In the morning a brief Puja, Shital bhog (cooling food offering) and Arati are first done. Then the Pujari and Tantradharak circumambulate the altar and perform the visarjan ritual.
In this ritual the Devi, who had been invoked in the Navapatrika and consecrated Image, is entreated to return to Her celestial abode. The Divine Mother, however, dwells for ever in the hearts of devotees.
In the evening the Image of Durga along with Navapatrika is taken in procession to the river bank and immersed in the river. The water taken from the spot, known as Shanti Jal is sprinkled on the devotees who embrace one another as an expression of their solidarity as children of the same Divine Mother. And thus the holy Durga Puja comes to an end leaving joyous memories in the souls of people.
Courtesy: Belur Math Website