scholarly journals Solar photocatalytic degradation of metformin by TiO2 synthesized using Calotropis gigantea leaf extract

2021 ◽  
Author(s):  
Venkatesan Prashanth ◽  
Kumari Priyanka ◽  
Neelancherry Remya
Keyword(s):  
Aqueous Phase ◽  
Leaf Extract ◽  
Quadratic Model ◽  
Optimum Conditions ◽  
Calotropis Gigantea ◽  
Diabetic Medicine ◽  
First Order Kinetics ◽  
Metformin Concentration ◽  
Average Size ◽  
Central Composite

Abstract A novel TiO2 nanoparticle was prepared through green synthesis using Calotropis gigantea (CG) leaf extract. Morphological analysis showed dispersed spherical CG-TiO2 nanoparticles with an average size of 42 nm. The prepared catalyst was used for the degradation of metformin (a widely used diabetic medicine) by solar photocatalysis. A three-factor central composite design (CCD) was used to explore the effect of independent variables, i.e., pH 3–7, metformin concentration 1–10 mg/L, and catalyst (CG-TiO2) dosage 0.5–2.0 g/L. A maximum metformin degradation of 96.7% was observed under optimum conditions i.e., pH = 9.7, initial metformin concentration = 9.7 mg/L and catalyst dosage = 0.7 g/L, with ∼86% mineralization efficiency. A quadratic model with an error <5% was developed to predict the metformin degradation and the rate of degradation under the optimum conditions followed pseudo-first-order kinetics (k = 0.014/min). CG-TiO2 exhibited higher metformin degradation efficiency (96.7%) compared to P-25 (23.9%) at optimum conditions. The recyclability study indicated effective reuse of the catalyst for up to three cycles. The proposed metformin degradation route is hydroxyl radical (•OH) generation on the CG-TiO2 surface, transfer of •OH to the aqueous phase from CG-TiO2 and subsequent oxidation of metformin in the aqueous phase.

scholarly journals Optimization of process variables for the biosorption of chromium using Hypnea valentiae

2021 ◽  
Vol 10 (2) ◽  
pp. 107-115
Author(s):  
M. Rajasimman ◽  
K. Murugaiyan
Keyword(s):  
Contact Time ◽  
Red Alga ◽  
Influential Factor ◽  
Quadratic Model ◽  
Batch Experiments ◽  
Process Variables ◽  
Optimum Conditions ◽  
Optimized Conditions ◽  
Central Composite ◽  
Maximum Removal

In this study, Hypnea valentiae, a red alga is used as a sorbent for the removal of chromium from aqueous solutions. The biosorption potential of Hypnea valentiae was investigated in batch experiments. The process parameters were optimized using response surface methodology. Based on the central composite design, quadratic model was developed to correlate the variables to the response. The most influential factor on each experimental design response was identified from the analysis of variance (ANOVA). The optimum conditions for the maximum biosorption of chromium are pH – 2.8, temperature – 48.2oC, sorbent dosage – 5.3 g/L, metal concentration – 103 mg/L and contact time – 27 min. At these optimized conditions the maximum removal was found to be 94.5%.

Silver Nanoparticles from Tabernaemontana Divaricate leaf extract: Mechanism of action and Bio-application for photo degradation of 4-Aminopyridine.

2021 ◽  
Author(s):  
Pratibha Attri ◽  
Sangeeta Garg ◽  
Jatinder Kumar Ratan ◽  
Ardhendu Sekhar Giri
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extract ◽  
Leaf Extract ◽  
Enol Form ◽  
Optimum Conditions ◽  
Ag Nps ◽  
Photo Degradation ◽  
Xps Spectra ◽  
E Coli ◽  
Average Size

Abstract Silver nanoparticles (Ag NPs) were synthesised by the reduction of Ag+ to Ag0 in the presence of enol form of flavonoids present in plant extract of Tabernaemontana Divaricate (T. Divaricate). Prepared Ag NPs were characterized using UV-Vis, XRD, HR-TEM with EDX and XPS techniques. XPS spectra exhibited peaks at 366 eV and 373 eV, which specified spin orbits for Ag 3d3/2, and Ag 3d5/2 that confirmed the formation of Ag NPs. Ag NPs were spherical in shape with an average size of 30 nm as revealed by HR-TEM and FE-SEM techniques. EDX studies verified the high purity of Ag NPs with silver 46.96 %, carbon 16.35 %, oxygen 16.22 %, nitrogen 20.25 % and sulphur 0.21%. LC-MS analysis of plant extract confirmed the qualitative presence of alkaloids, tannins, flavonoids, phenols, and carbohydrates. Prepared Ag NPs showed good photocatalytic activity towards degradation of 4-Amniopyridine with 61% degradation efficiency at optimum conditions in 2 hrs of reaction time under visible light. The number of intermediates were found were ten within the mass number of 0–450. Ag NPs synthesized using bio-extract have also showed good inactivation against Escherichia Coli (E. Coli) and Bacillus Subtilis (B. Subtilis) bacteria due to availability of free radicals.

