Water quality index (WQI) is a single value numerical expression, which can evaluate the quality of given water body at particular position and time. Five different industrial wastewaters WQI are formulated by Delphi process (before and after treatment) and the results obtained for each samples are reported. It has been observed that the individual parameters vary quite widely whereas when it is converted to a single value indicator like WQI, their values varied quite narrowly. It is observed from the results that depending on the seasonal variation, WQI value is also changed. Thus, it becomes more convenient to opine on the quality of water with respect to its pollution level.
Keywords: water quality index, WQI, pollutants, aggregative method, Delphi process, multiplicative method