This book begins with an investigation on the range of macrofauna and meiofauna species with potential for use as indicators of the benthic conditions throughout the eutrophic Kingston Harbour, presented in Chapter One. Chapter Two evaluates the percentage of a fish skin dye effluent rejection by means of polyethersulfone, polysulfone and Na Cl blends, made with okara (BOK), corn straw (BCO) and without presence of biomass (BP). Chapter Three compares the photodegradation of Reactive Blue 198 (RB198) and Reactive Blue 250 (RB250) dyes and evaluates the effect of the dyes’ chemical structure and catalyst concentration in the photocatalytic process. Chapter Four covers the degradation of fish skins tanning process wastewater using Zn O supported on Na Y and Na A zeolites. In Chapter Five, the authors evaluate the p H effect and the direct electrical current on COD reduction in treatment of the galvanic industry effluent applying the electrocoagulation. In Chapter Six, the authors performed the electrocoagulation process for water treatment, comparing the efficiency of the results with the addition of an organic coagulant (Tanfloc SG). Finally, Chapter Seven covers a study on the use of natural coagulant Moringa oleifera extracted in saline sodium chloride (KCl 1M) in the process of coagulation/flocculation/sedimentation for water treatment.