Economic assessment of environmentally safe wastewater treatment technologies

Summary

In the competitive environment in Russia customers and investors shall take into account economic factors when designing municipal wastewater treatment facilities. Cost-effective and environmentally efficient wastewater treatment technologies are determined with account of regional specific features when siting the treatment facilities. Three representative groups of settlements are specified: rural (less than 20 thousand residents), towns (50-100 thousand residents), cities and megacities. The characteristics of municipal wastewater typical for every group are presented. Wastewater of rural settlements contains high concentrations of suspended solids and nutrients. Effluents of towns and cities contain heavy metals resulting as a rule from raw industrial wastewater discharges. The requirements to the effluent quality of typical settlements are presented. For every group of settlements the environmentally acceptable treatment technologies are suggested and economically substantiated. The following wastewater treatment technologies have been analyzed: full aerobic biological treatment; advanced biological treatment with nutrients removal (nitrogen, phosphorus); advanced biological treatment with nutrients removal (nitrogen, phosphorus) with tertiary treatment at filtration facilities and sorption filters. The suggested approach to the selection of a wastewater treatment technology with account of the economic and environmental conditions can be used in designing other systems of ecological purpose.

Key words

biological treatment , best available techniques , ecological safety , biogenic elements , municipal wastewater , economic assessment