Velizarov S, Rodrigues C M, Reis M A, Crespo J G
Department of Chemistry - CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, P-2825-114 Caparica, Portugal.
Biotechnol Bioeng. 2000;71(4):245-54. doi: 10.1002/1097-0290(2000)71:4<245::aid-bit1014>3.0.co;2-f.
The mechanism of anionic pollutant removal in an ion exchange membrane bioreactor (IEMB) was studied for drinking water denitrification. This hybrid process combines continuous ion exchange transport (Donnan dialysis) of nitrate and its simultaneous bioreduction to gaseous nitrogen. A nonporous mono-anion permselective membrane precludes direct contact between the polluted water and the denitrifying culture and prevents secondary pollution of the treated water with dissolved nutrients and metabolic products. Complete denitrification may be achieved without accumulation of NO3(-) and NO2(-) ions in the biocompartment. Focus was given to the effect of the concentration of co-ions, counterions, and ethanol on the IEMB performance. The nitrate overall mass transfer coefficient in this hybrid process was found to be 2.8 times higher compared to that in a pure Donnan dialysis process without denitrification. Furthermore, by adjusting the ratio of co-ions between the biocompartment and the polluted water compartment, the magnitude and direction of each individual anion flux can be easily regulated, allowing for flexible process operation and control. Synthetic groundwater containing 135-350 mg NO3(-) L(-1) was treated in the IEMB system. A surface denitrification rate of 33 g NO3(-) per square meter of membrane per day was obtained at a nitrate loading rate of 360 g NO3(-) m(-3)d(-1), resulting in a nitrate removal efficiency of 85%.
为实现饮用水脱氮，研究了离子交换膜生物反应器（IEMB）中阴离子污染物的去除机制。这种混合工艺结合了硝酸盐的连续离子交换传输（唐南透析）及其同步生物还原为气态氮的过程。无孔单阴离子选择透过性膜可防止污染水与反硝化培养物直接接触，并防止处理后的水被溶解的营养物质和代谢产物二次污染。在生物隔室中可实现完全反硝化，而不会积累NO3(-)和NO2(-)离子。重点研究了共离子、抗衡离子和乙醇浓度对IEMB性能的影响。发现该混合工艺中硝酸盐的总传质系数比无反硝化的纯唐南透析工艺高2.8倍。此外，通过调节生物隔室和污染水隔室之间的共离子比例，可以轻松调节每个阴离子通量的大小和方向，实现灵活的工艺操作和控制。在IEMB系统中处理了含有135 - 350 mg NO3(-) L(-1)的合成地下水。在硝酸盐负荷率为360 g NO3(-) m(-3)d(-1)时，膜表面反硝化速率为每天每平方米膜33 g NO3(-)，硝酸盐去除效率达85%。
