官厅水库上游区域面源型氮磷污染特征

官厅水库是北京市重要的地表水源之一.通过对官厅水库上游区域代表性地表水和沉积物的氮磷含量调查,以及对两个典型地块进行了模拟地表径流的降雨试验,研究了官厅水库上游区域面源型氮磷污染特征.结果表明:官厅水库上游区域大部分的地表水中氮/磷浓度高于《地表水环境质量标准》(GB 3838-2002)中地表水V类水标准限值,地表径...     

基于光纤分布式测温的污水管道入流识别方法研究

针对排水管网物探检测需断水操作和无法对管道内部实时探查的问题,建立了一种基于光纤分布式测温的污水管道入流诊断方法,实现了无干扰条件下污水管道污水和雨水入流实时监控.采用感温光缆对选择的试验管段开展了时空高精度观测(空间精度1m、时间精度1min),获得了超过118万个管道水温数据.基于解析出的管道水温时空图像,提出了基于水温温差背景噪声值的入流定位方法;确定出无外部入流影响时管道水温空间和时间温差的背景噪声值分别约为±0.2℃和±0.5℃.采用水温图像降噪处理方法,自动识别出污水管道的旱天污水接入和雨天雨水接入事件,与现场调查结果一致.因此,该方法对污水管道入流的动态识别定位具有可靠性.     

聚四氟乙烯高压密封罐消解样品测定五氧化二钒

利用聚四氟乙烯高压密封罐消解矿石样品测定五氧化二钒，具有操作手续相对简便、轻松、快捷等优点，与传统的硫酸－磷酸混合酸消解或采用碱熔融前处理法比较，相对误差小于１．６％，样品的添加标准回收率为９２．９％～１０３．５％。     

River channel network design for drought and flood control: A case study of Xiaoqinghe River basin, Jinan City, China

Vulnerability of river channels to urbanization has been lessened by the extensive construction of artificial water control improvements. The challenge, however, is that traditional engineering practices on isolated parts of a river may disturb the hydrologic continuity and interrupt the natural state of ecosystems. Taking the Xiaoqinghe River basin as a whole, we developed a river channel network design to mitigate river risks while sustaining the river in a state as natural as possible. The river channel risk from drought during low-flow periods and flood during high-flow periods as well as the potential for water diversion were articulated in detail. On the basis of the above investigation, a network with “nodes” and “edges” could be designed to relieve drought hazard and flood risk respectively. Subsequently, the shortest path algorithm in the graph theory was applied to optimize the low-flow network by searching for the shortest path. The effectiveness assessment was then performed for the low-flow and high-flow networks, respectively. For the former, the network connectedness was evaluated by calculating the “gamma index of connectivity” and “alpha index of circuitry”; for the latter, the ratio of flood-control capacity to projected flood level was devised and calculated. Results show that the design boosted network connectivity and circuitry during the low-flow periods, indicating a more fluent flow pathway, and reduced the flood risk during the high-flow periods.     

混凝辅助电化学法处理橙黄G染料废水

以石墨板为阳极，研究了电化学氧化法对橙黄G染料废水的降解效果。比较了在NaCl、Na2 SO4以及NaCl与FeSO4·7H2O组合的支持电解质体系中的处理效果，同时考察了电压、初始pH、电解质浓度、电极间距和电解时间等因素对废水中橙黄G脱色率及COD去除率的影响。研究结果表明，橙黄G的脱色主要是活性氯的氧化作用，橙黄G分子的矿化可能主要是电解过程中产生的·OH的作用，FeSO4·7H2O的加入增加了混凝作用，使得处理效果进一步提高。最佳脱色条件下橙黄G脱色率和COD的去除率分别为97．6％和56．3％，B／C（BOD／COD）由0．09提高至0．41，可生化性有较大改善，并且随着降解时间的增加，COD去除率逐渐升高。此结果表明，橙黄G废水COD的去除相对于脱色存在滞后性。     

Dyella ginsengisoli LA-4吸附Cu2+特性及其动力学研究

研究一种新型吸附菌剂Dyella ginsengisoli LA-4(以下简称菌株LA-4)对Cu2+的吸附特性及其动力学,并利用表面响应法优化菌株LA-4对Cu2+的吸附条件.结果表明:(1)菌株LA-4的接种量、pH对Cu2+的吸附有重要的影响.(2)根据表面响应法 优化模型预测出菌株LA-4吸附Cu2+的最...     

