多孔钛板负载Pd-Sn电催化去除硝酸盐氮的研究  

Study on electrocatalytic reduction of nitrate nitrogen by porous titanium plate loaded Pd-Sn

作　　者：周丽[1] 邓慧萍[1] 刘振中[1] 桑松表[1] 

机构地区：[1]同济大学环境科学与工程学院,上海200092

出　　处：《供水技术》2007年第5期32-36,共5页Water Technology

基　　金：国家科技攻关计划课题"小城镇环境保护关键技术研究及设备开发"(2003BA808A17)

摘　　要：研究了多孔钛板负载催化剂Pd-Sn(4∶1)作为阴极,利用电化学反应器脱除饮用水中的硝酸盐氮。在通常饮用水水源的硝酸盐氮含量范围内,电化学催化反硝化的活性可达39.97mg/(g·h),在pH值为7,电流密度为2.3mA/cm2,反应600min后,NO3--N的浓度从22.6mg/L下降到0.3mg/L,去除率达到98%,出水浓度远远低于饮用水水质标准要求的10mg/L。然而此催化剂负载比例下对副产物氨氮和亚硝酸盐氮尤其是对氨氮的选择率非常高。低电流密度和低pH值时,NO3--N去除率比较高,而中间产物NO2-生成较少,NH4+的生成量则随着电流密度和pH值的降低而增加,并且随着电流密度的增加,硝酸盐还原的电流效率显著降低。Pd-Sn的协同作用,提高了反应活性和氮气的选择率。Removal of nitrate nitrogen with porous titanium plate loaded Pd-Sn (4:1) catalyst as negative electrode was investigated. The activity of electrocatalytic denitrification was 39.97 mg/(g.h) within nitrate nitrogen concentration of source water, concentration of NO-3-N was reduced from 22.6 mg/L to 0.3 mg/L and up to 98% NO-3-N was removed under the condition of pH 7, current density 2.3 mA/cm2 and reaction time of 600 min, effluent concentration was much lower than 10 mg/L of drinking water quality standards. However there was a high selectivity of by-products such as ammonia nitrogen and nitrite nitrogen, especially for ammonia nitrogen. Lower current density and lower pH made a higher nitrate removal rate, less nitrite concentration and higher ammonia concentration; meanwhile higher current density resulted in lower current efficiency. Synergistic effects of Pd-Sn led to higher activity and nitrogen selectivity.

关 键 词：多孔钛板 Pd-Sn负载 电催化还原 副产物 

分 类 号：TU991.112[建筑科学—市政工程]