Cook pasta according to package directions, omitting salt and fat.
Meanwhile, sprinkle 1/4 teaspoon salt, paprika, pepper, and garlic powder evenly over scallops.
Heat 1 1/2 teaspoons butter in a large nonstick skillet coated with cooking spray over medium-high heat. Add 12 scallops to pan; cook 4 to 5 minutes or until done, turning once. Remove scallops; set aside and keep warm. Repeat with remaining butter and scallops.
Add water to pan; bring to a boil, scraping pan to loosen browned bits. Remove from heat; add pasta, spinach, lemon rind, lemon juice, and 1/2 teaspoon salt. Toss gently. Divide evenly among 4 serving plates. Top with scallops; serve immediately with lemon wedges.