Somerville aldermen will pick up their review of a proposed ban on polystyrene containers and cups on Wednesday. The proposal, offered by Alderman Bob Trane in November, calls for all restaurants to cease use of the materials. The ban was discussed by members of the aldermen’s Legislative Matters Committee in January, and aldermen heard from residents and businesses in a public hearing on Feb. 27. The Legislative Matters Committee is slated to meet next on Wednesday and is expected to discuss the proposed ban, committee chairwoman Rebekah Gewirtz said. The meeting will be held at 6 p.m. in City Hall .