Advanced photo catalytic techniques to treat waste water

1. ADVANCED PHOTOCATALYTICADVANCED PHOTOCATALYTIC
OXIDATION OF WASTE WATEROXIDATION OF WASTE WATER
MOTILAL NEHRU NATIONAL INSTITUTE OF
TECHNOLOGY
Submitted by : Submitted to:
Nidhi Srivastava Dr. Sushil Kumar
Diksha Bhardwaj
Navolina Potter
Yashvi Sharma
Shweta Shah

2. IINTRODUCTIONNTRODUCTION
 Advanced photocatalytic oxidation is a new innovative
advanced wastewater treatment technology.
 Highly effective and environmental friendly technology.
 It is used in the treatment of effluent of industry which is a
mixture suspended, dissolved organic and inorganic
pollutants.
 By using the APOP-concept a non-hazardous effluent from
wastewater treatment plant can be achieved.

3. Continued…Continued…
 AOP treatment methods are used globally, mainly in order to remove
small amounts of health hazardous pollutants, some of which are even
toxic for municipal treatment plants (e.g. hormone disruptors, pesticides,
etc.) and thus need to be treated using other methods before they are
released into municipal waters. This method is also useful for the pre‐
treatment of certain types of polluted waters where complex molecules
are broken up into smaller and less hazardous ones, making water more
biologically degradable
 Advanced oxidation processes are being used for the treatment of
industrial wastewater more often than ever.

4.  Waste from industry:Waste from industry:
Levels of wastewater treatmentLevels of wastewater treatment

5. CHARACTERISTICS:CHARACTERISTICS:
 Simple system for disinfection of wastewater.
 Simple system for removal of endocrine
disruptors and other hazardous compounds.
 Flexible system.
 Easily installation.
 Advanced process control technology.

6. APPLICATIONSAPPLICATIONS
 Textile wastewater,
 Food industry wastewater,
 Pharmaceutical wastewater,
 Ballast water (disinfection environmental
requirements),
 Closed loop water (microorganism removal‐
cooling water conditioning).

7. Existing AOP technologiesExisting AOP technologies
 TiO2 photo catalysis,
 Ozonisation
 UV disinfection
 UV wastewater treatment,
 The application of hydrogen peroxide
(H2O2),
 Fenton/Photo Fenton reaction‐
and various combinations of the above methods can
be used.

8. PPHOTOCATALYTICHOTOCATALYTIC RREACTORSEACTORS
Reactor during
experiment in
laboratory

9. How photocatalytic degradation
(PCD) occur…???…???
 The APOP-system is able to eliminate pathogenic
microorganisms and endocrine disruptors from
wastewater.
 The principle in the system is that light from ultraviolet
lamps is able to destroy mechanisms inside bacteria and
remove chemical substances from wastewater with use of
oxidants, e.g. ozone, chloride or titanium dioxide.
 The particles of catalyst(titanium dioxide nano particles) is
suspended in polluted water, in contrast to some products,
in which the catalyst layer is applied on solid carriers in
order to increase the specific surface of the active material
in comparison to suspended particles.

10. How OHHow OHoo
mineralize the pollutant ?mineralize the pollutant ?
OHCOOH 22pollutant +→+°

11. Photocatalytic degradation (PCD)Photocatalytic degradation (PCD)

12. TiO2 photo catalysisTiO2 photo catalysis
 Photocatalysis with titanium dioxide is an AOP wastewater
treatment method.
 It requires a UV light source for its functioning. In addition to
the strength of the UV light source
 It is relatively cheap and abundant. It is non-toxic, insoluble in
water and resistant to most chemicals, such as acids, bases or
solvents.

13. OZONATIONOZONATION
 Ozone is a very strong oxidant and viruscide, therefore it is
used for disinfection of wastewater.
 Mechanisms of disinfection using ozone include:
 Direct oxidation/destruction of the cell wall with leakage of cellular
constituents outside of the cell.
 Reactions with radical by-products of ozone decomposition.
 Damage to the constituents of the nucleic acids (purines and
pyrimidines).
 Ozone decomposes in water, the free radicals hydrogen
peroxy (HO2 ) and hydroxyl (OH) that are formed, have great
oxidizing capacity and play an active role in the disinfection
process. It is generally believed that the bacteria are destroyed
because of protoplasmic oxidation.

