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Evaluation of Capacity Expansion and Treatment Improvement of Wastewater Treatment Plant in Częstochowa, Poland Using Vacuum Mixed–Liquor Degassing System

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This paper presents the principles of the degasification technology and a plant performance evaluation of a full-scale case study of the City of Częstochowa Wastewater Treatment Plant before and after the mixed-liquor degasification-system installation. Vacuum degasification of mixed liquor is a physical process used in biological nutrient removal to improve settleability and allow for achieving higher mixed-liquor suspended solids. Degassing installation is located between the last cell of the bioreactor and secondary clarifiers. Gas bubbles contained in mixed-liquor are removed, and concentration of gasses (nitrogen gas) dissolved in the liquid is reduced. Lack of gas bubbles and concentration of dissolved nitrogen gas below saturation in mixed liquor significantly improved sludge settling in secondary clarifiers and eliminates floating scum. Plants equipped with vacuum degasification operate at final clarifier solids surface loading rates of 180 to 240 kg/m2d, with deep sludge blankets and reactor MLSS at or above 6,000 to 8,000 mg/L.

Keywords: (MLVDS), denitrification; biological nutrient removal (BNR); foaming and bulking; mixed-liquor suspended solids (MLSS); mixed-liquor vacuum-degassing system; secondary clarifier performance; settleability; vacuum degasification

Document Type: Research Article


Publication date: January 1, 2011

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  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

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