Pilot-Scale Demonstration of Membrane-Based Nitrogen Recovery from Swine Manure

Abstract

Gas-permeable membranes technology presents a high potential for nitrogen (N) recovery from wastewaters rich in ammonia (NH3). The EU project Ammonia Trapping (AT) is aimed at transferring knowledge from the lab-scale level to on-farm pilot-scale level, using this technology to recover NH3 from livestock wastewaters. The goal of this study is to report the results of an on-farm pilot-scale demonstration plant using gas-permeable membranes to recover N from raw swine manure. After a setup optimization of the plant, stable, and continuous operation was achieved. The maximum NH3 recovery rate obtained was 38.20 g NH3-N m−2 membrane day−1. This recovery rate was greatly affected by the temperature of the process. In addition to its contribution to NH3 emissions reduction, this technology contributes to the recovery of nutrients in the form of a concentrated stable ammonium sulphate solution. This solution contained 3.2% of N, which makes it suitable for fertigation. The economic approach revealed an economic feasibility of the technology, resulting in a cost of 2.07 € per kg N recovered.