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Basic Sciences & Humanities - Faculty Publicaations

Name of the Staff: PHONSY P D

Journal Name: Research Journal of Recent Sciences

Tittle of the Paper:

 

Enhancement of Semiconductor Mediated Photo catalytic Removal of Polyethylene Plastic Wastes from the Environment by Oxidizers.

 

Year of Publication: 2015

Abstract:

Plastics have become an essential ingredient of modern life with wide range of applications. At the same time the ‘white pollution’ caused by plastic wastes is a major environmental problem due to their recalcitrant nature. Even the simplest form of plastics, i.e., polyethylene is strong and highly durable and takes upto 1000 years for natural degradation in the environment. Current study reveals that  photocatalysis can be used successfully as an Advanced Oxidation Technique for the slow but steady degradation of polyethylene plastics (PEP). Semiconductors such as ZnO and TiO2 assist the photodegradation of PEP through the generation of highly reactive free radicals which interact with the pollutant. TiO2 is at least 20% more efficient than ZnO as a photocatalyst in this respect. The process is pH dependent and acidic condition favours the degradation. Oxidizing agents such as H2O2 and peroxydisulphate (PDS) accelerate the semiconductor catalyzed degradation. The enhancement depends on the concentration of the oxidizer and stabilises at an optimum range. Critical parameters for optimum efficiency for the degradation of PEP are identified and evaluated. A tentative mechanism for the degradation is also proposed based on the observations.

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Name of the Staff: PHONSY P D

Journal Name: Science & Technology Network

Tittle of the Paper:

 

          Semiconductor Mediated Photocatalytic Degradation of Plastics and Recalcitrant Organic Pollutants in Water: Effect of Additives and Fate of Insitu Formed H2O2.

 

Year of Publication: 2015.

 Abstract:

Contamination of water by chemical and bacterial pollutants as well as ‘white pollution’ caused by carelessly discarded waste plastics are major environmental problems. In the current study, the possibility of using semiconductor photocatalysis for the removal of last traces of organic water pollutants of different types is investigated. Semiconductors ZnO and TiO2 were characterized by standard techniques and evaluated as photocatalysts. The pollutants tested include low density polyethylene plastics (PEP), phenol, catechol and organophosphorous pesticides such as phosphamidon, monocrotophos and dichlorvos. Hydrogen peroxide (H2O2) and peroxydisulphate (PDS) enhance the TiO2 catalysed photomineralization rate. More than 10% of PEP could be irreversibly degraded in presence of UV-TiO2-PDS in 300 hr time. The degradation is pH dependent in all cases though no thumb rule can be applied. H2O2 formed insitu during the degradation undergoes parallel decomposition resulting in stabilization or oscillation in its concentration depending on the equilibration or domination of the formation/ decomposition process. Anions naturally present in water such as NO3-, Cl- and CO32- inhibit the degradation while SO42- enhances the same. However, this effect depends on a number of factors and no generalized conclusions are possible. The results and the probable mechanism for the degradation of the pollutants are discussed.

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Name of the Staff: P.D.Phonsy

Name of the Journal: Indian Journal of Applied Research

 Tittle of the journal: Pattern of the use and disposal of plastic products in a Typical village community in kerala state, india A case study.

Year of Publication: 2016

Abstract–

 The ‘white pollution’ caused by littering plastic waste is becoming severe environmental hazard in India by every passing day. However, not many systematic studies have been reported on the quantification of plastic waste. This gap is addressed in a small way in the current study by investigating the pattern and quantity of use as well as the mode of disposal of plastic waste in a small village community in central Kerala. The quantity of plastic waste thrown around by the entire cross section of the society, irrespective of income or education is alarming. The numbers will be fright­ening when extrapolated to the entire nation of around 1.30 billion people. 

 

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