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%.

scholarly journals Utilization of Waste Leaves Biomass of Myrica Esculenta for the Removal of Pb (II), Cd (II) and Zn (II) Ions from Waste Waters

2018 ◽  
Vol 34 (5) ◽  
pp. 2548-2553 ◽  
Author(s):  
Naveen Chandra Joshi ◽  
Ajay Singh ◽  
Himanshu Rajput
Keyword(s):  
Contact Time ◽  
Metal Ion ◽  
Isotherm Models ◽  
Waste Waters ◽  
Ion Concentrations ◽  
Batch System ◽  
Langmuir Isotherm Model ◽  
Myrica Esculenta ◽  
Optimized Conditions ◽  
Maximum Removal

In the present study, we have used the waste leaves of Myrica esculenta for the removal of Pb2+, Cd2+ and Zn2+ ions from the synthetically prepared waste water. The adsorption based removal process has been carried out under the batch system. The batch system was included pH, contact time, dosage, concentration and temperature. The maximum removal efficiency was achieved at optimized conditions i.e. higher contact time, higher pH, lower metal ion concentrations and moderate temperatures. The presence of various organic binding groups was characterized by FTIR spectroscopy. The percentage adsorption of Pb2+, Cd2+ and Zn2+ ions was found 97.02%, 92.52% and 81.99% at pH 6 after contact time 25 minutes. The data of adsorption were tested with Langmuir, Freundlich and Temkin isotherm models. The adsorption capacity of Pb2+, Cd2+ and Zn2+ ions was evaluated as 8.264, 5.617 and 7.751mgg-1 by Langmuir isotherm model.

scholarly journals Galacto-oligosaccharides Production Using Permeabilized Cells of Kluyveromyces marxianus

2010 ◽  
Vol 6 (6) ◽  
Author(s):  
Ana Paula Manera ◽  
Fátima Aparecida de Almeida Costa ◽  
Maria Isabel Rodrigues ◽  
Susana Juliano Kalil ◽  
Francisco Maugeri Filho
Keyword(s):  
Kluyveromyces Marxianus ◽  
Enzyme Concentration ◽  
Human Intestine ◽  
Central Composite Rotatable Design ◽  
Optimum Conditions ◽  
Permeabilized Cells ◽  
Lactose Concentration ◽  
Optimized Conditions ◽  
Central Composite ◽  
Stimulation Of

Galacto-oligosaccharides are non-digestible carbohydrates and are recognized as important prebiotics for than stimulation of the proliferation of lactic acid bacteria and bifidobacteria in the human intestine. GOS can be produced by a transgalactosylation reaction catalysed by ?-galactosidase enzyme, and microorganisms can be used as a source of ?-galactosidase. In this work, a process for producing GOS using permeabilized cells of Kluyveromyces marxianus CCT 7082 was proposed. The effects of the concentrations of lactose and enzyme, temperature and pH were studied using a fractional design followed by a central composite rotatable design. The optimum conditions for galacto-oligosaccharides production were found to be: lactose concentration 500 g/L, enzyme concentration 10 U/mL, 45°C and pH 7.0. Under optimized conditions, the GOS concentration, yield and productivity were 83 g/L, 16.5% and 27.6 g/L.h, respectively.

scholarly journals Bagasse Fly Ash as an Effective Adsorbent: Evaluation of Adsorptive Characteristics for 4-Nitroaniline Removal

2021 ◽  
Vol 7 (05) ◽  
pp. 155-161
Author(s):  
Amarnath P.C & Shashikala K. J. Praveen Kumar D. G., Kalleshappa C.M.,
Keyword(s):  
Fly Ash ◽  
Contact Time ◽  
Order Kinetic ◽  
Batch Experiments ◽  
Bagasse Fly Ash ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorbent Dose ◽  
Maximum Removal

In the present study we explored the adsorptive characteristics of 4-nitroaniline from synthetic aqueous solution onto bagasse fly ash (BFA). Batch experiments were carried out to determine the influence of parameters like initial pH (pH0), adsorbent dose (m), contact time (t) and initial concentration (C0) on the removal of 4-nitroaniline. The maximum removal of 4-nitroaniline was determined to be 98% at lower concentrations (50 mg/L) and 41% at higher concentrations (300 mg/L), using a BFA dosage of 10 g/L at 303K. Kinetic study of 4-nitroaniline removal by BFA was well represented by pseudo second-order kinetic model. The 4-nitroaniline desorption from 4-nitroaniline loaded BFA shows that only 27% and 36% of 4-nitroaniline could be recovered using ethyl alcohol and acetone respectively.

