Agitation Speed Research Articles

Synthesis and characterisation of novel beta-cyclodextrin based Fe3O4 nanocomposite: adsorption behaviour and photocatalytic dye degradation studies

ABSTRACT Novel Beta-Cyclodextrin-based Fe3O4 nanocomposite has been synthesised through copolymerisation by incorporating Fe3O4 nanoparticles into the polymer matrix. Ultraviolet-Visible (UV-Visible) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric (TGA) analysis, Point of Zero Charge, X-ray diffraction (XRD), and Scanning electron microscopy (SEM) analysis have been used to characterise the Fe3O4 Nanoparticles and β-CDHs@Fe3O4 nanocomposite. The synthesised β-CDHs@Fe3O4 nanocomposite has been utilised for the adsorption of methylene blue (MB) dye from aqueous solutions. The maximum percentage removal of MB dye at optimum pH 7 and was found to be 98.51%. The adsorption capacity (qe) of β-CDHs@Fe3O4 nanocomposite has been found to be 268.09 mg/g at optimum dosages 1.2 g/L, pH 7, temperature 25°C, concentration 100 mg/L and an agitation speed of 200 rpm. Adsorption data have been fitted with three isotherm models namely Langmuir, Freundlich, and Temkin, and it was found to be the best fit with the Langmuir isotherm model. Kinetic studies like the pseudo-first order, pseudo-second order, and intra-particle diffusion model were also performed to study the adsorption mechanism. Further, thermodynamic studies demonstrate that the reaction was exothermic and spontaneous. Photocatalytic degradation of MB dye under visible light has also been studied, and 79.01% degradation of the dye was observed. Also, desorption of the nanocomposite was performed, and it was found to be reusable up to 5 times with 90% dye-desorption in the fifth cycle.

Deracemization of sodium chlorate by hydrodynamic attrition of Taylor vortex flow

We investigated the deracemization of sodium chlorate in the unique hydrodynamic environment of Taylor vortex flow (TVF) in Couette-Taylor (CT) crystallizer. Our findings revealed a remarkable enhancement in the deracemization due to the effective hydrodynamic attrition of crystals, as compared to conventional mixing tank (MT) crystallizers utilizing the turbulent eddy flow (TEF). So, the deracemization of initial ee = 0 % in the CT crystallizer was significantly enhanced as increasing the rotation speed whereas the deracemization in the MT crystallizer occurred seldom with increase of agitation speed. Using the sparsely soluble solvent, it was demonstrated the TVF was much more effective for the hydrodynamic attrition of the crystals than the TEF. The deracemization depended not only on the flow intensity (viscous energy dissipation) but also the flow pattern. So, the TVF always produced the higher deracemization than the TEF at the same viscous energy dissipation. Also, the flow intensity and flow pattern significantly dictated the crystal agglomeration of homo-chiral (L-form and D-form) and hetero-chiral (L/D-form) forms during the deracemization. Our findings demonstrated the potential of the periodic TVF in the deracemization. The hydrodynamic attrition effect in the CT crystallizer provides a means to enhance enantiomeric purity and offers insights into the design of novel deracemization systems.

Effect of agitation speed on methylene blue discoloration kinetics via ambient air cold plasma

AbstractThis research investigates the kinetics of methylene blue (MB) discoloration using ambient air cold plasma, with a focus on the impact of agitation speed (100 and 750 rpm). The study revealed pseudo‐first‐order kinetics for MB discoloration, pinpointing optimal conditions at 35.00°C and 100 rpm. These parameters minimized half‐life times, correlated with observed kobs values. A decreasing pH trend, more pronounced at 750 rpm, was attributed to increased acidic nitrogen species (HNO3 and HNO2) production, adversely affecting dye discoloration. Concurrently, enhanced electrolyte concentration was noted from rising conductivity due to plasma production of reactive species followed by solubilization in the aqueous phase. The calculated thermodynamic activation parameters comprised: Ea = 7.96 kJ mol−1, ΔH‡ = +5.53 kJ mol−1, ΔS‡ = −253.23 J K−1 mol−1, and ΔG‡ = +79.77 kJ mol−1 (100 rpm); and Ea = 12.94 kJ mol−1, ΔH‡ = +13.78 kJ mol−1, ΔS‡ = −239.06 J K−1 mol−1, and ΔG‡ = +80.58 kJ mol−1, (750 rpm). The lowest Ea and ΔG‡ values at 100 rpm reinforced lower agitation favoring the reaction. The study demonstrated a linear decay of the reaction rate constant with the square root of ionic strength. This result, besides the negative activation entropy and moderate activation enthalpy led to a proposition to the determinant step for the transition state formation, involving an associative step between a solvated electron and the protonated substrate. The optimal dye discoloration rate and energy yield were observed at 35.00°C and 100 rpm, with values of 97.2% and 3.371 × 10−2 g kW−1 h−1, respectively.

