Neva River
The Neva is a river in northwestern Russia flowing from Lake Ladoga through the western part of Leningrad Oblast to the Neva Bay of the Gulf of Finland. Despite its modest length of 74 kilometers, it is the fourth-largest river in Europe in terms of average discharge.
The Neva is the only river flowing from Lake Ladoga. It flows through the city of Saint Petersburg, three smaller towns of Shlisselburg, Kirovsk, and Otradnoye, and dozens of settlements. It is navigable throughout and is part of the Volga–Baltic Waterway and White Sea-Baltic Canal. It is a site of many major historical events, including the Battle of the Neva in 1240 which gave Alexander Nevsky his name, the founding of Saint Petersburg in 1703, and the Siege of Leningrad by the German army during World War II. The river played a vital role in trade between Byzantium and Scandinavia.
Environmental challenges associated with Neva river
A Greenpeace study in St Petersburg, Russia, says 40% of the city’s waste is dumped into the Neva river due to a shortage of waste treatment facilities. And this has been contaminating fish stock, which is sold in markets. The study found that pollutants from untreated and industrial waste included arsenic and polychlorobiphenyl, which is a lethal organic pollutant. Also, levels of copper in the city’s main waterway have crossed the accepted norm by 73 times and levels of manganese, by 26 times.
Heavy nutrient and organic matter loading, resulting in enhanced primary productivity, is currently recognized as the most serious environmental problem for the Neva Estuary and adjacent parts of the eastern Gulf of Finland. The introduction of alien species is an emerging issue for the Neva Estuary and should seriously be taken into account, considering the rapid development of the shipping industry in the area. These environmental problems along with the prevailing strategy of transport-oriented development of the coastal zone in the Neva Estuary and insufficient legislative background are the main challenges for coastal zone management in the eastern Gulf of Finland.
Extremely high concentrations of heavy metals however persist in backshore (coastal/beach) sediments around Neva Bay and continue to represent an anthropogenically imposed stress on the environment. Identification of off-shore pollution sources should be the subject of future investigations.
CBC OneDrop project addresses challenges of Neva River contamination with a novel sodium ferrate treatment technology
Replacement of primary chlorination with ferrate treatment of drinking water at wastewater treatment plants
Drinking water treatment with ferrate at water treatment plants:
- Chlorine only on secondary chlorination to preserve water after disinfection
- reduction of toxic organochlorine compounds by 3-10 times
- improvement of the ecological situation in the region, including in the Neva basin and the Gulf of Finland
- reducing the dose of coagulants and flocculants (processing is 7 times less expensive).
Advantages of using ferrate for post-treatment and disinfection of domestic wastewater
Post-treatment of household wastewater with sodium ferrate has been tested in St. Petersburg:
- meeting the requirements for the number of microorganisms (bacteria, viruses, cysts) in water the Neva and the Gulf of Finland
- half the price of electrolysis hypochlorite
- lack of chlorine and its compounds in the drain
- reduction of toxic mutagenic organochlorine