狭长空间内火灾烟气与人员疏散控制研究

本文采用了理论分析、火灾与疏散的组合模拟程序FDS＋EVAC，以一狭长空间为例，进行了火灾烟气作用时的人员疏散仿真研究，分析了通风排烟设备对火灾烟气运动和人员疏散的影响。     

Measurement of air exchange rates in different indoor environments using continuous CO2 sensors

A new air exchange rate (AER) monitoring method using continuous CO₂ sensors was developed and validated through both laboratory experiments and field studies. Controlled laboratory simulation tests were conducted in a 1-m³ environmental chamber at different AERs (0.1-10.0 hr^-1). AERs were determined using the decay method based on box model assumptions. Field tests were conducted in classrooms, dormitories, meeting rooms and apartments during 2-5 weekdays using CO₂ sensors coupled with data loggers. Indoor temperature, relative humidity (RH), and CO₂ concentrations were continuously monitored while outdoor parameters combined with on-site climate conditions were recorded. Statistical results indicated that good laboratory performance was achieved: duplicate precision was within 10%, and the measured AERs were 90%-120% of the real AERs. Average AERs were 1.22, 1.37, 1.10, 1.91 and 0.73 hr^-1 in dormitories, air-conditioned classrooms, classrooms with an air circulation cooling system, reading rooms, and meeting rooms, respectively. In an elderly particulate matter exposure study, all the homes had AER values ranging from 0.29 to 3.46 hr??1 in fall, and 0.12 to 1.39 hr^-1 in winter with a median AER of 1.15.     

制药废水二级出水中溶解性有机物混凝去除特性研究

制药废水二级出水中溶解性有机物(DOM)由于组成复杂、难去除、具有多异质性和分散性,是污水深度处理与回用的主要去除对象和关键限制因子.本论文以发酵制药废水二级出水的DOM为研究对象,采用投加聚合氯化铝(PAC)混凝剂去除DOM,考察混凝剂投加量和混凝pH值对去除效果的影响,并结合分子量分级、亲疏水性分级以及三维荧光光谱-平行因子分析方法等对DOM进行了系统表征和分析,进一步阐述混凝过程DOM的去除特征.结果表明,PAC投加量为250 mg·L~(-1)、pH=7时,混凝沉淀30 min对DOC、UV_(254)、色度和浊度的去除率分别为13.05%±0.29%、23.65%±0.75%、12.66%±1.34%、63.67%±0.89%;混凝对分子量10 kDa的组分和疏水中性(HON)组分去除效果分别为50.33%±0.98%、21.56%±0.42%,而对分子量1 kDa组分去除率较低为2.26%±0.12%;三维荧光光谱-平行因子分析将制药废水二级出水分为2个类腐殖质组分(C1、C3)和1个类蛋白组分(C2),混凝对类腐殖酸组分(C1)最大荧光强度去除率(F_(max))最高为46.22%,而亲水性的小分子和蛋白类物质混凝去除效果较差.     

Removal of polycyclic aromatic hydrocarbons from different soil fractions by persulfate oxidation

Removal of polycyclic aromatic hydrocarbons (PAHs) from different soil fractions of contaminated soil was investigated by using activated persulfate oxidation remediation in our research. The results showed that the light fraction, which accounted for only 10% of the soil, contained 30% of the PAHs at a concentration of 4352?mg/kg. The heavy fraction contained more high-molecular-weight PAHs, and the total PAH concentration was 625?mg/kg. After being oxidized, the removal rate of PAHs was 39% in the light fraction and nearly 90% in the heavy fraction. Among the different fractions of the heavy fraction, humic acid contained the highest concentration of PAHs, and consequently, the highest removal efficiency of PAHs was also in humic acid. Compared with the light fraction, the heavy fraction has more aromatic compounds and those compounds were broken down during the oxidation process, which may be the removal mechanism involved in the oxidation of high-ring PAHs. Similarly, the enhancement of C = C bonds after oxidation can also explain the poor removal of high-ring PAHs in the light fraction. These results imply that different fractions of soil vary in composition and structure, leading to differences in the distribution and oxidation efficiencies of PAHs.