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1.
城市污水厂污泥由于产生量大且成分复杂,如何对它进行稳定化、无害化处理已越来越受到人们的关注。本研究基于好氧发酵仓式堆肥系统,研究了城市污泥处理过程中温度、含水率、pH、有机质、水溶性有机碳、总氮和发芽指数等指标参数的变化规律。研究结果表明:当物抖初始含水率控制在65%左右时,在强制通风量112.5m^3/12hr,搅拌频率30min/24hr的工艺条件下,堆肥过程可以实现顺利升温并在55℃以上维持3天,满足杀灭致病茵要求的条件;14天反应用期结束时,物抖含水率、水溶性有机碳和有机质含量显著降低,堆肥产品腐熟,卫生学指标达到了美国EPA污泥产品A类标准;得列的污泥产品成为性质优良的土壤质量调节荆。  相似文献   
2.
在分析了送风机主要噪声源及频谱、噪声特性的基础上,应用噪声控制理论,设计并实施了噪声控制方案,达到了预期的治理效果。  相似文献   
3.
ABSTRACT: Forced artificial mixing of temperature-stratified ponds, or small lakes or reservoirs, by liquid jets can enhance water quality and can also be energy efficient. Based on previous studies of jet mixing mechanics of stratified water bodies, a conceptual design approach is presented. The main “operational” and “system” design parameters are considered in the proposed method. Using minimization of a total cost estimate as a criterion, an iterative method for the selection of the number and size of the jets is developed and illustrated.  相似文献   
4.
本文提出一种利用静电场的印染废水处理方法,印染废水中的污染颗粒在电场的作用下,朝一定的方向迁移,从而发生“强制电中和”作用,这种电中和作用的场能消耗极小,而被中和的污染物颗粒由于凝聚作用,则会不断长大而易于通令过滤去除,这一处理工艺在经“自数”预处理之后,可继续使COD和色度的去除百分数分别达60%和63%以上。  相似文献   
5.
Haug R 《Disasters》2002,26(1):70-84
The Hawaweer, a nomadic, pastoralist group in northern Sudan, were seriously affected by the drought in the Sahel during the mid-1980s. Their experience illustrates the connection between internally displaced people, normal mobility, forced migration, dilemmas and opportunities of return and how new livelihoods can be successfully constructed based on traditional rights, strong local institutions and external resources. Some displaced Hawaweer got the chance to return to their homeland as new livelihood opportunities were established; others did not get this opportunity nor would they have returned if they had been given the chance. In both situations, the processes of displacement and return had an impact on the sense of belonging and identity.  相似文献   
6.
MSW(城市固体废物)生物反应器型填埋是一种较新颖的方法.在系统分析现有填埋方法优缺点的基础上,对其加以改进,将强制通风好氧和渗滤液循环2种方式有机地结合在一起,构建了MSW好氧生物反应器.考察了NH3、CH4、CO2、pH和温度等因素,并监测分析了渗滤液中的COD、BOD5、Zn^2+、NH4^+和NO3^-等指标,旨在研究其中垃圾的降解及渗滤液中COD、BOD5、Zn^2+、NH4^+和NO3^-的去除情况,探讨该生物反应器对垃圾和渗滤液相关参数的作用机理.结果表明,该反应器对渗滤液中COD、BOD5、NO3^-的去除率分别达到96.34%、94.58%和99.9%,对其中的Zn^2+也有较好的脱除效果.  相似文献   
7.
目的 解决220 V-6 kW石英灯管阵列在试件表面1200 ℃持续40 min以上试验过程中的热破坏问题。方法 对灯管破坏形貌进行分析,通过热应力计算找到了爆灯的主要原因。针对现有加热器灯阵中灯头部位的热结构问题设计一套气体强制对流冷却装置,利用流体仿真分析方法获得出气管上不同出气孔孔径在相同间距条件下的气流速度、出气管外空流场状态和有灯阵时的灯头绕流冷却效果,为结构设计提供依据。结果 在相同地面热环境模拟试验中成功进行了考核试验。对比有无冷却装置时的试验结果,对流换热装置能够增加灯管使用寿命,保证试验质量。结论 针对灯头部位进行强制对流保护的方法,能够提高加热器在试验过程中的热环境模拟温度上限和有效试验时间,对高温长时间类热环境试验具有较好的应用和推广价值。  相似文献   
8.
