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排序方式: 共有1151条查询结果,搜索用时 62 毫秒
851.
优化控制SBR工艺处理养猪废水中试研究   总被引:2,自引:1,他引:1  
采用优化控制SBR工艺对北京某种猪场的养殖粪尿污水进行了中试处理研究。所建立的自控系统通过ORP实时曲线上的“硝酸盐膝点”和pH实时曲线上的“氨谷点”分别对碳源投加和曝气时间进行优化控制,实现根据水质变化适当补充所需碳源,并有效节省曝气能耗。中试反应器10个月的连续运行结果表明,系统对于氨氮和COD的去除率分别达到97%和95%。  相似文献   
852.
从曝气系统节能的角度出发,分析污水处理活性污泥法中曝气系统溶氧速率与耗氧速率之间的关系,提出了经济溶解氧浓度的概念,并通过理论分析及实际分析论证了其存在的可能性。通过实验,验证了经济溶解氧在曝气系统中的存在,并且对反应器处于经济溶解氧下的运行效果进行了分析。研究表明,在经济DO浓度下,出水水质符合标准要求,系统运行稳定,跟实测的DO浓度比较,平均DO浓度下降0.7mg/L,节能效果显著。  相似文献   
853.
基质结构对水平潜流人工湿地净化效果影响   总被引:3,自引:2,他引:1  
为研究基质填充结构变化对人工湿地净化效果的影响,构建2个不同基质结构的对比水平潜流人工湿地实验系统,对城市污水处理厂出水进行深度处理。实验结果表明,1~7 mm石英砂均混填充结构人工湿地系统对COD、NH4+-N和TP的平均去除率分别为49.5%,40.1%和56.1%;比较而言,1~7 mm石英砂分层填充结构湿地系统对3种污染物的平均去除率分别为53.7%,60.4%和68.6%。方差分析表明,不同石英砂结构的人工湿地对COD、NH4+-N及TP的净化效果差异显著(p<0.05)。此外,不同水力停留时间条件下,基质填充结构不同的湿地系统对以上3种污染物的净化效果也存在显著差异(p<0.05),去除率随着水力停留时间的增加而升高,当HRT为36 h时,各系统均能取得较好的净化效果。  相似文献   
854.
常温常压催化湿式氧化降解偶氮染料废水的研究   总被引:4,自引:3,他引:1  
以过渡金属Fe、Mn、Cu和Zn的硝酸盐为活性组分的前驱物,以γ-Al2O3为载体,制备了负载型催化剂Fe2O3/γ-Al2O3、MnO/γ-Al2O3、CuO/γ-Al2O3和ZnO/γ-Al2O3,并分别以H2O2和NaClO为氧化剂,对比了在常温常压条件下催化湿式氧化工艺处理甲基橙模拟废水的效果.结果表明,Fe2...  相似文献   
855.
856.
白文元  王蕊 《安全》2008,29(7):40-41
目前,大家普遍认为安全生产事故的发生主要有两方面的原因:一方面是人的不安全行为;另一方面是物的不安全状态。统计表明,由于人的不安全行为导致的伤亡事故占伤亡事故总数的70%-90%。因此,如何控制人的不安全行为,已经成为企业安全管理的关键所在。  相似文献   
857.
石油焦化冷焦废水封闭分离与利用技术   总被引:1,自引:1,他引:0  
提出了一种多级降温冷凝-梯级污染物分离-组分机械纯化的集成石油焦化冷焦废水封闭分离与利用技术。将其应用于1Mt/a冷焦废水处理系统,运行结果表明,废水循环再生率、污油循环使用率、石油焦粉回收使用率、挥发性有机物回收利用率均达100%。与国内外同类技术相比,该技术具有冷焦废水处理效果好、投资小、经济和社会效益显著等优点,具有很好的推广应用前景。  相似文献   
858.

