Glutaraldehyde (GA) has been used extensively as a biocide in hydraulic fracturing fluids leading to the contamination of the compound in produced water. In this study, the performances of photolysis and photocatalysis for removal of GA in synthetic produced water were investigated. The photolytic degradation rate of GA increased with increasing incident ultraviolet light intensity and decreasing pH. Increasing initial GA concentration resulted in a reduced rate of GA degradation. At high salt concentrations, similar to the levels found in produced water, the photodegradation rate of GA was better than those at zero/low salt concentrations. In photocatalytic experiments, GA could be degraded efficiently under both simulated visible light and natural sunlight. Photolysis and photocatalysis are promising technologies for removing GA in produced water due to their small footprint, ease of operation, and efficiency. This study helps in addressing an obstacle associated with produced water treatment and disposal.