对污水深度处理滤池工艺设计的探讨

首先介绍和分析了重力式滤池两种流向 (上向流式和下向流式 )的过滤机理 ,并从多方面阐明了污水深度处理宜采用上向流式滤池的观点 .其次 ,对上向流滤池的运行特性进行了分析 ,从而得出冲洗工序对滤后水质有影响的结论 .最后还介绍了上向流滤池的应用实例及其工艺设计参数 .     

上流式反应器用于劣质渣油加氢处理的初步探索

以3种典型渣油为原料,考察了上流式反应器的原料适应性和胶体稳定性,对上流式反应器加氢反应过程的反应温度、反应压力、液态空速(LHSV)和氢油体积比等工艺条件进行优化,并进一步对上流式反应器与固定床反应器组合的加氢性能进行了评价。实验结果表明,上流式反应器对渣油原料适应性好,脱杂质性能(尤其是脱金属性能)优异。反应条件对上流式反应器加氢反应过程影响大小的顺序为:反应温度LHSV反应压力氢油体积比。适宜的工艺条件为:360~390℃,15~19 MPa,LHSV=(0.8~1.3)h~(-1),V(H2)∶V(oil)=(250~450)∶1。原料经过上流式反应器加氢处理后,沥青质含量(w)从6.81%下降至3.87%,脱除率达43.17%。经上流式反应器与固定床渣油加氢组合处理后,加氢后油品的脱硫率、脱残炭率、脱金属率和脱沥青质率可分别达到92.47%,64.46%,91.57%,86.93%;对应油样中的硫、残炭、沥青质和金属(Ni+V)含量(w)分别为0.32%,5.37%,0.89%,12.89×10-6;胶体稳定性参数由1.81升至3.25。     

Modelling of simultaneous methanogenesis and denitrification in an upflow packed-bed biofilm reactor

The performance of an upflow packed-bed biofilm reactor was investigated by considering simultaneous methanogenesis and denitrification reactions under step and sinusoidal variations of feed concentration and temperature. For simultaneous step inputs of 20 mg dm⁻³ of NO₃⁻—N and 60 mg dm⁻³ of methanol, the proposed model shows that major conversion of both the substrates takes place in the first half of the reactor. However, when the inlet concentration of methanol is subjected to sinusoidal variation, while that of NO₃⁻—N is maintained stepwise, the exit concentration of both methanol and NO₃⁻—N follow a sinusoidal response. On the other hand, when the inputs are reversed (methanol stepwise and NO₃⁻—N sinusoidal), the response exhibits similar behaviour. For sinusoidal variation of feed temperature the exit concentration profiles of both substrates also follow a sinusoidal pattern. For methanol, the mean steady state conversion under sinusoidal variation is higher than the corresponding steady state concentration when feed temperature is constant at 30°C. The model predictions are in good agreement with the experimental data available in the literature. ©1997 SCI     

Combinated Flow Pattern Map for Cocurrent and Countercurrent Air-Water Flows in Vertical Tube

Flow patterns for cocurrent and countercurrent air-water flows in vertical tubes (40 and 80mm I.D.) at volumetric flux densities of air and water in the ranges ?115–158 and ?100–102 cm/s were observed. A flow pattern map presenting the entire data of the observed flow patterns, i.e. bubbly, slug and annular flow for each mode of flow operation (upflow, countercurrent flow and downflow) were presented on the j_l vs. j_g plane. The flow pattern maps showed significant difference of flow pattern transition boundaries with upflow, countercurrent flow and downflow. Flow pattern transition curves were smoothly continuous with the change of the direction of water flow, on the other hand the change of flow direction of air showed complicated effect on flow pattern transition near zero j_g . Comparison of the present flow pattern data with the reported general flow pattern maps for upflow showed that the correlation of Taitel et al. for bubble-slug flow transition is applicable to both cocurrent and countercurrent air-water flows.     

