Removal of citric acid from water by tributyl amine in octyl acetate: equilibrium and optimization by central composite design

2020 ◽  
Vol 185 ◽  
pp. 277-285
Author(s):  
Tais Evlik ◽  
Yavuz Selim Aşçi ◽  
Nilay Baylan ◽  
Süheyla Çehreli
2020 ◽  
Vol 11 (3) ◽  
pp. 3897-3904
Author(s):  
Arbab Husain ◽  
Fahad Khan ◽  
Khwaja Osama ◽  
Sadaf Mahfooz ◽  
Adeeba Shamim ◽  
...  

Cyanobacteria represent the richest sources of phycobiliproteins with especial reference to C-phycocyanin (C-PC), which in turn holds exhaustive therapeutic implications. Screening of several cyanobacterial strains namely Anabaena sp., Nostoc muscorum, Cylindrospermum sp., Plectonema sp., Scytonema sp., Spirulina sp., Synechococcous sp. and Tolypothrix sp. was carried out for their C-PC producing capacity, however the produced quantity of C-PC varies greatly among different strains. Owing to the crucial role of different media constituents on productivity of C-PC the current study was designed to optimize most appropriate media composition for augmented CPC production by selected superior producer. 36 factorial central composite design (CCD) dependent response surface methodology (RSM) was utilized to estimate the important medium components attributed with influencing C-PC productivity. RSM analysis of five independent coded factors including Na2CO3, K2HPO4, NaNO3, citric acid and EDTA were analyzed preceded by recognition of efficient variables for algal components production by Plectonema sp. Investigation of results revealed that the eminent medium components were NaCO3 (0.4 g/L); NaNO3 (0.5 g/L); K2HPO4 (2.8 g/L); citric acid (0.08 g/L) and EDTA (0.01 g/L) respectively. The optimized combination yielded 0.5536 mg/ml of C-PC. The increment of C-PC yield is R-Sq = 88.2%. Thus, our study led to the recognition of critical nutritional component that can be used further for enhanced productivity of C-PC.


2021 ◽  
Vol 16 ◽  
Author(s):  
Ramesh Kumar ◽  
Ravinder Verma ◽  
Ritu Kaushik ◽  
Prerna Kaushik ◽  
Parijat Pandey ◽  
...  

Background: Over the years, effervescent orally disintegrating tablets (ODTs) have proved their worth over conventional tablets in overcoming the swallowing problems associated with the geriatric and pediatric population. The addition of effervescent agents in ODT provides a rapid disintegration along with masking of the slightly bitter taste of drugs and is worth exploring. Objective: The present research investigation deals with the preparation of effervescent ODTs by direct compression with rapid disintegration and adequate hardness using the central composite design response surface methodology. Method: Central composite design was used to study the effect of concentration of crospovidone (X1) and concentration of citric acid and sodium bicarbonate (X2) as independent factors on the two responses: disintegration time (Y1) and drug release (Y2). The tablets were prepared by direct compression approach using directly compressible mannitol. Results: Central composite design was used to study the effect of concentration of crospovidone (X1) and concentration of citric acid and sodium bicarbonate (X2) as independent factors on the two responses: disintegration time (Y1) and drug release (Y2). The tablets were prepared by direct compression approach using directly compressible mannitol. Conclusion: The results obtained in the present investigation revealed a successful development of famotidine effervescent ODTs with a better release profile compared to marketed formulation.


2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Andrew N Amenaghawon ◽  
Eboseremen Ebewele ◽  
Izoduwa Osakue ◽  
Richard Obaseki

In this study, design of experiment (DOE) for response surface methodology (RSM) was used to analyse and optimise the compositions of the nutrient medium (calcium ion, peptone, ethanol and manganese ion) for citric acid production from yam peels via solid state fermentation (SSF) using Aspergillus niger. A four variable, central composite design (CCD) was used to develop a statistical model for the process while RSM was used to optimise it. The results obtained showed that the model was statistically significant (p<0.0001) and displayed a good fit with the experimental observations (R2 = 0.997). Citric acid production was significant at high levels of ethanol and calcium while the reverse was the case for manganese and peptone. The optimum values of ethanol, manganese, calcium and peptone were 7.0% v/v, 1.0 g/l, 0.1 g/l and 0.1 g/l respectively. Under these conditions, the citric acid concentration was obtained as 66 g/l. Validation of the statistical model showed an insignificant difference between experimental and model predicted results.


2009 ◽  
Vol 00 (00) ◽  
pp. 090721051030036-8
Author(s):  
Jaleh Varshosaz ◽  
Solmaz Ghaffari ◽  
Mohammad Reza Khoshayand ◽  
Fatemeh Atyabi ◽  
Shirzad Azarmi ◽  
...  

2020 ◽  
Vol 25 (6) ◽  
pp. 2033-2044
Author(s):  
CATERINA TOMULESCU ◽  
◽  
MIŞU MOSCOVICI ◽  
ROXANA MĂDĂLINA STOICA ◽  
GABRIEL BUJOR ALBU ◽  
...  

The objective of this work was to optimize the bioprocess parameters, using Klebsiella oxytoca ICCF 419 to obtain an exopolysaccharide based on lactose as substrate. A kinetic study was employed and Logistic and Gompertz models were applied to describe the polysaccharide production, in relation with biomass growth and substrate consumption. The RSM methodology based on Central Composite Rotatable Design was used to evaluate and optimize the effect of lactose, corn extract, KH2PO4 and citric acid concentrations as independent variables on the polysaccharide production, biomass growth and substrate consumption as the response functions. The interaction effects and optimal parameters were obtained using Design Expert Software (version 9.0.6.2). The significance of the variables and their interactions was tested by means of ANOVA analysis with a 99% confidence level. The optimum culture conditions were determined and the model prediction was compared with experimental results. At an initial value of 23.45 for the C/N in the fermentation medium, the strain produces 17.41 g/L of crude polysaccharide and 2.53 g/L dry biomass. The EPS production was significantly influenced by lactose, corn extract and KH2PO4, while the citric acid had no influence. The biomass growth was influenced by the corn extract, KH2PO4 and citric acid.


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