American Journal of Innovative Research and Applied Sciences. ISSN 2429-5396 I www.american-jiras.com

|El Mouraille Nadia

| Belmouden Moustapha *

| and | Ait Ichou Yahia

Ibn Zohr University | Department of Chemistry | Agadir | Morocco |

ABSTRACT

Background: The use of pesticides massively in agriculture is considered among the causes of pollution most probable of surface and

ground water. These organic compounds are very hazardous and harmful to health, as most are toxic and carcinogenic, even at low

concentrations. For these reasons, in recent years, environmental regulations in many countries have become strict for the production

of drinking water and wastewater treatment, in particular concerning pollution by pesticides. Objective: The removal of pesticides

from contaminated water is an extremely complex problem due to the wide range of pesticides of multiple chemical structures and

properties. Among the unconventional methods of treatment of polluted water, heterogeneous photocatalysis has been used for the

treatment of several pollutants such as pesticides. The objective of this work is the evaluation of this method for the elimination of a

pesticide under different operating conditions Methods: Photocatalytic degradation of aqueous commercial pesticide "Mythos" solution

has been tested by using TiO

as a photocatalyst and a new batch reactor using low voltage UV lamps as an irradiation source. The

influence of some parameters such as the presence of UV irradiation, aeration, pH, pesticide concentration and time of reaction was

examined. The effect of some inorganic anions, such as Cl-, SO

and NO

, commonly present in real effluents, on the photocatalytic

degradation, was also studied. Results: The degradation rates were found to be strongly influenced by all the above parameters,

except pH which has a moderate effect. It is found that the photocatalytic degradation process follows first-order reaction kinetics

represented by the Langmuir-Hinshelwood mechanism. The presence of Cl- and SO

anions led to a slight decrease of the

effectiveness of the photocatalytic degradation. However, the observed inhibitive effect on the degradation of the tested fungicide is

shown to follow the order: Cl

< SO

< CO

< PO

< NO

. The aeration of the medium bulk enhanced the photodegradation rate of

the pollutant. Conclusion: based on the results, the photocatalytic degradation using a low-voltage UV light could be a useful method

for the removal, of wastewaters containing Mythos.

Keywords: Photocatalysis, TiO

, low-voltage UV, Mythos, kinetic model.

1. INTRODUCTION

A diversity of organic pollutants especially pesticides are introduced into the water system from different sources such as

industrial water discharges, agricultural runoff, and chemical spills [1,2]. Their toxicity, stability to natural decomposition,

and persistence in the environment have been the cause of much concern to the societies and regulatory authorities

around the world [3,4].

The control of organic pollutants in water is an important measure in environmental protection. Among many processes

proposed and/or being developed for the destruction of the organic contaminants, biodegradation has received the

greatest attention. However, many organic chemicals, especially those that are toxic or refractory, are not amendable to

microbial degradation [5].

On recent years, novel methods for water and air purification have been developed including chemical, electrochemical

and photochemical processes [6,7]. Indeed; photocatalytic degradation has been shown to be a promising technology for

the treatment of water contaminated with organic and inorganic pollutants [8,9].

Heterogeneous photocatalysis involves the use of a semiconductor material which is excited by light with energy equal to

or greater than the band gap. This leads to the formation of electron/hole pairs which react at the particle-water

interface resulting in the degradation of chemical species by both oxidative and reductive pathways. Titanium dioxide

(TiO

) is the photocatalyst of choice for water decontamination treatment because it is not soluble under normal pH

ranges found in natural water. In the other hand, it is photoactive, photostable, and relatively inexpensive. However, TiO

is a wide band gap semiconductor (E

= 3.2 eV for anatase) and can only be excited by UV light, meaning that only 5%

of the solar spectrum can be utilised.

ORIGINAL ARTICLE

UV/TiO

PHOTOCATALYTIC OXIDATION OF COMMERCIAL

PESTICIDE IN AQUEOUS SOLUTION

Innovative Research and Applied Sciences are the property of Atlantic Center Research Sciences, and is protected by copyright laws CC-BY. See: http://creativecommons.org/licenses/by-nc/4.0/.

