农业废弃物为碳源去除硝酸盐氮研究

目的]探讨以农业废弃物为碳源去除硝酸盐氮的效果。方法]以棉秆、玉米秆、玉米芯和稻壳为碳源,采用静态和动态试验,研究不同碳源的COD释放情况和脱氮效果。结果]静态试验中,玉米芯和玉米秆的COD释放速率比稻壳和棉秆的高,棉秆和稻壳pH的变化较小,玉米秆和玉米芯的pH先降后略有升高,最高趋于稳定。动态试验中,随着停留时间(241、26、h)的缩短,硝酸盐氮的浓度均逐渐升高,玉米秆和玉米芯中硝酸盐氮的去除率依然在70%以上,而棉秆和稻壳则下降比较明显;出水COD浓度随停留时间的缩短在减小,玉米秆和玉米芯的出水COD浓度均在100 mg/L以上,出水浓度偏高,反硝化所需要的碳源则过剩。结论]该研究为开发新的脱氮效率较高的碳源物质提供参考依据。

Study on Removing Nitrate with Agriculture Waste as Carbon Source

Objective] The study aimed to discuss the effect of removing the nitrate with the agriculture waste as the carbon source.Method] With the cotton stalk,corn stalk,corn cob and rice husk as the carbon source,the release of COD and the removal of nitrate were studied by the static and dynamic experiments.Result] In the static experiments,the COD release rates of the corn cob and corn stalk were higher than the rice husk and cotton stalk;the pH in the rice husk and cotton stalk had little change,that in the cotton stalk and corn stalk was first decreased and then slightly increased,and trended to be stable at highest value.In the dynamic experiments,the nitrate concn.was gradually increased with the retention time(24,12,6 h) becoming shorter,the removal rates of the nitrate in the corn stalk and corn cob were still more than 70%,while that in the cotton stalk and rice husk was decreased obviously.The COD concn.in the effluent was decreased with the shorter retention time,and both of the COD concn.in the effluent of the corn stalk and corn cob were more than 100 mg / L.The COD concn.in effluent was high and the carbon source needed by the denitrification was excessive.Conclusion] The study provided the reference basis for the development of the new carbon source materials with higher nitrate removal rate.