This book will be a guiding path to understand the photocatalytic process and mechanism for the deterioration of heavy metals, persistent organic pollutants and pathogens from wastewater. Environmental remediation is of crucial importance in the context of human sustainability in the present and future times. The unplanned anthropogenic activities and revolutionary industrialization end up in environmental contamination with noxious organic-inorganic and biogenic pollutants. The photocatalytic disinfection and detoxification is the only solution to preserve and restore the ecological balance. The main emphasis is to explore and enhance the photocatalytic potentials of solar active-materials.