Pollen in the atmosphere is one of the common bioaerosol materials that can be harmful to human health. To collect and predict the pollen in the atmosphere, a sampling module of a cyclone wet-wall ...bioaerosol sampler was designed using the computational fluid dynamics (CFD) method and response surface method (RSM). The parabolic shape was chosen for the sampling module based on the axial and tangential velocities of flow in the module. Then, the main diameter of the sampling module was determined. The significance analysis of the main parameters of the sampling module on the capture rate was conducted using the Plackett-Burman (PB) design method. In descending order, the items are inlet width > outlet diameter > inlet height > base diameter > cone height > cylinder height > outlet pipe insertion depth. The test center point of Box-Behnken design (BBD) for the four significant parameters, namely inlet width, outlet diameter, inlet height, and cone height, were determined using the steepest climb test. Then, the optimal parameters of the sampling module were obtained using RSM and the optimal parameters were an inlet height of 15.4 mm, an inlet width of 5.4 mm, an outlet diameter of 14.7 mm, and a base diameter of 13.3 mm. Finally, the simulated capture rate of the sampling module was validated by the experimental results. The capture rate of the optimal sampling module for 2.5 μm PSL particles was 82.93 ± 4.25%. The results of this study can provide a practical method for designing the sampling module using the CFD model and RSM. Additionally, it can provide a high collection rate sampling module for pollen and bioaerosol in the environment.
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•The main parameters of the sampling module on the capture rate were determined.•The optimal parameters of the sampling module were obtained using response surface methodology.•The designed sampling module was verified by the experiments.•The capture rate of the sampling module with optimal parameters was 82.93 ± 4.25%.
•Preparation and characterization of clay.•Detailed predictive modeling of the EBT adsorption process utilizing RSM, ANN and ANFIS models.•Critical comparative analysis of the three ...models.•Evaluation of mechanistic modeling of the adsorption process.•Optimization using genetic algorithm.
The application of artificial neural network (ANN), response surface methodology (RSM), and adaptive neuro-fuzzy inference system (ANFIS) in modeling the uptake of Eriochrome black-T (EBT) dye from aqueous solution using Nteje clay was the focus of this work. Acid activation with hydrochloric acid (HCl) was used to prepare the adsorbent while Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were utilized in the characterization of the adsorbent. The ANN, RSM, and ANFIS models were analyzed by considering the adsorbent dosage, contact time, solution temperature, and pH of the adsorption process. Sensitivity analyses involving six statistical error functions were further used to compare the acceptability of the models. Four mechanistic models (Weber and Morris, Film diffusion, Bangham, and Dummwald-Wagner models) were used to determine the mechanism of the EBT uptake. The result showed that the activation process enhanced the adsorption capacity of the clay. The ANFIS, ANN, and RSM models gave a high accuracy in predicting the adsorption of the EBT dye with correlation coefficients of 0.9920, 0.9910, and 0.9541, respectively. Further statistical indices lent credence to ANFIS as the best predictive model and RSM the least in adsorption of EBT dye. Process optimization using genetic algorithm gave optimum adsorption efficiency of 95.8%. Mechanistic modeling indicated film diffusion as the rate-limiting mechanism. The maximum amount of EBT adsorbed was 24.04 mg/g. The HCl-modified clay could be utilized as an efficient adsorbent in EBT uptake from wastewater.
