Due to the importance of the H2O scheme, it was considered the issue of H2O security and the importance of preserve H2O resources are a large instance in human life, has besides became an pressing demand to back up a planetary stableness at all degrees of scientific and environmental and economic and societal development. It has been estimated the universe ‘s H2O demand will transcend supply by 56 % in 2025 ( WWO, 2007 ) .

Desalination is one of human race earliest signifiers of H2O intervention, and it is still a popular intervention solution throughout the universe today. Most desalinization workss presently are used the regular energy resource such as oil and natural gas which are dearly-won and exhaustible, It has been estimated that the production of 1000 m3 per twenty-four hours of fresh water requires 10,000 dozenss of oil per twelvemonth ( Kalogirou, 2005 ) , hence the scientists began to develop the researches of other beginnings of renewable energy like solar energy in the last three decennaries. Some states really began to utilize this engineering to bring forth electricity at distant countries. After that they concerned about H2O desalinization with solar energy, they reconsider about solar still which foremost appeared on modern epoch extends back to the early 1950s when simple solar stills were studied for remote desert and coastal communities. However, due to the H2O pumps are non dearly-won and the energy monetary value was low in the twentieth century, solar stills were non a good solution for the H2O desalinization to the society.

Solar still is composed of basin which is painted in dark colour to absorb more solar energy. The saline H2O is placed on the basin and the top of the basin is opened and covered by glass or translucent plastic which is placed in the diagonal place about 10o i?? 50o.The underside has holes to come in the saline H2O and issue the salts remainder. Its map is similar to rainfall, the basin is heated with solar radiation, and so the saline H2O that contacts with the basin is evaporated up to the glass screen and so is condensed, due to the low temperature of the screen. Due to the glass screen is titled in specific angle, the desalinated H2O flows down to be collected by the vas.

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Fig.1. Solar still procedure

The solar desalinization system divided into two groups which are inactive distillment and active solar still. The inactive solar still depends its energy merely on Sun, in other manus the active solar still, excess thermic energy is given to the inactive solar still for faster vaporization. The types of solar still can be summarized in the undermentioned table1:

Table 1 Types of solar still

However, the rate of production of the solar stills is low comparing to other methods of desalinization procedure, because of this the scientists worked on several surveies toincrease the rate of production of the solar still. One of these surveies is utilizing photocatalysts for solar stills.

Semiconductors have been utilizes as exposure accelerators for illustration TiO2, ZnO, Fe2O3, CuO, etc. The basic procedure of photocatalytsis is the exposure catalysts cuprous oxide will make a brace of negatrons and holes, when it absorbs UV radiation from the Sun. The negatron of the valency set of the cuprous oxide will go aroused when exposed to sun visible radiation. The negative negatron ( e- ) and the positive hole ( h+ ) will be created, when the extra energy of the aroused negatron promoted the negatron to the conductivity set of the cuprous oxide.

CuO + hv? e- + h+

Then the H2O molecules will be broken by the positive hole of the cuprous oxide to organize H+ and hydroxyl extremist ( .OH ) .

H2O + h+ ? H+ +i??OH

Then the undermentioned reactions occur:

O2 + e- ? O2-

O2- + H+ ? i??HO2

i??HO2 + e- ? H2O2

H2O2 + 2 H+ + e- ? HO2

Fig.2. Mechanism of photocatalyst

Chapter 2

2. Literature reappraisal

There are a batch of surveies have been worked on solar still to better its public presentation such as its designs and its parametric quantities ( wind speed, ambient temperature, screen incline, angle, feed H2O temperature, solar strength and other consequence ) . The surveies can be summarized with the undermentioned fact:

1- Inclination and the way of the screen that used to roll up the condensate H2O so to be collected in the vas, if the disposition is low, so the condensate H2O may falls down to the basin or if the disposition is high, the solar radiation strength possibly low ( Singw et al.,1995 ) . The disposition and the way of the screen depend on the location and latitude, so assorted research workers studied about the disposition of a screen home base and the latitude. This can be summarized in the tabular array 1.

