黑曲霉分泌微生物絮凝剂的效果及其絮凝特性

Microbial flocculant secretion by Aspergillus niger and its flocculation properties

为了降低黑曲霉分泌絮凝剂的培养成本,提高微生物絮凝剂活性和产量,优化了培养条件,获得该菌产絮凝剂的最佳培养条件为:初始pH 7条件下,25℃恒温培养48 h,此时制备的絮凝剂对高岭土絮凝率达到96%以上.利用红外光谱法分析絮凝剂成分,推断其主要由多糖、核酸和蛋白质构成.在此基础上研究微生物絮凝剂对污泥脱水和Cr(Ⅵ)还原能力,结果显示黑曲霉分泌的微生物絮凝剂对污泥脱水有良好效果,当其投加质量浓度为27mg/L时,污泥含水率从97.1%降至78.2%.微生物絮凝剂处理Cr(Ⅵ)溶液时,对低质量浓度Cr(Ⅵ)还原效果较好,在pH值1~5,还原能力均较高,对质量浓度为20 mg/L的Cr(Ⅵ)的还原率均大于99%.

To reduce the cultivation cost of microbial flocculant secreted by Aspergillus niger,and improve the activity and production of bioflocculant,the culture conditions were investigated. The result showed that under the optimal cultural conditions of initial pH value 7,cultural time 48 h,cultural temperature 25 ℃,the flocculation effect of kaolin suspensions using this bioflocculant was over 96. 0%. Infrared spectroscopy observation revealed that the produced bioflocculant was mainly composed of polysaccharides,nucleic acid and protein. The bioflocculant was found as a highly effective dewatering agent of sludge. At the dose of 27. 0 mg / L,the moisture content of sludge decreased from 97. 1% to 78. 2%. When dealing with different concentrations of Cr( Ⅵ) solution,the bioflocculant showed better reduction efficiency towards Cr( Ⅵ) solution of lower concentration as pH value ranged from 1 ~ 5,and the reduction rate of 20 mg / L Cr( Ⅵ) exceeded 99%.