preview

photo catalytic degradation review

Satisfactory Essays
INTRODUCTION
In Post-industrial era majority of the water bodies (surface water, ground water and river bodies) and industrial water .Most of them are toxic endocrine disrupting, causing genetic defects or causes cancer to humans, animals and aquatic life in general.

There are various ways for the treatment of wastewater, which are categorized as Physical which includes treatment by screening, sedimentation, floatation and filtration of the contaminants present in the water; The chemical method which comprises of precipitation, coagulation, carbon filtering and disinfection. The most widely used technique is a combination of physical and chemical processes which include activated carbon adsorption, multiple oxidation and reduction reactions, and ion exchange and membrane processes. One such emerging phsio-chemical technique is the Advanced Oxidation Processes or the (AOP’s).

Advanced Oxidation Processes (AOPs) have been proposed in recent years as an attractive alternative for the treatment of contaminated ground, surface, and wastewater containing pesticides or organic effluents. The most commonly used AOPs utilized H2O2, O3 or O2 as the oxidant. Among AOPs, the combined systems UV/TiO2/H2O2 and UV/Fe3C/H2O2 are considered as the most promising for the remediation of contaminated waters. A wide range of applications has been reported for different compounds using these systems.

The advantage of AOP is that they provide many ways for the production of intermediate transitory radicals & thus increases the flexibility for specific chemical treatments. AOPs are classified according to the reactive phase (homogeneous and heterogeneous) or by formation of transient radical methods (chemical, electro-chemical, sono-chemical and phot...

... middle of paper ...

... recovery of the Catalyst should be simple and it could be reused effectively for more no of time.
• The pollutant should be degraded efficiently.

These catalysts like behave like a single electron characteristics in the outer orbital have lesser bandwidth than TiO2, some of which are tabulated below.

Other Catalyst Band Gap
NaBiO3 2.14579 eV
BioI 1.8 eV
BiOBr 2.31
Bi3O4Br 2.17 eV
TiO2 doped with 0.5 wt.% of Sm3+ 2.80 eV
Chitosan (bio polymer) embedded with TiO2 & Pd 2.60 eV

Certain zinc oxides have also shown promising photocatalytic effect but it has been shown that the end products which have been degraded are highly toxic.
However a vast number of these photo catalysts have shown satisfying degradation effect in the visible region, a detailed description of which is tabulated below.

2.2.1 Al2O3-supported Fe(III)-5-sulfosalicylic acid (ssal) catalyst
Get Access