Municipal wastewater is generally thought of two types: domestic and industrial. Domestic wastewater is sewer water from homes and shops. Industrial wastewater is sewer water from factories, meat packing houses, laundries, vegetable canneries, poultry farms, metal plating shops, chemical dye plants, and so forth. Typically domestic wastewater contains a collection of pollutants like suspended matter, ammonia, biological organisms and chemicals, oil and soaps. Industrial wastewater can contain all of this plus be either acidic or alkaline, contain heavy metals, complex hydrocarbons, and many other potentially harmful pollutants. Scientists, so far, usually rely on the biological and physical parameters (BOD, COD, TOC and toxic elements) and/or the study of living organisms in this wastewater body to elucidate the level of wastewater pollution. However, the concentrations of these chemical parameters are not conservative, and they intrinsically provide little insight into the dynamics of the water mixing downstream from the influent. As for the biological parameters, their detemination are fairly cumbersome not to mention time consuming. In this thesis, we present a new approach to elucidate and manage the impact of wastewater effluents on natural water quality using the dissolved Rb/Sr ratio. Rubidium is present in larger qualities than strontium in biological matrices (such as faces and urine), so that the ratio of these two elements represents an effective tracer. This is especially true in the regions where the natural Rb/Sr ratio is low (calcareous regions). For a given water quality, the Rb/Sr ratio will remain constant, regardless of the river flow. It has been found by the use of Rb/Sr ratio, that the wastewater effluents on Woluwe river, Brussels region, have been successfully qualified and quantified. In the river Woluwe, the Rb/Sr ratio was found to be very low at the source and increased when there were impacts from wastewater effluents. In the sewer system, the Rb/Sr ratio is quite high and reaches the maximum at the junction of wastewater pipes. The Rb/Sr ratio can also be used to model the capacity to withstand the effect of wastewater effluent to river water and to recover its natural quality that is needed for calculating the capacity of water treatment plant constructed in future. |