CFD modeling of H2S removal from liquid sulfur in a pilot-scale gas-liquid contactor

Removal of hydrogen sulfide (H2S) from liquid sulfur is essential to product quality and safe operation in sulfur processing recovery. This paper presents computational fluid dynamics (CFD) models of sulfur degassing performance in a pilot-scale gas-liquid contactor. Two mass transfer models with and without considering the decomposition of hydrogen polysulfide (H2Sx) to H2S are established. They are then used to explore the effects of various operating parameters, including residence time, injected liquid sulfur flow rate, impeller type, and agitation speed, on degassing efficiency. Results show that the relative errors between calculation and experimental data are within ±6.2 %. Furthermore, the impeller geometry is optimized, and the efficiencies of three degasser shapes are compared using the verified CFD tool. The optimized impeller structure can increase degassing efficiency by about 9 % compared to the original one. The CFD model can be further improved to guide the design and scale-up of diverse H2S degassers.

Optimizing bio-vanillin synthesis from ferulic acid via Pediococcus acidilactici: A systematic approach to process enhancement and yield maximization

The use of lignocellulosic biomass to create natural flavor has drawn attention from researchers. A key flavoring ingredient that is frequently utilized in the food industry is vanillin. In this present study, Pediococcus acidilactici PA VIT effectively involved in the production of bio-vanillin by using Ferulic acid as an intermediate with a yield of 11.43 µg/mL. The bio-vanillin produced by Pediococcus acidilactici PA VIT was examined using FTIR, XRD, HPLC, and SEM techniques. These characterizations exhibited a unique fingerprinting signature like that of standard vanillin. Additionally, the one variable at a time method, placket Burmann method, and response surface approach, were employed to optimize bio-vanillin. Based on the central composite rotary design, the most important process factors were determined such as agitation speed, substrate concentration, and inoculum size. After optimization, bio-vanillin was found to have tenfold increase, with a maximum yield of 376.4 µg/mL obtained using the response surface approach. The kinetic study was performed to analyze rate of reaction and effect of metal ions in the production of bio-vanillin showing Km of 10.25, and Vmax of 1250 were required for the reaction. The metal ions that enhance the yield of bio-vanillin are Ca2+, k+, and Mg2+ and the metal ions that affects the yield of bio-vanillin are Pb+ and Cr+ were identified from the effect of metal ions in the bio-vanillin production.

Biological control of the shot-hole disease in flowering cherry tree using antimicrobial compounds produced by Bacillus velezensis 8–2

