To overcome the easy loss of microorganism, the mass production of sludge and the consumption of aeration energy during biological treatment of anaerobically digested swine wastewater, this study used chitosan–sodium alginate composite carrier to prepare immobilized bacteria pellets. The heterotrophic bacteria tolerant to high concentrations of ammonia nitrogen were isolated and the conditions for immobilizing bacteria were optimized. The performance of immobilized bacteria pellets to remove ammonia nitrogen from ADSW was determined and the corresponding mechanism was investigated. Results showed that the isolated bacteria were Bacillus subtilis, and the optimal conditions to prepare the immobilized bacteria pellets by response surface methodology tests were sodium alginate of 0.84% (m/V), chitosan of 0.22% (m/V), embedding time of 32 min and embedding amount of 15% (V/V). In ADSW treatment, at pH 6, 20 g/L of the immobilized bacteria pellets removed 96.5% of ammonia nitrogen. Both adsorption and microbial action contributed to ammonia nitrogen removal, and their contributions were 54.3% and 42.2%, respectively. Compared with the immobilized bacteria pellets using chitosan–sodium alginate as carrier, the one using mono alginate as carrier had a weaker ability to remove ammonia nitrogen, with a removal efficiency of 67.4%. The main mechanism was the formation of polyelectrolyte membrane by the connection between amino groups of chitosan and carboxyl groups of sodium alginate, which stabilized the immobilized bacteria pellets and prolonged their service life. To sum up, the immobilized bacteria pellets using chitosan–sodium alginate as an embedding agent have a promising prospect in ammonia nitrogen removal from wastewater.

为克服厌氧消化猪废水生物处理过程中微生物易流失、污泥大量产生和曝气能量消耗等问题，本研究采用壳聚糖-海藻酸钠复合载体制备固定化菌丸。分离出耐高浓度氨氮的异养菌，优化固定菌条件。确定了固定化细菌颗粒从 ADSW 中去除氨氮的性能，并研究了相应的机制。结果表明分离的细菌为枯草芽孢杆菌,响应面法测试制备固定化菌丸的最佳条件为海藻酸钠0.84% (m/V)、壳聚糖0.22% (m/V)、包埋时间32 min、包埋量15% ( V/V)。在 ADSW 处理中，在 pH 值为 6 时，20 g/L 的固定化细菌颗粒去除了 96.5% 的氨氮。吸附作用和微生物作用都对氨氮去除有贡献，它们的贡献分别为 54.3% 和 42.2%。与以壳聚糖-海藻酸钠为载体的固定化菌丸相比，以海藻酸钠为载体的固定化菌丸去除氨氮的能力较弱，去除率为67.4%。主要机理是壳聚糖的氨基与海藻酸钠的羧基连接形成聚电解质膜，从而稳定了固定化细菌颗粒并延长了它们的使用寿命。综上所述，以壳聚糖-海藻酸钠为包埋剂的固定化菌丸在去除废水中的氨氮方面具有广阔的应用前景。