Can I replace a 32 watt floresent bulb with a 40 watt bulb?

No, notice the 32 watt lamp is a T8,or 1" in diameter. the F40 should be a T12, or 1.5 " in diameter. The ballast for each is different, as the T8 lamp is around 200 milliamp, and the T12 lamp needs about 450 Ma.

Stick with the T8 32 watt lapm. Fir severral reasons, one is energy savings and greater light output.