BackgroundEffective control of shot-hole disease in flowering cherries is challenging because of multiple causative pathogens (bacteria and fungi). Bacillus species are well-known for their ability to control plant pathogens; therefore, biological control potential of a Bacillus isolate, B. velezensis 8–2, against SH disease on flowering cherry trees was investigated.ResultsThis study revealed strong antimicrobial activity of Bacillus velezensis 8–2 against various plant pathogenic bacteria and fungi, particularly focusing on Xanthomonas arboricola pv. pruni (Xap) and Mycosphaerella cerasella (Mc), which cause shot-hole (SH) disease in flowering cherry trees. In vitro assays showed that the fermentation filtrate of B. velezensis 8–2 inhibited bacterial and fungal growth with minimum inhibitory concentrations of 1.25–10% and 2.5–10%, respectively. UPLC-Q–Orbitrap–MS analysis revealed that B. velezensis 8–2 produced antagonistic compounds, including polyketides (difficidin and oxydifficidin) and cyclic lipopeptides (iturin A, fengycin, and surfatin). To enhance antimicrobial activity, fermentation parameters for optimal production of two antibacterial and three antifungal compounds were investigated in a 5 L jar fermenter. By regulating the agitation speed to sustain the state of vegetative cells, the production period was extended by 20 h at 400 rpm, resulting in maximum yields of 86.6 μg/mL for difficidin and 150.0 μg/mL for oxydifficidin within a 72 h fermentation period. In a field trial, a 500-fold diluted 10% suspension concentrate formulation of B. velezensis 8–2 effectively inhibited the development of SH disease, demonstrating 66.6% disease control and a 90.2% disease symptoms reduction.ConclusionsThis is the first report to assess the disease control efficacy of B. velezensis for the biocontrol of SH disease in the field. These results suggest that the application of B. velezensis 8–2 could serve as a practical alternative for managing various bacterial and fungal diseases, including the management of SH disease in flowering cherry trees.Graphical

Nano-CaO as a heterogeneous catalyst for biodiesel synthesis by transesterification of Jatropha oil

BackgroundThis research employs response surface methodology, specifically Central Composite Design (CCD), to optimize the process parameters for the effective production of biodiesel. Jatropha oil was utilized as the raw material to minimize expenses. A nanocatalyst was utilized as a solid catalyst, developed from CaCO3 via waste snail shells, offering advantages such as recyclability and improved catalytic activity during a transesterification process. The developed nanocatalyst was analyzed using various techniques, including dynamic light scattering (DLS), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, and Fourier-transform infrared (FTIR). The BET analysis revealed a surface area of 5.1m2/g and the Barrett-Joyner-Halenda (BJH) analysis provided insights into the pore volume and diameter of the synthesized nano-CaO, showing values of 0.002556 cc/g and 1.1 nm, respectively, indicating the presence of both microspores and active sites on the external surface of the nano-CaO catalyst. Biodiesel conversion was controlled by adjusting factors like the methanol to oil ratio, catalyst weight, reaction time, reaction temperature, and agitation speed. A quadratic model was established to explore the correlation between the independent variables and the biodiesel conversion rate. The results showed a maximum biodiesel conversion rate of 96.73% under the optimal conditions: methanol to oil ratio (6:1), catalyst weight (1.4 wt%), reaction time (60 min), reaction temperature (55 °C), and agitation speed (250 rpm). These parameters were determined through 32 experimental trials. The RSM technique yielded impressive results with a determined coefficient of determination (R2) of 0.9834, adjusted R2 of 0.8503, predicted R2 of 0.8309, and a coefficient of variance (CV) 0.75%. Based on the analysis of variance (ANOVA) findings, the model exhibits a high level of significance (p<0.0001), which is less than 0.05 and F- Value 29.71.The study aims to enhance the yield and efficiency of the transesterification process, thereby increasing the overall production of fatty acid methyl ester from Jatropha oil. This innovative approach efficiently generates biodiesel from renewable resources, in a manner that is both environmentally friendly and maximizes the effectiveness of the process parameters. The evaluation conform that the quality of the biodiesel met the standards set by ASTM D 6751 and EN 14214.

Antimicrobial Effect of Response Surface Optimized Pyocyanin Produced by Pseudomonas aeruginosa

