Известия Томского политехнического университета: Инжиниринг георесурсов (Oct 2023)
USE OF THE DYNAMIC LIGHT SCATTERING TO ASSESS THE EFFICIENCY OF SEPARATION OF SUSPENDED AND COLLOIDAL PARTICLES IN RIVER WATERS BY FILTRATION AND CENTRIFUGATION
Abstract
Link for citation: Shulkin V.M. Use of the dynamic light scattering to assess the efficiency of separation of suspended and colloidal particles in river waters by filtration and centrifugation. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 88-97. In Rus. The relevance of the study is stipulated by the need to control the completeness and accuracy of the separation of suspended and colloidal particles using filtration and centrifugation methods during the analysis of the chemical composition of river waters. The main goal: to test and evaluate the possibility of using the method of dynamic light scattering to monitor the effectiveness of separation of suspended and colloidal particles of river waters by filtration and centrifugation. Objects: waters of typical rivers of the south of the Russian Far East with different levels of anthropogenic load and landscape structure of watersheds, which leads to obvious variations in the concentration levels of dissolved, colloidal and suspended forms of chemical elements in rivers, as well as to different content and grain size composition of suspended matter. Methods: measurement of the dynamic light scattering intensity, including its size distribution, using the Photocor COMPACT Z device in unfiltered samples of river waters, as well as in the filtrates through capsule and membrane filters with varying degrees of clogging, and in the supernatants obtained under various conditions. At the same time, the sum content of suspended and coarse-colloidal particles in the initial samples of river waters was determined gravimetrically after filtration through membrane filters with a pore size of 0,45 μm. Results. The dynamic light scattering intensity in unfiltered river waters demonstrates a significant linear dependence on the suspension content in the range of 5–150 mg/l, determined gravimetrically. In filtrates via a membrane or capsule filter of 0,45 μm, the dynamic light scattering intensity does not depend on the suspension content in the unfiltered samples. Analysis of the size distribution of dynamic light scattering intensity in the unfiltered samples, and in the filtrates confirms the removal efficiency of particles larger than 0,45 μm both at the filtration through membrane or capsule filters, and at the centrifugation for 30' at 4500 rpm. Dynamic light scattering allows characterizing the efficiency of separation of suspended and coarse-colloidal particles in river waters from thin colloids and dissolved forms using membrane and capsule filters, as well as centrifugation. Thus, it becomes possible to control the processes of filters clogging and choose the optimal method for separation of suspended and colloidal particles at the chemical analysis of river waters.
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