Endang Tri Wahyuni

By Endang Tri Wahyuni and Roto Roto

This chapter deals with preparation and characterization of silver nanoparticles incorporated in titania or TiO2-AgNP in short and its performance study as a visible light responsive photocatalyst for bacterial inactivation and dye degradation. The preparation of TiO2-AgNP performed by several methods including sol-gel, impregnation, precipitation, and photocatalytic deposition is described. Characterizations by XRD, XPS, FTIR, DRUV, and SEM/TEM machines to confirm the formation of the metallic silver nanoparticle, as well as the shape and size, and to follow the interaction between Ag atoms and other atoms in the crystal lattice of TiO2, are presented. Further, the antibacterial performance and dye degradation activity of TiO2-AgNP, both under UV and visible light, are described.

Part of the book: Titanium Dioxide

By Endang Tri Wahyuni and Nurul Hidayat Aprilita

This chapter presents the study of TiO2 photocatalyst for the photoreduction of several reducible chemicals. The photocatalytic reduction of several toxic metal ions, including Ag(I), Cu(II), Cr(VI), Hg(II), and U(VI) in the presence of TiO2, in order to decrease their toxicity, is described. Photodeposition of the noble metals, such as Ag(I), Au(III), Pt(IV), and Pd(II) for doping purposes by photocatalytic reduction over TiO2, is also addressed. Conversion of the greenhouse gas of CO2 into useful hydrocarbons and methanol by photocatalytic reduction using TiO2 photocatalyst is highlighted. Several operating parameters in photoreduction processes that are photocatalyst dose, time of the irradiation, pH of the solution, and the initial concentration of the substrates (the reducible chemicals) are also reviewed.

Part of the book: Photocatalysts

By Endang Tri Wahyuni

In this chapter, surfactants as cleansing agent in detergent used in laundry, are described. The negative effects of the laundry wastewater on the environment and human health are highlighted. Several methods examined for laundry wastewater treatment are also illustrated. Among the treatment methods, photo-process in the presence of TiO2 photocatalyst and Fenton reagents are described in more detail. Furthermore, the factors influencing the effectiveness of photo-process including reagent dose, reaction time, and pH are discussed. Additionally, modifications of the photo-process to improve its performance that is associated with effectiveness and operational cost are also demonstrated. The photo-methods discussed in this chapter offered low-cost due to simplicity and effective technique for treating the laundry wastewater.

Part of the book: Promising Techniques for Wastewater Treatment and Water Quality Assessment

By Endang Tri Wahyuni and Eko Sri Kunarti

This chapter deals with chemical analysis and pollutant removal methods that follow some of the 12 principles of Green Chemistry. In this chapter, the 12 principles of the Green Chemistry along with the short description are highlighted. Several chemical analysis methods are presented, that are both used for chemical identification and concentration determination, whether conventionally or instrumentally. The conventional chemical analysis methods evaluated in this chapter include volumetric and gravimetric, while the instrumental ones presented are limited to atomic absorption spectrometry (AAS) and X-ray fluorescence (XRF) for determination of the analyte concentration, and Infrared spectrometry (IR) and X-ray diffraction (XRD) for chemical identification. Additionally, the pollutant removal methods involving conventional and advanced processes, are reviewed. The conventional chemical removal methods such as precipitation, coagulation, and adsorption are illustrated. The advanced methods in removing chemical pollutants discussed in this chapter are photocatalytic degradation, photo-oxidation/reduction, Fenton and Photo-Fenton, and ozonation. In the description of the chemical analysis and the chemical pollutant removal methods, the evaluation of the unsuitableness or suitableness toward some of the Green Chemistry principles are also accompanied. In addition, the ways to make the less green methods to be greener are also proposed.

Part of the book: Green Chemistry