Pseudomonas aeruginosa is notable for its natural bluish-green pigment production, known as pyocyanin. Researchers have credited pyocyanin as an antimicrobial agent, in addition to its other biomedical applications. This study focused on isolating Pseudomonas aeruginosa from the local environment with the ability to synthesize pyocyanin and optimize its cultural conditions for improved yield. A total of thirty-one experimental combinations of process variables using the Central Composite Design (CCD) of Response Surface Methodology (RSM) was ran to find the best conditions for the organism to make pigments. Of the fermentation media evaluated, nutrient broth supplemented with maltose was the best fermentation medium for the organism’s pyocyanin production. A regression model described the interaction between the test variables and the pyocyanin yield with an R2 value of 87.52%, indicating that the model had a satisfactory fitness level. The determined optimal conditions include a maltose concentration of 18 g/L, a pH of 6.8, an inoculum size of 2.3 mL, and an agitation speed of 120 rpm. The optimized condition resulted in a 4.12-fold increase in pyocyanin yield compared to an unoptimized condition. Pyocyanin exhibits high antimicrobial activity compared to the conventional antibiotics assessed against E. coli and Candida albicans. Our study’s findings suggest that statistical models can improve pyocyanin synthesis by Pseudomonas aeruginosa. Furthermore, this pigment has the potential to replace conventional antibiotics in the treatment of microbial infections

Selective extraction of germanium from iron-bearing ammonia leaching residue via low-temperature molten NaOH leaching

To address the insolubility of x(SiO2)·GeO2 and y(Fe3O4)·GeO2, this study introduced a two-step leaching (NaOH leaching-NL and low-temperature molten NaOH leaching- LTMNL) method. During the NL process, 51.30 % of germanium (Ge), 84.96 % of aluminum (Al), and 56.45 % of silicon (Si) were leached. Moreover, in the LTMNL process, over 97.43 % of Ge and nearly all amphoteric metals (e.g., Al, Zn, and As) were dissolved under optimized conditions (including a NaNO3-to-ore mass ratio of 0.15, leaching temperature of 170 °C, alkali-to-ore mass ratio of 10, agitation speed of 500 rpm, and reaction time of 2 h). The leachate obtained from the LTMNL process was used as a lixiviant in the NL process to facilitate the recyclable utilization of NaOH and enrich Ge in the leachate solution. This approach resulted in an overall germanium recovery efficiency of 98.72 %. The germanium concentration in the NL leachate exceeded 400 mg/L, thereby facilitating subsequent germanium recovery. Additionally, the LTMNL residue, containing an iron concentration of 52.46 wt%, served as an iron resource. Therefore, the two-step leaching process achieved high germanium recovery and efficient separation of Ge and Fe compared with conventional H2SO4 leaching methods. This indicates that the two-step leaching process is a promising and efficient method for treating germanium-bearing material in the form of x(SiO2)·GeO2 and y(Fe3O4)·GeO2).

Removal of a model reactive azo dye from aqueous solution by a bioadsorbent in batch and fixed-bed column modes: Application of the developed technology to a textile wastewater

Sugarcane bagasse (SB) was used to produce a new bioadsorbent (STEA), drawing on circular economy concepts. STEA was synthesized using a two-step one-pot reaction, employing epichlorohydrin and triethylamine in the presence of N,N-dimethylformamide, without the use of a petroleum-based catalyst. The structure and surface of STEA were characterized by elemental C, H, N, and Cl analysis, X-ray diffraction, infrared spectroscopy, 13C solid-state nuclear magnetic resonance spectroscopy, thermogravimetric analysis, specific surface area and pore size distribution determination, and point of zero charge measurement. Batch adsorption and desorption tests were performed with the model dye Remazol Golden Yellow (RGY) RNL, a reactive anionic azo dye widely used in textile industry, to evaluate the potential reuse and application of STEA in a fixed-bed column for wastewater treatment. For batch adsorption, the best dose and agitation speed were 0.2 g L−1 and 50 rpm, respectively. STEA effectively removed RGY over a wide range of pH (2.00–10.00). The equilibrium time, maximum adsorption capacity (Qmax), and desorption efficiency (Edes) were 720 min, 369 mg g−1 (0.71 mmol g−1), and 49.5 %, respectively. The fixed-bed column fed with a spiked aqueous RGY solution could be operated for 415 min, with Qmax of 422 mg g−1 (0.81 mmol g−1) and Edes of 58.9 %. Batch and continuous experiments using real textile industry wastewater containing reactive azo dyes showed high color removal efficiency by STEA, with no interference of other compounds present in wastewater on adsorption of the reactive azo dyes (overshooting effect). The technology was validated in a relevant environment and achieved technology readiness level 5, showing potential to be upscaled. Therefore, STEA proved to be an efficient bio-based technology for application in tertiary treatment of real textile plant wastewater to remove reactive anionic azo dyes.

Novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel development for Methyl orange removal from waste water

In the modern era, with the rapid growth of various industries, the issues of energy crisis and environmental pollution have garnered increasing attention. One significant source of industrial pollution is printing and dyeing wastewater. This wastewater often contains dyes that have aromatic structures and azo groups, such as Methyl orange (MO), which are both toxic and difficult to degrade. If these dyes are released into the wastewater stream without any treatment, they can have adverse effects on ecological balance and human health. Therefore, it is crucial to identify suitable treatment strategies to efficiently remove dyes from wastewater systems before discharge. In this study, the Methyl orange (MO) azo dye has been removed from dyes-contaminated wastewater, for the first time, using a novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel (AECMC). Different characterization methods, including FTIR, TGA, and DSC were used to characterize the generated AECMC compounds. The water absorption and cationic exchange capacities were assessed. Factors affecting the MO anions adsorption including MO concentration, adsorption pH, temperature, time, adsorbent dose, and agitation speed have been investigated. Moreover, the kinetics of the adsorption process was assessed by the use of three models: pseudo-first-order, Pseudo-second-order, and Elovich. Moreover, the mechanism of the adsorption process was monitored using the Intraparticle diffusion and Boyd models. Additionally, the adsorption isotherm was examined using established models such as Langmuir, Freundlich, and Temkin isotherms. The thermodynamic characteristics of the MO adsorption process have been investigated at various adsorption temperatures using the Van't Hoff model. The results obtained from the study indicate that the process of MO adsorption adhered to the Pseudo-second-order kinetic model, the Langmuir isotherm model was found to be applicable, and spontaneous and exhibited an endothermic character. In conclusion, the developed novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogels (AECMC) have successive in the removal of the MO anionic dye from contaminated wastewater.

Isolation and characterization of fungi producing L-asparaginase with reduced L-glutaminase activity from soil samples

BackgroundL-asparaginase (L-ASNase) is an essential enzyme used to treat acute lymphoblastic leukemia (ALL) by depleting L-asparagine, a vital nutrient for leukemia cells. However, its clinical use is challenged by adverse effects linked to its bacterial origin and L-glutaminase (L-GLNase) co-activity. This study aims to identify fungi capable of producing L-ASNase with reduced L-GLNase co-activity. ResultsAmong the fungal iolates, isolate JK12 and ChL11 showed high L-ASNase activity (34.04 ± 1.83a U/ml and 30.84 ± 0.53b U/ml, respectively) with reduced L-GLNase co-activity (4.95 ± 0.28c U/ml and 4.80 ± 0.02d U/ml, respectively). Sequencing of the internal transcribed spacer (ITS) region of these isolates identified them as Candida palmioleophila isolate JK12 (≥99% identity with Candida genus) and Trichosporon asahii isolate ChL11 (≥98% identity with Trichosporon genus). Moreover, these isolates exhibited distinct preferences for carbon (C) and nitrogen (N) sources, as well as culture conditions for L-ASNase production. C. palmioleophila isolate JK12 demonstrated the highest L-ASNase production in fructose and yeast extract (67.6 ± 0.04a U/ml and 51.4 ± 0.04a U/ml, respectively), following 96 h of incubation at 25°C (43.8 ± 1.22a U/ml, 55.8 ± 0.02a U/ml, respectively), with an agitation speed of 100 rpm (59.9 ± 0.04a U/ml). On the other hand, T. asahii isolate ChL11 exhibited maximum L-ASNase production in sucrose and L-asparagine (64.2 ± 0.08a U/ml and 63.6 ± 0.01a U/ml, respectively), after 120 h of incubation at 35°C. ConclusionsThe fungal isolates T. asahii isolate ChL11 and C. palmioleophila isolate JK12 have been identified as promising L-ASNase sources of safer therapeutic prospects in cancer therapy due to the reduced GLNase co-activity.How to cite: Sisay T, Mobegi VA, Wachira S, et al. Isolation and characterization of fungi producing L-asparaginase with reduced L-glutaminase activity from soil samples. Electron J Biotechnol 2024. https://doi.org/10.1016/j.ejbt.2024.05.002.

