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851.
An innovative shortcut biological nitrogen removal system, consisting of an aerobic submerged membrane bioreactor (MBR) and an anaerobic packed-bed biofilm reactor (PBBR), was evaluated for treating high strength ammonium-bearing wastewater. The system was seeded with enriched ammonia-oxidizing bacteria (AOB) and operated without sludge purge with a decreased hydraulic retention time (HRT) through three phases. The MBR was successful in both maintaining nitrite ratio over 0.95 and nitrification efficiency higher than 98% at a HRT of 24 h. The PBBR showed satisfactory denitrification efficiency with very low effluent nitrite and nitrate concentration (both below 3 mg/L). By examining the nitrification activity of microorganism, it was found that the specific ammonium oxidization rate (SAOR) increased from 0.17 to 0.51 g N/(g VSS·d) and then decreased to 0.22 g N/(g VSS·d) at the last phase, which resulted from the accumulation of extracellular polymers substances (EPS) and inert matters enwrapped around the zoogloea. In contrast, the average specific nitrite oxidization rate (SNOR) is 0.002 g N/(g VSS·d), only 1% of SAOR. Because very little Nitrobactor has been detected by fluorescence in situ hybridization (FISH), it is confirmed that the stability of high nitrite accumulation in MBR is caused by a large amount of AOB. 相似文献
852.
Nitrogen removal via nitrite from municipal landfill leachate 总被引:2,自引:0,他引:2
A system consisting of a two-stage up-flow anaerobic sludge blanket (UASB), an anoxic/aerobic (A/O) reactor and a sequencing
batch reactor (SBR), was used to treat landfill leachate. During operation, denitrification and methanogenesis took place simultaneously
in the first stage UASB, and the e uent chemical oxygen demand (COD) was further removed in the second stage UASB. Then the
denitrification of nitrite and nitrate in the returned sludge by using the residual COD was accomplished in the A/O reactor, and ammonia
was removed via nitrite in it. Last but not least, the residual ammonia was removed in SBR as well as nitrite and nitrate which were
produced by nitrification. The results over 120 d (60 d for phase I and 60 d for phase II) were as follows: when the total nitrogen
(TN) concentration of influent leachate was about 2500 mg/L and the ammonia nitrogen concentration was about 2000 mg/L, the shortcut
nitrification with 85%–90% nitrite accumulation was achieved stably in the A/O reactor. The TN and ammonia nitrogen removal
e ciencies of the system were 98% and 97%, respectively. The residual ammonia, nitrite and nitrate produced during nitrification in
the A/O reactor could be washed out almost completely in SBR. The TN and ammonia nitrogen concentrations of final e uent were
about 39 mg/L and 12 mg/L, respectively. 相似文献
853.
悬浮填料流化池预处理原水中氨氮的研究 总被引:2,自引:0,他引:2
采用悬浮填料接触氧化生物预处理试验装置,对珠江原水进行中试研究。结果表明:原水的氨氮平均浓度为3.82mg/L,该工艺对氨氮的平均去除率达到83.7%,其出水氨氮平均浓度降为0.56mg/L,高锰酸盐指数的平均去除率可达14.3%。该工艺是处理高氨氮微污染原水的一种高效的生物反应器。 相似文献
854.
855.
针对目前水体中MCPA检测灵敏度不够,缺乏一种无需前处理、可直接上机、简单便捷方法的问题,以超高液相色谱串联质谱仪,建立了一种以电喷雾离子源ESI-为电离模式、MRM为监测模式、可直接进样测定水体中MCPA残留的方法。结果表明,最优方法条件为定量离子对199.0/140.9(m/z),流动相乙腈和水梯度洗脱,色谱柱Acquity UPLC HSS T3。在MCPA质量浓度为0.1~100μg/L范围内线性良好(R2=99.99%),检出限为0.006μg/L,定量限为0.018μg/L,是现有直接进样法的23~83倍,完全满足水体中MCPA的检测要求(<0.1μg/L)。在添加水平为1~100μg/L时,回收率为94.30%~105.60%,相对标准偏差为1.05%~3.61%,具有前处理简单、准确性高、精密度好、灵敏度高等优点。 相似文献
856.
运用工作危害分析对脱硫塔更换填料中的危险进行了分析,制定了相应对策,保证了施工过程的安全. 相似文献
857.
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860.
采用新型酶促厌氧填料、半软性填料、酶促好氧填料和PYC挂膜陶粒填料对两段错向流曝气生物滤池反应器进行污水处理试验研究,分析了4种填料对反应器污水处理效能的贡献并为反应器填料的选择提供科学依据.结果表明,以半软性填料和酶促好氧填料为组合填料的两段错向流曝气生物滤池反应器污水处理效能均优于其它填料. 相似文献