Table 2. Surveies of the optimal angle at different location

Researcher Tested angles Optimum angle Location and latitude

Baibutaev

and

Achilov ( 1970 ) 30o and 40o 30o Bukhara-Uzbekistan,

39.47oN

Garg and

Mann ( 1976 ) 10o, 20o and 30o 10o Tamil nadus 13.06oN, Jodhpur

26.3oN-India

Al-Jubouri

and

Khalifa ( 1982 ) 5o, 15o, 20o and 25o 25o Baghdad-Iraq, 33.3oN

Akash et Al. ( 2000 ) 15i??55o measure 10o 35o Amman-Jordan, 31.57oN

Al-Hinai et Al. ( 2002 ) 5i??40o measure 5o 23o Muscat-Oman, 23.36oN

Abd Elkader ( 1998 ) 30o, 35o and 40o 30i??35o Port Said-Egypt, 31.17oN

Kumar et Al. ( 2000 ) 5i??30o measure 5o 15o New Delhi-India, 28.36oN

Meukam

et Al. ( 2004 ) 13i??17.5o measure 1.5o 16o Cameron, 5oN

Omri et Al. ( 2005 ) 25o and 35o 35o Tunisia, 34.0oN

Bahadori and

Edlin ( 1973 ) 1.5o, 3o, 6o and 10o 1.5o Arizona-USA, 34.0oN

Khalifa and

Hammod ( 2009 ) 5i??45o measure 10o 35o Baghdad-Iraq, 33.3oN

Dev and

Tiwari ( 2009 ) 15o, 30o and 45o 45o

New Delhi-India, 28.36oN

Aybar and

Assefi ( 2009 ) 5i??85o measure 10o 35o North Cyprus-35oN

2- Glass is the preferable stuff for screen, because it has higher solar transmission for different angle and it has long life. The surface moistures with condensed H2O and let movie condensation at the underside surface which consequences in less loss in transmission. The other inexpensive transparent plastic stuffs do non make the above required qualities ( Malik et al. , 1982 ) .

3- The solar conduction depends on the thickness of the screen home base, so Ghoneyem ( 1997 ) noticed that the glass screen of the solar still with 3 millimeters can bring forth H2O 17 % more than the glass screen with 6 millimeters.

4- When the screen temperature is diminishing, the productiveness is increasing, because the temperature difference between the screen and the basin additions, due to the heat transportation of vaporization and convection addition between basin and the glass. The speed of air current is impacting the screen temperature. At higher air current speed the convective heat transportation from the screen to atmosphere additions, due to increase in convective heat transportation coefficient between screen and atmosphere. This consequence increases the condensation and vaporization rate and productiveness of the still ( El-Sebaii, 2000 ) .

5- Cooper ( 1969 ) observed that when the deepness of H2O is low the productiveness additions, because it will decreases sum of basin heat capacity, so it will increase the H2O temperature.

6- Around 12 % of radiation received by the still basin is reflected back without utilizing it, this loss can be minimized, if the soaking up coefficient of the still basin and H2O is increased ( Malik et al. , 1982 ) . Rajvanshi ( 1981 ) reported that when the black dye is added to the H2O, the rat of vaporization additions, so the productiveness increases, due to the basin radiation soaking up additions.

7- Some black stuffs can hive away more sum of heat energy and increase the heat capacity of the basin in add-on to increasing the basin soaking up ( Nafey et al. , 2001 ) . Abdel-Rehima and Lasheen ( 2002 ) tested the black gum elastic and crushed rock for hive awaying the heat energy, they found that the black gum elastic can increase the productiveness about 20 % and the crushed rock about 19 % .

8- Nafey et Al. ( 2000 ) reported that solar still with black aluminium painted home base additions the productiveness about 17 % for 4 centimeter of H2O bed and about 39 % for 6.5 cm H2O bed. However, El-sebaii et Al. ( 2000 ) found that mica home base as suspended absorbers can increases the productiveness about 43 % .