Hyper β-glucosidase producer Beauveria bassiana SAN01—optimization of fermentation conditions and evaluation of saccharification potential

AbstractThe hyper-production of β-glucosidase by a local strain of Beauveria bassiana under submerged conditions is reported in this study. The initial screening of seven agricultural residues showed that the haulm of Bambara—an underutilized African legume—supported the highest β-glucosidase production; hence, statistical optimization of enzyme production was done using this biomass as the sole carbon source. Plackett–Burman design identified the concentrations of Bambara haulm, KCl, and NaCl as well as agitation speed and incubation time as the most significant factors affecting enzyme production. Subsequently, the central composite design predicted the optimal conditions (Bambara 57 g/L, KCl 302 mg/L, NaCl 154 mg/L, agitation speed 150 rpm, and incubation 223 h) for B. bassiana β-glucosidase production, which were further validated. The generated quadratic model was deemed significant judging from its F-value (201.63), adequate precision ratio (45.74), as well as the R2 (0.9988), adjusted R2 (0.9938), and predicted R2 (0.9195) values. The optimization resulted in a ~5.36-fold increase in enzyme levels from the unoptimized production of ~133 to 711 U/mL. The enzyme was also demonstrated to efficiently hydrolyze cellobiose, converting more than 90% of the substrate to glucose. These results further establish the resourcefulness of the B. bassiana strain for the production of β-glucosidase enzyme, having immense potential, especially in the food and energy industries.

Optimisation of fermentation conditions for the production of gamma-aminobutyric acid (GABA)-rich soy sauce

This study addresses the challenge of enhancing gamma-aminobutyric acid (GABA) content in soy sauce through optimized fermentation condition. Using a multiple starter culture, consisting of Aspergillus oryzae strain NSK, Bacillus cereus strain KBC and Tetragenococcus halophilus strain KBC, the incubation conditions including the percentage of bacterial inoculum (10, 15 and 20 %), pH (3, 5 and 7) and agitation speed (100, 150 and 200 rpm) were optimized through Response Surface Methodology (RSM). Under the optimal conditions (20 % inoculum, pH 7 and stirring at 100 rpm), the multiple starter culture generated 128.69 mg/L of GABA after 7 days and produced 239.08 mg/L of GABA after 4 weeks of fermentation, which is 36 % higher than under non-optimized conditions (153.48 mg/L). Furthermore, sensory analysis revealed high consumer acceptance of the fermented soy sauce than the control (soy sauce without any treatment and additional bacteria) and commercial soy sauce. Consumers indicated that the starter culture offered an improved umami taste and reduced bitter, sour and salty flavours compared to the commercial product. Under optimal fermentation conditions determined by RSM statistical analysis, the multiple starter culture is able to produce high levels of GABA and is more likely to be accepted by consumers. The findings of this research have the potential to impact the food sector by offering a functional soy sauce with added health benefits and also being well-received by consumers.

The role of shear forces in primary and secondary nucleation of amyloid fibrils

Shear forces affect self-assembly processes ranging from crystallization to fiber formation. Here, the effect of mild agitation on amyloid fibril formation was explored for four peptides and investigated in detail for A[Formula: see text]42, which is associated with Alzheimer's disease. To gain mechanistic insights into the effect of mild agitation, nonseeded and seeded aggregation reactions were set up at various peptide concentrations with and without an inhibitor. First, an effect on fibril fragmentation was excluded by comparing the monomer-concentration dependence of aggregation kinetics under idle and agitated conditions. Second, using a secondary nucleation inhibitor, Brichos, the agitation effect on primary nucleation was decoupled from secondary nucleation. Third, an effect on secondary nucleation was established in the absence of inhibitor. Fourth, an effect on elongation was excluded by comparing the seeding potency of fibrils formed under idle or agitated conditions. We find that both primary and secondary nucleation steps are accelerated by gentle agitation. The increased shear forces facilitate both the detachment of newly formed aggregates from catalytic surfaces and the rate at which molecules are transported in the bulk solution to encounter nucleation sites on the fibril and other surfaces. Ultrastructural evidence obtained with cryogenic transmission electron microscopy and free-flow electrophoresis in microfluidics devices imply that agitation speeds up the detachment of nucleated species from the fibril surface. Our findings shed light on the aggregation mechanism and the role of detachment for efficient secondary nucleation. The results inform on how to modulate the relative importance of different microscopic steps in drug discovery and investigations.

