Modified UASB reactor for dairy industry wastewater: performance indicators and comparison with the traditional approach

A new system for dairy wastewater treatment that is composed of a modified UASB (Up flow Anaerobic Sludge Bed) reactor with a scum extraction device and a lamella settler is presented in this work. The system operates stably with a high methanisation level and achieves a granulated sludge. The new system is compared with the traditional wastewater treatment approach, which includes a dissolved air flotation (DAF) unit, a pH conditioner, an anaerobic contact reactor and a clarifier. The performance indicators of both systems are compared. For similar methane recovery levels, the new system is simpler, with fewer processing units and a 40% lower volume per kg of COD (Chemical Oxygen Demand) to be treated compared with the traditional approach; hence the new system requires reduced investment and operational costs.