best activated thermal conditions for dye removal (T: 500 °C). Muscovite and other minerals were found in the DWTS. Experimental conditions (batch mode) were determined: contact time (CT), pH, adsorbent dose (AD), and dye initial concentration (Co). SBET = 54.77 and 67.90 m2/g by DWTS and TA-500. The best removal efficiency was achieved at 500 °C (R = 85.57 ± 0.76 %, q max = 37.45 ± 0.14 mg/g), which, compared to other unconventional adsorbents, is more reliable and competitive. The adsorption process was adjusted to the Langmuir mathematics model, following pseudo-second-order kinetics (R2 = 0.99).

Electrochemical flow-through disinfection of Escherichia coli versus Staphylococcus aureus: Identifying impacts of flow patterns on efficiency

While Ti4O7 reactive electrochemical membrane (REM) treatment exhibits high efficiency in inactivating bacteria, it remains obscure about the disinfection and antifouling mechanism. Herein, we highlighted the decisive impact of flow patterns on the electrochemical inactivation of both Escherichia coli and Staphylococcus aureus during dead-end filtration mode. Specifically, 5.22 and 5.47 log removal for E. coli and S. aureus were achieved by a single pass under anode-to-cathode (AC) flow pattern at 7 mA cm−2 respectively, while the inactivation rates immediately decreased to less than one log for cathode-to-anode (CA) flow pattern. Further analysis demonstrated that the remarkable inactivation efficiency in neutral condition, the complete inactivation of E. coli and S. aureus in the parallel plate batch mode were achieved in 15 min and 30 min at 7 mA cm−2 respectively, was significantly inhibited during alkaline and acidic exposure, thereby which explained the slow disinfection rates in CA flow pattern due to the formed alkaline experiment near anodic reaction section. The disinfection efficiency and comparative differences of E. coli and S. aureus were also affected by their hydraulic condition and cell wall structure. Functional groups model substances experiments and molecular dynamics simulation elucidated that the response changes of cell structure especially denser membrane protein complex under alkaline and acidic exposure resisted electrooxidation attack to the membrane structure. These findings here provide insights into the application of Ti4O7 REM technologies in controlling waterborne disease transmission.