Spérandio M, Queinnec I
LIPE-DGPI-INSA, 135 Avenue de Rangueil, 31077 Toulouse cedex 04, France.
Water Sci Technol. 2004;49(1):31-8.
Biological nitrogen removal is susceptible to disturbances in activated sludge processes. Significant improvement of performances are obtained by controlling the process taking into account wastewater modifications and sludge activity. In this work a specific sensor is developed, based on oxidation-reduction potential (ORP) and dissolved oxygen (DO) measurements performed in a completely mixed reactor which can be the activated sludge basin itself. This reactor is continuously fed by wastewater and sludge issued from the recirculation stream of the process, and submitted to alternating aeration. DO profiles and ORP bending point are linked to nitrification and denitrification in the sensor. Signal dynamics are treated with a physical model for simultaneously estimating nitrifiable nitrogen concentration in wastewater, nitrification rate, and denitrification rate. Results show very good prediction of experimental oxygen profiles and the software sensor allows us to recalculate nitrate and ammonia profiles in the reactor with a good accuracy. The estimation of nitrifiable nitrogen and removal rates has been validated experimentally. The system allows us to follow highly variable influent nitrogen concentration, toxic events, and changes in the COD concentration or quality in wastewater.
生物脱氮在活性污泥工艺中容易受到干扰。通过考虑废水特性和污泥活性来控制工艺，可显著提高处理效果。在这项工作中，基于在完全混合反应器（该反应器可以是活性污泥池本身）中进行的氧化还原电位（ORP）和溶解氧（DO）测量，开发了一种特定的传感器。该反应器由工艺循环流产生的废水和污泥连续进料，并进行交替曝气。传感器中的DO分布和ORP拐点与硝化和反硝化作用相关。利用物理模型处理信号动态，以同时估算废水中可硝化氮浓度、硝化速率和反硝化速率。结果表明，对实验氧分布的预测效果很好，并且该软件传感器使我们能够以较高的精度重新计算反应器中的硝酸盐和氨分布。可硝化氮和去除率的估算已通过实验验证。该系统使我们能够跟踪进水氮浓度的高度变化、有毒事件以及废水中COD浓度或质量的变化。
