The substantial sludge, composed of organic compounds, was detected in sediments samples of Anzali wetland. Photocatalysts have a great potential for decomposing organic compounds. In the present research, an attempt was made to decompose the sludge of Anzali wetland using titanium dioxide nanoparticles (TiO 2 NPs). For this purpose, Luzchem’s CCP-4 V photoreactor, which is equipped with 12 UV lamps, was used. The influences of UV intensity, TiO 2 concentration and exposure time were investigated for the removal of sludge. The statistically analysis showed that exposure time was the most effective factor in removal of sludge. The results also revealed that 10-µg/L TiO 2 after long-term exposure (5 days) would decompose about 37% of organic contents of sludge. Further detailed studies revealed that due to the decomposition of organics, about 2100, 1700, 1650, 270 and 181 µg/L of Sr, Mn, Si, Al and P would be released into the water column, respectively.