Environmental and process assessment of a vibratory nanofiltration system for the recovery of water from soluble coffee manufacturing waste

Abstract

AbstractA case study has been conducted for the recovery of water from complex wastewater at a soluble coffee manufacturing factory. The study has evaluated separation methods for process intervention based on environmental and economic assessments. A novel vibratory field membrane separation was evaluated at the laboratory scale using actual factory wastewater, and was scaled‐up using appropriate design protocols. The recovery of water from an intermediate waste stream proved the most effective, both environmentally and economically. The proposed full‐scale vibratory membrane process recovers 378,541 L of water per day that meets specifications for reuse in the factory cooling tower. The proposed design reduced the daily well freshwater withdrawn by 21% and the amount of wastewater discharged from the factory by 28.5%. Annual operating costs were reduced by 22.5% and total life cycle emissions were reduced by 27.8%. These reductions are mainly the result of the reduced volume of wastewater discharged from the factory and the reduced energy requirement of the on‐site pretreatment processes. Economic assessment showed a net present value after 10 years is $181,100, while the payback time is under 3 years. Overall, the proposed vibratory membrane process used for water recovery presents favorable economics, and significant environmental emission reduction.