This monograph contains seven chapters that each detail a recent advancement in environmental research. Chapter One summarises the reactivity, mechanism and toxicity assessment of pesticides and pharmaceuticals by chlorine dioxide. Chapter Two presents a review of liquid fertiliser generation technologies. Chapter Three analyses the consequences of digital transformation technologies on the environmental sustainability of Brazilian agribusiness. Chapter Four presents results on mineralogical, chemical, and physiochemical characterisation of coal briquette ash. Chapter Five describes the potential of ecological sanitation as an innovative, environmentally sound technology for minimising waste and providing renewable energy. Chapter Six presents up-to-date information on commonly used pesticides and their possible immunotoxic effects. Finally, Chapter Seven provides information about toxic heavy metals, their toxicity mechanism, and their effects on the environment.