Hi C.W.,
You are right. These are the heterogeneous reactions. You can look for aerosol species involved in reactions in the mechanism definition file here: CMAQ/mech_cb6r3_ae7_aq.def at master · USEPA/CMAQ · GitHub
Generally, particulate chloride (ACLI and ACLJ) are lost while ANO3 species are produced (see reactions beginning with “HET_” label). There are also heterogeneous reactions contributing to formation of isoprene SOA (AISO3J) via IEPOX uptake, hydrolysis of Monoterpene SOA (AMTNO3J to AMTHYDJ) and oligomerization of AAVB, AISO1, AISO2, and ASQT species to form AOLGAJ and AOLGBJ.
You can see the production and loss of each of these reaction directly in CMAQ/hrprodloss.F at master · USEPA/CMAQ · GitHub
Best wishes,
Ben Murphy