Method for removing heavy metal in excess activated sludge

• Main Authors: DENG FEI, ZENG MENG, ZHENG CHENGGANG, HUANG ANHUI, SONG CUNJIANG, MENG FENGLIN, SUN YAMIN, TAO JIAN
• Format: Patent
• Language: Chinese; English
• Published: 08.09.2010
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

This invention discloses method and apparatus for removing heavy metals. The method comprises: inoculating Thiobacillus ferrooxidans and eosinophilic heterotrophic bacteria (3.0-8.0%) into residual active sludge for biological reaction, automatically flowing the reaction solution by a constant flow pump into a precipitation barrel, precipitating heavy metals in the supernatant with heavy metal chelating agent or CaO, and refluxing the eosinophilic heterotrophic bacteria by the constant flow pump to the reaction barrel. Since Thiobacillus ferrooxidans is sensitive to soluble organic matters, inoculation of Thiobacillus ferrooxidans together with eosinophilic heterotrophic bacteria can reduce the contents of soluble organic matters in the reaction solution, thus can shorten the growth period of Thiobacillus ferrooxidans and improve the removal effect of heavy metals. When the method and apparatus are utilized for biological reaction for 5-7 days, the removal effect of heavy metals in residual sludge is obvious.