American Journal of Innovative Research and Applied Sciences. ISSN 2429-5396 I www.american-jiras.com

In our previous paper [10], we mentioned that during the adsorption phase, consider as the vital stage in photocatalytic

degradation of organic pollutants on TiO

surface, the amount of pyrimethanil fixed by the particles of TiO

, and depend

on several parameters. The time needed to reach adsorption equilibrium increase with concentration, but not exceed 30

minutes. The uptake of pyrimethanil was found to increase with the increase of salt’s concentration especially in the

presence of NaCl and NaHPO

In the present work, photocatalysis based on TiO

and a batch reactor using low voltage UV lamps as an irradiation

source were applied to degrade the commercial solutions of pyrimethanil, named Mythos. The effects of the major

system parameters (pH, initial concentrations of Mythos, concentration of ions and presence of O

) on the degradation of

this fungicide in presence of TiO

were studied.

2. MATERIALS AND METHODS

2.1. Chemicals

Pyrimethanil is an anilinopyrimidine, 4,6-dimethyl-N-phenyl-2-pyrimidinamine. Imazalil sulfate: 1-[2-(2,4-dichlorophenyl)-

2-(2-propenyloxy)ethyl]-1H- imidazole sulfate. The commercial pyrimethanil used is named MYTHOS SC300 purchased

from Bayer Corporation. The molecular structure of this pesticide is shown in Figure 1. All chemicals used in the

experiments were of analytical pure grade and used without further purification. A stock pyrimethanil standard solution

(100 mg in water) was prepared in doubly distilled water.

The photocatalysts used in this experiment were technical grade: Titanium (IV) oxide, anatase (purity > ≥99%), was

purchased from Sigma-Aldrich and used as received, and TiO

Degussa P-25 (anatase/rutile, surface area 56 m

-1

nonporous).

Figure 1: The figure presents the molecular structure of Pyrimethanil.

2.2. Photocatalytic Reactor: This photo-reactor, of a capacity of 1 L, has a cylindrical form made with Pyrex vessel.

The cover of the photoreactor has several ports for sampling and for introducing oxygen into the reaction mixture. It's

placed in the center of a stainless steel cylinder with 6 low-pressure UV lamps (8 watts, TUV G8T5, Philips), with

maximum emission wavelength mainly around 365 nm, on axial position allowing that the intensity received by the

effluent in the Pyrex reaction vessel is uniform. The photoreactor has placed in a closed box (1m

). The ventilation of this

enclosure is ensured by two fans.

2.3. Analysis and procedure: Absorbance was measured using UV-Vis spectrophotometer (Jasco V630). The

photocatalytic experiments were performed using a volume of the solution of 1L containing the concentration 15 mg/L of

Mythos in the presence suspension of 1 g/L TiO

powder. Before irradiation, the suspension was magnetically stirred in

the dark for 60 min to reach adsorption–desorption equilibrium. During irradiation, a test of samples was withdrawn with

the help of a syringe and filtered through syringe (45 µm) filters to remove TiO

particles before analysis. Total volume of

the samples withdrawn from each experiment was less than 10% (by volume) of the reaction solution. The pH of the

reaction solution was adjusted by adding H

or NaOH. Materials and Methods are written in this area. Describe in

detail the technic used, the Name and the references of laboratory materials used should be cited.

3. RESULTS

3.1. Photolysis

As shown in Figure 2, the degradation of Mythos in aqueous solution by photolysis at 365 nm (without TiO

) is very slow

in comparison with photocatalytic degradation, as only 10% of the initial amount of the compound is degraded after 5 h

of irradiation without TiO

American Journal of Innovative Research and Applied Sciences. ISSN 2429-5396 I www.american-jiras.com

Figure 2: The figure presents the degradation

kinetics of Mythos in the presence and the absence of

TiO

P25 and TiO

Sigma, using UV/O

system

([Mythos] = 15 mg/L; TiO

= 1 g/L).

This fact could be attributed to a relatively low substrate adsorption at this wavelength and the quantum yield of

photolysis. Conversely, in the presence of TiO

91% and 82% of initial concentration the Mythos was degraded,

respectively for TiO

P-25 and TiO

anatase. Consequently, the decrease of the Mythos concentration in the presence of

TiO

is mainly due to the photocatalytic degradation. Similar results were observed for photocatalysis of diuron,

imidacloprid, formetanate and methomyl [10]. As the TiO

P-25 gives a slightly better result than the other form, it will be

used for the rest of this work.

3.2. Effect of substrate initial’s concentration

Figure 3 presents the evolution of illuminated suspensions containing different concentrations of Mythos in the presence

1 g/L of TiO

, at free pH, as a function of time. The increase in the initial concentration in the range of 15-60 mg/L is

traducing by a decreased of a reaction rate. Thus, the higher the initial concentration of the pesticide, the longer the time

it takes to remove it. Similar trends have been observed for the photocatalytic degradation of triclopyr and daminozid

[12], carbofuran [13], propham and tebuthioron [14].

