Environmental Impact, Sustainability and Control of Production of Basic Chromium Sulphate

Author G A Gasmelseed
Co-Author M. A. Taha, Tomadir A. I. Hamed
DOI https://ww

Country : Sudan
Subject : Chemical Engineering

Keywords : Chromium Recycling · Leather Tanning· Environmental Mit- igation· Control Systems · Sustainable Manufacturing

Abstract

This study addresses the significant environmental impact of chromium waste generated by the leather tanning industry. Traditionally, basic chromium sulfate, derived from the reduction of sodium or potas- sium dichromate, has been used for chrome tanning, leading to high resid- ual Cr2O3 content in wastewater. This process, utilizing chrome liquors with 11% Cr2O3, evolved to produce chrome powder containing 21-26% Cr2O3 through concentration and spray drying. Although improvements in chromium uptake and exhaustion rates have been significant, the ox- idation of chromium (III) to the more harmful chromium (VI) remains a concern, especially under prolonged high-temperature conditions. The aging of wet-blue, crust, and finished chrome-tanned leather can pro- duce chromium (VI), posing risks to consumers. Additionally, wastewa- ter containing chromium (III) can oxidize to chromium (VI), and chrome shavings used in brick making can leach chromium (VI) into the environ- ment, causing toxicity to wildlife and humans. To mitigate these risks, we developed a smart control strategy that identifies and analyzes relevant transfer elements (TEs) and selects controllers to minimize overshoot. This approach effectively recycles chromium, ensuring compliance with environmental standards and promoting sustainability in the leather tan- ning industry. The proposed method demonstrated significant reductions in chromium waste and environmental impact, highlighting its potential for widespread application in industrial settings.

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