Sing to photocatalyst, ( Cermanati,1997 ) proposed about mechanism of photocatalyst in H2O purification by usage quinoline, photofenton generate OH groups and superoxide dismutase. Guillard et Al. ( 2003 ) conducted an experiment to look into about utilizing Ti dioxide as photocatalyst for chlorophenol, yearss and pesticides. Dillert et Al. ( 1999 ) used photocatalyst for effluent intervention. Herrmann et Al. ( 1998 ) noticed that Ti dioxide as photocatalyst can take toxic stuff from H2O. Suresh et Al. ( 2005 ) conducted an experiment about solar still by utilizing different photocatalysts ( Mno2, and PbO2 ) . They found that the production rate of the desalinated H2O by utilizing different photocatalyts increased the entire sum of desalinated H2O about double comparing entire sum of desalinated H2O without photocatlayts and besides found the H2O quality can be improved.

Chapter 3

3.1 Materials

Photocatalaysts.

CuO Fe2O3 ZnO

-Glass screen 3mm thickness.

Two aluminium trays ( 421*282*70 )

Pipe.

Adhesive materials.

Waterproof hardboard 18 millimeter.

Car reflector

PVA binder

Chapter 4

4.1 Fabrication of solar still ( see figures 3, 4 & A ; 5 )

1- Glass screen ( 760*600 ) millimeter and 3 millimeter thickness was used to let the Sun beam to come inside the solar still. The disposition of the glass screen is 23i?? which is optimal disposition fixed to the perpendicular wall of the solar still. The way of the glass screen is south to acquire maximal radiation.

2- The organic structure of the solar still is 18 mm thickness of rainproof chipboard to cut down the heat loss from the underside every bit good as from the side of the still. The perpendicular wall is 710 millimeter.

3- The white pigment was used to paint the perpendicular walls and the side walls for reflecting the incident radiation.

4- The supply which is used to roll up the condensed H2O inside the solar still was fixed at the lower terminal of the glass screen. The pipe 1 metre length was fixed on the supply and base on balls through the hole so to the vas.

5- The aluminium tray entryway ( 600*200 ) millimeter was made.

6- The adhesive was used to cover the spreads to salvage maximal heat inside the solar still.

Fig.3. Design of solar still

Fig.4. Solar still in front side

Fig.5. Solar still in back side

4.2 Calculation of desalinated H2O ( without photocatalyst )

1- Amount of sea H2O was placed on the two aluminium trays ( without exposure accelerator ) . One twenty-four hours for 3 litres ( 1.5 litres each tray, 11 millimeter ) and the following twenty-four hours for 6 litres ( 3.0 litres each tray, 23 millimeter ) for 10 yearss.

2- Amount of desalinated H2O and temperature were noted hourly from 8 a.m. to 8 p.m.

3- The First experiment started on 30/3 and continued to 10 yearss the maximal temperature was 39, the upper limit desalinated H2O for 3000ml was 499 milliliter and 421ml for 6000 milliliter as shown in following graphs and tabular arraies:

A ) Table 3. Input signal 3000 milliliter of sea H2O

B ) Table 4. Input 6000ml of sea H2O

Graph 1. Production rate of desalinated H2O at different deepnesss

4.3 computation of desalinated H2O utilizing different reflector

The auto reflector was added alternatively of white colour for contemplation to prove if the sum of desalinated H2O could be increased, the consequence was the entire desalinated H2O increased approximately 20 % as shown in the tabular arraies and graphs.

Fig. 6. Solar still with auto reflector

A ) Table 5. Input signal 3000 milliliter of sea H2O

B ) Table 6. Input signal 6000 milliliter of sea H2O

Time A.Temp

( Ci?? ) Desalinted H2O ( milliliter ) Production rate

( ml/hr )

8 34 0 0

9 36 2 2

10 39 12 10

11 40 37 25

12 41 109 72

13 40 203 94

14 39 317 114

15 39 424 107

16 38 489 65

17 36 529 40

18 34 574 18

19 30 552 5

20 28 552 0

Graph. 2.

Graph. 3. Production rate of desalinated H2O with different reflctors

4.4 Calculation of desalinated H2O ( with photocatalyst )

Each two G.I home bases ( 421*282 ) were coated with one photocatalyts ( ZnO, CuO, Fe2O3 ) by utilizing PVA binder and they were palced on the aluminium trays as shown in the ( figures 7, 8 & A ; 9 ) .

