عنوان البحث(Papers / Research Title)
Photocatalytic Killing of Staphylococcus Aureaus Bacteria by Using Naked and Coupled TiO2 in Aqueous Solution.
الناشر \ المحرر \ الكاتب (Author / Editor / Publisher)
فاطمة الزهراء جبار جاسم عبد حسن
Citation Information
فاطمة,الزهراء,جبار,جاسم,عبد,حسن ,Photocatalytic Killing of Staphylococcus Aureaus Bacteria by Using Naked and Coupled TiO2 in Aqueous Solution. , Time 6/20/2011 8:49:30 AM : كلية الصيدلة
وصف الابستركت (Abstract)
Titanium dioxide (TiO2) used as photocatalyst to sterilize an aqueous solution containing staphylococcus
الوصف الكامل (Full Abstract)
Photocatalytic Killing of Staphylococcus Aureaus Bacteria by Using Naked and Coupled TiO2 in Aqueous Solution.
Fatima Al-Zahra,a G.GassimCollege of Science for GirlsBabylon University
Abstract:-
Titanium dioxide (TiO2) used as photocatalyst to sterilize an aqueous solution containing staphylococcus aureus bacteria under near UV-visible irradiation source in presence of oxygen. This research aimed to purify and disinfect water from S.aureus bacteria by using naked and coupled TiO2 instead of using disinfectants that are used extensively in hospitals and other health care setting.
Primary experiments has been carried out to determined the optimum conditions which give high killing efficiency of S.aureus bacteria in aqueous solution. Survival ratio and rate constant of photocatalytic S.aureus photokilling were also determined under optimum conditions. These results indicate that 0.33 mg/ml TiO2 concentration for photocatalytic S.aureus photokilling process.
The results also indicate that the rate of photocatalytic killing was increased when TiO2 was coupled with cadmium sulphate (CdS) instead of naked TiO2 as photocatalyst, while the kinetic studies of this system reveal that the highest killing efficiency of S.aureus in aqueous solution was obtained in presence of CdS as photocatalyst. According to the experimental results the general photocatalytic reaction mechanism for this bacteria was suggested.
Introduction:-
Disinfectants are antimicrobial agents that are used in health care setting for a variety of topical and hard surface applications(1). Compared to the widely used disinfectants applications of photocatalyst based untimicrobial disinfectant technologies are still in developmental stage(2).
Wast water from hospital ,food factories and contaminated sites. sometimes , virus and organic compound must be sterilized .One of the typical sterilization by illumination of UV light with the wave length of 254nm(3),which provides a high rate of sterilization at room temperature. Alternately, it is well known that the TiO2 in anatase form is capable of oxidizing and decomposing various kinds compound(4).
TiO2 is stable to photocorrosion and nontoxic and inexpensive. The band gap energy of TiO2 is 3.2 ev and therefore absorbs in near UV- light ((?<387 nm.)(5).Other semiconductors piratical such as CdS has band gap energy about 2.5 ev(6)and absorbs larger fractions of the solar spectrum than TiO2 (about 496nm)but CdS does not reveal good results in water detoxification process.This is because CdS under go rapid photocorrosion.
Coupled TiO2/CdS semiconductors have more stability than CdS and absorbs larger wave length than naked TiO2(7) .Coupled TiO2/CdS semiconductors can be explained according to the following scheme.
تحميل الملف المرفق Download Attached File
|
|