Dept. of Mechanical & Process Engineering, Institute of Bioprocess Engineering, University of Kaiserslautern, Kaiserslautern D-67663, Germany.
Biotechnol Prog. 2010 May-Jun;26(3):756-62. doi: 10.1002/btpr.384.
Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg x L(-1) and crossflow units with membrane areas from 0.02 to 0.80 m(2) were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed.
硝酸盐是几种食物中不受欢迎的成分。乳清浓缩物是一种典型的高硝酸盐含量污染的情况，其中含有高达 25 l 的硝酸盐。本文描述了 Paracoccus denitrificans 在形成无害氮的同时通过细胞保留反应器来微生物去除硝酸盐的情况。重点在于节约资源的微生物反硝化工艺的设计。比较了两种方法。比较了聚乙烯醇固定化细胞的应用，该方法可以在乳清进料中多次应用，与两步反硝化系统的实施进行了比较。首先，通过离子交换去除乳清浓缩物中的硝酸盐，然后通过错流过滤保留微生物，将洗脱液再生。通过市售的 Reflectoquant 设备进行反射比色测量来确定亚硝酸盐和硝酸盐的浓度。必须确定这些介质的校正因子。在中试开发期间，检查了 4 至 250 mg x L(-1)的生物反应器和 0.02 至 0.80 m(2)的膜面积的错流单元。基于中试装置的结果，讨论了每天 1000 吨反硝化的示例过程的放大。
