What did lin zexu do with the 20,000 chests of opium that were surrendered at canton in 1839?

He burned it. He set about destroying the held opium. After enclosing the site with a bamboo barrier to avoid theft, three stone quarries, lined with wood, were excavated into which was discharged the seized opium along with salt and lime. A minor disruption happened when one man was caught trying to take away an amount of the drug—he was then executed right at that moment. Once the excavation had been occupied with sea water, laborers plodded the mixture to safeguard the drug's annihilation. The remainder was then flushed through a waterway into the South China Sea while Lin said an appeal saying sorry for the pollution they have caused.