The pretreatment of refractory polyvinyl-alcohol （PVA） wastewater with low value of CODcr by Fenton＇s reagent was investigated to enhance the biodegradabilily. The effects of operating conditions such as pH of the ...The pretreatment of refractory polyvinyl-alcohol （PVA） wastewater with low value of CODcr by Fenton＇s reagent was investigated to enhance the biodegradabilily. The effects of operating conditions such as pH of the solution, Fe2＋ dosage, H2O2 dosage, reaction time and initial PVA concentration on the removal efficiency of CODCr were discussed. It is demonstrated that the optimum value of pH for removal of CODcr is 5 and the most suitable dosages of H2O2 （2%） and FeSO4 （10 mg/L） are 5% and 8.0%, respectively. When the initial CODcr value of the PVA water is 760 mg/L, the favorable reaction time is 110 min. Under these optimum conditions, the removal ratio of CODcr is 58.6% 61.4%, and the value of biodegradability （CODB/CODcr） increases markedly from 8.9% 9.7% to 62.6% 68.3%.展开更多
该研究分别以嗜热链球菌与5株乳杆菌组合(SN_4)、嗜热链球菌与保加利亚乳杆菌组合(SN_2)、5株乳杆菌组合(SN_3)三组益生菌组合对羊乳进行发酵,对发酵过程中(0~12 h)活菌数、pH值、酸度、持水力及凝乳点的质构特性、流变特性、菌群结构...该研究分别以嗜热链球菌与5株乳杆菌组合(SN_4)、嗜热链球菌与保加利亚乳杆菌组合(SN_2)、5株乳杆菌组合(SN_3)三组益生菌组合对羊乳进行发酵,对发酵过程中(0~12 h)活菌数、pH值、酸度、持水力及凝乳点的质构特性、流变特性、菌群结构、功能性差异代谢物等进行分析研究。结果显示,SN_4、SN_2、SN_3的凝乳时间依次为4.70、5.60、10.60 h;活菌数均可达到109 CFU/mL以上;发酵至凝乳点,链球菌属和乳杆菌属均被检出;SN_4组合发酵酸乳的持水力、质构特性和流变特性等均表现最优,SN_2次之;在P<0.05水平上,SN_4与SN_2相比,18种肽类、2种糖类、7种有机酸差异代谢物中分别有13种、2种和2种上调;SN_4与SN_3相比,18种肽类、7种糖类、6种有机酸差异代谢物中分别有5种、4种和6种上调;SN_3 VS SN_2、SN_4 VS SN_2、SN_4 VS SN_3差异代谢物通路分别涉及7条、5条、4条。研究结果表明,SN_4发酵酸乳特性均优于SN_2、SN_3。研究结果可为进一步研制感官优良、功能性强的多菌群发酵酸乳提供理论依据与技术支撑。展开更多
基金Project(08JCYBJC02600) supported by the Natural Science Foundation of Tianjin,ChinaProject(2008ZX07314-005-011) supported by the National Major Technological Program of China
文摘The pretreatment of refractory polyvinyl-alcohol （PVA） wastewater with low value of CODcr by Fenton＇s reagent was investigated to enhance the biodegradabilily. The effects of operating conditions such as pH of the solution, Fe2＋ dosage, H2O2 dosage, reaction time and initial PVA concentration on the removal efficiency of CODCr were discussed. It is demonstrated that the optimum value of pH for removal of CODcr is 5 and the most suitable dosages of H2O2 （2%） and FeSO4 （10 mg/L） are 5% and 8.0%, respectively. When the initial CODcr value of the PVA water is 760 mg/L, the favorable reaction time is 110 min. Under these optimum conditions, the removal ratio of CODcr is 58.6% 61.4%, and the value of biodegradability （CODB/CODcr） increases markedly from 8.9% 9.7% to 62.6% 68.3%.
文摘该研究分别以嗜热链球菌与5株乳杆菌组合(SN_4)、嗜热链球菌与保加利亚乳杆菌组合(SN_2)、5株乳杆菌组合(SN_3)三组益生菌组合对羊乳进行发酵,对发酵过程中(0~12 h)活菌数、pH值、酸度、持水力及凝乳点的质构特性、流变特性、菌群结构、功能性差异代谢物等进行分析研究。结果显示,SN_4、SN_2、SN_3的凝乳时间依次为4.70、5.60、10.60 h;活菌数均可达到109 CFU/mL以上;发酵至凝乳点,链球菌属和乳杆菌属均被检出;SN_4组合发酵酸乳的持水力、质构特性和流变特性等均表现最优,SN_2次之;在P<0.05水平上,SN_4与SN_2相比,18种肽类、2种糖类、7种有机酸差异代谢物中分别有13种、2种和2种上调;SN_4与SN_3相比,18种肽类、7种糖类、6种有机酸差异代谢物中分别有5种、4种和6种上调;SN_3 VS SN_2、SN_4 VS SN_2、SN_4 VS SN_3差异代谢物通路分别涉及7条、5条、4条。研究结果表明,SN_4发酵酸乳特性均优于SN_2、SN_3。研究结果可为进一步研制感官优良、功能性强的多菌群发酵酸乳提供理论依据与技术支撑。
