Application of response surface method to carbamazepine removal in photo-ozonation reaction under alkaline condition

2013 ◽  
Vol 67 (1) ◽  
pp. 74-81 ◽  
Author(s):  
J. K. Im ◽  
K. D. Zoh

In this study, the photo-ozonation reaction for carbamazepine (CBZ) removal was investigated under alkaline conditions. Response surface methodology based on a central composite design was used to obtain the optimum experimental conditions, and examine both main and interaction effects of the photo-ozonation reaction variables such as O3 concentration, H2O2 concentration and UV intensity. The level of O3 concentration significantly influenced CBZ removal (p < 0.001). CBZ removal increased with increasing both O3 and H2O2 concentration up to a certain level, whereas further increase in O3 and H2O2 concentration resulted in an adverse effect due to the hydroxyl radical scavenging effect. The optimum conditions for complete CBZ removal at pH 9 were found to be 0.89 mg of O3 l−1, 4.85 mg of H2O2 l−1 and 3.18 mW of UV intensity cm−2, respectively.

2012 ◽  
Vol 28 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Md Atiar Rahman ◽  
Rumana Sharmin ◽  
Md Nazim Uddin ◽  
Md Sohel Rana ◽  
Nazim Uddin Ahmed

Antibacterial effect of Crinum asiaticum bulb extract (1mg/disc) was tested on four Gram- positive and six Gram-negative bacteria by disc diffusion method using kanamycin (30 ìg/disc) as standard antibiotic disc. The bulb extract (250-1000mg/disc) showed significant zone of inhibition against all Gram-positive and Gram-negative bacteria ranging from 12-14 mm in diameter. Antioxidant potential of the same extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The extract showed remarkable free radical scavenging effect (95.96%) providing the IC50 value of 5.62 for the bulb extract and 5.46 for ascorbic acid (standard antioxidant) at the concentration of 1000 ìg/ml. The bulb extract was found to be (LC50 value 94.06 ?g/ml) in Brine-Shrimp lethality test. DOI: http://dx.doi.org/10.3329/bjm.v28i1.11801 Bangladesh J Microbiol, Volume 28, Number 1, June 2011, pp 1-5


2008 ◽  
Vol 73 (5) ◽  
pp. 531-540 ◽  
Author(s):  
Ljiljana Stanojevic ◽  
Mihajlo Stankovic ◽  
Vesna Nikolic ◽  
Ljubisa Nikolic

The anti-oxidative and antimicrobial activities of different extracts from Hieracium pilosella L. (Asteraceae) whole plant were investigated. The total dry extracts were determined for all the investigated solvents: methanol, dichloromethane, ethyl acetate and dichloromethane: methanol (9:1). It was found that the highest yield was obtained by extraction with methanol (12.9 g/100 g of dry plant material). Qualitative and quantitative analysis were performed by the HPLC method, using external standards. Chlorogenic acid, apigenin-7-O-glucoside and umbelliferone were detected in the highest quantity in the extracts. The qualitative and quantitative composition of the extracts depends on the solvent used. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of the extracts was determined spectrophotometrically. The highest radical scavenging effect was observed in the methanolic extract, both with and without incubation, EC50 = 0.012 and EC50 = 0.015 mg ml-1, respectively. The antimicrobial activities of the extracts towards the bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Salmonella enteritidis and Klebsiella pneumoniae) and the fungi (Aspergillus niger and Candida albicans) were determined by the disc diffusion method. The minimal inhibitory concentrations were determined for all the investigated extracts against all the mentioned microorganisms.


2021 ◽  
Vol 69 (4) ◽  
pp. 871-904
Author(s):  
Zlate Veličković ◽  
Bogdan Vujičić ◽  
Vladica Stojanović ◽  
Predrag Stojisavljević ◽  
Zoran Bajić ◽  
...  

Introduction/purpose: In this study, we investigated the possibility of removing the organophosphorus pesticide malathion from water using a new adsorbent based on the biowaste of river shell shards from the Anodonta Sinadonta woodiane family, a material that accumulates in large quantities as waste on the banks of large rivers. Two adsorbents were tested - mechanically comminuted river shells (MRM) and mechanosynthetic hydroxyapatite from comminuted river shells (RMHAp). Methods: The obtained adsorbents were characterized and tested for the removal of the organophosphorus pesticide malathion from water. In order to predict the optimal adsorption conditions using the Response Surface Method (RSM), the authors investigated the influence of variable factors (adsorption conditions), pH values, adsorbent doses, contact times, and temperatures on the adsorbent capacity. Results: The best adsorption of malathion was achieved at mean pH values between 6.0 and 7.0. The adsorption data for malathion at 25, 35, and 45 °C were compared using the Langmuir, Freundlich, DubininRadushkevich (DR), and Temkin isothermal models, as well as pseudofirst order, pseudo-second order and Elovic kinetic models for modeling adsorption kinetics. The maximum Langmuir adsorption capacity for MRM and RMHAp at 25 °C was 46,462 mg g-1 and 78,311 mg g-1 , respectively. Conclusion: The results have showed that malathion adsorption on both adsorbents follows the pseudo-second kinetic model and the Freundlich isothermal model. The thermodynamic parameters indicate the endothermic, feasible, and spontaneous nature of the adsorption process.


INDIAN DRUGS ◽  
2020 ◽  
Vol 57 (06) ◽  
pp. 49-59
Author(s):  
Priyambada Kshiroda Nandini Sarangi ◽  
Jyotirmaya Sahoo ◽  
Chita Ranjan Sahoo ◽  
Sudhir Kumar Paidesetty ◽  
Guru Prasad Mohanta

A series of eight quinoline-thiazole hybrid-bearing diazenylsulfonamides, 4a-4h, were synthesized and characterized by UV-Vis, FT/IR, 1H NMR and lC-MS. These compounds were formed when two prepared intermediate precursors of Schiff-base compounds, (E)-N-((2-chloroquinolin-3-yl)methylene)-4phenylthiazol-2-amine (3a) and (E)-N-((2-chloroquinolin-3-yl)methylene)-4-chlorophenylthiazol-2-amine (3b) were converted to the corresponding diazenyl compounds 4a-4h by treating and coupling with the individual diazonium salts of sulfa-drugs. The results of in vitro cytotoxic activity of the synthesized compounds in two cancer cell lines MCF 7 (human breast cancer cell line) and K562 (myelogenousleukemia cell line) have shown the IC50 values as given: 4b against MCF 7 19.52 and against K562 20.55µM; 4d against MCF 7 15.96 and against K562 13.05µM. Moreover, the compound 4-(((Z)-(2-chloroquinolin-3yl)(4-phenylthiazol-2-ylimino)methyl)diazenyl)benzenesulfonic acid (4d) induced maximum percentage of apoptosis. Furthermore, the in vitro antioxidant activity study revealed that among all the synthesized compounds, compound 4d has an excellent radical scavenging effect. Molecular docking was additionally performed to investigate the binding affinity of H-bonding interaction of synthesized compounds with a targeted enzyme and to compare it with the anticancer drugs, dasatinib, bosutinib and dacarbazine.


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