Ophiorrhiza mungos (O. mungos), a significant medicinal plant belonging to the Rubiaceae family, is native to the Indian subcontinent and predominantly found in countries like India, Nepal, Bhutan, ...Bangladesh, and Sri Lanka. Recently, it has gained recognition as a promising alternative source of anticancer compounds. The presence of camptothecin (CPT), a modified monoterpene indole alkaloid, in notable quantities has sparked interest in researching O. mungos. This present study is focused on enhancing the synthesis of CPT through in vitro shoot growth of O. mungos using a half-strength Murashige and Skoog growth medium supplemented with specific precursors. Among the precursors tested, L-tryptophan and geraniol exhibited the most significant increase in CPT levels, with a 33 % enhancement compared to the untreated shoots. The researchers employed response surface methodology to explore the combined effect of these precursors on CPT production. In the study, in vitro plantlets were treated with L-tryptophan and geraniol at a concentration of 1.5 mM each, resulting in the highest CPT levels ranging from 1658.52 to 1747.63 µg/g. The validity of the experimental approach was confirmed by the close agreement between the experimental value and the predicted value of 1702.00 µg/g, demonstrating a 99.3 % validity of the model. This study underscores the significance of utilizing a combination of precursors to enhance the production of secondary metabolites, specifically CPT, in O. mungos shoot cultures. Furthermore, it identifies L-tryptophan and geraniol, along with their respective doses, as effective precursors for improved CPT synthesis. Notably, this research employed response surface methodology to investigate the potential of L-tryptophan and geraniol as precursors for CPT production in the in vitro shoot growth of O. mungos, marking a significant contribution in this field of study.Top of Form
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•Precursor feeding of Ophiorrhiza mungos in vitro shoots to enhance camptothecin production.•The potential of L-tryptophan and geraniol as precursors for camptothecin production.•L-tryptophan and geraniol at a concentration of 1.5 mM each, for increased camptothecin levels in Ophiorrhiza mungos in vitro shoots.
In this study, biochar derived from spent coffee grounds (SCGB) was used to adsorb norfloxacin (NOR) in water. The biochar properties were interpreted by analysis of the specific surface area, ...morphology, structure, thermal stability, and functional groups. The impacts of pH, NOR, and ion's present on SCGB performance were examined. The NOR adsorption mode of SCGB is best suited to the Langmuir model (R2 = 0.974) with maximum absorption capacity (69.8 mg g−1). By using a Response Surface Method (RSM), optimal adsorption was also found at pH of 6.26, NOR of 24.69 mg L−1, and SCGB of 1.32 g L−1. Compared with biochars derived from agriculture such as corn stalks, willow branches, potato stem, reed stalks, cauliflower roots, wheat straw, the NOR adsorption capacity of SCGB was 2–30 times higher, but less than 3–4 times for biochars made from Salix mongolica, luffa sponge and polydopamine microspheres. These findings reveal that spent coffee grounds biochar could effectively remove NOR from aqueous solutions. Approaching biochar derived from coffee grounds would be a promising eco-friendly solution because it utilizes solid waste, saves costs, and creates adsorbents to deal with emerging pollutants like antibiotics.
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•Norfloxacin was removed using biochar derived from spent coffee grounds (SCGB).•pH significantly influenced the Norfloxacin (NOR) adsorption of the SCGB.•Based on Langmuir model, the maximum absorption capacity was 69.8 mg g−1 at pH 6.•The adsorption process was optimized by using the response surface methodology.•Optimal adsorption conditions were achieved at pH of 6.26 and SCGB of 1.32 g L−1.
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•A novel PGP hydrogel was synthesized by a facile synthesis route.•Hydrogel with a rGO-to-P25 mass ratio of 1:0.5 showed higher photocatalytic activity.•Radical scavenger experiments ...revealed hydroxyl radical as the main oxidative species.•PGP composite showed high reusability up to five cycles.•RSM was employed to determine the optimal conditions for enhanced MB removal.
An environment-friendly hydrogel was synthesized by entrapping Degussa P25 on the surface of a reduced graphene oxide (rGO)-polyacrylamide (PAM) matrix.The PAM content of the P25-rGO-PAM (PGP) hydrogel considerably influenced the adsorption and photocatalytic degradation of methylene blue (MB), and the optimal PAM content was 10% (w/v). Furthermore, rGO not only enhanced the adsorption capacity of the hydrogel by increasing the surface area but also increased the photodegradation efficiency synergistically by separating electron-hole pairs. The reaction kinetic constant for MB degradation by the hydrogel was 0.0276 min−1, which was three and five times the reaction kinetic constants of P25-PAM and rGO-PAM hydrogels, respectively. The synthesized PGP showed high stability and its MB degradation efficiency was considerably high up to five consecutive cycles under UV-irradiation. The eco-friendly nature of the hydrogel was evaluated on the basis of bacterial inactivation, and the treated water was found to be safe for use. Three key operating parameters (initial MB concentration, temperature, and pH) were optimized for maximizing MB removal using a response surface methodology. The complete MB removal efficiency was obtained for the optimal conditions of pH 9.4, a temperature of 31.2 °C, and an initial MB concentration of 5.2 mg/L.