2种MSW好氧生物反应器型填埋方式的对比实验   总被引:2,自引:1,他引:1  
在系统分析现有MSW生物反应器型填埋方法优缺点基础上,对其改进,将强制通风好氧和渗滤液循环2种方式有机结合组成新的反应器(称之为反应器A) ,与只有强制通风好氧的反应器(称之为反应器B)作对比.实验过程中对2反应器中NH3、CH4、CO2、pH、温度、电导率及沉降进行控制和监测,对渗滤液中Fe3+和NH4+进行监测与分析,研究2种MSW好氧生物反应器对所填垃圾降解及所产生渗滤液中COD、Fe3+和NH4+的去除效果,探讨两者对所填埋垃圾降解和渗滤液中所测参数去除机理,从而得出反应器A比反应器B对垃圾和渗滤液有更好的降解和去除效果.  相似文献   
9.
在喷射鼓泡反应器上进行了控制氧化对湿法烟气脱硫过程的影响研究,测定了脱硫率η和pH随时间t的变化规律,得出了η与t的回归式及η与pH值的关系规律,讨论了不同曝气强度及抑制剂浓度对CaCO3利用率α、pH值及脱硫率η的影响。实验表明强制氧化及抑制氧化均能提高脱硫效率η及CaCO3利用率α,但对浆液pH值的影响正好相反,强制氧化使浆液pH值下降的更快,而抑制氧化则使浆液pH值有所提高。  相似文献   
10.
An integral model for the plane buoyant jet dynamics resulting from the interaction of multiple buoyant jet effluxes spaced along a diffuser line is considered as an extension of the round jet formulation that was proposed in Part I. The receiving fluid is given by an unbounded ambient environment with uniform density or stable density stratification and under stagnant or steady sheared current conditions. Applications for this situation are primarily for submerged multiport diffusers for discharges of liquid effluents into ambient water bodies, but also for multiple cooling tower plumes and building air-conditioning. The CorJet model formulation describes the conservation of mass, momentum, buoyancy and scalar quantities in the turbulent jet flow in the plane jet geometry. It employs an entrainment closure approach that distinguishes between the separate contributions of transverse shear and of internal instability mechanisms, and contains a quadratic law turbulent pressure force mechanism. But the model formulation also includes several significant three-dimensional effects that distinguish actual diffuser installations in the water environment. These relate to local merging processes from the individual multiple jets, to overall finite length effects affecting the plume geometry, and to bottom proximity effects given by a “leakage factor” that measures the combined affect of port height and spacing in allowing the ambient flow to pass through the diffuser line in order to provide sufficient entrainment flow for the mixing downstream from the diffuser. The model is validated in several stages: First, comparison with experimental data for the asymptotic, self-similar stages of plane buoyant jet flows, i.e. the plane pure jet, the pure plume, the pure wake, the advected line puff, and the advected line thermal, support the choice of the turbulent closure coefficients contained in the entrainment formulation. Second, comparison with data for many types of non-equilibrium flows with a plane geometry support the proposed functional form of the entrainment relationship, and also the role of the pressure force in the jet deflection dynamics. Third, the observed behavior of the merging process from different types of multiport diffuser discharges in both stagnant and flowing ambient conditions and with stratification appears well predicted with the CorJet formulation. Fourth, a number of spatial limits of applicability, relating to terminal layer formation in stratification or transition to passive diffusion in a turbulent ambient shear flow, have been proposed. In sum, the CorJet integral model appears to provide a mechanistically sound, accurate and reliable representation of complex buoyant jet mixing processes, provided the condition of an unbounded receiving fluid is satisfied.  相似文献   
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