Nitrogen Recovery from Landfill Leachate Using Lab- and Pilot-Scale Membrane Contactors: Research into Fouling Development and Membrane Characterization Effects

Abstract

Membrane contactor technology affords great opportunities for nitrogen recovery from waste streams. This study presents a performance comparison between lab- and pilot-scale membrane contactors using landfill leachate samples. Polypropylene (PP) and polytetrafluoroethylene (PTFE) fibers in different dimensions were compared in terms of ammonia (NH3) recovery on a lab scale using a synthetic ammonium solution. The effect of pre-treating the leachate with tannin coagulation on nitrogen recovery was also evaluated. An ammonia transfer on the lab and pilot scale was scrutinized using landfill leachate as a feed solution. It was found that PTFE fibers performed better than PP fibers. Among PTFE fibers, the most porous one (denoted as M1) had the highest NH3 flux of 19.2 g/m2.h. Tannin pre-treatment reduced fouling and increased NH3, which in turn improved nitrogen recovery. The mass transfer coefficient of the lab-scale reactor was more than double that of the pilot reactor (1.80 × 10−7 m/s vs. 4.45 × 10−7 m/s). This was likely attributed to the difference in reactor design. An analysis of the membrane surface showed that the landfill leachate caused a combination of inorganic and organic fouling. Cleaning with UV and 0.01 M H2O2 was capable of removing the fouling completely and restoring the membrane characteristics.

Impact of Implementing Circular Waste Management System and Energy Recovery in a City with 100,000 Inhabitants on Nitrogen Emissions by 2035

“…Variants with methane fermentation are characterized by high nitrogen content in wastewater (Figure 10). A good direction of action in this area is the development of recycling or recovery technologies for nitrogen contained in wastewater [32].…”

Membrane Technologies for Nitrogen Recovery from Waste Streams: Scientometrics and Technical Analysis

“…Other inorganic constituents, such as metals and metalloids, can precipitate on membrane surfaces in the form of salts (e.g., Mg(OH) 2 ) depending on their solubility in the applied treatment conditions [ 33 ]. Organics present in the waste stream are in general troublesome for nitrogen recovery as they could cause fouling of all membrane technologies [ 10 , 34 ], and may compete with NH 3 transfer in the case of GPM if they are present in the volatile form. It should be mentioned though that the tolerance of membranes to organic fouling depends on the used technology.…”

“…Hence, for a more practical approach, we propose the use of GPM with FO for nitrogen recovery from the reject water stream only as the volume of this stream is manageable ( Figure 9 c). It should be noted that this configuration is currently being investigated by the NPHarvest team at Aalto University in Finland who developed an efficient membrane contactor for nitrogen recovery from streams with high solids content [ 10 , 23 , 26 ]. The team also devised a cost-efficient ballasted flocculation-sedimentation process for phosphorus and solids removal.…”

“…The benefits of nitrogen recovery have led to the emergence of a large number of innovative technologies. These technologies include electrochemical and bio-electrochemical processes, conventional stripping process (ammonia air stripping), struvite precipitation process, and membrane separation processes [ 1 , 10 , 11 ]. Combinations of these technologies have also been reported in the literature in various degrees of complexity.…”