The city and its partners have received a important permit from the state in order to begin construction on the $1.6 billion downtown revitalization in February. According to planning director Dennis Harrington, the project this month received Massachusetts Environmental Policy Act approval, allowing developer Beal/Street-Works to move forward with the construction of Merchants Row. The work, on a downtown block within Hancock Street, Chestnut Street, and Cottage Avenue, will renovate the Granite Trust building and erect two apartment buildings, one with 246 units and the other with 60. At a City Council meeting Monday, Harrington said he had scheduled a Planning Board meeting for January to issue final approvals for Merchants Row. “There are no impediments [to] moving forward with this project,’’ he said.