Figure 3: The figure presents the influence of the

initial concentration on the photodegradation of Mythos

in the presence of 1 g/L of TiO

P-25.

As indicated in several investigations, this trend maybe explains considering that as the concentration of the target

pollutant increase, more molecules of the compound are adsorbed on the surface of the photocatalyst. Therefore, the

reactive species (OH

•

and O

•

) required for the degradation of the pollutant must increases. However, the formation of

•

and O

•

on the catalyst surface remains constant for a given light intensity, catalyst amount, and duration of

irradiation. Hence, the available OH

•

radicals are inadequate for pollutant degradation at higher concentrations.

Consequently, the pollutant degradation rate decreases as the concentration increases [15]. In addition, an increase in

substrate concentration can lead to the generation of higher concentration of intermediates, which may adsorb on the

surface of the catalyst. Slow diffusion of the generated intermediates from the catalyst surface can result in the

0.2

0.4

0.6

0.8

1.2

-60 0 60 120 180 240 300

C/Co

temps (min)

Photocatalysis (P25)

Photocatalysis (T-Sigma)

Photolysis

0.2

0.4

0.6

0.8

1.2

-60 0 60 120 180 240 300

Ce/Co

Time (min.)

5 mg/L

10 mg/L

15mg/l

30mg/l

45 mg/L

60 mg/L

American Journal of Innovative Research and Applied Sciences. ISSN 2429-5396 I www.american-jiras.com

deactivation of active sites on the photocatalyst and result in a reduction in the degradation rate. However, at low

concentration, the number of catalytic sites will not be limiting factor and the rate of degradation will be proportional to

the substrate concentration. Similar trends have been reported for the photocatalytic degradation of propachlor [14],

acephate [16], 2,4-DNP [17], isoproturon [18], and diphenamid [19].

3.3. Kinetic study

A Linear relationship was found by plotting ln(C

) versus irradiation time (t) (Figure 4) displayed that Mythos

photocatalytic degradation followed the pseudo-first-order kinetic for the different concentrations studied. The pseudo-

first-order rate constants (k

app

) were determined from the slope value of the line upon linear regression according to "Eq.

(1) ":











 



 (1)

Figure 4: The figure presents the variation of ln(C

) versus irradiation

time for Mythos ([TiO

] = 1g/L).

3.3.1. Analysis of degradation using the Langmuir-Hinshelwood (L-H) Kinetic Model

The Langmuir-Hinshelwood model has been used to describe the kinetics of the reaction [21, 22]. This model has been

used extensively to describe experimental results in heterogeneous photocatalysis reactions [23, 24]. The rate of the

photocatalytic reaction depends on the fraction of the sites covered by the Pyrimethanil and the k

a rate constant which

depends on the concentration of HO

•

produced.

Although some authors consider the Langmuir-Hinshelwood model not to be a sufficient process (Yu et al., 2003; Zhu et

al., 2005), this model is widely used because it correlates the rate of degradation to the instantaneous concentration. The

equation used is:





 





   



  















(2)

The linear form of "Eq. (2)" is presented in "Eq. (3)"



















(3)

Where,

: Mythos initial concentration (mg/L),

L-H :

Adsorption equilibrium constant under irradiation (L/mg),

: Substrate degradation reaction rate (mg/L.min),

-6

-5

-4

-3

-2

-1

0 60 120 180 240 300

Ln(Ce/Co)

Time (min.)

5 mg/L 10 mg/L

15 mg/l 30 mg/l

45 mg/L 60 mg/L

American Journal of Innovative Research and Applied Sciences. ISSN 2429-5396 I www.american-jiras.com

T: irradiation time (min),

: Specific rate constant for the oxidation of the organic compound (mg /L min).

The slop of





as a function of





is linear, and the calculated constants k

and K

L-H

were k

= 0.0373 mg/L.min and K

L-H

0.572 L/mg, respectively. Hence, the calculated values of K

L-H

(0.572 L/mg) and K

ads

(0.0422 L/mg L) were different. The

difference obtained in this study can be attributed to the inexactitude of Langmuir and Langmuir–Hinshelwood

alignments. Thus, the adsorption affinity of Mythos on the surface of TiO

can be reflected by the parameter K

L-H

3.3.2. Half-life of the reaction

One of the most useful indications for evaluating the reaction rate of first order kinetics is the calculation of the half-life

of the reaction. The integration of the Langmuir-Hinshelwood equation (L-H) over time gives "Eq. (4)":

 

























  



 (4)

Where C

: Initial pollutant concentration (mg/L),

C: Concentration of organic compound (mg/L),

t: Reaction time during substrate degradation (min).

