Model of behaviour of conductivity versus pH in acid mine drainage water, based on fuzzy logic and data mining techniques

Acid Mine Drainage is a water pollution type characterized by several topics such as high acidity, sulfate and heavy metal concentrations. One of the chemical characteristics is the absence of correlation between pH and conductivity, as could be expected. This last parameter is well correlated with other variables such as sulfate concentration and can be used as a field assessment. The absence of pH/conductivity correlation is largely discussed by several authors. In this work, the use of fuzzy logic algorithms in a large temporal database (over 20,000 records) has allowed us to study the “hidden” relation between them. This work finds this correlation, with some conditions such as the range of pH where it happens. Maybe the study of the usual range of pH values in previous studies has disturbed the correlation because of other chemical processes.