Comparative study of MWCNT and alumina supported CоMо hydrotreating catalysts prepared with citric acid as chelating agent

2020 ◽  
Vol 357 ◽  
pp. 221-230 ◽  
Author(s):  
M.O. Kazakov ◽  
M.A. Kazakova ◽  
Yu.V. Vatutina ◽  
T.V. Larina ◽  
Yu.A. Chesalov ◽  
...  
Keyword(s):  
Citric Acid ◽  
Comparative Study ◽  
Chelating Agent ◽  
Hydrotreating Catalysts

scholarly journals A comparative study on glycerol metabolism to erythritol and citric acid inYarrowia lipolyticayeast cells

2014 ◽  
Vol 14 (6) ◽  
pp. 966-976 ◽  
Author(s):  
Ludwika Tomaszewska ◽  
Magdalena Rakicka ◽  
Waldemar Rymowicz ◽  
Anita Rywińska
Keyword(s):  
Citric Acid ◽  
Comparative Study ◽  
Glycerol Metabolism

A Comparative Study of Ferric Nitrate and Citric Acid in Washing Heavy Metal-Contaminated Soil

2021 ◽  
Author(s):  
Zhihong Guo ◽  
Shuqin Zhang ◽  
Dajun Ren ◽  
Xiaoqing Zhang ◽  
Shuang Liu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Citric Acid ◽  
Comparative Study ◽  
Contaminated Soil ◽  
Ferric Nitrate

A comparative study of ultrasonic degumming of silk sericin using citric acid, sodium carbonate and papain

2019 ◽  
Vol 135 (3) ◽  
pp. 195-201 ◽  
Author(s):  
Wuchao Wang ◽  
Yi Pan ◽  
Kang Gong ◽  
Qi Zhou ◽  
Tonghua Zhang ◽  
...  
Keyword(s):  
Citric Acid ◽  
Comparative Study ◽  
Sodium Carbonate ◽  
Silk Sericin

Removal of Bound PAH Residues in Contaminated Soils by Fenton Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 619 ◽  
Author(s):  
Xuqiang Zhao ◽  
Li Qin ◽  
Michael Gatheru Waigi ◽  
Pengfei Cheng ◽  
Bing Yang ◽  
...  
Keyword(s):  
Citric Acid ◽  
Oxalic Acid ◽  
Contaminated Soils ◽  
Chelating Agent ◽  
Fenton Oxidation ◽  
Valuable Insight ◽  
First Order Kinetics ◽  
Bound Residues ◽  
Polycyclic Aromatic ◽  
Insight Into

The availability of bound residues of polycyclic aromatic hydrocarbons (PAHs), in reference to their parent compounds, can be enhanced by microbial activity and chemical reactions, which pose severe risks for the ecosystems encompassing contaminated soils. Considerable attention has been raised on how to remove these bound residues from PAH-contaminated soils. This paper provides a novel application of Fenton oxidation in the removal of bound residues of model PAHs, such as naphthalene (NAP), acenaphthene (ACP), fluorene (FLU) and anthracene (ANT), from naturally contaminated soils. The citric acid-enhanced Fenton treatment resulted in the degradation of bound PAH residues that followed pseudo-first-order kinetics, with rate constants within 4.22 × 10−2, 1.25 × 10−1 and 2.72 × 10−1 h−1 for NAP, FLU, and ANT, respectively. The reactivity of bound PAH residues showed a correlation with their ionization potential (IP) values. Moreover, the degradation rate of bound PAH residues was significantly correlated with H2O2-Fe2+ ratio (m/m) and H2O2 concentrations. The highest removal efficiencies of bound PAH residues was up to 89.5% with the treatment of chelating agent oxalic acid, which was demonstrated to be superior to other acids, such as citric acid and hydrochloric acid. This study provides valuable insight into the feasibility of citric acid-Fenton and oxalic acid-Fenton treatments in rehabilitating bound PAH residues in contaminated soils.