Ecological wastewater treatment plant (EWWTP), a kind of emerging wastewater treatment plant (WWTP) in recent years, combined microbiology with botany which is efficient for the removal of nitrogen and organic matter, as well as deodorization. The occurrence and removal of micro-organic pollutants in EWWTPs were still not well known. Polycyclic aromatic hydrocarbons (PAHs) and their typical derivatives (SPAHs) including the oxygenated PAHs (OPAHs), chlorinated PAHs (ClPAHs), and methyl PAHs (MPAHs) were investigated in an EWWTP in Guangdong Province, China. The concentrations of the Σ6 OPAHs (114–384 ng/L) were higher than the Σ16 PAHs (92–250 ng/L), and much higher than the Σ4 MPAHs (13–64 ng/L) and Σ9 ClPAHs (2–3 ng/L) in the EWWTP and the effluent receiving river. The total removal efficiencies of the PAHs, OPAHs, MPAHs, and ClPAHs in the EWWTP (43?±?14%, 41?±?7%, 55?±?16%, and 18?±?4%) were lower than the traditional WWTPs, probably due to the lower concentration of the sludge in the ecological treatment. The advanced treatment process (microfiltration and UV disinfection treatment) contributed much less (0–20%) to the whole removal efficiency than the ecological treatment (80–100%). The effluent from the EWWTP slightly reduced the PAHs and SPAHs concentrations in the receiving river. The high concentrations of the PAHs and SPAHs in the receiving river were similar to the influent of the EWWTP, indicating that some untreated wastewater was directly discharged to the river, especially in the upstream.

  相似文献   
859.
Herein, we prepared alginate (SA)/carboxymethyl cellulose (CMC) gel beads through Ca2+ and glutaraldehyde (GA) crosslinking and investigated their adsorption performance on lysozyme from aqueous solution. Taking advantage of the abundant active carboxyl groups on SA and CMC, the obtained SA/CMC gel beads present an excellent integrated lysozyme adsorption performance with a high capacity of 236.34 mg g?1, short equilibrium time of 8 h, ease of elution, and good reusability. Furthermore, the resultant SA/CMC gel beads also possess unique selectivity for positively charged proteins, confirmed by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis. Considering the nature of biopolymers and advantages of favorable physical properties, high efficiency, cost-effectiveness, intriguing adsorption capacity and easier separation from the reaction system, the SA/CMC gel beads may find more potential in protein separation and purification than that of synthetic material.  相似文献   
860.
Urban tinkering     
Cities are currently experiencing serious, multifaceted impacts from global environmental change, especially climate change, and the degree to which they will need to cope with and adapt to such challenges will continue to increase. A complex systems approach inspired by evolutionary theory can inform strategies for policies and interventions to deal with growing urban vulnerabilities. Such an approach would guide the design of new (and redesign of existing) urban structures, while promoting innovative integration of grey, green and blue infrastructure in service of environmental and health objectives. Moreover, it would contribute to more flexible, effective policies for urban management and the use of urban space. Four decades ago, in a seminal paper in Science, the French evolutionary biologist and philosopher Francois Jacob noted that evolution differs significantly in its characteristic modes of action from processes that are designed and engineered de novo (Jacob in Science 196(4295):1161–1166, 1977). He labeled the evolutionary process “tinkering”, recognizing its foundation in the modification and molding of existing traits and forms, with occasional dramatic shifts in function in the context of changing conditions. This contrasts greatly with conventional engineering and design approaches that apply tailor-made materials and tools to achieve well-defined functions that are specified a priori. We here propose that urban tinkering is the application of evolutionary thinking to urban design, engineering, ecological restoration, management and governance. We define urban tinkering as:
A mode of operation, encompassing policy, planning and management processes, that seeks to transform the use of existing and design of new urban systems in ways that diversify their functions, anticipate new uses and enhance adaptability, to better meet the social, economic and ecological needs of cities under conditions of deep uncertainty about the future.
This approach has the potential to substantially complement and augment conventional urban development, replacing predictability, linearity and monofunctional design with anticipation of uncertainty and non-linearity and design for multiple, potentially shifting functions. Urban tinkering can function by promoting a diversity of small-scale urban experiments that, in aggregate, lead to large-scale often playful innovative solutions to the problems of sustainable development. Moreover, the tinkering approach is naturally suited to exploring multi-functional uses and approaches (e.g., bricolage) for new and existing urban structures and policies through collaborative engagement and analysis. It is thus well worth exploring as a means of delivering co-benefits for environment and human health and wellbeing. Indeed, urban tinkering has close ties to systems approaches, which often are recognized as critical to sustainable development. We believe this concept can help forge much-closer, much-needed ties among engineers, architects, evolutionary ecologists, health specialists, and numerous other urban stakeholders in developing innovative, widely beneficial solutions for society and contribute to successful implementation of SDG11 and the New Urban Agenda.
  相似文献   
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