Institute of Environment and Sustainable Development in Agriculture, Chinese Academy ofAgricultural Sciences, Beijing 100081, China.
J Environ Sci (China). 2011;23(8):1279-85. doi: 10.1016/s1001-0742(10)60542-6.
A self-design bioreactor system employing a fixed bed operation process with immobilized Bacillus subtilis AYC beads for NH4+-N removal from slightly polluted water was proposed. Polyvinyl alcohol and Na-alginate were used as a gel matrix to entrap Bacillus subtilis AYC to form the immobilized beads. The NH4+-N removal process was studied in a intermittent operation mode to examine the start-up and steady state behaviors of the immobilized AYC in the reactor. The results indicated that the reactor was in the start-up state during the first week. NH4+-N began to be steadily removal since the second week, and the nitrogen removal rate was between 84.61% and 96.19% when the hydraulic retention time (HRT) was 30 min. To apply Bacillus subtilis AYC to develop a practical nitrogen removal system and further understand its nitrogen removal ability, the bioreactor was continuously operated under different experimental perameters. The results showed that under the optimum conditions of an HRT of 20 min and DO of 3.77-5.80 mg/L, the NH4+-N removal rate reached 99.55%. The NH4+-N removal rate increased as the C/N ratio increased. However, a high C/N may cause a high residual carbon level in the effluent, therefore, the most suitable C/N ratio was 10. In addition, the results showed that the bioreactor system could remove many types of nitrogen such as NH4+-N, NO3--N and organic-N, and had a good performance for inorganic nitrogen removal from sewage.
采用固定床操作工艺的自设计生物反应器系统，使用固定化枯草芽孢杆菌 AYC 珠粒从轻度污染水中去除 NH4+-N。聚乙烯醇和海藻酸钠用作凝胶基质来固定枯草芽孢杆菌 AYC 以形成固定化珠粒。NH4+-N 去除过程在间歇操作模式下进行，以检查反应器中固定化 AYC 的启动和稳定状态行为。结果表明，在第一周内，该反应器处于启动状态。自第二周开始，NH4+-N 开始稳定去除，当水力停留时间（HRT）为 30 分钟时，氮去除率在 84.61%至 96.19%之间。为了应用枯草芽孢杆菌 AYC 开发实用的氮去除系统并进一步了解其氮去除能力，生物反应器在不同的实验参数下连续运行。结果表明，在 HRT 为 20 分钟和 DO 为 3.77-5.80mg/L 的最佳条件下，NH4+-N 去除率达到 99.55%。NH4+-N 去除率随着 C/N 比的增加而增加。然而，高 C/N 可能导致出水的残余碳水平较高，因此，最合适的 C/N 比为 10。此外，结果表明，该生物反应器系统可以去除多种类型的氮，如 NH4+-N、NO3--N 和有机-N，并且对污水中的无机氮去除具有良好的性能。