垃圾焚烧发电厂垃圾渗滤液处理工程实例

介绍了镇江垃圾焚烧发电厂渗滤液处理工程的概况,详细介绍了处理工艺流程、构筑物设计参数及调试方案。调试结果表明,该渗滤液处理工程可全量处理电厂产生的渗滤液,出水水质可达到《污水综合排放标准(》GB 8978—1996)的三级标准,对其COD、氨氮的去除率分别可达98.99%和99.43%。系统运行稳定,直接运行成本低,不产生二次污染。     

发酵甘油废水的处理工艺

针对发酵甘油生产过程中的淀粉质原料浸泡废水固体悬浮物质量浓度高和提取废水难以生物降解的特性,分别采用沉淀法和Fenton试剂法对其进行预处理,再与发酵废水混合后,采用UASB-SBR组合工艺进行处理.结果表明:当进水COD为6 800-7 360 mg／L时,处理后出水COD可降到100 mg／L以下,出水NH3-N降到15 mg／L以下,系统出水可以达标排放.     

厌氧反应器的酸化及其恢复研究进展

随着升流式厌氧污泥床(UASB)、厌氧折流板反应器(ABR)、内循环反应器(IC)等厌氧反应器在高浓度有机废水处理中的应用,其启动及运行过程中出现的酸化现象日益受到关注,酸化问题一定程度地抑制了厌氧反应器的推广.针对厌氧酸化问题的产生及危害,着重讨论了厌氧酸化后物理、化学和生物恢复方法,以期为高效厌氧反应器的稳定化运行...     

斜窄流分级设备在磷酸原料磨矿中的应用

介绍了斜窄流的定义、斜窄流分离设备的应用领域及斜窄流分级设备在磷酸原料（磷矿石）闭路湿磨中的应用情况。云南三环化工有限公司对磷酸原料采用斜窄流分级闭路湿磨新工艺,分级质效率达60％左右,改善了磨矿产品的粒度组成,磨矿产品中0．15—0．010mm合格粒级占到81％以上,极大地减少了欠磨和过磨粒级,使下游萃取磷酸工艺转化率提高2—3个百分点、洗涤率提高1—2个百分点、P2O5总回收率提高2．5个百分点以上,降低了生产成本,取得满意的技术经济指标。     

Liquid back-mixing in packed-bubble column reactors: a state-of-the-art correlation

The extent of liquid back-mixing in gas–liquid concurrent upflow packed-bubble column reactors is quantified in terms of an axial dispersion coefficient or its corresponding dimensionless Péclet number. Effects of reactor operating conditions on the axial dispersion coefficient are not properly accounted for by the available literature correlations, wherein most often the Péclet number is expressed solely in terms of the gas and liquid Reynolds numbers or superficial velocities. Based on the broadest experimental databank (1322 measurements, 11 liquids, four gases, 28 packing materials, 14 columns diameters, Newtonian, non-Newtonian, aqueous, organic, coalescing and non-coalescing liquids, high pressure, bubble and pulsing flow regime conditions), a state-of-the-art liquid axial dispersion coefficient correlation is obtained by combining neural network modeling and dimensional analysis. Thorough qualitative and quantitative analyses of the constructed databank demonstrate the robustness of the proposed correlation to restore the variety of trend variations of liquid Péclet numbers reported in the literature.     

上向流厌氧氨氧化生物滤池的启动与脱氮性能

利用上向流陶粒滤池反应器进行了厌氧氨氧化工艺的启动与性能研究.以A/O除磷工艺出水为试验原水,先以自然挂膜的方法启动好氧硝化生物膜,再通过自然筛选和人工诱导的方式将其转化为厌氧氨氧化生物膜,7个月后实现了厌氧氨氧化工艺的启动,TN去除负荷达到了6.8 kg/(m~3·d),微生物表观比生长速率为0.0018h~(-1).试验表明,上向流的运行方式有利于提高厌氧氨氧化生物滤池的脱氮性能,最高TN去除负荷达到12.37 kg/(m~3·d),比目前文献所报道的最高值还要高出很多.另外,试验滤池厌氧氨氧化过程的化学计量学和COD去除特性表明该过程中存在一定程度的异养反硝化过程,且对滤池的厌氧氨氧化脱氮有利.