摘要
从土壤中分离筛选到1株硅酸盐细菌SDB6,经鉴定为胶质芽孢杆菌.探讨了氮源、初始pH值、温度、转速以及装液量对菌体生长的影响,并对影响因素进行正交优化,得到最佳培养条件为:质量浓度10 g/L酵母粉为氮源,250 mL锥形瓶中装液量为50 mL,初始pH值7.5,温度30℃,转速180 r/min.利用1株耐重金属黑曲霉AS 3.879M对原始飞灰和SDB6脱硅处理后的飞灰进行生物淋滤处理20 d,对比分析淋滤液中有机酸浓度、溶出金属浓度以及处理后飞灰的浸出毒性.结果表明,与未脱硅飞灰相比,脱硅与生物淋滤组合处理后的飞灰中金属溶出效果显著提高.Cu、Mn、Cr、Zn以及Fe的溶出率分别达到了31%、75%、60%、60%和48%,飞灰中50%的金属(Cd、Cr、Cu、Fe、Mn、Pb、Zn)被浸出.处理后飞灰浸出毒性远低于国家标准,可以安全地进入填埋场或进行资源化利用.
One silicate bacteria strain SDB6 with good performance in silicon removal was isolated and screened from soil.Based on the morphological,physiological,biochemical characteristics and 16S rDNA sequence analysis,SDB6 was identified as Bacillus mucilaginosus strain.The effects of nitrogen source,pH,temperature,rotate speed and medium volume on the growth of SDB6 were investigated.The above factors were optimized using the orthogonal design.The optimized condition was described as follows： 10 g/L yeast,250 mL flask with 50mL culture medium,pH 7.5,30℃,180 r/min.The bioleaching of un-desilicated and desilicated fly ash using the adapted Aspergillus niger AS 3.879M strain was carried out for 20d.The results indicated that the metal extraction yield in bioleaching increased obviously with desilication treatment comparing to that without desilication treatment.The extraction yield of Cu,Mn,Cr,Zn and Fe from desilicated fly ash was 31%,75%,60%,60% and 48%,respectively.The total metals extracti.on yield of desilicated fly ash increased to 50%.The TCLP results of the fly ash after bioleaching indicated that the leaching toxicities of the treated fly ash were far lower than the regulated levels of China and permitted to the further landfill or reuse.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2010年第1期266-272,共7页
Environmental Science
基金
国家自然科学基金项目(20577047)
国家高技术研究发展计划(863)项目(2002AA644010)