Understanding Process Variables and their Interactions for Maximizing Production of Artemisinin Derivative Artemether (Anti-Malarial Drug) Through Cunninghamella echinulata var elegans at 5 L Bioreactor Level

2019 ◽  
Vol 15 (4) ◽  
pp. 442-452
Author(s):  
Kashyap Kumar Dubey ◽  
Punit Kumar
Keyword(s):  
Experimental Finding ◽  
Culture Broth ◽  
Quadratic Model ◽  
Optimum Conditions ◽  
Reverse Phase Hplc ◽  
Polar Solvents ◽  
Reverse Phase ◽  
Experimental Conditions ◽  
Cunninghamella Echinulata ◽  
Life Threatening

Background: Malaria is one of the life threatening diseases which is caused by Plasmodium sp. of protozoa and uses Anopheles mosquitos as vector. Plasmodium vivax and Plasmodium falciparum are common form of malaria parasite. Artemisinin is reported for its antimalarial activities and Artemether which is a methyl ether derivative of Artemisinin, has been found effective against P. falciparum. Methods: In the present study, bioconversion of Artemisinin into Artemether was carried out experimentally and the statistical tools like experimental factorial design and Response Surface Methodology were used to find optimal conditions (concentration of Artemisinin, age of inoculum, temperature & pH) using Cunninghamella echinulata var. elegans. Experimental conditions for maximum product recovery from culture broth were also optimized using various polar and non-polar solvents for extraction. Artemether purity was analyzed by reverse-phase HPLC. Experimental data was fitted in a quadratic model and effect of various parameters was analyzed. Results: It was found that bioconversion of Artemisinin into Artemether is growth associated process. It was observed that molasses used as carbon source supported production of Artemether to 3.4g/L. The biomass and oxygen are key element affecting of bioconversion of Artemisinin into Artemether such as higher dissolved oxygen reduced the Artemether bioconversion. The highest bioconversion of Artemisinin into Artemether was obtained at temperature 25.5oC, 5g/L concentration of Artemisinin, at age of inoculum of 44.5 h and at pH 6.0. Model suggested the highest bioconversion of Artemisinin into Artemether was 54% at shake flask level which was near about experimental finding. An optimal condition for bioconversion was also analyzed and 64% bioconversion was obtained in 5L bioreactor. Conclusion: The outcomes of the study provided optimum conditions for bioconversion of Artemisinin into Artemether.

scholarly journals Leaching and solvent extraction purification of zinc from Mehdiabad complex oxide ore

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Faraz Soltani ◽  
Hossna Darabi ◽  
Reza Aram ◽  
Mahdi Ghadiri
Keyword(s):  
Solvent Extraction ◽  
Environmental Pollution ◽  
Central Composite Design ◽  
Complex Oxide ◽  
Hydrometallurgical Process ◽  
Purification Process ◽  
Optimum Conditions ◽  
Leaching Experiments ◽  
Central Composite ◽  
Sulphuric Acid Concentration

AbstractAn integrated hydrometallurgical process was used for the zinc leaching and purification from a zinc ore containing 9.75 wt% zinc. The zinc minerals in the ore were hemimorphite, willemite, and calcophanite. Main gangue minerals were quartz, goethite, hematite, and calcite. Central composite design (CCD) method was used to design leaching experiments and the optimum conditions were found as follows: 30% of solid fraction, 22.05% sulphuric acid concentration, and the leaching temperature of 45 °C. The PLS containing 35.07 g/L zinc, 3.16 g/L iron, and 4.58 g/L manganese impurities was produced. A special purification process including Fe precipitation and Zn solvent extraction was implemented. The results showed that after precipitation of iron, Zn extraction of 88.5% was obtained with the 2 stages extraction system composed of 30 vol% D2EHPA as extractant. The overall Zn recovery from the ore was 71.44%. Therefore, an appropriate solution containing 16.6 g/L Zn, 0.05 g/L Fe, and 0.11 g/L Mn was prepared for the electro-winning unit without using the roasting and calcination steps (conventional method), which result in environmental pollution.

