厌氧消化液不同投加方式对AOA-SBR系统处理效果的影响

为研究厌氧消化液的不同投加方式对AOA-SBR(厌氧/好氧/缺氧序批式反应器)系统处理效果的影响,在温度为20.0 ℃、生活污水与厌氧消化液体积比为24∶1、污泥中AOB(氨氧化菌)所占比例为7.34%条件下,考察了不投加、厌氧阶段开始一次性投加、好氧阶段开始一次性投加和好氧阶段分次投加等6种厌氧消化液投加方式(分别记为SBR-a、SBR-b、SBR-c、SBR-d、SBR-e、SBR-f)下AOA-SBR系统中SCOD_Cr(溶解性化学需氧量)、PO₄3--P、NH₄+-N的处理特性. 结果表明:厌氧消化液的投加方式对SCOD_Cr的去除基本没有影响,但厌氧消化液的投加使系统中PLR(PO₄3--P进水容积负荷)提高了104.88%,导致除SBR-a外各试验组出水ρ(PO₄3--P)均大于2.0 mg/L,为AOA-SBR处理生活污水与厌氧消化液联合废水的主要限制因素. SBR-b~SBR-f的SNPR(比亚硝酸盐生成速率)均高于SBR-a,表明厌氧消化液的添加有助于稳定污水短程硝化. 研究显示,厌氧开始阶段一次投加厌氧消化液(SBR-b)对系统脱氮效果影响最小,为最佳进水方式,此时SAUR(比氨氧化速率)为0.168 0 g/(g·d),SNPR(比亚硝酸盐产生速率)为0.136 3 g/(g·d),SND(同步硝化反硝化)作用率为26.64%.      

Mineralization of p-nitrophenol by a new isolate Arthrobacter sp. Y1

Arthrobacter sp. Y1, capable of metabolizing p-nitrophenol (PNP) as the sole carbon, nitrogen and energy source was isolated from activated sludge. The bacterium could tolerate concentrations of PNP up to 600 mg L^{? 1}, and degradation of PNP was achieved within 120 h of incubation. PNP and its metabolites were analyzed by high performance liquid chromatography (HPLC). The metabolite formed indicated that the organism followed the 4-nitrocathechol (4-NC) pathway for metabolism of this compound. The relevant degrading-enzyme was extracellular. Addition of other carbon source (glucose 0～ 30 g L^{? 1}) led to accelerated degradation. If the glucose concentration exceeded 30 g L^{? 1}, however, degradation was repressed. Spectrophotometry assay of the nitrite and genotoxic study showed that strain Y1 could detoxify PNP. Therefore, the present study may provide a basis for the development of the bioremediation strategies to remedy the pollutants in the environment.     

Fast start-up anammox process using Acyl-homoserine lactones (AHLs) containing supernatant

N-dodecanoyl homoserine lactone (C₁₂-HSL) was detected in the supernatant of an anammox granular sludge reactor (AGSR). C₁₂-HSL could enhance the specific anammox activity of anammox biomass. Adding C₁₂-HSL-containing AGSR supernatant into the continuously stirred tank reactors reduced the start-up time of the anammox process from 80 to 66 days. Moreover, the nitrogen loading rate was also enhanced to 1.6 times that of the control reactor. AHLs could increase the secretion of extracellular polymeric substances and anammox obtained better enrichment with the addition of AHLs-containing AGSR supernatant. Denaturing gradient gel electrophoresis analysis further revealed that AHLs played a role in mediating microbial community parameters. In conclusion, adding AHL-containing supernatant could be an effective and economical way to accelerate the start-up of anammox.     

侧流磷回收强化低碳源污水脱氮除磷效果的模拟与实验研究

以实验室营养物(BNR)去除工艺为研究对象,通过模拟预测与实验验证,对侧流磷回收强化低碳源污水脱氮除磷效果的影响进行研究.实验结果与模拟预测均显示,在低碳源生活污水(BOD5/TKN=3.2,COD/TKN=4.8,COD/TP=48.9)前提下,厌氧上清液侧流磷沉淀/回收可以使得出水氮、磷达标(TP≤0.5 mg P/L、TN≤15 mg N/L).研究结果表明,侧流磷回收可以相对提高后续生物脱氮除磷所需C/N、C/P比,从而强化低碳源污水生物营养物去除效果.模拟预测与实验验证几乎一致的结果表明,数学模拟技术完全可以取代传统实验,对所关心的工艺运行问题进行准确预测.