水力负荷和回流比对前置反硝化BAF系统处理玉米青贮液的影响

采用前置反硝化BAF系统处理玉米青贮液，在前期实验的基础上重点考察了水力负荷和回流比对COD、NH3-N、TN的去除效果。结果表明，前置反硝化BAF系统处理玉米青贮渗出液有着良好的除碳脱氮效果；在气水比为2：1、水力负荷2．60m3／（m2·h）、回流比为300％的条件下COD、NH3-N、TN的去除率分别达到89．6％、84．5％和81．3％；出水浓度分别为22．36、16．28和22．81mg／L；水力负荷影响着系统内生物膜的更新速度、生物膜的厚度以及水的剪切力大小；回流比对该系统脱氮性能有着重要影响，当回流比从50％提高到300％时TN去除率显著提高，从42．3％增加到81．3％，增加了39．0％。

Influence of hydraulic loading and reflux ratio on treatment of corn silage effluent using a pre-denitrification BAF

The objective of this test was to develop a pre-denitrificaiton BAF system for treating corn silage effluent and to evaluate its feasibility. The performance of this BAF in terms of organic matter, ammonium, and total ammonium removal was investigated at different hydraulic loading and reflux ratios. The results showed that good results were obtained by pre-denitrification BAF process. The removal efficiencies of COD, NH3-N and TN were 89.6% , 84.5% and 81.3% , respectively, mg/L, respectively, when gas-water ratio was 2： and the outlet concentrations were 22.36, 16.28 and 22.81 1, hydraulic loading was 2.60 m3/（m2 . h） and reflux ratio was 300%. Renewal of biofilm, biofilm thickness and fluid shear stress were affected by hydraulic loading. Ni- trogen removal performance of pre-denitrification BAF was greatly affected by reflux ratio. The removal efficiency of TN increased from 42.3% to 81.3% , and by 39.0% with an incarese in reflux ratio from 50% to 300%.