Removal and Recovery of Sulfide from Tannery Wastewater.

摘要

Recovery of sulfide from tannery waste was accomplished through acidification with sulfuric acid in a closed system and removing hydrogen sulfide formed by blowing with air. Sulfide was then absorbed in caustic solution to produce re-usable sodium sulfide/sulfhydrate liquor for the tanning un-hairing process. Plant scale equipment was used in demonstration. The recovered sulfide was reused at the tannery and resulted in an annual savings of $397,437for chemicals. The annual cost of the recovery system was $305,385. Operational difficulties,design modifications,and cost effectiveness are discussed in detail. Protein recovery is recognized as an adjunct to the acidification procedure and significant reduction in BOD loading is achievable by subsequent clarification.