14. Some reaction for photo-catalysis by
ozone and hydrogen peroxide
OHCOOH 22pollutant +→+°
°
°
°
→
+→+
+→+
OHOH
OOHOOH
OOHOOH
uv
uv
2
2
32
22
232
2322
OXIDANT

15. Photo-Fenton Reactions
 The best known process for UV-degradation in which metal ions are used as
catalyst is photo-fenton reaction process.
 During the process hydroxyl radicals are generated via photo reduction of the
metal ions and initiate the degradation process described. In addition, many other
reactions play a part in this process, also resulting in the degradation of organic
water ingredients.
 By means of an intra-complex charge-transfer-reaction shown above,
photoreactions become very effective when well applied.
 Many reactions which are happening in parallel or in sequences play important
roles in the photo-Fenton reaction, as they also lead to the oxidation of the
target(s). The photo-Fenton reaction shows many advantages in comparison with
the classical Fenton reaction:
 - Degradation in the photo-Fenton reaction is many times higher, as the classical
Fenton reactions become self-locking through the increasing sludge volume.
 - Operational cost of the photo-Fenton process are significantly lower, as the
chemical consumptions are lower
 -The photo-Fenton process leads to negligible formation of sludge, whilst the
classical Fenton entails a wearisome and costly removal of the sludge

16. MECHANISIMMECHANISIM

17. UV- DisinfectionUV- Disinfection
 Ultraviolet (UV) rays are part of the light that comes from the sun. The
UV spectrum is higher in frequency than visible light and lower than x-
rays.
 As a water treatment technique, UV is known to be an effective
disinfectant due to its strong germicidal (inactivating) ability. UV disinfects
water containing bacteria and viruses and can be effective against
protozoans like, Giardia lamblia cysts or Cryptosporidium oocysts
 UV has been used commercially for many years in the pharmaceutical,
cosmetic, beverage, and electronics industries, especially in Europe.
 Its major drawbacks were high operating costs, unreliable equipment, and
the expanding popularity of disinfection by chlorination.
 Because of safety issues associated with the reliance of chlorination and
improvement in the UV technology, UV has experienced increased
acceptance in both municipal and household.

18. AOP WASTEWATERTREATMENTAOP WASTEWATERTREATMENT
PLANTPLANT..
 The APOP-system can be implemented on any scale.
 The first APOP-system was installed at Usserød
Wastewater Treatment Plant (Denmark). Usserød WTP
has a capacity of 50,000 person equivalents.
 The APOP-system at Usserød WTP consist of two
channels with three racks in each. 16 ultraviolet high
pressure lamps (APOP-lamps) is installed in every racks.
 Usserød WTP is installed with dispersing system with
the availability of using different oxidants for removal of
hazardous compounds in the wastewater.

19. APOP-system installed at Usserød WTPAPOP-system installed at Usserød WTP
The system has a hydraulic capacity of 700 m3/h

21. Dose response curve for disinfectionDose response curve for disinfection

22. DRAWBACKSDRAWBACKS
 Among all of the advantages of wastewater treatment
using titanium dioxide nano-particles, the main issue is
removing them from water once the treatment process
is concluded. In order to achieve the maximum efficiency
of the material , the particles need to be suspended in
polluted water, in contrast to some products, in which
the catalyst layer is applied on solid carriers (smaller
specific surface of the active material in comparison to
suspended particles.
 Ultrafine TiO2 is characterized by non selective removal‐
of a wide range of pollutants.

23. Figure: Photocatalytic degradation of SFigure: Photocatalytic degradation of S22OO33 and correspondingand corresponding
formation of SOformation of SO44
Time (min)
0 20 40 60 80 100 120 140 160 180 200
S2
O3
,SO4
(mg/l)
0
20
40
60
80
100
120
Degradation of S2O3 100 mg/l [pH 7]
Formation of SO4 [pH 7]

24. Thank youThank you