提出CH-1菌解毒铬渣及回收铬资源的新工艺。采用扫描电镜、透射电镜以及能量弥散X射线分析(EDXA)和电子顺磁共振(EPR)等分析手段对还原反应前后细菌细胞形貌进行观察,并对还原反应沉淀产物的元素组成进行定性分析,研究并计算了示范工程中铬的回收率及平衡。结果表明Cr(Ⅵ)的还原反应在细菌体外发生,反应产物的主要组成元素为Cr^3+,反应产物成分为Cr(OH)3。铬渣中90%以上的Cr(Ⅵ)以Cr(OH)3淤泥的形式得以回收,20t/批规模的示范工程可回收Cr(OH)3(含量32.8%)淤泥694.2kg,实现铬的再生,并从根本上消除铬渣的污染问题。
A novel technology of chromium recovery from chromium-containing slag by Achromobacter sp. CH-1 based on the principle of bacterial leaching and bacteriosmelt was proposed. Scanning electron microscope(SEM), translated transmission electron microscope(TEM), energy dispersive X-ray analysis (EDXA) and electron paramagnetic resonance (EPR) were utilized to observe the appearance of bacterial cells before and after Cr(Ⅵ) reduction, and to analyze the elemental composing of precipitate product during the process. Recovery rate and balance of chromium in demonstration projects were investigated and calculated. The results indicate that the major element composing precipitate is trivalent chromium, which implies that the reduction product is Cr(OH)3. More than 90% Cr(Ⅵ) in chromium-containing slag is recovered in the form of Cr(OH)3-containing sludge. 694.2 kg sludge containing Cr(OH)3 (mass fraction of 32.8%) are recovered, which eliminates the pollution of chromium-containing slag thoroughly.