Anaerobic ammonium oxidation(Anammox)has become a promising method for biological nitrogen removal.However,this biotechnology application is always limited due to the low growth rate and biomass yield of Anammox bacteria.This study investigated the process of fast reactivation of an Anammox consortium idled for 2 years via hydrodynamic stress control.The results showed that the Anammox system was efficiently and quickly reactivated by shortening of the hydraulic retention time(HRT)of the reactor from 12 to6 hr within 68 days of operation.Moreover,at a 4-hr HRT with an influent total nitrogen loading rate of 1.2 kg N/(m3·day),the reactor maintained high biological performance with an ammonium removal loading rate of 0.52 kg N/(m3·day)and a nitrite removal rate of0.59 kg N/(m3·day).In the reactivated Anammox reaction,the stoichiometric coefficients of NH4+–N to NO2-–N and NH4+–N to NO3-–N were 1:1.04±0.08 and 1:0.31±0.03,respectively.The specific Anammox activity and hydrazine oxidoreductase activity,both of which represent the degree of Anammox bacteria present,increased as the hydrodynamic stress increased and were maximally(125.38±3.01 mg N/(g VSS·day)and 339.42±6.83μmol/(min·g VSS),respectively)at 4-hr HRT.Microbial response analysis showed that the dominant microbial community was obviously shifted and the dominance of Anammox bacteria was enhanced during the hydrodynamic selection.
为了研究固相餐厨垃圾厌氧发酵产甲烷特性,对固相餐厨垃圾进行批式厌氧发酵实验,主要考察了p H、VFA、COD以及纤维素酶活的变化情况,并运用修正Gompertz模型对其产气模型进行动力学拟合。实验结果表明,缓冲溶液的添加可明显促进厌氧发酵产甲烷。在添加缓冲溶液条件下,污泥与餐厨垃圾比例为2∶1,1∶1,2∶3和1∶2时,餐厨垃圾都能很好地进行厌氧发酵产甲烷,最大产甲烷产量分别为594.66、449.74、392.93和333.36 m L/g TS。采用修正Gompertz模型分别对2∶1、1∶1、2∶3和1∶2实验组产甲烷曲线进行拟合,得到产甲烷潜力分别为567.57、437.89、381.12和305.60 m L/g TS,最大产甲烷速率分别为89.38、59.81、47.26和25.80 m L/(d·g VS)。对厌氧发酵过程中纤维素酶活的变化进行了研究,结果表明,CMC酶活性在提高餐厨垃圾厌氧发酵过程中纤维素的降解起重要作用。
