借鉴欧洲经验加快我国颗粒物污染防治

本文回顾了欧洲颗粒物污染控制的历程,从法规标准、管理制度、控制措施等方面,系统分析了欧洲颗粒物污染控制策略特点。通过总结欧洲颗粒物污染控制的经验,为我国的颗粒物污染控制提供借鉴。     

生化-混凝-吸附-离子交换工艺处理电镀废水

采用生物接触氧化-混凝沉淀-磁性树脂吸附-离子交换组合工艺对某公司排出的电镀综合废水进行处理,系统地阐述了各处理单元对废水的处理效果,经该工艺处理后的废水能稳定达到GB 21900—2008《电镀污染物排放标准》表3水污染物特别排放标准。     

含铊硫铁矿生产硫酸过程中铊的排放特性

通过焙烧实验探讨了含铊硫铁矿生产硫酸过程中铊的排放特性.结果表明,硫铁矿焙烧过程中,铊排放与焙烧温度、停留时间、焙烧气氛、硫铁矿的粒度等因素有关.不同的温度条件下,铊排放率不同,这主要是与矿石中铊的赋存形态有关;实验条件下,550℃—950℃是Tl排放的主要阶段,Tl排放量约占硫铁矿中总Tl的33.9%.Tl的排放率随...     

高风速下沙粒跃移跃距的实验研究

跃距是颗粒运动的重要参数之一,沙粒跃距的实验研究对沙粒跃移理论研究有重要的参考意义.由于高风速下沙粒跃移轨迹平缓,飞行距离较长,因而,高风速下沙粒跃距的实验研究很少.通过对沙粒跃移特点进行分析,提出同时采用水平集沙仪和垂直集沙仪观测沙粒跃距的方法,并采用该方法对高风速下沙粒跃距进行野外观测研究.结果表明,沙粒跃距随粒径减小呈指数规律增大,沙粒粒径与运动方式转换趋势与前人研究结果基本一致,说明该方法测量沙粒跃距是可行的.     

基于正交试验的煤矿安全开采充填材料配比优化研究

针对目前我国"三下"压煤的现状,以及煤矿固体废弃物以煤矸石、粉煤灰为主的情况,结合岱庄煤矿膏体充填工程实践,以水泥为胶结料,煤矸石和粉煤灰为粗细骨料,运用正交试验的方法定量确定了水泥、粉煤灰和煤矸石不同配比和膏体浓度对煤矸石膏体充填各性能指标的敏感程度,以及各指标随各因素的变化趋势。结果表明:提高水泥掺量可以缩短膏体的凝结时间并提高膏体的强度;膏体的塌落度即流动性主要通过调节其浓度来实现;加入适量的粉煤灰可以提高膏体的流动性,但随着粉煤灰的增多,分层度和泌水率都有所增加。当水泥∶粉煤灰∶煤矸石为1∶2.22∶4.44,浓度为75%时,充填膏体的可泵性和强度都达到最佳,充填效果显著,有助于煤矿安全开采。     

太湖湖西典型区水体硝酸盐含量对反硝化作用影响实验研究

以太湖湖西为例,采用流动培养同位素添加法,分别模拟了湖西北、湖西南地区不同温度及有机碳浓度下的底泥原位反硝化作用,结果表明只有水体硝酸盐含量高的湖西北地区底泥反硝化速率受温度和有机碳影响明显,水体硝酸盐含量低的湖西南地区底泥反硝化速率受水体温度、有机碳含量影响较小.研究结果表明,太湖湖西北地区22、27、32℃时反硝化速率分别为(77.62±5.23)、(156.01±12.01)、(309.36±20.31)μmol·m^-2·h^-1.湖西北区域上覆水有机碳含量为0、4、10 mg·L^-1时,沉积物平均反硝化速率分别为177.39、203.48、275.85μmol·m^-2·h^-1.根据皮尔逊相关性分析可知,太湖反硝化速率与水体硝酸盐含量呈显著相关,即水体氮素构成是影响底泥反硝化速率的最根本原因,只有硝酸盐供给充足,底泥反硝化速率才会随着温度及水体碳源的变化而变化.     

