不同改性玉米芯作为反硝化固体碳源的比选

Comparative Selection of Different Modified Corncobs as Solid Carbon Sources for Denitrification

为解决低碳氮比污水反硝化碳源不足及投加液体碳源存在弊端的问题,试验分别采用1.5%NaOH、O_(3)、1.5%NaOH+O_(3)、O_(3)+1.5%NaOH对天然纤维素材料玉米芯进行改性处理,考察改性后的玉米芯作为反硝化固体碳源时的静态释放特性及静态反硝化脱氮性能。结果表明,1.5%NaOH+O_(3)改性处理玉米芯浸出液的15 d累计总有机碳(TOC)释放浓度最高,达到425 mg/L,且持续释碳能力最强,不产生二次污染;其作为反硝化固体碳源时,4~50 d内硝酸盐去除率高达98%,且无亚硝酸盐的积累,出水pH也稳定在7.6。因此,1.5%NaOH+O_(3)改性处理是玉米芯作为反硝化固体碳源时提高性能的最佳改性方式。

In order to solve the problem of insufficient carbon source for denitrification and the drawbacks of adding liquid carbon source in low carbon-nitrogen ratio sewage,the experiment uses 1.5%NaOH,O_(3),1.5%NaOH+O_(3),O_(3)+1.5%NaOH to modify natural cellulose material corncobs,respectively,thus investigating the static release characteristics and static denitrification performance of modified corncob as a solid carbon source for denitrification.The results show that the 1.5%NaOH+O_(3)modified corncob leaching solution has the highest cumulative total organic carbon(TOC)release concentration in 15 d,reaching 425 mg/L,and the continuous carbon release ability is the strongest,without generating secondary pollution;when it is used as a solid carbon source for denitrification,the nitrate removal rate is as high as 98%within 4~50 d,and there is no accumulation of nitrite,and the effluent pH is also stable at 7.6.Therefore,1.5%NaOH+O_(3)modification is the best modification way to improve the performance of corncob as a solid carbon source for denitrification.