Dreissena polymorpha (zebra mussel) is an invasive freshwater bivalve mollusc that causes important technical and environmental problems. Titanium dioxide solar photocatalysis was checked for disinfestation of veligers of zebra mussel. Approximately 70% damaged larvae were observed after 2 h of solar irradiation with 0.2 and 0.5 g/l of TiO2. Neutral photo-Fenton could be a promising alternative as ca. 80% damaged larvae were detected in only 3 h irradiation in the presence of H2O2 (10 mg/l). This process was clearly more effective than sunlight irradiation, H2O2, or dark Fenton. The performance of the process was slightly improved when a pH value of 5.5 was employed, although further research is needed to explore the compatibility of this medium with irrigation. Finally, the process was scaled up to 41 using a solar photo-reactor; again in this case, 90% of the veligers were damaged after 3 h of irradiation. (C) 2011 Elsevier B.V. All rights reserved.