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•Peroxymonosulfate and electrolysis have synergistic effect on the degradation of CECs.•The mechanism of electrochemically activated peroxymonosulfate is proposed.•A prediction model ...on the effect of water matrices on SMX removal is built using RSM.•Electrochemically activated peroxymonosulfate has great potential for application.
Electrochemically activated persulfate is an emerging advanced oxidation process for the removal of contaminants of emerging concern (CECs). The degradation of CECs, including carbamazepine (CBZ), bisphenol S (BPS), propranolol (PPL) and sulfamethoxazole (SMX) using electrochemically activated peroxymonosulfate (EA-PMS) was systematically investigated in this work. Over 80% of all the forementioned CECs were removed within 30 min. It exhibited a good synergistic effect between PMS and electrolysis on the degradation of CECs. The results of linear sweep voltammetry (LSV) indicated that a transition structure between BDD anode and PMS (BDD (PMS)*) was likely responsible for the synergistic effect. Hydroxyl radical (HO·) and sulfate radical (SO4·−) were proved to be the primary reactive species, of which HO· played the leading role. The increase of current density and PMS dosage accelerated the degradation of SMX, while initial pH from 3.0 to 11.0 had a limited effect on the degradation of SMX. Moreover, the influences of common ions and natural organic matter (NOM) on the degradation of SMX were comprehensively assessed using response surface methodology (RSM), and a prediction model was built via RSM. The performance of EA-PMS on the degradation of SMX in actual water was even better than that in pure water in this study. EA-PMS can serve as a novel and promising technology for the degradation of CECs and has great potential in practical application.
A novel adsorbent, lanthanum hydroxide-doped activated carbon fiber (ACF-LaOH), was prepared by the ultrasound-assisted chemical precipitation method for phosphate removal from waste water. Ligands ...exchange, electrostatic interactions and Lewis acid–base interaction are the three main mechanisms for phosphate adsorption. The ligands exchange, electrostatic interactions would become weaker and the Lewis acid–base interaction be strengthened with the increase of pH values giving rise to the decrease of adsorption amount. Display omitted
► The preparation and performance of ACF-LaOH for phosphate removal were investigated. ► The adsorption mechanisms were investigated by SEM, FT-IR and pH analysis. ► Ligands exchange, electrostatic interactions and Lewis acid–base interaction are the 3 mechanisms. ► Ligands exchange, electrostatic interactions are weaker with the increase of pH values.
A novel adsorbent, lanthanum hydroxide-doped activated carbon fiber (ACF-LaOH), has been prepared by the ultrasound-assisted chemical precipitation method for phosphate removal from waste water. Based on the single-factor method, response surface methodology (RSM) by using a Box–Behnken design (BBD) was applied to assess the mutual interactions and effects between the three factors and the optimized preparation conditions (concentration of La3+ of 0.11mol/L, ultrasonic power at 206W and ultrasonic time of 7.3min). Adsorption kinetics and isothermal adsorption studies showed that the pseudo second-order model and the Langmuir isotherm fitted the experimental data quite well, indicating that the adsorption process was mainly through chemical interactions. At last whereas most importantly, the phosphate adsorption mechanism was investigated by analyzing the scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy and the relationship between the adsorption amount and the pH of phosphate solution. The results demonstrated that ligands exchange, electrostatic interactions and Lewis acid–base interaction were the three main mechanisms for phosphate adsorption. The ligands exchange and electrostatic interactions became weaker, but the Lewis acid–base interaction was strengthened with the increase of pH values giving rise to the decrease of adsorption amount.
Freshwater resources are limited; thus, different technologies for desalination of brackish and seawater have been developed. Capacitive deionization (CDI) is one of the most promising desalination ...technologies owing to its low cost, simplicity, nonmoving parts, and low energy consumption. However, its energy consumption significantly increases with desalination of high-salinity water. In this regard, a good understanding of the effects of different process parameters on CDI energy consumption is crucial for further performance improvement. Therefore, the surface response methodology (RSM) was adopted to systematically study the effects of applying voltage, Stern layer capacity, volume and concentration of feed water, and volume of micropores on energy consumption and desalination time. The results showed that the Stern layer capacity and volume of micropores reduced desalination time by approximately 25% without significant changes in energy consumption. With the design of an improved electrode (improving the micropore structure for ion adsorption), the desalination time (Cycle) was reduced and a slight reduction in energy consumption was achieved. It can be claimed that any improvement in the physical (porosity) and electrical properties of the electrodes, results in an important increase in the performance of the CDI system.
