Cook noodles according to package directions, omitting salt and fat. Drain; set aside.
While noodles cook, heat oil in a large Dutch oven over medium-high heat. Add mushrooms and garlic, and sauté 3 minutes or until lightly browned.
Add broth, water, lemon rind, and 1 tablespoon lemon juice to pan; bring to a boil. Add asparagus; cook 1 minute. Reduce heat, add scallops, and simmer 3 to 4 minutes or until scallops are opaque and asparagus is tender.
Stir in cooked noodles, remaining 1 tablespoon lemon juice, basil, salt, and pepper; cook 1 minute. Divide evenly among 4 shallow soup bowls. Sprinkle each portion evenly with green onions.