The Use of Non-conservative

Juanico M., Ronen D. and Shelef G. (1990). The use of non-conservative parameters to trace wastewater effluents in water bodies. Wat. Res., 24(10):1245-1250.

ABSTRACT

This paper describes an alternative method to label wastewater effluent entering water bodies when "classic" tracers (artificial tracers and conservative parameters of the water masses) cannot be used. The method is based on the simultaneous use of several non-conservative effluent quality parameters (e.g. electrical conductivity, detergents, TDS, P04, alkalinity, Na, Kjeldahl, NH4 and N02). The simultaneous use of several parameters enables to smooth out the high variability of single non-conservative parameters disclosing their common trend. The obtained estimates are not quantitative but can be expressed in an ordinal scale. The performance of the new multi-tracer method is tested in a case study to estimate the relative amount of effluent in the outflow of an operational reservoir which receives freshwater and sporadic inputs of treated wastewater. The multi-tracer method disclosed poor mixing conditions between freshwater and effluents within the reservoir, plug flow-like movement of the effluent pulses with a delay of 1-3 weeks between an in-pulse and its corresponding out-pulse, and the existence of dead spaces in the reservoir.

KEYWORDS

tracers, multi-tracer, effluent, wastewater, flow pattern, reservoirs.