In situ h2s scavenger additive generation

A method of generating an additive in situ in a borehole or subterranean formation or pipeline and scavenging hydrogen sulfide with the additive the method comprising:

• placing a delivery molecule in the borehole or subterranean formation or pipeline, the delivery molecule comprising a precursor having an end terminating in degradable linkages bonding the precursor to bridged groups and another end terminating in a leaving group, wherein the delivery molecule is stable under external conditions;
• contacting the delivery molecule in situ with an initiator acid, wherein the initiator acid catalyzes degradation of the degradable linkages and elimination of the leaving group, thereby releasing the precursor from the delivery molecule and auto-catalytically generating a strong, acid and the additive from the precursor, wherein the additive is furthermore suitable for biocide treatment and the strong acid is suitable for borehole cleaning and scavenging hydrogen sulfide from the borehole or subterranean formation or pipeline with the additive.