Advances in Chemical Engi neering and Science , 20 1 1, 1, 33-36
doi:10.4236/aces.2011.12006 Published Online April 2011 (http://www.scirp.org/journal/aces)
33
Preparation of Nano-Modified Polyacrylamide and Its
Application on Solid-Liquid Separation in Waste
Drilling Mud
Fanghui Wang, Jiantao Fan, Hong Zhu*, Kefei Han, Jing Zou, Haiyun Sun
Institute of Modern Catalyst, State key Laboratory f Chemical Reso urce Engineering, School of Science,
Beijing University of Chemical Technology, Beijing, China
Received December 13, 2010; revised January 10, 2011; accepted March 30, 2011
Abstract
To satisfy the requirement on solid-liquid separation in high-density waste drilling mud, prepare the na-
no-modified polyacrylamide (PAM) flocculant for high density waste drilling mud by in-situ dispersion me-
thod, direct dispersion method and simultaneous formation method. The result showed the flocculent effect
of nano-modified polyacrylamide prepared by simultaneous formation method was the best. When the con-
tent of water glass and acrylamide (AM) were respectively 3% and 15%, reaction temperature was 60˚C and
reaction time was 3 h, the performance of product was the best. The water content in filter cake was 24.32%
after the waste drilling mud disposed by the optimization flocculant. The flocculent effect of optimization
flocculant was superior to that of other flocculant in market.
Keywords: In-Situ Dispersion Method, Direct Dispersion Method, Simultaneous Formation Method,
Nano-Modified Polyacrylamide, High Density Waste Drilling Mud
1. Introduction
The waste drilling fluids was the inevitable industrial
waste while Oil and Gas exploration drilling. It had be-
come one of the most severe pollution sources, whose
effect on environment has been concerned gradually
[1-3]. There were many methods [4-6] to dispose the
waste drilling mud and drilling wastewater. The solid-
liquid separation [7] was the most important and widely
application method. At deep well drilling, the component
of waste drilling mud was complexity, the density of
waste drilling mud was higher and higher, and the waste
drilling mud treatment was more and more hard [8]. The
flocculant in market had not deal with the high density
waste drilling mud. So a new nano-modified polyacry-
lamide flocculant for high density waste drilling mud
was prepared.
2. Experiment
2.1. Agent
Cation polyacrylamide (GP), anion polyacrylamide (GP),
silane coupling agent KH570 (GP), homemade nano–
SiO2 (40 - 60 nm), water class (modulus = 3.2~2.3), hy-
drochloric acid (AR), absolute ethyl alcohol (AR), acry-
lamide (AR), Potassium peroxydisulfate (AR), Sodium
sulfite (AR), oxalic acid (AR), Nitrogen.
High density waste drilling mud, the density is 1.639 g/mL
and the solid content is 56.72%.
2.2. Preaparation of Nano-Modified
Polyacrylamide
2.2.1. In- Situ Dispersion M e thod
(1) Preaparation of nano-modified Cation polyacryla-
mide (CPAM)
Dissolve respectively 4.2 g Na2SiO3 in 10 ml deio-
nized water and 8.0 g CPAM in 380 ml deionized water,
then drop the Na2SiO3 solution into CPAM solution and
mix equably. Make HCl to adjust the pH of above mix-
ture to about 7 and keep the system react for 3 h at room
temperature.
(2) Preaparation of nano-modified anion polyacryla-
mide (APAM)
Dissolve respectively 4.2 g Na2SiO3 in 10 ml deio-

F. H. WANG ET AL.
34
nized water and 8.0 g APAM in 380 ml deionized water,
then drop the Na2SiO3 solution into APAM solution and
mix equably. Make HCl to adjust the pH of above mix-
ture to about 7 and keep the system react for 3 h at room
temperature.
2.2.2. Direct Dispersion Method
Disperse 8.0 g homemade nano SiO2 in 50 ml absolute
ethyl alcohol, add 2 ml KH570 into above mixture, then
keep stirring and reacting for 48h at room temperature.
Drying above mixture in the end at 60˚C to gain the nano
SiO2 modified by silane coupling agent. Disperse 4.0 g
nano SiO2 modified by silane coupling agent in 100 ml
deionized water, add 5 g acrylamide into above mixture
and removal of oxygen dissolved in the solution by
blowing continuously nitrogen. Then add 0.1 g potas-
sium persulfate to initiate polymerization and keep the
system react for 4 h to gain product.
2.2.3. Simulta neous Formation Metho d
Dissolve 4 ml water class into 80 ml deionized water,
adjust the pH of the water class solution to 3 - 4 by HCl
and react for 1 h at room temperature. Dissolve 1 ml
KH570 into 10 ml absolute ethyl alcohol, adjust the pH
of the KH570 solution to 3 by oxalic acid and hydrolyze
for 1 h at room temperature. Add KH570 solution into
water class solution, then add 20 acrylamide into above
mixture and removal of oxygen dissolved in the solution
by blowing continuously nitrogen. Finally add 0.1 g po-
tassium persulfate and 0.1 g sodium sulfite into above
system to initiate polymerization. Keep the system react
for 4 h to gain product.
2.2.4. Floccule nt Treatment
Add 4ml MgCl2 solution (0.2 g/ml) as gel breaker to 200
g waste drilling mud (1:1-fold diluted with water), then
add some flocculant to above system and stir, centrifugal
separation (4000 r/min) for 10 min. Weight the quality of
filter cake (m1) and soild phase after baking (m2). Gain
the water content in filter cake by the formula as follows:
The water content in filter cake =

