Nitrogen Recovery from Swine Manure Using a Zeolite-Based Process

Markus Ellersdorfer,Kristina Stocker,Sandro Pesendorfer

doi:10.3390/pr8111515

Abstract

Intensive pig farming produces huge amounts of swine manure, which can cause regional nutrient imbalances and represent a potential source of soil and water pollution due to manure over-application. In order to improve nutrient stewardship, technologies for manure treatment and selective recovery of nutrients (especially ammonia) have to be developed to foster agriculture–food system sustainability. In the present study, a combined stripping and ion exchange process using natural zeolite (ion-exchanger-loop-stripping process) is tested for nitrogen recovery from swine manure to determine its technical feasibility in this novel field of application. Ammonium removal rates of 85 to 96% were achieved in pilot scale experiments with preprocessed manure (~500 L h−1 after mechanical filtration; input concentration: ~1.3 g NH4+ L−1). NH4+ was successfully transferred to a concentrated ammonium sulfate solution (final concentration: 66 g NH4+ L−1), with no significant transfer of other manure components. Hence, various utilizations of the product solution are possible, e.g., for industrial off-gas cleaning (DeNOx) or as raw material for fertilizer production. Based on these findings, the ILS-process can be regarded as a promising option for nitrogen recovery from swine manure.

Highlights

Intensification and industrialization of livestock raising generates huge amounts of swine wastes, which include an important quantity of nutrients, especially nitrogen and phosphorus compounds [1].In 2019, Austria’s livestock farmers produced around 4.7 million pigs [2]
Huge amounts of swine manure have to be stored over certain periods of the year, which leads to significant additional cost
Mixed manure comprises significantly higher ammonium and total nitrogen concentrations, which is a result of the different conditions during pig breeding and pig fattening

Summary

Introduction

Intensification and industrialization of livestock raising generates huge amounts of swine wastes, which include an important quantity of nutrients, especially nitrogen and phosphorus compounds [1].In 2019, Austria’s livestock farmers produced around 4.7 million pigs [2]. Intensification and industrialization of livestock raising generates huge amounts of swine wastes, which include an important quantity of nutrients, especially nitrogen and phosphorus compounds [1]. Given an average manure production of ~0.5 m3 per pig and year [3], the overall quantity of swine manure is around 2.3 million m3 per year from pig fattening (pig breeding not included). In some regions (e.g., southern Styria and the Murtal region), intensive pig farming has led to significant imbalances between nutrient demand for crop farming and the amount of available nutrients from locally produced manure [5]. Huge amounts of swine manure have to be stored over certain periods of the year (i.e., manure storage capacities for at least 10 months are mandatory), which leads to significant additional cost. As an important part of the new Processes 2020, 8, 1515; doi:10.3390/pr8111515 www.mdpi.com/journal/processes

Methods

Results

Conclusion