Scientists from Veliky Novgorod have presented a new method for wastewater treatment that removes heavy metals twice as effectively, opening up opportunities for recycling toxic waste. This was reported in the press service of the department.
One of the main problems of wastewater treatment in Russia is that 90% of the resulting sludge is buried in sludge sites, the area of which exceeds 100,000 hectares. The concentration of heavy metals in the sludge is so high that they become unsuitable for use as fertilizers. The goal was to find the most effective reagents for detoxifying sludge and extracting heavy metals from it.
The purification process is based on the use of microorganisms that absorb harmful substances, concentrating heavy metals in the resulting sludge. This sludge becomes dangerous to the environment and unsuitable for further use.
To purify the sludge, specialists tested various substances capable of extracting metals, and poorly soluble calcium salts showed the best result.
The introduction of calcium salts disrupts the connection of metals with sludge particles, which allows transferring harmful substances into solution and separating them. The purification efficiency of some calcium salts reached more than 60%.
After treatment with the new method, the metal content in the sludge does not exceed the norms of the state standard. This allows using recycled sludge as fertilizer or for land reclamation. The technology review was carried out with the support of a grant from the Ministry of Education and Science of Russia as part of the Decade of Science and Technology.
Earlier www1.ru reported that chemists from Novosibirsk have developed a method for purifying wastewater from toxic ammonia impurities.
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