Effective Removal of Nitrogen and Phosphorus from a Black-Odorous Water by Novel Oxygen-Loaded Adsorbents

Black-odorous water, caused by hypoxia and overloading of nitrogen and phosphorus, is ubiquitous in global urban rivers. In this study, we developed oxygen-loaded adsorbents by loading oxygen into activated carbon, Attapulgite, Phoslock, and Muscovite via vacuum-pressure swing method, and investigated their aeration and removal efficiency of phosphate, ammonia nitrogen, and total nitrogen in black-odorous water. Results showed that the addition of oxygen-loaded coal-based columnar activated carbon (OCC) or oxygen-loaded Muscovite (OM) alone could increase the dissolved oxygen (DO) concentration at the sediment-water interface to more than 6 mg center dot L-1 on the first day, and OCC could maintain the high level of oxidation-reduction potential (ORP) (up to + 327 mV) for 15 days. Most oxygen-loaded adsorbents remarkably reduced phosphate in water, essentially from 0.27 mg center dot L-1 to < 0.05 mg center dot L-1. Additionally, ammonia nitrogen and total nitrogen were reduced by more than 50 % by adding materials after oxygen loading treatment. The 16 s RNA results showed that Dechloromonas was dominant in abundance, and the reduction of nitrogen was mainly affected by microbial activity. Our results provided a series of oxygen-loaded adsorbent materials with potential engineering applications for rapid treatment of urban black-odorous water.