The half-life of the reaction corresponds to the disappearance of half of the initial amount of the substrate. The

theoretical reaction time t

1/2

is estimated by "Eq. (5)":





































(5)

On the other hand, for the apparent reaction constant reaction, the half-life (t'

1/2

) is calculated according to "Eq. (6)":























(6)

The different values of t

1/2

(estimated) and t'

1/2

(calculated) obtained for Mythos for different initial (15 to 60 mg/L) in the

presence of TiO

(1 g/L) are given in the Table below.

Table 1: Estimated and calculated half-life values for the various

initial concentration of Mythos.

[Mythos] mg/L

1/2

cal.

(min.)

1/2

est.

(min.)

∆t

1/2

(min.)

46.2

33.8

12.4

70.7

56.5

14.2

99.0

79.3

19.7

173.3

147.5

25.8

261.6

215.8

45.1

346.6

284.0

62.6

The graphical exploitation of the half-life time as a function of the initial concentration gives straight lines (Figure 5).

Figure 5: The figure presents the half-life time

estimated (t

1/2

est) and calculated (t

1/2

cal) as a function

of different concentrations of Mythos, [TiO

= 1 g /L].

100

200

300

400

0 20 40 60

t1/2 (min.)

[Mythos] (mg/L)

t1/2 cal

t1/2 est

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These Figures show a difference between t

1/2

and t'

1/2

, which has become significant with the increase in the initial

concentration of the dye. This behaviour could be explained by the fact that the photodecomposition of the Mythos gives

rise to intermediates, which could also be competitively adsorbed on the surface of TiO

, resulting in the delay of half-life

time.

3.4. Effect of pH

Many studies have indicated that the pH of a solution is an important parameter in the adsorption and photocatalytic

degradation of organic compounds. This is because pH of the aqueous solution affects the surface charge of

photocatalyst of an organic pollutant. Thus the electrostatic interaction between semiconductor surface, solvent

molecules, substrate and charged radicals formed during photocatalytic oxidation [12,15,25].

In addition protonation and deprotonation of the organic pollutants can take place depending on the solution pH.

Sometimes protonated products are more stable under UV-radiation than its main structures [27].

For this study, the effect of initial’s pH of solution on the photodegradation of the pesticide is given in Figure 6. The

analysis of the results show that the pH has a slight effect was observed under the conditions examined. At acid pH, a

total degradation was observed after 240 minutes of irradiation, compared to 91% degraded for pH 6 and pH 9. Similar

observation has also been made for the degradation rate of methamidophos was nearly independent of solution pH when

Re-doped TiO

was used as the photocatalyst [28].

Figure 6: The figure presents the effect of pH effect on

photocatalytic degradation of Mythos ([Mythos] = 15

mg/L, TiO

=1g/L).

3.5. Effect of Inorganic ions

A number of studies demonstrated that some anions (phosphate, nitrate, sulfate, and chloride), found in natural or

polluted waters, can affect the photocatalytic degradation rate of organic pollutants since they can be adsorbed onto the

surface of TiO

[29, 30]. Thus, the presence of anions is reported to alter the ionic strength of the solution, which

influences the catalytic activity and the photocatalytic degradation. Depending on the solution pH, they can also compete

with the target pollutant for the active sites. The adsorption of water components can reduce the formation of OH

•

radicals. Although hydroxyl radical scavenging by the anions bicarbonate, phosphate, nitrate, sulfate, and chloride

resulted in corresponding anion radicals, they have lower oxidation potential. Consequently, all these reactions can

influence the overall rate of photocatalytic oxidation.

In order to examine the influence of certain ions on the photocatalytic degradation of Mythos, experiments were carried

out in the presence of 0.1 mol/L of the following ions: Cl

, NO

, PO

, and SO

. Figure 7 presents the results founded.

The observed inhibitive effect on the degradation of the tested fungicide is shown to follow the order: Cl

< SO

< PO

. Negligible inhibition was observed for sulfate and chloride relative to the other ions. Similar trends have been

observed for the photocatalytic degradation of 4-flurophenol and turbophos [31,32].

