Scientists from Veliky Novgorod have presented a new method for wastewater treatment that is twice as effective at removing heavy metals, 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 fields, 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 treatment process is based on the use of microorganisms that absorb harmful substances, concentrating heavy metals in the resulting sludge. This sludge becomes hazardous to the environment and unsuitable for further use.
To treat 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 bond between metals and sludge particles, which allows harmful substances to be transferred into solution and separated. The treatment 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 the recycled sludge to be used 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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