沸石强化生化装置脱氮功能的效果及机理初探

针对石化工业废水开展沸石强化脱氮处理试验研究，通过比较沸石浓度25mg/L与空白，以及沸石浓度25 mg/L与50mg/L两阶段脱氮效果，探讨沸石促进脱氮功能的机理，结果表明，曝气池中投加沸石可明显提高氨氮和总氮的去除率，硝化细菌总数和硝化功能也得到增强。与空白对照组相比， 沸石浓度25mg/L的试验组运行稳定后，氨氮去除率提高约10%~13%，总氮去除率约提高13%，出水中NO3--N含量约提高100%，氨氮与总氮之比下降6%，内源硝化耗氧呼吸速率可提高138%，硝化细菌总数是空白对照组2.2folds。沸石浓度提高到50mg/L后，试验组的脱氮效果略有增加，但效果不明显。通过对试验结果的关联分析，认为沸石提高系统脱氮能力的原因一方面是因为沸石对NH4+及硝态氮的交换吸附，另一方面NH4+离子富集于沸石表面及内部、沸石颗粒独特的好氧-缺氧微环境，以及沸石离解出CO32- 或HCO3-增加碱度等条件，促进了硝化细菌和反硝化细菌的生长，从而提高了系统脱氮能力。

Experimental Study on the Processes and Mechanism of Enhanced Denitrification by Addition Zeolite in Wastewater Treatment

Aim to enhanced nitrogen removal from wastewater by addition zeolite to aeration tank, The result showed that addition of zeolite could improve the nitrification/denitrification efficiencies by comparing two phase experiment of 25mg/L with blank and 25mg/L with 50 mg/L. and the population of nitrifying bacteria in activated sludge increased obviously. When 25mg/L zeolite was added into aeration tank, NH4+-N and TN removal increased 10~13% and 13% respectively, endogenous respiration rate of nitrification increased about 138%,and the population of nitrification bacteria increased about 2.2 folds; But the nitrogen removal and endogenous respiration rate of 50 mg/L enhanced indistinct comparing with 25 mg/L. These results indicated that NH4+ ion-exchange and accumulation to the interior/outer surfaces of zeolite, co-existence of aerobic and anoxic micro-environments were responsible for the enhanced denitrifying function.