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471.
在出水基质浓度Ce,沼气产生速率Qg对进水基质浓度C0序列的传递函数模型的基础上,采用卡尔曼滤波法对Ce和Qg序列进行估计和预测,标准误差分别为6.19%和10.4%。 相似文献
472.
A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A^2/O-BAF) combined system was carded out to treat wastewater with lower C/N and C/P ratios. The A^2/O process was operated in a short aerobic sludge retention time (SRT) for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification. The BAF effluent was partially returned to anoxic zone of the A^2/O process to provide electron acceptors for denitrification and anoxic P uptake. This unique system formed an environment for reproducing the denitdfying phosphate-accumulating organisms (DPAOs). The ratio of DPAOs to phosphorus accumulating organisms (PAOs) could be maintained at 28% by optimizing the organic loads in the anaerobic zone and the nitrate loads into the anoxic zone in the A^2/O process. The aerobic phosphorus over-uptake and discharge of excess activated sludge was the main mechanism of phosphorus removal in the combined system. The aerobic SRT of the A^2/O process should meet the demands for the development of aerobic PAOs and the restraint on the nitrifiers growth, and the contact time in the aerobic zone of the A^2/O process should be longer than 30 min, which ensured efficient phosphorus removal in the combined system. The adequate BAF effluent return rates should be controlled with 1--4 mg/L nitrate nitrogen in the anoxic zone effluent of A^2/O process to achieve the optimal nitrogen and phosphorus removal efficiencies. 相似文献
473.
研究城市生物沥浸污泥脱水性能与污泥静置沉降时间的关系,对城市污泥生物沥浸工程化应用具有指导性作用.因此,以城市生物沥浸污泥为研究对象,研究了低温条件下(5℃和15℃)污泥静置0~6d过程中,污泥pH值和脱水性能(用比阻γ表征)的变化情况.同时,对实验室污泥比阻与厢式压滤机中试结果进行了相关性分析.结果表明:温度增加将有利于污泥沉降,在实际运行中沥浸污泥可选择静置0.5d再进行压滤脱水.随着静置时间的延长,冬季(5℃)和春季(15℃)城市沥浸污泥pH值和比阻均呈逐渐上升的趋势.静置6d后,pH值分别从3.93和3.87上升到5.10和5.32,比阻γ分别从1.72×1012m·kg-1和1.76×1012m·kg-1上升到3.08×1012m·kg-1和5.82×1012m·kg-1.实验室污泥比阻测定和厢式压滤机中试结果表明,不同静置时间下污泥比阻γ与压滤机压滤脱水V-t/V曲线(V:滤液体积;t:过滤时间)斜率k呈极显著正相关关系,说明用污泥比阻γ能准确地反映出生物沥浸污泥的压滤脱水性能.这对生物沥浸技术在工程上的应用和推广具有重要意义. 相似文献
474.
Performances of biological aerated filter employing hollow fiber membrane segments of surface-improved poly (sulfone) as biofilm carriers 总被引:2,自引:0,他引:2
SHEN Ying-jie WU Guang-xi FAN Yao-bo ZHONG Hui WU Lin-lin ZHANG Shao-lai ZHAO Xian-hong ZHANG Wei-jun 《环境科学学报(英文版)》2007,19(7):811-817
Using the surface of poly (sulfone) hollow fiber membrane segments as grafted layer, the hydrophilic acrylamide chain was grafted on by UV-photoinduced grafting polymerization. The gained improvement of surface wettability for the modified membrane was tested by measuring the contact-angle as well as FTIR spectra. Then correlation between the hydrophilic ability of support material and the biofilm adherence ability was demonstrated by comparing the pollutant removal rates from urban wastewater via two identical lab-scale up-flow biological aerated filters, one employed the surface wettability modified poly (sulfone) hollow fiber membrane segment as biofilm carder and the other employed unmodified membrane segment as biofilm carder. The experimental results showed that under the conditions of influent flux 5 L/h, hydraulic retention time 9 h and gas to liquid ratio (G/L) 10: 1, the removal rates of chemical oxygen demand (COD) and ammonium nitrogen (NH4^+-N) for the modified packing filter and the unmodified packing filter was averaged at 83.64% and 96.25%, respectively, with the former filter being 5%-20% more than the latter. The effluent concentration of COD, NH4^+-N and turbidity for the modified packing filter was 25.25 mg/L, 2 mg/L and 8 NTU, respectively. Moreover, the ammonium nitrogen removal performance of the filter packing the modified PSF was compared with the other bioreactor packing of an efficient floating medium. The biomass test indicated that the modified membrane matrixes provided better specific adhesion (3310-5653 mg TSS/L support), which gave a mean of 1000 mg TSS/L more than the unmodified membrane did. In addition, the phenomenon of simultaneous denitrification on the inner surface of the support and nitrification on the outer surface was found in this work. 相似文献
475.
生物膜滴滤塔性能受多孔填料、生物膜和气液两相流体流动特性的共同影响,传质过程复杂,流体流动强烈地影响生物滴滤塔生物膜的形成和分布,同时生物膜在滴滤塔中的分布反过来影响填料层内气液两相流体流动。实验研究了生物滴滤塔挂膜前后填料层的孔隙率和不同气、液流量下压强降的变化,结果表明:滴滤塔内生物膜分布不均匀,填料层孔隙率随填料层高度增加而增加,填料层中下部,孔隙率低,生物量最大,填料层顶部,孔隙率与挂膜前相等,无生物膜生长;挂膜前气体流量对填料层压强降影响较液体流量影响大,挂膜后液体流量对填料层压强降影响较气体流量影响大;同时微生物挂膜成功后填料层气体压强降远大于挂膜前压强降。 相似文献
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