Sum of sea H2O was placed on the two aluminium trays ( with exposure accelerator ) . The experiments were as followers:

Two yearss for G.I home bases ( on the aluminium trays ) which were coated with ZnO 2.6 litre ( 1300 milliliter each tray. 11 mm deepness )

Two yearss for G.I home bases coated with CuO 2.6 litre ( 1300 milliliter each tray. 11 mm deepness )

Two yearss for G.I home bases coated with Fe2O3 2.6 litre ( 1300 milliliter each tray. 11 mm deepness )

One twenty-four hours for trays which do non incorporate G.I plates that coated with photocatalyst 3 litres ( 1500 milliliter each tray,11 mm deepness ) .

The experiments took 8 yearss in sequence to compare if the exposure accelerators could increase the entire sum of desalinated H2O

The consequence was Fe2O3 and CuO increased sum desalinated H2O, nevertheless ZnO alternatively of increasing the entire sum of desalinated, it decreased it comparing with entire sum of desalinated H2O without photocatalyst as shown graph 4 and tabular arraies ( 7, 8, 9 & A ; 10 ) .

Fig. 7. Fe2O3 Fig. 8. CuO

Fig. 9. ZnO

Table 7. Input signal 3000 milliliter ( 11mm deepness ) of sea H2O without photocatalyst

Time A.Temp ( Ci?? ) Desalinted H2O ( milliliter ) Production rate ( ml/hr )

8 33 0 0

9 34 5 5

10 35 26 21

11 38 60 34

12 39 153 93

13 40 258 105

14 39 385 127

15 39 497 112

16 38 568 71

17 37 617 49

18 34 639 22

19 31 644 5

20 29 644 0

Table 8. Input signal 2600 milliliter ( 11mm deepness ) of sea H2O with photocatalyst ( ZnO )

Time A.Temp ( Ci?? ) Desalinted H2O ( milliliter ) Production rate ( ml/hr )

8 33 0 0

9 35 4 4

10 37 16 12

11 38 47 31

12 39 90 43

13 40 158 68

14 39 237 79

15 38 308 71

16 36 361 53

17 33 399 38

18 31 420 21

19 30 427 7

20 29 427 0

Table 9. Input signal 2600 milliliter ( 11mm deepness ) of sea H2O with photocatalyst ( CuO )

Time A.Temp ( Ci?? ) Desalinted H2O ( milliliter ) Production rate ( ml/hr )

8 34 0 0

9 35 7 7

10 37 28 21

11 38 71 43

12 39 195 124

13 40 336 141

14 39 495 159

15 38 634 139

16 35 701 67

17 32 742 41

18 31 762 20

19 30 770 8

20 29 770 0

Table 10. Input signal 2600 milliliter ( 11mm deepness ) of sea H2O with photocatalyst ( Fe2O3 )

Time A.Temp ( Ci?? ) Desalinted H2O ( milliliter ) Production rate ( ml/hr )

8 33 0 0

9 35 7 7

10 37 30 23

11 38 82 52

12 39 225 143

13 40 391 166

14 39 572 181

15 38 726 154

16 36 795 69

17 33 834 39

18 31 855 21

19 30 862 7

20 29 862 0

Graph. 4. Production rate of desalinated H2O ( with & A ; without photocatralyst )

4.5 comparing the quality of desalinated H2O with and without photocatalyst

Parameters Unit Raw stuff Desalinated H2O without photocatalyst Desalinated H2O with utilizing photocatalyst

CuO Fe2O3 ZnO

pH 8 5.63 6.3 6.8 5.7

Conductivity us/cm 58300 326 160 123 321

TDS Us/cm 39253 163 107 82.2 215

Entire Alkalinity ppm 162 34 18 21 27

Entire Hardness ppm 6780 28 12 10 32

Calcium Hardness ppm 1210 8 4 3 10

Chloride ppm 21276 78 64 60 60

Magnesium ppm 1336.8 4.8 3.2 3.3 3.2

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