Kinetics and Equilibrium of Radioactive Metal Adsorption onto Sugarcane Bagasse Waste: Comparison of Batch and Column Adsorption Modes

2021 ◽  
Vol 235 (3) ◽  
pp. 281-294
Author(s):  
Abida Kausar ◽  
Haq Nawaz Bhatti ◽  
Munawar Iqbal
Keyword(s):  
Sugarcane Bagasse ◽  
Flow Rate ◽  
Breakthrough Curves ◽  
Quadratic Model ◽  
Waste Biomass ◽  
Initial Concentration ◽  
Bed Height ◽  
Column Adsorption ◽  
Central Composite ◽  
Bagasse Waste

Abstract Sugarcane bagasse waste biomass (SBWB) efficacy for the adsorption of Zr(IV) was investigated in batch and column modes. The process variables i.e. pH 1–4 (A), adsorbent dosage 0.0–0.3 g (B), and Zr(IV) ions initial concentration 25–200 mg/L (C) were studied. The experiments were run under central composite design (CCD) and data was analysed by response surface methodology (RSM) methodology. The factor A, B, C, AB interaction and square factor A2, C2 affected the Zr(IV) ions adsorption onto SBWB. The quadratic model fitted well to the adsorption data with high R2 values. The effect of bed height, flow rate and Zr(IV) ions initial concentration was also studied for column mode adsorption and efficiency was evaluated by breakthrough curves as well as Bed Depth Service and Thomas models. Bed height and Zr(IV) ions initial concentration enhanced the adsorption of capacity of Zr(IV) ions, whereas flow rate reduced the column efficiency.

scholarly journals Optimization of Supercritical Extraction Conditions of Senna Alata and Evaluation of Biological Activity

2018 ◽  
Vol 7 (3.11) ◽  
pp. 94
Author(s):  
Istikamah Subuki ◽  
Aiman Nabilah Abdul Malek ◽  
Saidatul Husni Saidin ◽  
Mazura Md. Pisar
Keyword(s):  
Crude Extract ◽  
Extraction Process ◽  
Quadratic Model ◽  
Total Flavonoids ◽  
Inhibition Activity ◽  
Backward Elimination ◽  
Total Flavonoids Content ◽  
Senna Alata ◽  
Central Composite ◽  
Experimental Runs

Supercritical fluid extraction (SFE) offer faster extraction process, decreased solvent usage and more selectivity on desired compounds. In this present study, the influence of pressure (100, 200 and 300 bar) and temperature (40, 50 and 60˚C) on the Senna alata crude yield were investigated with fixed supercritical carbon dioxide (SC-CO2) at the flow rate of 35 g/min. The parameters were optimised and modelled using response surface methodology (RSM) and central composite design (CCD). The analysis of variance (ANOVA) experimental design consists of 13 experimental runs with 5 replicates at the central points. Well-fitting quadratic model were successfully established for crude extract through backward elimination. The optimum crude extract yield pointed out by RSM was at the pressure of 300 bar and temperature 40˚C respectively. Extraction yields based on SC-CO2 varied in the range of 0.28 to 3.62%. The highest hyaluronidase inhibition activity and total flavonoids content obtained by S.alata crude extracts were 41.19% and 52.53% w/w, respectively. SC-CO2 proves to have great potential for extraction of yield, hyaluronidase inhibition activity and total flavonoids content for S.alata.  

Development and Characterization of Quercetin Loaded Nanoparticle for Skin Cancer

2019 ◽  
Vol 32 (1) ◽  
pp. 1-6
Author(s):  
Nikita Verma
Keyword(s):  
Skin Cancer ◽  
Drug Loading ◽  
Quadratic Model ◽  
Precipitation Method ◽  
Dietary Flavonoid ◽  
Ultraviolet Ray ◽  
Average Size ◽  
Different Characteristics ◽  
Polymer Ratio

As a disease skin cancer has obtained different characteristics over the decades. Solar radiation that contains ultraviolet ray is the prime cause of skin cancer. In this present research, the nano-precipitation method was applied for preparing Quercetin loaded Nanoparticle (Qu-Nps) with much enhanced loading properties and improves incorporation of corresponding drugs. At the same time, the Quadratic model that takes help of the Response Surface Method was applied to observe the effects of some specific parameters maintained in the development of nanoparticle. Here, the sonication time was 20 min and delivery system F6 (with Drug: Polymer ratio of 1:45) provided optimum drug entrapment ability which is 70%. The optimized formulation for average size was almost 102.39 ±7.64 nm with zeta potential diameter averaging -28.43mV. Quercetin is a dietary flavonoid possessing multidimensional properties that is used in various other diseases including viral infection, bacterial infection, diabetes mellitus, and cancer. All outcomes support the view that Quercetin loaded nanoparticles (Qu-Nps) has high entrapment and drug loading abilities.