m1 m2m1.
3. Result and Discussion
3.1. Flocculent Effect of Three Kinds of
Preparation Method
(1) Nano-modified CPAM flocculant prepared by in-situ
dispersion method
(2) nano-modified APAM flocculant prepared by
in-situ dispersion method
(3) nano-modified PAM flocculant prepared by direct
dispersion method
(4) nano-modified PAM flocculant prepared by simul-
taneous formation method
From Tables 1-4, we can know that flocculent effect of
nano-modified polyacrylamide prepared by simultaneous
formation method was the best Among three preparation
methods. The optimum conditions for preparing nano-
modified polyacrylamide prepared by simultaneous for-
mation method was obtained through orthogonal expe-
riments.
3.2. Optimization of the Simultaneous
Formation Method
Content of water class and acrylamide, react temperature
and react time were selected and tested by four-factors-
three-level orthogonal processing test. The test result is
shown in Table 5.
From Table 5, we can know the test number 2 was the
best.
3.3. Analysis of FTIR
Figure 1 was The FTIR spectrum of the sample (test
number 2 in Table 5). As can be seen from the Figure 1,
the peak of IR spectra of N-H stretching vibration ap-
peared at 3419 cm–1 and 3197 cm–1; the peak of IR spec-
tra of –CH2– asymmetry stretching vibration and –CH2–
symmetric stretching vibration appeared respectively at
2922 cm–1 and 2850 cm–1; the absorption peak appeared
at 1652 cm–1and 1417 cm–1 was caused respectively by
the stretching vibration of C=O in acylamide group and
vibration of saturated C-H. The absorption peak of
Si-O-C and Si-O-Si appeared at 1120 cm–1.
Table 1. The effect of Content of nano-modified CPAM on
the water content in filter cake.
Content of flocculant (%) 0.2 0.4 0.60.8
The water content in filter cake (%) 51.05 52.30 46.04 47.62
Table 2. The effect of Content of nano-modified APAM on
the water content in filter cake.
Content of flocculant (%) 0.2 0.4 0.60.8
The water content in filter cake (%) 56.37 54.47 48.76 50.07
Table 3. The effect of Content of flocculant on the water
content in filter cake.
Content of flocculant (%) 0.2 0.4 0.6 0.8
The water content in filter cake (%) 35.98 35.24 34.87 35.13
Table 4. The effect of Content of flocculant on the water
content in filter cake.
Content of flocculant (%) 0.2 0.4 0.6 0.8
The water content in filter cake (%) 33.01 32.55 30.68 31.73

F. H. WANG ET AL. 35
Table 5. The test result of orthogonal experiment.
Test number Content of
water class/%
Content of
acrylamide/% React temperaturee/℃ React time/h the water content in filter cake/%
1 3 10 50 2 30.23
2 3 15 60 3 24.32
3 3 20 70 4 25.98
4 5 10 60 4 26.67
5 5 15 70 2 25.49
6 5 20 50 3 26.35
7 7 10 70 3 26.22
8 7 15 50 4 28.38
9 7 20 60 2 29.89
Figure 1. The FTIR spectrum of the nano-modified PAM
flocculant.
So, we can think that there must have some structural
units of AM and SiO2 in the nano-modified flocculant.
3.4. Contrast of Flocculent Effect
We contrast the flocculent effect of nano-modified floc-
culant prepared by simultaneous formation method with
that of the other coagulant in matket, such as, Non-ionic
polyacrylamide, cationic polyacrylamide, anionic polya-
crylamide, polymerization ferric sulphate, Polymeriza-
tion aluminum sulfate, nano-modified flocculant.
From Figure 2 we can see that adding the same
amount of flocculant, the flocculent effect of organic
flocculants was better than that of inorganic coagulant,
but the results were not satisfactory, the water content in
filter cake ≥ 50%. The flocculent effect of the na-
no-modified flocculant is significantly better than that of
the other coagulant in matket, water content of waste
drilling mud after treated is 24.32%.
4. Conclusions
Water class and acrylamide used as raw matierial and
potassium persulfate as initiator to prepare nano-
1—Non-ionic polyacrylamide 2—cationic polyacrylamide
3—anionic polyacrylamide 4—polymerization ferric sulphate
5—Polymerization aluminum sulfate 6—nano-modified flocculant
Figure 2. Floccuent effect of some flocculant.
modified PAM flocculant by simultaneous formation
method. The optimum conditions were obtained through
orthogonal experiments. When making the nano-modified
PAM flocculant prepared under the optimum conditions
to treat the high-density waste drilling mud, the water
content in filter cake is 24.32% which was significantly
better than that of the other coagulant in market.
5. Acknowledgements
The authors gratefully acknowledge the financial sup-
ports from National Hi-Tech Research and Development
Program of China (863program) (2008BAC43B02).
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