Specifics of surface runoff contents and treatment in large cities
The degree of surface runoff pollution in large cities has been assessed in modern conditions in the case study of production sites of St. Petersburg. Increased content of petroleum derivatives and heavy metal ions both in rainwater runoff and especially in snowmelt runoff has been revealed. It has been established that the composition of infiltration runoff from the newly built-up sites within the city limits commonly depends on their background, especially in the places of former unauthorized dumps, which are usually buried under the building sites. The content of petroleum derivatives in such surface runoff can exceed significantly their content in the runoff of landfills. Most petroleum derivatives appear in the surface runoff as emulsified and associated with suspended matters forms, which are a source of secondary pollution of waste water as it is accumulated in settlers and traps of local waste water treatment plants. Filtrational-sorptive technologies of surface runoff treatment are the most effective and simple in terms of both treatment and waste disposal.