The detrimental effect of the tested anions may be attributed to their competition for the active sites on the TiO

surface

and catalyst deactivation which subsequently, decrease the degradation rate. A major drawback from the high reactivity

and non-selectivity of OH

•

is that it also reacts with non-target compounds present in the background water. This results

in a higher OH

•

demand to accomplish the desired degree of degradation [30,32]. This inhibition may also be due to the

reaction of positive holes and hydroxyl radicals with anions that behaved as radical (h+ and OH

•

) scavenger resulted in

longer Mythos removal [32,33].

0.2

0.4

0.6

0.8

-60 0 60 120 180 240 300

Ce/Co

Time (min.)

pH=3

pH=6

pH =9

American Journal of Innovative Research and Applied Sciences. ISSN 2429-5396 I www.american-jiras.com

Figure 7: The figure presents the degradation of Mythos in

the presence of 0.1 mol/L of different ions ([Mythos] = 15

mg/L, TiO

1g/L]).

3.6. Effect of medium bulk aeration

In the water purification by heterogeneous photocatalysis, the pollutants are usually organic. Their reaction in the

presence of oxygen is:

•

+ pollutants + O

+ H

O + intermediate products [34].

Oxygen is essential for complete degradation and should not be in competition at the level of adsorption with other

reactive species on the catalyst for this, we studied the effect of the aeration of the medium bulk on the photocatalytic

degradation of pollutants. The results are shown in Figure 8:

We note that with aeration of the heterogeneous medium (TiO

/UV), there is an acceleration of the decrease in the

concentration of the pollutant. Other research has shown that the rates and efficiencies of photo-assisted degradation of

organic substrates are reported as significantly improved in the presence of oxygen or by the addition of several oxidizing

species such as peroxydisulfate or peroxides [35-37]. This acceleration may be related to inhibition of the recombination

of electron-hole pair and also by the production of more radicals OH

•

in the middle, so we conclude that oxygen (O

)

here plays the role of a catalyst but since it is not regenerated at the end of the reaction, it affects the performance of

the degradation reaction by increasing, so we can conclude that reacts with the pollutant.

Figure 8: The figure presents the effect of aeration on the

Mythos’s photodegradation. ([Mythos] = 15 mg/L, TiO

= 1g/L).

0.2

0.4

0.6

0.8

-60 0 60 120 180 240 300

Ce/Co

Time (min.)

0 mol/L

0,1 mol/L NaCl

0,1 mol/L Na2SO4

0,1 mol/L NaHPO4

0,1 mol/L NaNO3

0.2

0.4

0.6

0.8

-60 0 60 120 180 240 300

Ce/Co

Time (min.)

Without aeration

With aeration

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5. CONCLUSION

Kinetics degradation of Mythos, a broad spectrum fungicide, often used to treat seeds, has been investigated in aqueous

solution using UV light in the absence and in presence of slurry titanium dioxide (TiO

). The degradation efficiency (%) of

Mythos by using TiO

photocatalyst depends strongly on the concentration of this pesticide. Kinetic parameters were

experimentally determined and an apparent first order kinetic was observed. The application of the Langmuir kinetic

model allowed us to determine the constants related to this model. On the other hand, we also determine the half-life

time. A difference between t

1/2

(estimated) and t'

1/2

(calculated) was found and become significant with the increase in

the initial concentration of the pesticide. The initial pH of pesticide has no significant effect on photodegradation of this

compound. In addition, the photodegradation efficiency of Mythos was slow in the presence of PO

and NO

. The

aeration of the medium bulk enhanced the photodegradation rate of the pollutant.

These results show that the photocatalytic process, based on TiO

and an economic UV light, are able to degrade the

pesticide Mythos and may find application in the remediation of water contaminated with pesticide residues.

6. REFERENCES

1. Bossana, D., Worthamb, H., Masclet, P. Chemosphere 1995; 30: 21-28.

2. Calvet, R. Tome 1: Constitution et structure, phénomènes aux interfaces, Dunod, Paris, 2003.

3. Desjardins, R. In Le traitement des eaux, 2

ème

Ed, Montréal: Ecole Polytechnique de Montréal. 1997 ; 1-10.

4. Narbonne, J.F. In Rapport du programme des Nations-Unies pour l‘environnement (PNUE). 2003; 265-73.

5. Vroumsia, T., Steiman, R., Seigle-Murandi, F., Benoit-Guyod, J.L., Khadrani, A. Chemosphere. 1996; 33: 2045-2056.

6. Oturan, M.A. J. Appl. Electrochem. 2000; 30: 477-478.

7. Malato, S., Solar photocatalytic decomposition of pentachlorophenol dissolved in water, ed. E.CIEMAT, Madrid, 1999.

8. Wu, R., Chena,C., Chen, M., Lu,C. Journal of Hazardous Materials. 2009; 162: 945–953.

9. Reddy, P., Kim, K.H., Song, H. Renewable Sustainable Energy Rev. 2013; 24: 578–585.

10. El Mouraille, N., Belmouden, M., Aitichou Y. Journal of Chemistry and Chemical Sciences. 2016; 6-9: 826-837.

11. Malato, S., Blanco, J., C`aceres, J., Fernandez-Alba, A.R., Aguera, A., Rodriguez, A. Catal. Today. 2002; 76; 209–220.

