Ammonia Removal from Swine Wastewater by Microwave-Assisted Stripping

This study detetmined optimal microwave irradiation (MI) conditions for removal of ammonia nitrogen (NH3-N) from swine wastewater. The wastewater was treated using a laboratory-scale industrial microwave unit (2,450-MHz frequency). The removal ofNH3-Nincreased with the increase of pH (9.5-12.5), final temperature (FT) (50 degrees C <= FT <= 100 degrees C), and MI time (MIT) (0 <= MIT <= 140 min). Compared with conventional heating (CH), MI removed moreNH3-N. The calculatedNH3-Nhalf-lives decreased asFTand pH increased.FT(80 degrees C-100 degrees C) andMIT(2.5-5.5 min) significantly affected theNH3-Nremoval. Within the design boundaries, optimal conditions forNH3-Nremoval (94.9%) wereFT=100 degrees C,MIT=5.5 min, and pH 10. This work shows the potential of MI as an effective method to reduce theNH3-Ncontent in swine wastewater. (c) 2020 American Society of Civil Engineers.