Tannery Wastewaters Treatment for Sludge Valorisation in Agriculture

Nowadays in our country tannery pollution control technologies are based on the classic physical chemical treatment with high consumption of reagents, resulting in large amounts of sludge which cannot be used in agriculture as fertilizer because of trivalent chromium content. In this paper an installation and a technological process were developed in order to obtain a sludge suitable for use in agriculture, based on the following processes: neutralization and dehydration of sludge; sterilization, biochemical treatment and enrichment of sludge from the treatment plant with elements necessary for plant growth and soil bioremediation (K, P, B, etc). The process contributes to both restoring poor and degraded soils to agriculture, and to reducing environmental pollution by exploiting sludge which is currently landfilled.