We used a ultrasound/Fe2＋/H2O2 process in continuous dosing mode to degrade the alachlor. Experimental results indicated that lower pH levels enhanced the degradation and mineralization of alachlor. The maximum alach...We used a ultrasound/Fe2＋/H2O2 process in continuous dosing mode to degrade the alachlor. Experimental results indicated that lower pH levels enhanced the degradation and mineralization of alachlor. The maximum alachlor degradation （initial alachlor concentration of 50 mg/L） was as high as 100% at pH 3 with ultrasound of 100 Watts, 20 mg/L of Fe2＋, 2 mg/min of H2O2 and 20℃ within 60 min reaction combined with 46.8% total organic carbon removal. Higher reaction temperatures inhibited the degradation of alachlor. Adequate dosages of Fe2＋ and H2O2 in ultrasound/Fe2＋/H2O2 process not only enhance the degradation efficiency of alachlor but also save the operational cost than the sole ultrasound or Fenton process. A continuous dosing mode ultrasound/Fe2＋/H2O2 process was proven as an effective method to degrade the alachlor.展开更多
文摘为研究阪崎克洛诺菌(Cronobacter Sakazakii)还原普通钙基蒙脱石中Fe3+的过程与机理,测定了体系中总蛋白与Fe2+含量变化,应用同步辐射XRD(SRXRD)与X射线吸收近边结构(XANES)研究反应产物。总蛋白与Fe2+数据表明在厌氧条件下Cronobacter sakazakii以乙酸作为电子供体,利用钙基蒙脱石中Fe3+作为电子受体进行生长代谢,还原蒙脱石中Fe3+形成Fe2+。反应中蒙脱石晶体结构部分破坏,原始的d001峰消失,出现一系列与新生矿物有关的衍射峰。XANES结果显示蒙脱石中Fe主吸收峰向低能量方向移动0.5 e V,边前峰峰位中心向低能量方向移动且峰面积减小,Fe氧化态降低,蒙脱石晶体结构发生变化。研究探讨了自然界中广泛分布的钙基蒙脱石可能受到的微生物还原作用。
基金supported by the National Science Council, Republic of China (No. 101-2221-E-264-005)
文摘We used a ultrasound/Fe2＋/H2O2 process in continuous dosing mode to degrade the alachlor. Experimental results indicated that lower pH levels enhanced the degradation and mineralization of alachlor. The maximum alachlor degradation （initial alachlor concentration of 50 mg/L） was as high as 100% at pH 3 with ultrasound of 100 Watts, 20 mg/L of Fe2＋, 2 mg/min of H2O2 and 20℃ within 60 min reaction combined with 46.8% total organic carbon removal. Higher reaction temperatures inhibited the degradation of alachlor. Adequate dosages of Fe2＋ and H2O2 in ultrasound/Fe2＋/H2O2 process not only enhance the degradation efficiency of alachlor but also save the operational cost than the sole ultrasound or Fenton process. A continuous dosing mode ultrasound/Fe2＋/H2O2 process was proven as an effective method to degrade the alachlor.
