The growths in worldwide population—of up to 8.5 billion people by 2030—and agriculture have put great pressure on water resources, above all in arid and drought-prone areas. Nowadays, water scarcity, drought and pollution of wastewater are considered major issues of concern. For this reason, the authors provided an overview of two methods of wastewater purification and removing pollutants for use in crop irrigation in a sustainable manner. The novelty lies in the reuse of recovered wastewater, purified through photodegradation and photocatalysis technologies using solar energy. The knowledge of the environmental impacts associated with the use of recycled water with these photo-processes to irrigate crops under field conditions is still scarce. In the future, this issue will be important. In particular, photodegradation and photocatalysis achieve a sustainable reduction in contaminants contained in wastewater of between 35% and 100%. The use of bismuth vanadate supports the complete removal of pollutants, and the implementation of catalytic membranes makes these processes more circular. This research was performed under the “Progetto GRINS “Growing Resilient, Inclusive and Sustainable” with the aim of “Building a dataset for the circular economy of the main Italian production systems”.