This paper proposed a newly explored composite photocatalyst, Chitin/ZnO, prepared via the sol-gel method for exploring its photocatalytic activity in the simulated aquaculture wastewater under UV irradiation. The study mainly involves the application of Chitin/ZnO from three aspects: the structure, the principle and the degradation efficiency. The effects of purification operation factors including mass ratio rate, dosage, calcination temperature, initial NH4+&ndash
N concentration and illumination conditions on the NH4+&ndash
N removal effectiveness were investigated. Optimum conditions were explored through orthogonal experiments, which revealed that 88.73% NH4+&ndash
N removal from 60 mg/L synthetic wastewater was achieved by direct illumination for 120 min. Additionally, Chitin/ZnO photocatalysts (mass ratio of 2:3) at a calcination temperature of 500 °
C were favorable for Chitin loaded over a ZnO lattice. The obtained nanoparticles of Chitin/ZnO were characterized using SEM and X-ray diffraction. The purpose of this paper is to grope for an economical and easy method of Chitin/ZnO powder preparation and to provide a practical approach for future research on the photocatalytic purification of aquaculture wastewater.