CHROMIUM REMOVAL FROM CHELTECH (ZARIA) TANNERY EFFLUENT AS A FORM OF EFFLUENT TREATMENT

📄 Project Abstract

Chrome is an indispensable input in chemical tanning of pelt. For mass transfer reasons, not more than 80% of the chrome feed is absorbed by the leather leaving a balance of over 20% in the effluent. This leads to material loss if disposed untreated. In addition, the attendant possible oxidation of chromium (III) to chromium (VI) (in the presence of manganese (IV) oxide or under alkaline conditions) known for its carcinogenic effect, makes it necessary to remove good part of the chrome from the effluent before its disposal to sewers or surface water. In this work, treatment CHELTECH (Zaria) tannery's 'mixed effluent' with varying amount of MgO (10 - 60 mg/l) at different contacting times (15 - 120 minutes) reduced the concentration of chromium in the effluent from 29.86 to 0.06 mg/l. This is equivalent to 99.8% chromium removal. The 0.06 mg/l minimum chromium concentration value in the treated effluent falls within the recommended limit for discharge into sewers and surface waters. Chr...