深圳妈湾排海工程非设计条件下泥沙沉积分析

本文在物理模型试型的基础上，通过理论分析和试验结果的相互验证，认为“悬浮指标”和“水流挟沙力”可作为泥沙沉积之水力条件的有效判据，且提供了判断方法，并由此得出了深圳妈湾排海工程防止泥沙沉积的临界排放流量，最后提出了防止泥沙沉积的运行管理防范措施和建议。     

Experimental Investigation of Potassium and Nitrate Dynamics in A Headwater Stream in Mid-Wales

Potassium and nitrate were added experimentally to a small moorland stream in the headwaters of the River Wye, mid-Wales, during summer and winter low-flow conditions. Nutrient losses at three downstream sampling locations were calculated using concentrations of an added bromide tracer to correct for dilution effects. During the summer experiment, approximately 18% of the added nitrate and 58% of the potassium were removed from the stream water between the point of addition and the catchment outlet. During the winter experiment, nitrate depletion was not observed and the added nitrate travelled along the stream at the same rate as the bromide tracer, while approximately 93% of the added potassium passed through the stream but, at a slower rate than the bromide and nitrate. the results show that in-stream processes, probably related to biological activity of macrophytes and microflora, can regulate stream water concentrations of nitrate and potassium in the summer under stable flow conditions. During the winter, no removal of nitrate or potassium was observed but ion exchange processes involving biofilms, Sphagnum and/or stream sediment may explain the temporary retention of potassium within the stream channel. If similar ion exchange processes operate at high flows, they may account for the hysteresis relationship observed between potassium and discharge during storm events in many upland streams.     

Nitric oxide removal by wastewater bacteria in a biotrickling filter

Nitric oxide(NO) is one of the most important air pollutants in atmosphere mainly emitted from combustion source. A biotrickling filter was designed and operated to remove NO from an air stream using bacteria extracted from the sewage sludge of a municipal sewage treatment plant. To obtain the best operation conditions for the biotrickling filter, orthogonal experiments(L9(34)) were designed. Inlet oxygen concentration was found to be the most significant factor of the biotrickling filter and has a significant negative effect on the system. The optimal conditions of the biotrickling filter occurred at a temperature of 40℃, a pH of 8.0 and a chemical oxygen demand of 165 mg/L in the recycled water with no oxygen in the system. The bacteria sample was detected by DNA sequencing technology and showed 93%–98% similarity to Pseudomonas mendocina. Moreover, a full gene sequencing results indicated the bacterium was a brand new strain and named as P. mendocina DLHK. This strain can transfer nitrate to organic nitrogen. The result suggested the assimilation nitrogen process in this system. Through the isotope experimental analysis, two intermediate products(15NO and 15N2O) were found. The results indicated the denitrification function and capability of the biotrickling filter in removing NO.     

Influence of sunlight on the proliferation of cyanobacterial blooms and its potential applications in Lake Taihu, China

To learn the relationship between sunlight intensity and cyanobacterial proliferations for the further control of the heavy blooms, enclosure experiment were conducted in Meiliang Bay, Lake Taihu by regulating the natural light intensities with different shading ratio （0% （full sunlight）, 10%, 25%, 50% and 75% of original natural sunlight intensities） from September to November in 2010. The results indicated that phytoplankton biomass （mean） decreased significantly when the shading ratios reached 50% or more. Higher shading ratios （e.g. 75%） were very efficient in controlling the average and total cyanobacterialbloom biomass, while 50% shading ratio was proven very effective either in controlling the peak value of phytoplankton biomass or postponing the occurrence of cyanobacterial blooms in Lake Talhu. In addition, phytoplankton composition and photosynthesis efficiency were also affected by altering the shading ratios, and in turn, they might also act on phytoplankton growth. Based on the results from the present study, intermediate shading strategies such as regulation of water level or turbidity through the hydrology regulations would probably be an effective and efficient method in controlling cyanobacterial blooms in large and shallow lakes.