The use of natural soil for the treatment of secondary effluent in a northern climate

Wrocław University of Science and Technology, Wrocław, Poland

^* Corresponding author: j.a.szpaczynski@gmail.com

Abstract

The aim of this study was to evaluate atomizing freeze crystallization as a valuable option for land application of pre-treated wastewater. Process factors, such as the concentration of nitrogen compounds, phosphorus and conductivity have been adopted as parameters of concern and were used to assess the effectiveness of the freeze crystallization process. Five monitoring wells were installed to control the ground water quality at the site and at its boundaries. It was found that there is no dissolved phosphorus in the ground water. In most measurements, available phosphorus for plants was not detected at a soil depth greater than 50 cm. NO₃^- -N in ground water from the up gradient well and from the down gradient wells was not detected in most sampling events. There was a small increase of NO₃^- -N near the location of the main snowpack, but it was always lower than the drinking water standard. Total ammonia as N in the up gradient control well was at the same level as in the down gradient well. Unfortunately, higher conductivity was reported in all down gradient wells. These conductivity values did not imply risks for vegetation yields or the texture of soil. It was concluded that the method of freezing effluent in the form of man-made snow proved to be effective for cold climate land application treatment.