An experimental study on the parthenium biosorbents for removals of chlorides and hardness from contaminated water

Among the problems most severe for the environment is the pollution of aqueous solution, specifically the creation of threats connected to hazardous heavy metals. In some rural places, it is hardness and chlorides that make groundwater or surface water dangerous in terms of the level of toxins. The requirement of hardness and chlorides is influenced because, in large quantities, when it comes to the quality of drinking water, it causes disease. Water is hazardous to the eyes because of its alkaline nature, inhalation organs, and skin problems. The more hardness and chlorides and related irritations there are, the larger the share. A naturally occurring physiochemical mechanism called biosorption enables certain biomass to passively adsorb hardness and chlorides into the biomass's cellular structure. In the lab, five distinct biosorbents were created, including parthenium, rice husk, rapeseed straw, sawdust, and egg cells, in that order. The parthenium biosorbents turned out to be the most successful biosorbents, despite the fact that each biosorbents has a different level of effectiveness in eliminating hardness and chlorides from water. By using the plant based biomass of parthenium, 65 % of chloride removal with 80 % of hardness removal was obtained. Having identified the best biosorbents, we optimized their parameters and took water samples from different sources. In chlorides removal over parthenium biosorbents, the optima dosage of biosorbents is 3.8 g, temperature is 35 °C, pH is 7, contact time is 120 min and optima agitation speed is 120 rpm. In hardness removal over parthenium biosorbents, the optima dosage of biosorbent is 5.4 g, temperature is 35 °C, pH is 6.5, contact time is 90 min and agitation speed is 150 rpm. Once the chlorides and hardness ions are removed from the water by the utilized biosorbents, the biosorption process may be homo cost effective through the regeneration and reuse of the biosorbent.

Adsorption efficiency of chitosan/clinoptilolite (CS/CZ) composite for effective removal of Cd+2 and Cr+6 ions from wastewater effluents of dairy cattle farms.

The wastewater effluent is responsible for the major ecological impact of the dairy sectors. To avoid the negative consequences of heavy metal pollution on the ecosystem, creative, affordable, and efficient treatment methods are now required before the effluent flows into the surrounding area. This study was aimed at assessing the effectiveness of three different adsorbents for Cd+2 and Cr+6 ions from wastewater effluents of dairy farms, including chitosan (CS), clinoptilolite zeolite (CZ), and chitosan/clinoptilolite zeolite (CS/CZ) composite. The adsorption kinetics of the CS/CZ composite were established using the effects of the key variables (pH, agitation speed, adsorbent concentrations, and contact durations). The removal (%) and adsorption capacities, qe (mg/g), were calculated using the data from the adsorption kinetics. Wastewater samples (n = 60) were collected from the wastewater effluents of five farms. Cd+2 and Cr+6 ion concentrations in all collected samples were determined. Following the CS/CZ composite creation, it was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (X-RD), and Fourier-transform infrared spectrum (FT-IR). The CS/CZ composite had an adsorption capacity of 92.4 and 96.5 mg/g for both Cd+2 and Cr+6 ions at a concentration of 2.0 g/100 ml, respectively, while the CZ adsorption capacities for the two ions were 87.5 mg/g and 61.0 mg/g, respectively, at 4.0 g/100 ml concentration. The CS was achieved at 55.56 mg/g and 33.3 mg/g, respectively, at the same concentration. The efficiency of heavy metal removal was enhanced by increasing adsorbent concentration, agitation speed, and contact duration. Using CS/CZ composite at 2.0 g/100 ml concentration, 180 min of contact time, and 300 rpm agitation speed, the greatest removal efficiencies for Cd+2 and Cr+6 ions (96.43 and 98.75%, respectively) were demonstrated.