•A batch CDI desalination cell is simulated.•RSM is used to obtain the effects of different parameters on the cell's performance.•A validated correlation based on the RSM results is presented.•Various contours are presented to help a designer find the best configuration.•The volume of micropores and Stern layer capacity are the most important parameters.
The effects of quadratic thermal radiation and quadratic Boussinesq approximation are investigated on the heat transport of a 36 nm Al2O3 − H2O nanofluid over a vertical plate. The modified ...Buongiorno model is used in the analysis that includes the effectual thermophysical properties of the nanofluid and the key slip mechanisms. Experimentally verified correlations are used for the thermophysical properties. The reduced nonlinear differential problem is solved numerically by the Finite Difference Method (FDM). Flow profiles are displayed and analyzed for changes in dimensionless parameters. Further, the heat transfer flux at the wall is analyzed for interactive impacts of the buoyancy ratio, Brownian random motion, and thermophoresis parameters using the face-centered Central Composite Design (CCD) of the Response Surface Methodology (RSM). A sensitivity analysis is carried out for the heat transfer flux of the nanoliquid. Quadratic thermal radiation was found to improve the temperature profile. Furthermore, the mechanisms of Brownian random motion and thermophoresis have a negative sensitivity towards the rate of heat transfer. In various thermal applications like solar collectors, the density variation in terms of temperature differences is significantly high. Such phenomena can be accurately modeled by utilizing the quadratic Boussinesq approximation and the novel quadratic thermal radiation aspect.
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•Carthamus lanatus L. seed oil used for biodiesel production by using CoWO3@rGO.•CoWO3@rGO is a novel, green and recyclable catalyst.•The properties of the produced fuels met EN ...14,214 and ASTM D 6751.•The optimal Carthamus lanatus L. biodiesel yield was predicted using RSM.•The green nanocomposite can be reused seven times without losing reactivity.
Sustainable and cheaper intercession coupled with green technologies could be the feasible and finest approach for addressing the solicitous snags like energy crises, greenhouse gas emissions and fossil fuel depletions globally. Biodiesel appeared as a feasible substitute to achieve net zero emissions globally. Biodiesel produced from waste, toxic and non-edible oil seeds is clean, cheaper and capable for producing greener energy which ultimately contributed positively in boosting bio-economy (close circular economy). In the present study, the potential of Carthamus lanatus L. seed oil (CSO) as novel, non-edible and waste feedstock was investigated for producing biodiesel using cobalt tungstate loaded reduced graphene oxide (CoWO3@rGO) as novel, green and recyclable catalysts. The catalyst (CoWO3@rGO) was synthesized via Hummers method followed by characterizations by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and energy dispersive X-ray analysis (EDX). Optimize biodiesel yield (99.7 wt%) was achieved with optimum reaction conditions of 0.8 wt% catalyst, oil to methanol molar ratio of 1:12 and temperature 65 °C for 2 h reaction time. The optimized Carthamus lanatus L. biodiesel (CBD) yield was also predicted by drawing 3D surface plots with response surface methodology (Box-Behnken design). The synthesized CBD was also characterized using latest techniques of nuclear magnetic resonance (NMR) (1H and 13C), Gas Chromatography/Mass spectroscopy (GC–MS) and FT-IR. The green nanocomposite exhibits excellent reusability of seven times without significant drop in its reactivity during transesterification process. Fuel properties of fatty acid methyl ester complied with biodiesel international standards EN 14214, China GB/T 20828–2007 and ASTM D 6751. Ultimately, biodiesel produced from wild, uncultivated and non-edible CSO can be commendably used to engender and adopt a greener and sustainable energy approach. The acceptance and adoption of the green energy approach could bring positive outcomes in the environment which ultimately create healthier societal and economic development.
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