Ca2+在净水生物膜团聚体培养中的影响研究

通过在5组相同型号的SBBR反应器(A、B、C、D和E)内调节进水中的Ca2+含量,研究Ca2+在净水生物膜团聚体培养过程的作用影响.结果表明,进水Ca2+投加浓度为25 mg/L时驯化培养的生物膜团聚体具有较好的抗挤压能力,抗压强度达到了22 N/cm2,密度为1.059 g/cm3,活性微生物的百分含量达到了86.90%,远远高于一般污泥团聚体中的微生物含量.分析运行效果,反应器C和D的生物膜团聚体通过29 d的驯化培养就达到了一个比较好的净水效果,并能维持稳定状态,相比于一般生物膜反应器的驯化时间有所缩短.不同进水负荷条件下氮氮的去除率变化表明,反应器C和D针对不同进水负荷表现出来的适应效果明显优于其他反应器.     

铁炭微电池电解填充流化床反应器水力学行为研究

本文提出了一种新型的铁炭微电池电解反应器———填充流化床反应器 ,并对该反应器的水力学行为进行了研究。通过床层压降法测定临界流化气速 ,建立了关于临界流化气速Uc 的经验关联式 :Uc=0 .0 15 6C0 .2 7Vt0 .14 H0 .31。通过脉冲示踪物信号法测得停留时间分布密度函数E(t) ,结果表明该反应器水力混合特性接近于完全混合反应器     

Comparison of the droplet size spectra produced by rotary atomizers and hydraulic nozzles under simulated aerial application conditions

Abstract

A wind tunnel was used to characterize the droplet size spectra of liquid sprays from several different atomizers and nozzles used under simulated aerial application conditions. The atomizers included a D8–46 nozzle, a Through Valve Boom (TVB) nozzle, and rotary cage and drum atomizers.

The D8–46 hydraulic nozzle was evaluated, using water, at orientations of 0, 10, 20, 30, 40, 50, 60, 70, 80 and 90° relative to 145 and 180 km/h airstreams. The TVB nozzle was evaluated using water, water with isopropyl alcohol, and water with a non‐ionic surfactant at airstream velocities between 130 and 180 km/h. The rotary atomizers were evaluated at different rotation rates, flow rates of water and an insecticide, in 130 and 180 km/h airstreams.

The volumetric droplet size spectra parameters (D_vo.x) decreased as the angle of the D8–46 nozzle and the airstream velocity increased. Empirical models were developed to predict these values for different windspeed and nozzle angle conditions. The TVB nozzle produced larger droplets than the other atomizers under similar conditions, with a decrease in the D_vo.x parameter values as the airstream velocity increased.

The D_vo.x parameter values produced by the rotary atomizers increased as the liquid flow rate increased, and as the rotation rate and airstream velocity decreased, and were lower for the insecticide than for water. The slotted rotary drum atomizer gave the best control over droplet size, generally producing mono‐modal droplet size spectra where the other atomizers often produced bi‐ and multimodal spectra.     

卡拉OK扰民噪声治理的研究

分析了卡拉OK扰民噪声的特点 ,通过现场实验和实测 ,研究了不同装修结构对房间隔声、隔振效果的影响     

侧沟式膜泥法一体化OCO工艺中水力停留时间对脱氮除碳的影响

在传统OCO工艺基础上设计了一体化OCO工艺,在厌氧区放置填料,将二沉池和生物反应器合建,并就水力停留时间(HRT)对生物反应器脱氮除碳的影响进行研究。在进水COD为260～360 mg/L,好氧区DO为2 mg/L左右,缺氧区<0.5 mg/L,MLSS为4 500 mg/L左右时,分别研究了不同HRT下的脱氮除碳效果。研究结果表明：随着HRT的逐渐增大,出水COD值无明显波动,COD去除率达到90%以上,出水氨氮随着HRT的增大而降低;但仅当HRT为12 h左右时,氨氮和总氮均有良好的去除效果,去除率分别可达到93%和80%。     

超声振动强化膜分离过程机理的研究

膜分离过程中的浓差极化现象是影响膜分离效果的主要因素之一 ,本文探索了利用超声振动的方法来强化膜分离反应过程。首先建立了其动力学模型 ,然后通过试验对其强化机理进行了深入的探讨 ,以达到经济、高效地提高膜分离效果的目的。     

基于Holt-Winters模型的济南泉域地下水资源保护研究

以济南名泉趵突泉历年的地下水位为研究对象,对2012年5月至2017年11月趵突泉地下水位波动规律进行分析,评价保泉形势,探索保泉供水的有效措施。通过模型的比选,最终确定利用HoltWinters指数平滑加法模型,从时间序列的角度分析预测趵突泉地下水位的变化趋势,并计算出了模型的拟合优度指标和拟合统计量。决定系数R2值为0.897,平稳的R2值为0.627,数值均较大且其余各项拟合优度指标均较好,说明模型的拟合效果整体精度较高。利用模型对2018年趵突泉的地下水位进行了预测并给出了预测值95%的置信区间,预测年平均水位为27.814 m,泉水位波动的峰值为28.291 m、谷值为27.329 m且谷值将出现于2018年的6月份,为近6年来的最低水位值,低于27.6 m的保泉红色警戒线,接近27.01 m的泉水停喷线。预测结果表明:2018年趵突泉将存在潜在停喷的危机,济南市的保泉任务依然严峻。为争取泉水持续喷涌,在此基础上提出了科学保泉建议和节水保泉措施,为济南市评判、预测、调整水系及地下水开采布局提供科学依据。     

内爆炸载荷作用下爆炸容器振动响应试验研究

为研究具有密闭结构的装备、建筑物或地下工事在内爆炸载荷作用下的冲击振动响应,通过某一尺寸爆炸容器的冲击振动环境试验构建内爆炸振源模型和密闭结构响应模型,比较测量了几个典型位置在不同强度载荷下的振动情况并进行频谱分析,提出了基于振动主频的判断结构损伤和防止共振响应的方法,并对试验数据进行数值拟合,弄清振动参数在结构上的衰...     

Interpreting Images of Fracking: How Visual Frames and Standing Attitudes Shape Perceptions of Environmental Risk and Economic Benefit

The news media’s increased reliance on visual communication to illustrate complex processes and promote learning stresses the importance of investigating how visual content impacts the understanding of scientific issues. In this paper, we investigate how members of the public interpret and make sense of differentially framed images of hydraulic fracturing (fracking) depicting environmental risk, economic benefit, or issue protest. For the analysis, a repeated measures online experiment was conducted with 250 participants to evaluate 40 photographs of fracking operations and consequences. Quantitative coding and thematic analysis of open-ended responses to the images reveal that standing attitudes, operationalized as support, opposition, or indecision about fracking, segments viewers into distinct groups and shapes interpretations of environmental risk and economic benefit. Issue opponents are more likely to indicate concern for the environment regardless of frame shown, whereas undecideds and supporters cite the impact on human health more frequently, largely in relation to job site safety. Supporters also see the least ambiguity, and most economic gains, in images about the controversial production practice.