scholarly journals Method for attachment of TiO2 using design of experiments: application to the photocatalysis of a model pollutant methylene blue dye

2020 ◽  
Vol 82 (10) ◽  
pp. 2076-2084
Author(s):  
Abdenour Aıt Atmane ◽  
Saliha Bourouına-Bacha
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Desirability Function ◽  
Glass Plate ◽  
Supported Catalyst ◽  
Quadratic Model ◽  
Blue Dye ◽  
Laboratory Reactor ◽  
Central Composite ◽  
Maximum Removal

Abstract The preparation of titanium dioxide (TiO2) supported on a glass plate by heat attachment method is presented. With the use of response surface methodology based on a central composite design we investigated the influence of the experiment parameters of the TiO2 deposition (temperature of calcination (T), time of calcination (ts) and the concentration of TiO2 ((TiO2))) on photocatalytic activity of the semiconductor for the degradation of a model pollutant: methylene blue. The analysis of variance results showed that the selected quadratic model with interaction (R2 = 0.9802) was statistically significant. The experimental results showed that the degradation quantity of methylene blue increased when the ts value increased and T decreased. We have evaluated the photocatalytic activity of this supported catalyst (TiO2-GP) with a laboratory reactor under natural condition; the maximum removal (96.03%) was obtained at ts = 331 min, T = 559 °C and (TiO2) = 2.38 g/l. The method of desirability function was used to obtain the best combination of factor settings for achieving the maximum of degradation quantity ((TiO2) = 2.6 (g/l), T = 600 (°C) and ts = 240 (min)). The additional tests on the catalyst plates confirmed that the deposits keep their catalytic activity for several cycles of use.

scholarly journals Sorption of Sr-85 and Am-241 from liquid radioactive wastes by alginate beads

Nukleonika ◽  
2015 ◽  
Vol 60 (4) ◽  
pp. 927-931 ◽  
Author(s):  
Agata Oszczak ◽  
Leon Fuks
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Decontamination Factor ◽  
Alginate Beads ◽  
Radioactive Wastes ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Liquid Radioactive Wastes ◽  
Initial Aqueous Solution ◽  
Initial Ph

Abstract The paper reports the adsorption of strontium(II) and americium(III) from aqueous solutions onto calcium alginate (CaA), barium alginate (BaA) and strontium alginate (SrA) beads. Adsorption process was studied in batch experiments as a function of the initial pH of the solution and the contact time. All sorbents were examined by the termogravimetric analysis (TG). Laboratory obtained spherical beads of CaA, BaA and SrA seem to be good metal sorbents from liquid radioactive wastes. A contact time of about 4 h and neutral pH of the initial aqueous solution have been proposed to be optimum conditions for Sr-85 and Am-241 removal from the contaminated solutions using alginate sorbents. Laboratory obtained beads of CaA, BaA and SrA are characterized by the decontamination factor (DF) equal to 85% for Sr(II) and 90% for Am(III).

scholarly journals Nickel adsorption onto polyurethane ethylene and vinyl acetate sorbents

2017 ◽  
Vol 76 (1) ◽  
pp. 219-235 ◽  
Author(s):  
Munawar Iqbal ◽  
Zahid Ali ◽  
M. Afzal Qamar ◽  
Abid Ali ◽  
Fida Hussain ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
Contact Time ◽  
Industrial Wastewater ◽  
Process Variables ◽  
Optimum Conditions ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
First Order ◽  
Pseudo Second Order ◽  
Nickel Adsorption

The present study was conducted to appraise the efficiencies of polyurethane ethylene sorbent (PES) and vinyl acetate sorbent (VAS) for nickel (Ni) adsorption. Process variables, i.e. Ni(II) ions initial concentration, pH, contact time and adsorbent dosage were optimized by response surface methodology (RSM) approach. The Ni(II) adsorption was fitted to the kinetic models (pseudo-first-order and pseudo-second-order) and adsorption isotherms (Freundlich and Langmuir). At optimum conditions of process variables, 171.99 mg/g (64.7%) and 388.08 mg/g (92.7%) Ni(II) was adsorbed onto PES and VAS, respectively. The RSM analysis revealed that maximum Ni(II) adsorption can be achieved at 299 mg/L Ni(II) ions initial concentration, 4.5 pH, 934 min contact time and 1.3 g adsorbent dosage levels for PES, whereas the optimum values for VAS were found to be 402 mg/L Ni(II) ions initial concentration, 4.6 pH, 881 min contact time and 1.2 g adsorbent dosage, respectively. The —OH and —C = O— were involved in the Ni(II) adsorption onto PES and VAS adsorbents. At optimum levels, up to 53.67% and 80.0% Ni(II) was removed from chemical industry wastewater using PES and VAS, respectively, which suggest that PES and VAS could possibly be used for Ni(II) adsorption from industrial wastewater.

