BIT Makes Research Progress in Deep Arsenic Removal by Bioleaching of Regenerated Products From Spent Denitration Catalyst
News Source: School of Materials Science and Engineering
Editor: News Agency of BIT
Translator: Huang Yuwei, News Agency of BIT
Beijing Institute of Technology, Dec 13th, 2020: SCR is widely used in many industries such as electric power, smelting, cement and solid waste incineration, but arsenic and other highly toxic metals accumulated in the flue gas can result in deactivation of SCR catalyst so that a large number of waste SCR catalysts are produced at home and abroad every year. A combination of alkali treatment and acid washing is usually used to regenerate spent SCR catalysts in industry, but it still remains high residual of arsenic in the regenerated products so that the service life of regenerated catalysts is greatly reduced.
Recently, Professor Xin Baoping from the School of Material Science and Engineering in Beijing Institute of Technology (BIT), leading the research group of waste materials/solid waste recycling to apply the green bioleaching technology to the deep arsenic removal of the regenerated products of waste SCR catalyst for the first time, discovered a new bioleaching mechanism and achieved a good effect of deep arsenic removal. Under the high solid-liquid ratio of 10%, the bioleaching rate of arsenic was 53.1% and the residual arsenic was 174 mg/kg, which was lower than the standard requirement of 200mg/kg. However, only 6.7% of arsenic could be removed by H2SO4 leaching and the residual amount could reach 345 mg/kg. The large amount of cysteine secreted by leaching strains plays a decisive role in the deep removal of arsenic. Sulfhydryl nucleophilic attacking on trivalent and pentavalent arsenic promotes arsenic shedding. Activating the recycled products when bioleaching arsenic significantly improves the NH3 adsorption capacity of the regenerated product, which means bioleaching technology can achieve simultaneous arsenic removal and performance activation. The research is of great significance to theory and practice of bioleaching technology and the expansion of its application fields.
Relevant findings “Deep removal of arsenic from regenerated products of spent V2O5-WO3/TiO2 SCR catalysts and its concurrent activation by bioleaching through a novel mechanism” was published in Chemical Engineering Journal (IF: 10.652).
Paper link: https://doi.org/10.1016/j.cej.2020.127722.