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XIA Mingfang WANG Zhiwei WU Zhichao WANG Xinhu ZHOU Zhen LU Jilai 《环境科学学报(英文版)》2009,21(12):1639-1645
The process of using flat-sheet membrane for simultaneous sludge thickening and digestion (MSTD) was employed. The variationsof sludge concentration and rheology were characterized and simulated. Based on mass balance analysis, mathematical models weredeveloped and successfully used to predict and evaluate the variations of sludge concentration and the digestion e ciency in the MSTDprocess. The apparent viscosity of sludge could be modeled as functions of mixed liquor suspended solids and shear rates. The sludgein the MSTD process showed both shear-thinning and viscoplastic behaviour, and under various shear rates di erent rheological modelscould be chosen to predict their flow behaviour. It was also found that sludge concentration and viscosity had significant correlationswith membrane fouling in the MSTD process. 相似文献
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对某城市6座污水处理厂污泥做真空抽滤浓缩,并对污泥特性进行了研究.结果发现,污泥中每g固体(TS)相当于1 g化学需氧量(COD);每g挥发性固体(VS)相当于1.5 g COD,其线性回归R2分别为0.931 4和0.922 8.污泥中携带的COD占污水去除COD总量的60%.污泥有机物组成表现为高蛋白质低脂肪特征.调查发现传统重力浓缩污泥浓度普遍低于3.3%,浓缩效率低.在真空度-34.7 kPa下的真空抽滤实验表明,浓缩速率受污泥种类、浓度、PAM分子量以及添加量的影响.其中,污泥种类对浓缩速率影响较大,初沉污泥干固体抽滤速率为31 ks/(m2·h),剩余污泥速度低于15 kg,(m2·h),重力浓缩污泥的抽滤浓缩速度达到43 kg/(m2·h).抽滤液悬浮固体浓度普遍低于1.5 g/L. 相似文献
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中温条件下,采用浓缩消化一体化反应器处理污泥,考察稳定运行阶段投配率、搅拌和容积负荷对反应器的运行效果的影响。研究结果表明,投配率在10%~20%之间,排泥的含水率有所降低,之后随着投配率的增加,排泥含水率急剧升高;投配率由10%至30%增加过程中,排泥有机物(VS)的去除率和产气量也呈上升的趋势,投配率由30%再增加时,VS的去除率和产气量急剧下降。搅拌对排泥的含水率影响较小,但能够提高VS去除率和产气量。随着进泥容积负荷的增大,反应器排泥含水率逐渐增大;随着容积负荷在一定范围内的增加, VS去除率也随之提高。 相似文献
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采用中试规模的反应器对平板膜-污泥浓缩消化(MSTD)工艺的污泥消化机制和膜污染机理进行了研究.结果表明,经过15d的运行,MSTD工艺的污泥浓度(MLSS)从最初的3.6g/L上升到约34.2g/L,MLVSS和MLSS的消解率分别达到52%和47%,实现了同步浓缩和消化.由于溶解氧的变化,MSTD工艺的消化机制分为好氧消化和类似的厌氧消化2个阶段,分别降解二价金属离子和铁离子连接的2类生物聚合物.在MSTD过程中,平板膜的截留和污泥消化导致污泥性质剧烈变化,从而造成膜过滤性能剧烈下降.MLSS、胞外聚合物(EPS)和溶解性微生物产物(SMP)均对膜污染有显著的影响. 相似文献
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Zhiwei WANG Qiaoying WANG Zhichao WU Xinhua WANG 《Frontiers of Environmental Science & Engineering》2010,4(3):272-279
A hybrid membrane process for simultaneous sludge thickening and digestion (MSTD) was studied. During one cycle (15 d) of operation under a hydraulic retention time of 1 d, the concentration of mixed liquor suspended solids (MLSS) continuously increased from about 4 g·L−1 to 34 g·L−1, and the mixed liquor volatile suspended solids (MLVSS) increased from about 3 g·L−1 to over 22 g·L−1. About 42% of the MLVSS and 39% of the MLSS reduction were achieved. The thickening and digestion effects in the MSTD were further analyzed based on a mass balance analysis. Test results showed that biopolymers and cations of biomass were gradually released to the bulk solution during the process. It was also found that the capillary suction time, colloidal chemical oxygen demand, soluble microbial products, viscosity, and MLSS had significant positive correlations with the membrane fouling rate, whereas extracellular polymeric substances, polysaccharides, and proteins extracted from biomass had negative impacts on membrane fouling. 相似文献
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目的研究一种具有变阻尼特性的剪切增稠液体(STF)隔振器。方法首先采用二氧化硅纳米颗粒和聚乙二醇200为工作介质合成剪切增稠液体,通过试验研究剪切增稠液体的流变特性。之后以剪切增稠液体为工作介质,设计一种活塞液压式减振增稠液体隔振器,建立隔振器的动力学模型,并通过数值仿真研究了该隔振器的减振性能;最后,研究剪切增稠液体隔振器隔振性能影响因素。结果当远离共振频率时,隔振器具有小阻尼特性;在共振区附近,由于剪切增稠效应,隔振器阻尼骤然增加,实现对共振峰的有效抑制。结论剪切增稠液隔振器可有效抑制共振峰,同时不会对高频隔振性能产生不利影响,有效解决了传统隔振器线性阻尼的固有缺点。 相似文献
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与固态微生物菌剂相比,液体复合微生物菌剂具有制备方法简单、易保存、运输方便、启动时间短等优点,可达到快速启动反应器和提高使用效果的目的. 借鉴食品保鲜与保藏等领域的技术手段研发液态复合微生物菌剂的新型保存技术,可为其规模化生产及实际应用提供重要参考. 研究增稠剂、乳化剂和抗氧化剂对菌剂保存效果的影响规律,同时进行响应面优化研究. 液态复合微生物菌剂制备的最佳工艺为0.401%的阿拉伯树胶、0.090%的吐温-20和0.042%的抗坏血酸. 效果验证和稳定性评价结果表明,抗坏血酸对纤维素酶和脱氢酶的酶活影响较大,此条件下保藏30 d后,微生物的存活率为63.9%,活菌数为1.86×109 CFU·mL−1,霉菌杂菌数为1.4×105 CFU·mL−1,杂菌率为0.022%,可达到我国《农用微生物菌剂》(GB 20287—2006)的技术指标要求. 本研究探索了食品保鲜与保藏等领域的技术手段对液态复合微生物菌剂保存效果的影响,为提高液态菌剂的保存提供了一种新方法. 相似文献