Chametz is not mentioned at all in today’s daf.
Daf 339 (Pesachim 16a-16b)
There are several related disputes here. Some hold that the prohibition against contaminated beverages is rabbinic, others that it is biblical. If the former opinion holds, then any object with which the beverage might have come into contact would be considered contaminated; if the latter, then only objects with which the beverage definitely connected are considered contaminated. Other rabbis maintain that beverages are subject to contamination but are not themselves transmitters of contamination.