An-Najah Staff

In our search for safe and economical techniques to eliminate pharmaceutical wastes, in water, this work has been conducted. Solar energy can be used in degrading these compounds in the presence of suitable photo-catalysts. TiO2 and ZnO were examined as photo-catalysts in degradation of pharmaceutical waste of a well-known compound, namely paracetamol. Both catalysts were used, each in different phase commercial (micro-sized particles) and synthetic (nano-sized particles). Commercial and prepared catalyst powders, of TiO2 and ZnO, were characterized by XRD, SEM, photoluminescence and electronic absorption spectra before being used as photocatalysts. The commercial phase catalysts were studied using UV light, while prepared catalyst phases were used under direct solar light. On the other hand, both catalyst systems (commercial and synthetic) were supported on activated carbon surface. The photodegradation reaction of paracetamol was investigated under different reaction conditions, such as contaminant concentration, catalyst concentration and pH. Under neutral conditions, the commercial TiO2 (both anatase and rutile) slowly catalyzed the photo-degradation of paracetamol under the used UV lamp radiation. Under direct sun light, the commercial anatase TiO2 showed higher efficiency than the synthetic TiO2. Rutile TiO2 showed efficiency with UV only under higher pH values. Different kinetic parameters were studied. The commercial ZnO showed sound efficiency under UV light and direct sun light. Under direct solar light, synthetic ZnO showed lower efficiency than the commercial ZnO system. Effects of different reaction conditions onto commercial ZnO catalyst were studied. Depending on reaction conditions, the commercial TiO2 in anatase form was mainly more efficient than the commercial ZnO in paracetamol photodegradation under UV. Under direct solar light, the commercial ZnO was more efficient than commercial TiO2 in anatase form. Under direct solar light, synthetic ZnO showed more efficiency than synthetic TiO2. Supporting commercial TiO2 onto activated carbon surfaces enhanced its catalytic activity under UV. The supported anatase phase showed higher efficiency than the rutile counterpart. Supporting synthetic TiO2 onto activated carbon surfaces also enhanced its catalytic activity under direct solar light. The supported synthetic TiO2 was more effective than supported commercial TiO2 under direct solar light. Supporting commercial ZnO increased its efficiency under UV radiation, whereas supporting synthetic ZnO increased the efficiency under direct solar light. The supported commercial ZnO was more efficient than the supported commercial anatase TiO2 under UV. The supported commercial anatase TiO2 and the supported commercial ZnO catalyst systems showed different behaviors when paracetamol concentration and pH were varied. The supported synthetic ZnO was more effective than the supported synthetic TiO2 under direct sun light. The study shows that supporting TiO2 and ZnO systems has the advantage of increasing their catalytic efficiencies, and making their separation easier.