NH -N degradation dynamics and calculating model of filtration bed height in Constructed Soil Rapid Infiltration

The research on Constructed Soil Rapid Infiltration (CSRI) system is in its infancy at home and abroad. There are several details about the mechanism and application of CSRI system needed to be further studied. A major limitation in the current research is the absence of degradation dynamics of pollutants, and the height of filtration bed in CSRI system currently determined by empirical judgment lacks accuracy and logicality. To solve these two problems, the soil column of CSRI system was utilized to treat domestic wastewater, meanwhile, the NH -N degradation dynamics were studied according to the Monod equation, the research of Mann A T and the NH -N degradation law. Then the mathematical model of filtration bed height was built based on NH -N degradation dynamics equation in the soil column. It has been proven that within a limited range this model can calculate the appropriate height of filtration bed accurately in order to optimize technological parameters of hydraulic load and the concentration of influent NH -N, improving the effluent quality of CSRI system. © 2011 Science Press, Northeast Institute of Geography and Agroecology, CAS and Springer-Verlag Berlin Heidelberg.