Studio sul trattamento di un refluo industriale per l’abbattimento della sostanza organica biorefrattaria

Inglese

INTRODUCTION: Water protection from pollution represents a major challenge in environmental management, particularly due to the increasing occurrence of non-biodegradable contaminants in receiving water bodies. Conventional activated sludge systems often require the integration of advanced treatment processes to effectively remove the non-biodegradable fraction of chemical oxygen demand (COD). AIM OF THE STUDY: This study aims to evaluate advanced treatment technologies for reducing COD in the final effluent of an industrial wastewater characterized by a significant fraction of unbiodegradable soluble COD (USCOD), while improving the overall efficiency of the Porto Torres municipal wastewater treatment plant. MATERIALS AND METHODS: The investigated processes included powdered activated carbon (PAC) dosing in the activated sludge reactor, granular activated carbon (GAC) filtration, chemical oxidation via the Fenton process, and coagulation–flocculation using polyaluminum chloride (PAC10). RESULTS AND DISCUSSION: PAC dosing achieved a 65% reduction in total COD. GAC filtration showed removal efficiencies decreasing from 80% in the initial phase to 40% in the intermediate phase. The Fenton process yielded removal efficiencies of 47–72% using FeSO4 and 67–77% using FeCl3. Coagulation–flocculation, applied to the entire influent stream, ensured COD reductions between 45% and 50%. CONCLUSIONS: Despite being applied to higher flow rates, coagulation–flocculation exhibited greater consistency in performance compared to the other tested technologies, along with improved technical and economic feasibility, making it the most suitable option for full-scale application.