MULTI-ELEMENT ANALYSIS OF ABOVE-SLUDGE WATERS IN THE ACCUMULATION CELLS OF BAYKALSK PULP AND PAPER MILL FOR TERRITORY REMEDIATION STRATEGY CHOOSING

Abstract

Introduction. Pulp and paper enterprises accumulate large volumes of industrial waste buried in special accumulation cells. In order to choose a technology for treating above-sludge waters, we need to monitor their composition, which depends on the history of cells’ filling and their subsequent use. Methods. In the course of the study, we applied inductively coupled plasma mass spectrometry (ICP-MS). Results. We determined the content of 72 chemical elements in above-sludge water of 11 cells at Baykalsk Pulp and Paper Mill and 4 open water flows near industrial waste landfills, and performed a cluster analysis of the sample composition. As a result, we revealed the peculiarities of water composition, related to the history of cell filling and subsequent pilot experiments. It has been found that the cells with non-disturbed sediments have cleaner water. Out of 16 chemical elements subject to limitation (Na, Al, P, S, Cl, K, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Mo, Cd, Pb), 11 elements exceed the limits established for wastewater discharged into water bodies within the ecological zones of the Baikal Natural Territory. Each cell is characterized by its own set of elements exceeding maximum allowable concentrations (MAC) and by the extent of such excess. Conclusion. Pilot experiments with cell sediments (joint grouting, drying, dewatering in press-filters) result in the disturbance of the “water/sediment” balance and increase the concentrations of most elements in above-sludge waters. The maximum amounts of elements (6–7) exceeding the MAC values are observed in water in the cells with disturbed sediments, water in the zone of ash slurry discharge, ash and sludge-lignin cells with industrial and household waste. When choosing a technology and procedures for treating above-sludge waters, it is necessary to take into account the specifics of their composition. Using the polluted water flow running into Lake Baikal during catastrophic floods in the summer of 2019 as an example, we show that it is possible to use multi-element ICP-MS analysis to search for sources of pollution from industrial facilities.