高效酶促进剂Accell在养猪废水处理工艺中的应用研究

为了考察高效酶促进剂在养猪废水处理工艺中的功能,在养猪废水治理工艺的生化段SBR反应器进水中投加高效酶促进剂Accell.两套相同的装置平行运行的效果对比表明:投加Accell可减少剩余污泥的排放量,增加溶氧效率,强化污染物的去除效果;投加高效酶的装置对COD的去除可在SBR反应器基础上再减少40%以上,对NH3-N的去除可进一步再减少25%以上,对P的去除也有一定的促进作用.     

The regulatory role of endogenous iron on greenhouse gas emissions under intensive nitrogen fertilization in subtropical soils of China

Environmental Science and Pollution Research - Anaerobic batch experiments were conducted to study the regulatory role of endogenous iron in greenhouse gas emissions under intensive nitrogen...     

低温低浊微污染水源水预氧化处理工艺设计

选用预氧化处理工艺以提高混凝絮凝效果,减少停留时间从而实现在小型设备中较高的处理量;占地面积小且速度快的气浮池代替了普通的沉淀池,并在混凝沉淀处理药剂和消毒处理药剂上选择了在低温条件下效果好的.     

不同温度对SBR腐殖活性污泥系统运行效能的影响

在10～22℃范围内,通过实验考察了温度对腐殖土间歇式活性污泥处理(SBR)系统的运行特性的影响.实验结果表明,降低温度对SBR腐殖活性污泥系统去除COD影响不大,当温度降至10℃时,COD去除率仍可达到80%以上;在22～14℃范围内,SBR腐殖活性污泥系统对NH+4-N和TN的去除影响不大,温度降至10℃时,NH+...     

A Modelling Study of Transient,Buoyancy-Driven Exchange Flow over a Descending Barrier

Results are presented from a series of model studies of the transient exchange flow resulting from the steady descent of an impermeable barrier separating initially-quiescent fresh and saline water bodies having density ₀ and ₀+()₀, respectively. A set of parametric laboratory experiments has been carried out (i) to determine the characteristic features of the time-dependent exchange flow over the barrier crest and (ii) to quantify the temporal increase in the thickness and spatial extent of the brackish water reservoir formed behind the barrier by the outflowing, partly-mixed saline water. The results of the laboratory experiments have been compared with the predictions of a theoretical model adapted from the steady, so-called maximal exchange flow case and good qualitative agreement between theory and experiment has been demonstrated. The comparisons indicate that head losses of between 7% and 3% are applicable to the flow over the ridge crest in the early and late stages, respectively, of the barrier descent phase, with these losses being attributed to mixing processes associated with the counterflowing layers of fresh and saline water in the vicinity of the ridge crest. The experimental data show (and the theoretical model predictions confirm) that (i) the dimensionless time of detection t _det(g/H _b)^1/2 of the brackish water pool fed by the dense outflow increases (at a given distance from the barrier) with increasing values of the descent rate parameter g'H _b/(dh _b/dt)² and (ii) the normalised thickness (x,t)/H _b of the pool at a given reference station increases monotonically with increasing values of the modified time (t–t _det)/(H _b/g)^1/2, with the rate of thickening decreasing with increasing values of the descent rate parameter g'H _b(dh _b/dt)². Here, g=(g/₀)()₀ is the modified gravitational acceleration, H _b is the mean depth of the water and dh _b/dt denotes the rate of descent of the barrier height h _b with elapsed time t after the two water bodies are first brought into contact.     

改性SBA-15对电厂尾气CO_2的吸附性能研究

文章以三嵌段共聚物P123为模板剂、正硅酸乙酯为硅源,水热合成了介孔分子筛SBA-15,以3-丙胺基三乙氧基硅烷(APTES)为氨基化剂,采用浸渍法将其嫁接到SBA-15孔内,形成氨基化的SBA-15用于吸附电厂尾气CO2。通过氮等温吸附-脱附、XRD、TEM等测试技术对其进行了表征,考察了改性前后SBA-15的吸附性能。结果表明:改性前后的SBA-15对电厂尾气中CO2均具有良好的吸附性能,改性的SBA-15比合成的SBA-15吸附性能要好。     

铬污染土壤电阻率特性及其影响因素研究

为了研究电阻率法用于土壤环境监测的可行性,本文采用SoilMillerBox法进行铬污染土壤的电阻率影响因素实验,依据实验数据建立了污染土壤电阻率与三因素（铬污染物含量、含水率、土壤孔隙比）之间的关系模型,并于模拟污染场地中利用电阻率层析成像法对其进行验证.结果表明,根据三因素正交实验得到影响污染土壤电阻率变化的主次因...     

Dominant features in three-dimensional turbulence structure: comparison of non-uniform accelerating and decelerating flows

The results are presented from an experimental study to investigate three-dimensional turbulence structure profiles, including turbulence intensity and Reynolds stress, of different non-uniform open channel flows over smooth bed in subcritical flow regime. In the analysis, the uniform flow profiles have been used to compare with those of the non-uniform flows to investigate their time-averaged spatial flow turbulence structure characteristics. The measured non-uniform velocity profiles are used to verify the von Karman constant κ and to estimate sets of log-law integration constant B_r and wake parameter П, where their findings are also compared with values from previous studies. From κ, B_r and П findings, it has been found that the log-wake law can sufficiently represent the non-uniform flow in its non-modified form, and all κ, B_r and П follow universal rules for different bed roughness conditions. The non-uniform flow experiments also show that both the turbulence intensity and Reynolds stress are governed well by exponential pressure gradient parameter β equations. Their exponential constants are described by quadratic functions in the investigated β range. Through this experimental study, it has been observed that the decelerating flow shows higher empirical constants, in both the turbulence intensity and Reynolds stress compared to the accelerating flow. The decelerating flow also has stronger dominance to determine the flow non-uniformity, because it presents higher Reynolds stress profile than uniform flow, whereas the accelerating flow does not.     

基于Fisher判别理论的尾矿库安全评价模型

结合多元统计分析中的判别分析思想,建立尾矿库安全等级评价的Fisher判别模型。以湖南某尾矿库为例,合理选取一星期内观测的44组尾矿库数据进行判别分析,其中4组为检验样本,不参与判别函数的训练。研究结果表明,安全超高与标准判别函数之间的汇聚组间绝对相关性最大;各类协方差矩阵F检验的显著性概率Sig.0.05,判别分析显著;训练样本回判的正确率高达95%,检验样本判别的正确率达到100%,判别结果与实际尾矿库的安全情况基本吻合,为尾矿库的安全评价提供了一条更加系统、精准的途径。     

汉江下游罗汉寺和岳家湾旧石器旷野遗址的年代学研究

近年来,秦岭地区发现了大量旧石器遗址,并开展了年代学研究。但是,秦岭南麓汉江下游地区的旧石器遗址研究相对较少。2018年夏天对汉江下游地区的野外考察中,在钟祥盆地和江汉平原发现了罗汉寺和岳家湾两处旧石器旷野遗址。两处遗址的剖面出土了较多原地埋藏的石制品,包括石片、石核,以及砍砸器、尖状器、刮削器、手稿、手斧等少量工具。利用石英单片再生剂量法（SAR-OSL）和热转移光释光（TT-OSL）技术,测得罗汉寺两个遗址点对应的文化层年代分别为53—30 ka和187 ka,岳家湾遗址旧石器文化层的年代为172—138 ka。这些年代有效填补了汉江下游地区部分旧石器时代遗址的年代空白。