Pollution is one of the big problems of continuous pollution in the Brantas River. The type of pollution that occurs in the sediment of a river is associated with the characteristics of its magnetic mineral. This study aims to determine the types of magnetic minerals in the Brantas River sediments. IRM data was taken from the measurement results in the Brantas River sediments. In this study, the IRMITS program is used to provides a deeper and better analysis and interpretation. From the processing results, IRMITS produces 3 graphs, namely the Linear Acquisition Plot (LAP) curve (b) the Gradient Acquisition Plot (GAP) curve; (c) Standardized Acquisition Plot (SAP) curve. From this study that has been done, it shows that magnetic minerals in the Brantas River are saturated in magnetic fields above 800mT with permanent coercivity occurring in the range 12-13 x 10−3 and z value 0 before saturation occurs. This indicates that most of the Brantas River sediments is dominated by magnetite minerals (Fe3O4).

Several vital activities in East Java are supported by the Brantas River, ranging from irrigation, supply of water raw materials, to industry. Along with the growing population, has the potential to increase the pollution that occurs in the Brantas River. VSM data was taken from the measurement results in Brantas River sediments. The aim of this study is to analyze the VSM measurement data in the Brantas River using the HYSITS script. The analysis was carried out to determine the type of magnetic domain contained in the Brantas river sediment. HYSITS program is used to provides a deeper and better analysis and interpretation. The results show that HYSITS produces 2 curves besides hysteresis loop graphic, that is 1st derivative of ΔM curve and ΔM curve. From the Hysteresis curve of sample, it is known that the Saturation Magnetization (Ms ) value are 5.3262 - 5.998587 emu/g, the Saturation Remanent Magnetization (Mrs ) value are 1.1537 - 1.545586 emu/g, the Magnetic Coercivity (Bc ) value are 0.0188 - 0.020784 T, and Magnetic Remanent Coercivity (Bcr ) are 0.059891 - 0.0815. Result of the analysis indicates that the magnetic minerals in Brantas River are strongly suspected to represent ferrimagnetic minerals with Pseudo-Single Domain (PSD).