THE INFLUENCE OF WASTE WATER SEDIMENT AS A COMPONENT OF ASPHALT CONTAINING HEAVY METALS AND DETECTING ITS EFFECT ON SOILS UNDER MODEL EXPERIMENTAL CONDITIONS

Abstract

Waste water sediment (WWS) is an ecological hazard to the environment and the search for its effective disposal is an urgent task. The main limitation of the WWS use is associated with the presence of the different ingredients - heavy metals, which can have a negative impact on the environment. There is asphalt production technolologies using WWS. This work considers the possibility of using asphalts with the WWS additives from car washes. This technology will reduce the negative influence on the environment due to the WWS recycling, as well as due to the possibility of using WWS instead of pure sand by replacing it in the standard asphalt production technology. In this work, a heavy metal content was determined by the ICP-OES method using an Agilent 5110 spectrometer; in the course of a model experiment, the effect on the soil of three model objects was studied: WWS from car washes in Moscow; the standard technology for asphalt production; asphalt fused with car wash WWS. We studied the change in the content of various forms of heavy metals penetrating the soil from wash-offs of these objects, and by comparing the results and assessing their absolute content, we assessed the possibility of using fused asphalt. The studies have shown that during the model experiment, the total content of heavy metals increased up to 7-10 times for Zn, Ni and Cr. In all variants of the experiment, the content of mobile forms of all Cr, Cu, Mn, Ni, Pb, V and Zn significantly decreased by the third stage of the experiment to 50--95%, which indicates the transition of mobile forms of heavy metals to the total content due to the processes of sorption and precipitation.