12. Qamar, M., Muneer, M., Bahnemann, D. Journal of Environmental Management. 2006; 80: 99–106.

13. Mahalakshmi, M., Arabindoo, B., Palanichamy, M., Murugesan, V. Journal of Hazardous Materials. 2007; 143; 240–245.

14. Muneer, M., Qamar, M., Saquib, M., Bahnemann, D. Chemosphere. 2005; 61: 457–468.

15. Bahnemann, W., Muneer, M., Haque, M.M. Catalysis Today. 2007; 124: 133-148.

16. Rahman, M.A., Qamar, M., Muneer, M., Bahnemenn, D. J. Adv. Oxid. Technol. 2006; 9(1): 103-109.

17. Vora, J.J., Chauhan, S.K., Parmar, K.C., Vasava, S.B., Sharma, S., Bhutadiya, L.S. E-Journal of Chemistry. 2009; 6(2): 531-536.

18. Haque, M.M., Muneer, M. Journal of Environmental Management. 2003; 69: 169–176.

19. Rahman, M., Muneer, M., Bahnemann, D. J. Adv. Oxid. Tech. 2003; 6(1): 100-107.

20. Tang, W. Z, An, H. Chemosphere. 1995; 31(9): 4157-4170.

21. Hermann, J.M Catalysis Today. 1995; 24(1-2): 157-164.

22. Guettai, .N; Ait Amar, H. Desalination. 2005; 185: 427–437.

23. Yu, J.C., Ho, W., Lin, J., Yip, H., Wong, P.K. Environ. Sci. Technol. 2003, 37: 2296-2302.

24. Zhu, X., Yuan, C., Bao, Y. Yang, J.Wu,Y. Journal of Molecular Catalysis Chemical. 2005; 229: 95-105.

25. Haque, M.M., Muneer, M. Bahnemann, D.W. Environ. Sci. Technol. 2006; 40: 4765-4770.

26. Singh, H.K., Saquib, M., Haque, M., Muneera, M., Bahnemann, D., J. Molecular Catalysis A: Chemical. 2007; 264: 66–72.

27. Saien, J., Khezrianjoo, S. Journal of Hazardous Materials. 2008; 157: 269–276.

28. Zhang, L., Yan, F., Su, M., Han, G., Kang, P. Russian Journal of Inorganic Chemistry. 2009; 54(8): 1210-1216.

29. Abdullah, M., Low, G., Mathews, R.W. Journal of Physical Chemistry. 1990; 94: 6820-6824.

30. Parent, Y., Blake, D., Magrini, B.K., Lyons, C., Turchi, A., Watt, E,, Praire, M. Solar Energy. 1996; 56: 429-437.

31. Selvam, K., Muruganandham, M., Muthuvel, I., Swaminathan, M. Chemical Engineering Journal. 2007; 128: 51-57.

32. Wu, R., Chena, C., Lu,C. Journal of Hazardous Materials. 2009; 162: 945-953.

33. Mahmoodi, N.M. Armani, M., Lymaee, N.Y., Gharanjig, K. Journal of Hazardous Materials. 2007; 145(1-2): 65-71.

34. Konstantinou, I.K., Albanis, T.A. Appl. Catal. B: Environ. 2003; 42(4): 319-335

35. Marinas, A., Guillard, C., Marinas, J.M., Fernandez-Alba., Aguera, A., Herrmann, J-M. Applied Catalysis B:Enviornmental. 2001; 34: 241-252.

36. Mathews, R. W. Water Research. 1986; 20(5): 569-578.

37. Shifu,C. Gengyu, C. Solar Energy. 2005: 79:1-9.

Cite this article: El Mouraille Nadia, Belmouden Moustapha, and Ait Ichou Yahia. UV/TiO2 PHOTOCATALYTIC OXIDATION OF

COMMERCIAL PESTICIDE IN AQUEOUS SOLUTION Am. J. innov. res. appl. sci. 2017; 5(4): 36-43.

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