24-hour nutrient mass balance of small storage reservoir included in municipal rainwater drainage system

摘要

The paper presents the results of research, which aimed at tracing the quantitative and qualitative effect of the "Tomaszowska" urban retention reservoir (located in the Lodz city) on the Olechowka River flowing through it over a period of one day. For this purpose, two measurement-control points were established located directly above the inflow of river to the reservoir, and below the weir. Hydrological and hydrochemical measurements were performed every two hours. Results obtained in this research present the reservoir as an object that in terms of the inflowing river, among others, in a daily balance of pollutants retains mineral and biogenic compounds, and releases dissolved and suspended organic compounds, and also changes the structure of pollution (in the case of total dissolved solids and total nitrogen, increasing the contribution of their organic forms).