Ruangchainikom Chalermchai, Liao Chih-Hsiang, Anotai Jin, Lee Ming-Tang
National Research Center for Environmental and Hazardous Waste Management, Chulalongkorn University, Bangkok, Thailand.
Chemosphere. 2006 Apr;63(2):335-43. doi: 10.1016/j.chemosphere.2005.06.049. Epub 2005 Aug 19.
In this study, CO2 was bubbled into Fe0-contained solution to create an acidic environment favorable to reduction of aqueous nitrate under various water qualities. Results showed that nitrate of 30 mg l(-1) could be removed from solutions almost completely within 30 min under the conditions of 2 g Fe0 l(-1) and CO2 bubbling flow rate of 200 ml min(-1). It was observed from the Fe0/CO2 system that one mole of nitrate reduced by Fe0 led to the formation of 6.6 mol of ferrous ions. The removal of nitrate increases with increasing Fe0 dosage, however, the removal makes no difference as the Fe0 is applied at a relatively higher dosage. In the system with various water qualities, nitrate removal was inhibited significantly in the presence of humic acid. Calcium ions strongly retard nitrate removal, whereas chloride ions promote the reduction of nitrate in a significant way. Sodium ions impose only slight inhibitive effect on nitrate removal. Water molecule in the studied system can be of significance due to its competitive capability of electrons released from Fe0.
在本研究中，将二氧化碳鼓泡通入含Fe0的溶液中，以在各种水质条件下营造有利于还原水中硝酸盐的酸性环境。结果表明，在2 g Fe0 l(-1)和二氧化碳鼓泡流速为200 ml min(-1)的条件下，30 mg l(-1)的硝酸盐可在30分钟内几乎完全从溶液中去除。从Fe0/CO2体系中观察到，1摩尔被Fe0还原的硝酸盐会导致形成6.6摩尔亚铁离子。硝酸盐的去除率随Fe0投加量的增加而提高，然而，当Fe0投加量相对较高时，去除效果并无差异。在具有各种水质的体系中，腐殖酸的存在会显著抑制硝酸盐的去除。钙离子强烈阻碍硝酸盐的去除，而氯离子则显著促进硝酸盐的还原。钠离子对硝酸盐的去除仅产生轻微的抑制作用。由于所研究体系中的水分子具有从Fe0释放电子的竞争能力，因此可能具有重要意义。