Preparation of Delafossite CuYO2 by Metal-citric Acid Complex Decomposition Method

2009 ◽  
Vol 1166 ◽  
Author(s):  
Keishi Nishio ◽  
Tomomi Okada ◽  
Naoto Kikuchi ◽  
Satoshi Mikusu ◽  
Tsutomu Iida ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Citric Acid ◽  
Single Phase ◽  
Raw Materials ◽  
Chelating Agent ◽  
Amorphous Powder ◽  
Heat Treating ◽  
Acid Complex ◽  
Synthesis Conditions ◽  
Starting Solution

AbstractDelafossite CuYO2 and Ca doped CuYO2 were prepared by thermal decomposition of a metal-citric acid complex. The starting solution consisted of Cu acetate, Y acetate and Ca acetate as the raw materials. Citric acid was used as the chelating agent, and acetic acid and distilled water were mixed as a solvent. The starting solutions were heated at 723 K for 5 h after drying at 353 K. The obtained powders were amorphous and single phase of orthorhombic Cu2Y2O5 was obtained by heat-treated the amorphous powder at a temperature range between 1073 and 1373 K for 3 h in air. Furthermore, Heat-treating the obtained orthorhombic Cu2Y2O5 at above 1373 K in air caused it to decompose into Y2O3, CuO and Cu2O. On the other hand, the sample powder prepared from a starting solution without citric acid, i.e., single phase of orthorhombic Cu2Y2O5 could not be obtained under the same synthesis conditions as that for a solution with citric acid. We were able to obtain delafossite CuYO2 and Ca doped CuYO2 from orthorhombic Cu2Y2O5 under a low O2 pressure atmosphere at above 1223 K. The obtained delafossite CuYO2 composed hexagonal and rhombohedral phases. The color of the CuYO2 powder was light brown and that of Ca-doped CuYO2 was light green. Diffraction peaks in the XRD pattern were slightly shifted by doping Ca for CuYO2, and these peaks shifted toward to a high diffraction angle with an increasing amount of doped Ca. From these results, we concluded that Ca doped delafossite CuYO2 could be obtained by thermal decomposition of a metal-citric acid complex.

scholarly journals Perbedaan daya pembersih kavitas saponin ekstrak kulit manggis (Garcinia mangostana Linn) 0,78% dan asam sitrat 6% (The difference of 0,78% saponin from mangosteen pericarp extract and 6% citric acid for cleanliness of cavity)

2019 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Ivon Dewi Setianingrum ◽  
Ketut Suardita ◽  
Ari Subiyanto ◽  
Dian Agustin Wahjuningrum
Keyword(s):  
Citric Acid ◽  
Chelating Agent ◽  
Smear Layer ◽  
Control Group ◽  
Garcinia Mangostana ◽  
Human Teeth ◽  
Inorganic Particles ◽  
The Difference ◽  
Dental Cavities ◽  
Better Than

Background: Cleanliness of cavity is considered important for a restoration. Smear layer formed after cavity preparation should be removed in order not to disrupt the bond adhesion between restorative materials and dental cavities. Saponins contained in mangosteen pericarp (Garcinia mangostana L.) have surfactant properties that can eliminate the smear layer assessed. 6% citric acid is a chelating agent which can eliminate the inorganic particles of the smear layer. Until now, the research on the differences of 0,78% saponin from mangosteen pericarp extract and 6% citric acid for cleanliness of cavity has never been done. Purpose: To see the differences between 0,78% saponin from mangosteen pericarp extract and 6% citric acid as cavity cleanser. Method: Eighteen human teeth with complete crown, no caries,  and no fractures were randomized in 3 groups (n≥6), in this experiment use (n=6). The cavity was prepared using wheels bur for hand use instrument. After instrumentation, each cavity on the first group used  0,78% saponin from mangosteen pericarp extract as cavity cleanser, the second group used 6% citric acid as cavity cleanser, and the control group used aquadest. Then, the teeth were split to be observed on Scanning Electron Microscope (SEM). Result: For Mann- Whitney test there were significant differences just between 078% saponin from mangosteen pericarp extract with 6% citric acid, and 6% citric acid with aquadest, but not for 0,78% saponin from mangosteen pericarp extract with aquadest. Median value of 6% citric acid showed 2,000 which is the smallest value compared to the value of the other groups. Conclusion: The cleanliness of cavity with 6% citric acid is better than that with 0,78%  saponin from mangosteen pericarp extract. 

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