An innovative material for simultaneous removal of phosphorus and ammonia nitrogen in river water: Preparation and application

摘要

In this study, an innovative material (nitrogen, phosphorus, and oxygen controlling agent, NOC) was synthesized by calcium peroxide (CaO_2), magnesium chloride (MgCl_2), bentonite, zeolite, cement, stearic acid (SA), citric acid (CA), and silver sand. The treatment performance of NOC in mimic black-odor river water was investigated in lab-scale, and the results showed that over 73.7% phosphorus and 77% ammonia nitrogen were removed from river water with the addition of 470 g NOC at 30 mL h~(-1) flow rate, demonstrating that the presence of NOC could remove phosphorus and ammonia nitrogen simultaneously. Moreover, the addition of NOC could release oxygen with tender influence on pH in water. Calcium phosphate (Ca-P), aluminum phosphate (Al-P), and ferric phosphate (Fe-P) in the river sediment increased from 1.6, 0.136, and 0.12 mg g~(-1) to 2.16, 0.242, and 0.196 mg g~(-1) for 28 days, respectively. The results manifested that the mobile phosphorus could be adsorbed by NOC and further transformed to inert phosphorus form, thereby restraining the release of endogenous phosphorus from sediment to the overlying water. Besides, the relative abundance of microorganisms could be enhanced with the existence of NOC, further promoting the removal of phosphorus. Hence, NOC could be applied to the efficient remediation of the black-odor river. Highlights 1. The presence of NOC enhanced DO level, and removed P and NH_3-N simultaneously. 2. The effect of NOC on P and NH_3-N removal in river water with various flow rate was investigated. 3. NOC had capacity to transform P from mobile fractions to inert fractions in sediment. 4. The relative abundance of microbial communities promoting P removal was increased by NOC.