摘要
与生物反硝化相比,化学催化还原法反应速度快,适于分散给水处理,被认为是最有应用前景的地下水脱硝方法。该方法以氢气、甲酸等为还原剂,利用适当的催化剂将水中的硝酸根还原为氮气,在反应过程中有可能由于氢化作用不完全形成亚硝酸盐,或由于氢化作用过强而形成NH4+等副产物。故有效提高硝酸盐还原速度的同时控制反应发生的方向是该技术的关键;寻求高效、高选择性和稳定性的催化剂,探索环境因素对于催化反应的影响是该领域的研究重点。在综述化学催化还原水中硝酸根研究进展的基础上,重点对关键影响因素:催化剂性质、水质因素、反应条件、传质过程进行了详细阐述,提出催化材料的功能设计、作用机理和实用化及高效组合工艺的建立和优化方面的研究是化学催化还原硝酸根的研究发展方向。
Nitrate pollution of groundwater has caused widespread concern.Compared with biological denitrification,chemical catalytic reduction of nitrate has fast response and it is suitable for decentralized water treatment.It is regarded as one of the most promising and flexible approaches for removal of nitrate from water.In this process,nitrate ions are reduced using reducer such as hydrogen and formic acid over catalyst.The reaction obeys a consecutive reaction scheme in which nitrite appears as an intermediate,while nitrogen and ammonia are the final products.Use appropriate catalyst restore the water nitrate nitrogen to N2,In the reaction may be due to incomplete formation of hydrogenation nitrite,or due to excessive formation of hydrogenation NH4＋ and other by-products.The key in this process is how to control the reactive direction when improving the reactive velocity.The most important Research focus for the catalytic reduction of nitrate is preparing the catalyst with high activity,selectivity and stability,as well as studying the effect of reaction conditions.On the basis of summarizing the effects and mechanisms of catalytic reduction of nitrate,the influences of key factors such as catalytic properties of catalyst,the quality of groundwater,reaction conditions,and mass transfer are reviewed in detail in this paper.The study and development tendency is focused on the functional design,mechanism and use in reality of catalyst,as well as the optimization of combination technology for catalytic reduction of nitrate.
出处
《水处理技术》
CAS
CSCD
北大核心
2010年第7期14-19,共6页
Technology of Water Treatment
基金
河海大学水文水资源与水利工程科学国家重点实验室开放基金(2008490111)
国家自然科学基金(50708007)
中央高校基本科研业务费专项资金资助
关键词
催化还原
硝酸盐
影响因素
水污染
catalytic reduction
nitrate
influence factors
water contamination