Kaempferol Extraction from Cuscuta reflexa using Supercritical Carbon Dioxide and Separation of Kaempferol from the Extracts

2011 ◽  
Vol 7 (4) ◽  
Author(s):  
Pranabendu Mitra ◽  
Kyu -Seob Chang ◽  
Dae-Seok Yoo
Keyword(s):  
Supercritical Co2 ◽  
Extraction Process ◽  
Optimum Conditions ◽  
Supercritical Co2 Extraction ◽  
Independent Variables ◽  
Cuscuta Reflexa ◽  
Optimal Processing ◽  
Layer Chromatography ◽  
Temperature Time ◽  
Central Composite

Kaempferol, a strong antioxidant, was extracted from Cuscuta reflexa (a medicinal plant) using supercritical CO2 and separated using thin-layer chromatography, column chromatography and HPLC analysis. A rotatable central composite design was used to determine the influence of process variables and arrive at optimal processing conditions in the supercritical CO2 extraction process of kaempferol. The kaempferol yield was effectively modelled as a function of the independent variables (temperature, time and pressure). The kaempferol yield increased with the increasing of temperature and time and decreasing of pressure of the supercritical CO2 extraction process. The predicted kaempferol yield at the optimum point was 52.92 µg/g and the optimum conditions were 50.7°C for 132.6 min and 15.9 MPa.

Preparation of Nanoscale CuO Powders

2010 ◽  
Vol 113-116 ◽  
pp. 1770-1773 ◽  
Author(s):  
Xi Hua Zhao ◽  
Min Xu
Keyword(s):  
Raw Materials ◽  
Precipitation Method ◽  
Optimum Conditions ◽  
Muffle Furnace ◽  
Factors Affecting ◽  
Direct Precipitation ◽  
Average Grain Size ◽  
Scherrer Formula ◽  
Average Size ◽  
Direct Precipitation Method

Cu(OH)2 precursor was synthesized by direct precipitation method and CuSO4 and NaOH were used as raw materials. Then, Cu(OH)2 precursor was calcined in muffle furnace at 400°C for 2h in order that CuO particle was obtained. Through the analysis of the factors affecting the CuO, the paper determined the optimum conditions for the synthesis of nano-CuO with the direct-precipitation method. Then the paper analyzed phase composition and crystal structure of samples using XRD and calculated the average grain size of samples by Scherrer formula, and observed and analyzed by TEM to characterize the morphology and particle size of samples. The optimum precipitation conditions are as follows: when the precipitation agent is 3.2:1, reaction time 40min and precipitant concentration 0.6mol.L-1. The average size of CuO particle prepared under the conditions is 18nm and the yield is 96%.

scholarly journals Powerful Concentration of Rhodium in Plating Wastewater Using Homogeneous Liquid–Liquid Extraction (HoLLE) and Study for Scale-up

2017 ◽  
Vol 7 (4) ◽  
pp. 44 ◽  
Author(s):  
Takeshi Kato ◽  
Shotaro Saito ◽  
Shigekatsu Oshite ◽  
Shukuro Igarashi
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Aqueous Phase ◽  
Scale Up ◽  
Volume Ratio ◽  
Liquid Extraction ◽  
Optimum Conditions ◽  
Homogeneous Liquid ◽  
Liquid Liquid Extraction ◽  
Plating Wastewater

A powerful technique for the concentration of rhodium (Rh) in plating wastewater was developed. The technique entails complexing Rh with 1-(2-pyridylazo)-2-naphthol (PAN) followed by homogeneous liquid–liquid extraction (HoLLE) with Zonyl FSA. The optimum HoLLE conditions were determined as follows: [ethanol]T = 30.0 vol.%, pH = 4.00, and Rh:PAN = 1:5. Under these optimum conditions, 88.1% of Rh was extracted into the sedimented liquid phase. After phase separation, the volume ratio [aqueous phase (Va) /sedimented liquid phase (Vs)] of Va and Vs was 1000 (50 mL → 0.050 mL). We then applied the new method to wastewater generated by the plating industry. The phase separation was satisfactorily achieved when the volume was scaled up to 1000 mL of the actual wastewater; 84.7% of Rh was extracted into the sedimented liquid phase. After phase separation, Va/Vs was 588 (1000 mL - 1.70 mL).

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