Advancing precision fermentation: Minimizing power demand of industrial scale bioreactors through mechanistic modelling

Minimizing power consumption in large-scale aerobic fermentation is essential for cost-effective operations. A mechanistic model of aerobic precision fermentation was developed integrating microbial growth parameters, thermodynamic data, and bioreactor properties. Results showed that agitation power dominated energy consumption at low oxygen transfer rates (OTR), shifting to aeration power (70 % of total) at high cell growth rates. In high OTRs, mixing time reduced to 60 s from an initial value of 211 s. Scale-up from 5 m³ to 100 m³ decreased total specific power by 88 %. Operating at elevated headspace pressure lowered agitation speed, reducing total power consumption at high OTR. Impeller to bioreactor diameter ratio impacted the required agitation speed without significantly altering total power demand. Experimental data in a 100 L case study indicated a 0.43 kW.m⁻³ average power requirement across a 96-hour fermentation period. Our model demonstrates effective strategies for minimization of power consumption in industrial-scale aerobic fermentations.

Production of high levels of 2,3-butanediol from renewable crude glycerol by Klebsiella pneumoniae GEM167 using metabolic engineering and control of oxygen transfer efficiency

Numerous industries use 2,3-butanediol as a bulk chemical. This study aimed to develop a technique for the commercial production of 2,3-butanediol from glycerol using K. pneumoniae GEM167 strain with enhanced oxidative pathways. We developed K. pneumoniae GEM167ΔadhEΔldhA, a strain that has decreased production of competitive metabolites (ethanol and lactate) and increased production of 2,3-butanediol. We investigated the correlation between the oxygen transfer coefficient and 2,3-butanediol production by modifying the agitation speed and aeration rate. K. pneumoniae GEM167ΔadhEΔldhA provided a high titer (102.9 ± 3.1 g/L) and productivity (2.14 ± 0.06 g/L/h) of 2,3-butanediol with no detectable 1,3-propaendiol production under specific culture conditions (37 °C, 700 rpm, 2.0 vvm, and pH 6.0). To the best of our knowledge, the productivity of 2,3-butanediol from glycerol in this study is the highest yet reported. And the substitution with crude glycerol enhanced the titer (105.3 ± 2.8 g/L) and productivity (2.19 ± 0.06 g/L/h) of 2,3-butanediol.

Chemical Composition, Nutritional Value, Antioxidative, and In Vivo Anti-inflammatory Activities of Opuntia Stricta Cladode.

The cactus family plant has been used in folk medicine for a long time. In this work, Opuntia stricta chemical composition and its antioxidative and anti-inflammatory properties were investigated. Our results showed that O. stricta is highly rich in fibers and minerals. The present study assessed the levels of polyphenol contents and antioxidant and in vivo anti-inflammatory activities. The highest phenolic compounds and antioxidant activity were observed in the methanolic extract. Concerning the qualitative analysis, nine phenolic and organic acids were identified and quantified by high-performance liquid chromatography (HPLC). Luteolin-7-Glu (4.25 μg/g), apigenin-7-Glu (3.15 μg/g), and catechin (2.85 μg/g) were identified as major phenolic compounds. The predominant fatty acids detected by gas chromatography (GC) coupled to a flame ionization detector were linoleic and linolenic acids (35.11%). A factorial design plan was used to determine the effect of temperature, agitation speed, and maceration period on phenolic contents. In vivo, the methanol extract from Opuntia stricta showed anti-inflammatory activity. The computational modeling reveals that O. stricta compounds bind VEGF, IL-6, and TNF-α with high binding scores that reach -8.7 kcal/mol and establish significant molecular interactions with some key residues that satisfactorily explain both in vitro and in vivo findings. These data indicate that Opuntia stricta cladode powder could be potentially useful in pharmaceutical and food applications.