A model is proposed for the optimal allocation of waste loads in a river basin, taking into account transverse mixing resulting from the confluence of tributaries with different pollutant levels and the variation of river flow rates. The model is stated as the minimization of cost of
wastewater treatment in the whole river basin, subject to the satisfaction of environmental standards imposed for the river quality at water intakes along the river. The flow rate of the river system is regarded as a random variable in the model and constraints on water quality levels are
expressed in a probabilistic form. The model is applied to a river with three tributaries joining at one point. The frequency of flow rate of the river system is approximately represented by that of flow rate groups obtained by using statistical methods. Results of the model application
show that the priority of wastewater treatment shifts from one tributary subbasin to another when environmental standards are changed, reflecting the effect of transverse mixing in the mainstream. Water quality violations caused by flow rate groups are discussed in the study.
Water Environment Research® (WER®) publishes peer-reviewed research papers, research notes, state-of-the-art and critical reviews on original, fundamental and applied research in all scientific and technical areas related to water quality, pollution control, and management. An annual Literature Review provides a review of published books and articles on water quality topics from the previous year. Published as: Sewage Works Journal, 1928 - 1949; Sewage and Industrial Wastes, 1950 - 1959; Journal Water Pollution Control Federation, 1959 - Oct 1989; Research Journal Water Pollution Control Federation, Nov 1989 - 1991; Water Environment Research, 1992 - present.