Raise or Fold?

[QBert]

4/8 live. Extremely loose (6-8 players/flop), passive (only maybe 1/4 hands raised pf). CO is a bad player and doesn't recognize relative hand value. He is hard to read simply because he often doesn't know what he has relative to what other people might have.

Hero is BB with 9c 9s. 6 players limp, SB completes, Hero raises. All limpers call.

Flop (16 SB): Qh 7c 5s. SB checks, Hero checks, 5 players check, CO bets, SB folds, Hero raises, 3 players call, CO calls.

Turn (13 BB): Jd. Hero checks, checked to CO who bets, Hero folds.

My line of thinking here was that, with 16:1 on the flop I either:

1) had the best hand, and CO was making a positional bet
2) had odds to draw to my set given implied odds should I hit on the turn

I raised to isolate the CO who may or may not have had a Q, to fold out overcards. The raise failed to isolate so I mucked the turn unimproved. Does anyone fold here or just call in the hopes of spiking the turn and getting paid?