METHOD FOR EXTRACTING HEAVY METALS FROM SLUDGE WITH ORGANIC ACIDS

摘要

A method for extracting heavy metals in sludge using organic acids is provided to remove extracted heavy metals as a dewatered cake and recycle the heavy metal-removed organic acids by mixing organic acids as a new extractant with sewage sludge and performing a coagulation process of the mixture. A method for extracting heavy metals in sludge using organic acids comprises: a step(10) of mixing an organic acid of oxalate or citrate having a mole concentration of 0.1 to 0.5 with sewage sludge containing heavy metals; a step(20) of extracting heavy metals contained in the sewage sludge into the mixed organic acid in a dissolved state of a liquid phase; and a step(30) of performing a coagulation reaction of heavy metals in the extracted organic acid to separate and remove the heavy metals in the form of a cake. The heavy metal removing step further comprises the step of reusing the heavy metal-removed organic acid in the sewage sludge.