Recovery of Ammonia in Raw and Co-digested Swine Manure Using Gas-Permeable Membrane Technology

Abstract

Anaerobic digestion of agro-industrial and livestock waste generates considerable digestate volumes that are important sources of nitrogen (N). However, on some occasions, the high concentrations of N present in the digestates may represent an obstacle to its use locally as fertilizer, since it can cause an environmental impact (European Community, 2000). This study analyzes the efficiency of gas-permeable membranes (GPM) in the recovery of the ammoniacal nitrogen (NH + 4 ) present in the swine manure (SM, Control) and three digestates generated from the anaerobic co-digestion of mixtures of SM, fruit and vegetable sludge (FVS) from the vegetable industry (peppers and artichokes), and by-products of the tomato processing industry (TW) (skins and seeds), which were mixed at three different proportions [TW + FVS]: [SM]. Their NHx + content was 2,240 mg L −1 for the SM and 4,670-5,370 for the digestate mixtures. Throughout the duration of the Necovery experiment (96 h), the percentages of NH + 4 removal and recovery achieved were consistent among treatments, approximatelly 78 and 96%, respectively. The recovery of NH 4 + for the digestate mixtures seems to be dependent on the treatment time, since the potential of N recovery was higher when the treatment time increased. However, for the control experiment (SM), with lower N concentration, the maximum N recovery was obtained at the experimental time established, without increasing the treatment time.

Hydrophobic membranes for ammonia recovery from digestates in microbial electrolysis cells: Assessment of different configurations

“…For example, continuous pH control and automatised acid replacement would be necessari in the ARC to achieve a more stable ammonia flux through the hydrophobic membrane. Anaerobically digested pig slurry Tank Tubular ePTFE 6 [28] Anaerobically codigested pig slurry Tank Tubular ePTFE 60 [87] Anaerobically digested pig slurry Tank Tubular ePTFE 6.6 [32] Anaerobically digested dairy manure Tank Tubular ePTFE 51 [69] Anaerobically digested chicken manure Tank Tubular PDMS 1.48 [70] Poultry litter Tank Flat ePTFE 17.78 [35] Swine manure Tank Tubular ePTFE 89 [33] Swine manure Tank Tubular ePTFE 2.27 [34] Swine manure Tank Tubular ePTFE 38 [38] Swine manure Tank Tubular ePTFE 27.1 [37] Urine EC Flat PTFE 94 [53] Synthetic wastewater EC Flat PTFE 69 [61] Centrate of anaerobically digested sewage sludge Tank Tubular ePTFE 133 [88] Urine EC Flat PP 1010…”

Application of Gas-Permeable Membranes For-Semi-Continuous Ammonia Recovery from Swine Manure

“…The gas-permeable membrane technology has been successfully applied to recover up to 99% of TAN from swine manure and anaerobically digested swine manure [5,14,[21][22][23]. Previous research mainly focused on the influence of operational conditions such as animal waste strength and pH on TAN recovery using gas-permeable membranes always operated at batch mode.…”

Stability of Thermophilic Pig Manure Mono-digestion: Effect of Thermal Pre-treatment and Separation

“…Side effects may be: process disturbance by too much air or oxygen dosing, damage of the equipment by insufficient replacement of the activated carbon or formation of impregnable phosphate components after digestate fertilization. Ammonia could be removed prior to digestion by means of a stripping and scrubbing process (Ghyselbrecht et al, 2018;Bijnagte, 2019) or through gaspermeable membranes (Filho et al, 2018). At this moment, such techniques still come at a high cost.…”