Thong tin luan an tieng anh

INFORMATION ON DOCTORAL THESIS - PHAM THI MINH - PhD
STUDENT
Thesis title: "Research characteristic of azo organic compounds mineralization
in dye textile wastewater by electro-Fenton method”
PhD student:

Pham Thi Minh

Training establishment:

Institute

of

Tropical

Technology

-

Vietnam

Academy of Science and Technology
Major:

Theoretical chemistry and Physical chemistry

Code:

62.44.01.19

Supervisors:

Assoc. Prof. Nguyen Thi Le Hien
Assoc. Prof. Dinh Thi Mai Thanh

 
1 . Objective of the thesis
1.1. Synthesize spinel oxide Cu1,5Mn1,5O4 by co-precipitation method.
1.2. Synthesize Ppy and Ppy(Cu1,5Mn1,5O4)/Ppy coatings on carbon substrate.
1.3. Determine the optimal conditions for processing treatment of azo organic
compounds in dye textile wastewater.
1.4. Research dyeing wastewater treatment in some dye textile manufactures by
electro-Fenton effects.
2. Main results of the thesis
2.1. Successfully synthesize spinel oxide Cu1,5Mn1,5O4 by co-precipitation
method with small, fine, uniform with spinel-structured particles.
2.2. Successfully synthesize Ppy and Ppy(Cu1,5Mn1,5O4)/Ppy coatings on carbon
–substrate by static-current method at current density i = 2 mA/cm 2. The
Ppy(Cu1,5Mn1,5O4)/Ppy cathode electrode has high stability and best catalytic


electrochemical ability for oxygen reduction process to produce H2O2 in the
solution with pH3, better than the C and C/PPY electrodes.
2.3. Colored azo compounds such as red methyl, orange methyl, red Congo can
be

completely

oxidized

by

electro-Fenton

effects

using

C/

Ppy(Cu1,5Mn1,5O4)/Ppy electrodes, at current density of 1 mA/cm 2 , in pH3
solution containing iron (II) of 1 mM concentration, and oxygen speed of 1
liter/minute.
By UV-Vis spectra, the decomposition efficiency has been identified
for red methyl as 0.35 mM , red Congo as 0.25 mM and orange methyl as
1.0mM attained respective values of 88 %, 75% and 72% after 5 hours
treatment.
By COD determination method, the result is consistent with the results
of UV - Vis analysis. The COD reduction efficiency of 0.35 mM red methyl;
0.25mM

red congo and 1.0 mM orange methyl after 20 hours treatment

attained respective values 76%, 91% and 74%.
2.4. The kinetics of azo compounds mineralization is identified on the basis of
experimental results according to the first-class supposed kinetic equation,
which is suitable for the studies published in some international journals.
2.5. The results of untreated textile wastewater processing from Van Phuc and
Duong Noi villages in laboratory in optimal conditions promise application
Fenton-Electro effect in treatment azo compound s in dye textile wastewater.

For Duong Noi dye textile wastewater, COD value decrease from 450
to 70 mg/l (the COD reduction yield attained 84% respectively), color grade
reduces from 1360 to 85 Pt - Co after 10 hours treatment.
For Van Phuc dye textile wastewater: COD value decrease from 1000
to 80 mg / l (the COD reduction yield attained 92%, respectively), color grade
reduces from 1750 to 95 Pt - Co after 14 hours treatment.


3. New findings and contributions of the thesis
3.1. Successfully synthesize spinel oxide Cu1,5Mn1,5O4 by co-precipitation
method with small, fine, uniform and spinel-structured particles.
3.2.

Synthesize

two

types

of

electrodes,

including

C/P PY

and

C/Ppy(Cu1,5Mn1,5O4)/Ppy by electrochemical method. These electrodes have

suitable electrocatalytic for the oxygen reduction process to create hydrogen
peroxide.
3.3. Find out the most suitable condition (the concentration of Fe2+, the imposed
current density, cathode electrode material and oxygen rate) to mineralize red
methyl, red congo and orange methyl by electro- Fenton method, setting the
basis for mineralization of azo compounds in textile wastewater.
3.4. Preliminarily use C/Ppy and C/Ppy(Cu1,5Mn1,5O4)/Ppy materials as the
cathode electrodes for Van Phuc and Duong Noi textile wastewater
mineralization by electro-Fenton method. The COD indicator and color grade of
wastewater after treatment achieved the standard of industrial wastewater Class
B ISO 2008/BTNMT.