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 Effect of Alcohol Structure on the Optimum Condition for Novozym 435-Catalyzed Synthesis of Adipate Esters

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Mohd Basyaruddin Abdul Rahman ◽  
Naz Chaibakhsh ◽  
Mahiran Basri
Keyword(s):  
Maximum Yield ◽  
Candida Antarctica ◽  
Novozym 435 ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Lipase B ◽  
Tert Butanol ◽  
Ester Yield ◽  
Optimized Conditions ◽  
Central Composite

Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol). Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning important reaction parameters which include time, temperature, substrate molar ratio, and amount of enzyme. Reactions under optimized conditions has yielded a high percentage of esterification (>96%) for n-butanol, iso-butanol, and sec-butanol, indicating that extent of esterification is independent of the alcohol structure for primary and secondary alcohols at the optimum conditions. Minimum reaction time (135 min) for achieving maximum ester yield was obtained for iso-butanol. The required time for attaining maximum yield and also the initial rates in the synthesis of di-n-butyl and di-sec-butyl adipate were nearly the same. Immobilized Candida antarctica lipase B was also capable of esterifying tert-butanol with a maximum yield of 39.1%. The enzyme is highly efficient biocatalyst for the synthesis of adipate esters by offering a simple production process and a high esterification yield.

scholarly journals Optimization of Cadmium Ions Biosorption Onto Trichoderma Fungi

2021 ◽  
Vol 12 (3) ◽  
pp. 3316-3331
Keyword(s):  
Contact Time ◽  
Cadmium Concentration ◽  
Environmental Pollutants ◽  
Quadratic Model ◽  
Mixing Rate ◽  
Experimental Conditions ◽  
Cadmium Ions ◽  
Low Concentrations ◽  
Trichoderma Fungi ◽  
Central Composite

Cadmium (Cd) is one of the heavy metal ions and environmental pollutants that can harm humans and other organisms by eliminating serious toxic effects even at low concentrations. Nowadays, the use of this element in various industries has increased its concentration in the environment. Therefore, it is necessary to find appropriate and practical ways to remove it from the environment. The purpose of this study is to evaluate the efficiency of Trichoderma in the absorption of cadmium ions from an aqueous solution by a central composite design (CCD) to optimize the experimental conditions. Analysis of variance (ANOVA) was performed to study the importance and effectiveness of the model. Design specialist software reviewed four independent variables: pH, mixing rate, contact time, temperature, and initial cadmium concentration. A second-order quadratic model was developed to predict the reactions. An ANOVA of cadmium decay in solutions by Trichoderma shows an F-value of 6655.67 for the quadratic model, which indicates that the model is significant. CCD was able to provide a statistical model for predicting response with high accuracy and reliability. Under optimal conditions, the average cadmium decrease (pH = 6, contact time of 120 minutes, initial concentration of cadmium ions of 25° C and 25 mg/L) is approximately 98.8%.

scholarly journals DETERMINING OPTIMIZED CONDITIONS FOR COAGULATION OF BASIC RED 46 DYE IN TEXTILE WASTEWATER BY POLY ALUMINIUM CHLORIDE USING EXPERIMENT PLANNING METHOD

2010 ◽  
Vol 13 (1) ◽  
pp. 29-34
Author(s):  
Duc Sy Dao
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Contact Time ◽  
Textile Wastewater ◽  
Aluminium Chloride ◽  
Experiment Planning ◽  
Operating Parameters ◽  
Optimum Conditions ◽  
Optimized Conditions ◽  
Basic Red 46

In this study, the coagulation using poly aluminium chloride (PAC) was applied in order to remove Basic Red 46, a cation dye from wastewater. The effects of some key operating parameters such as PAC dose, pH as well as contact time on the COD and color removal were investigated. Response surface methodology (RSM) showed that PAC dose of 785 mg/L; pH of 12; contact time of 105 minutes were optimum conditions for the coagulation of BR46.

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