吐氏酸废液资源化技术的研究

研究了用化学萃取法回收吐氏酸废母液中染料中间体的多种影响因素,静态试验表明：通过萃取工艺,吐氏酸废母液中的染料中间体回收率可达９０％以上,萃余液中ＣＯＤｃｒ在５００～３０００ｍｇ／Ｌ之间;该工艺可使废母液中的回收物浓缩５～１０倍,根据静态试验得出的工艺参数,进行了动态模拟试验,取得了与静态试验非常接近的结果,为以后的示范工程提供了可靠的设计依据。     

利用毛细管柱测定水和废水中的苯系物

本文研究了利用毛细管柱分离、测定水样中的苯系物。该方法用二硫化碳萃取水样中的苯系物,细口径毛细管柱分离,ＦＩＤ测定。在分流比为１００∶１的条件下,方法最低检出浓度在００２５～００４７ｍｇ／Ｌ之间,低于填充柱法。该方法适用于地表水、地下水和废水中微量苯系物的测定。     

微波催化氧化法处理炼油废水

研究了应用微波辐射技术处理炼油废水,考察了活性炭用量,微波辐射时间,微波辐射功率,双氧水用量等因素对出水水质的影响。设计了实际废水的实验流程,检测了一部分生活杂用水(CJ25.1-89)中的主要指标,取得了较好的结果。     

气浮-生化处理-砂滤工艺处理高浓度食品生产废水

食品生产废水属于高浓度有机废水,具有排水量大、污染物浓度、水质水量变化大的特点,如不处理就直接排放,将会对水环境造成严重的污染.本工程中废水原水水质参数为:CODCr＜5000mg/L,BOD5＜3000mg/L,SS＜500mg/L,pH5.0～7.5,水温20～30℃.针对该废水水质特点,采用气浮-生化-砂滤工艺处理食品生产废水.运行结果表明,该处理工艺具有处理效率高、操作管理简便、抗冲击负荷、污泥量小、出水水质稳定、运行成本低等优点,处理后出水CODCr85mg/L,BOD524.3mg/L,SS56.2mg/L,pH6～8,达到<污水综合排放标准>(GB8978-1996)中的一级标准.     

Cesium migration in saturated silica sand and Hanford sediments as impacted by ionic strength

Large amounts of 137Cs have been accidentally released to the subsurface from the Hanford nuclear site in the state of Washington, USA. The cesium-containing liquids varied in ionic strengths, and often had high electrolyte contents, mainly in the form of NaNO3 and NaOH, reaching concentrations up to several moles per liter. In this study, we investigated the effect of ionic strengths on Cs migration through two types of porous media: silica sand and Hanford sediments. Cesium sorption and transport was studied in 1, 10, 100, and 1000 mM NaCl electrolyte solutions at pH 10. Sorption isotherms were constructed from batch equilibrium experiments and the batch-derived sorption parameters were compared with column breakthrough curves. Column transport experiments were analyzed with a two-site equilibrium-nonequilibrium model. Cesium sorption to the silica sand in batch experiments showed a linear sorption isotherm for all ionic strengths, which matched well with the results from the column experiments at 100 and 1000 mM ionic strength; however, the column experiments at 1 and 10 mM ionic strength indicated a nonlinear sorption behavior of Cs to the silica sand. Transport through silica sand occurred under one-site sorption and equilibrium conditions. Cesium sorption to Hanford sediments in both batch and column experiments was best described with a nonlinear Freundlich isotherm. The column experiments indicated that Cs transport in Hanford sediments occurred under two-site equilibrium and nonequilibrium sorption. The effect of ionic strength on Cs transport was much more pronounced in Hanford sediments than in silica sands. Effective retardation factors of Cs during transport through Hanford sediments were reduced by a factor of 10 when the ionic strength increased from 100 to 1000 mM; for silica sand, the effective retardation was reduced by a factor of 10 when ionic strength increased from 1 to 1000 mM. A two order of magnitude change in ionic strength was needed in the silica sand to observe the same change in Cs retardation as in Hanford sediments.     

Effect of soil layering on NAPL removal behavior in soil-heated vapor extraction

Soil heating has been proposed as a method to enhance the vapor extraction of NAPLs from contaminated soils. Three-dimensional fluid flow and heat transfer simulations have been performed for soil-heated vapor extraction to determine the transient system performance for a hypothetical configuration. Soil layering has been considered in evaluation of the initial non-aqueous phase liquid (NAPL) distribution and in evaporation and transport to the vapor extraction location. Results from this layered model are compared with results for a homogeneous system with an initially uniform NAPL, indicating the influence of layering, the initial NAPL distribution, the type of NAPL, and the possibility of enhanced vapor diffusion. Not only is the NAPL removal time reduced significantly with the addition of heat, but the uncertainty in the removal time owing to a number of difficult to characterize in situ factors, such as layering and the initial NAPL distribution, is much less than for standard soil vapor extraction without heating, owing to the rise in temperature and increase in NAPL vapor pressure with time.     

A model of oscillatory transport in granular soils, with application to barometric pumping and earth tides

A simple algebraic model is proposed to estimate the transport of a volatile or soluble chemical caused by oscillatory flow of fluid in a porous medium. The model is applied to the barometric pumping of vapors in the vadose zone, and to the transport of dissolved species by earth tides in an aquifer. In the model, the fluid moves sinusoidally with time in the porosity of the soil. The chemical concentration in the mobile fluid is considered to equilibrate with the concentration in the surrounding matrix according to a characteristic time governed by diffusion, sorption, or other rate processes. The model provides a closed form solution, to which barometric pressure data are applied in an example of pore gas motion in the vadose zone. The model predicts that the additional diffusivity due barometric pumping in an unfractured vadose zone would be comparable to the diffusivity in stagnant pore gas if the equilibration time is 1 day or longer. Water motion due to the M2 lunar tide is examined as an example of oscillatory transport in an aquifer. It is shown that the tidal motion of the water in an aquifer might significantly increase the vertical diffusivity of dissolved species when compared to diffusion in an absolutely stagnant aquifer, but the hydrodynamic dispersivity due to tidal motion or gravitational flow would probably exceed the diffusivity due to oscillatory advection.     

Analysis of heavy metal distribution in superficial estuarine sediments (estuary of Bilbao, Basque Country) by open-focused microwave-assisted extraction and ICP-OES

Open-focused microwave-assisted extraction and ICP-OES determination of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn from surface sediments of the estuary of Bilbao (Basque Country, North of Spain) was carried out. All the samples were collected at three different tributaries of the estuary (Asua, Galindo and Nerbioi-Ibaizabal) every two months during 1999. The digestion procedure was proposed from the conclusions of a fractionated factorial design, and the precision and accuracy of the method was verified using a certified reference sediment (RTC008-050). The results of the analysis were statistically treated by means of principal component analysis and correlation analysis. The principal component analysis of sediment data (32 samples × 9 metals) indicated different patterns of contamination regarding the tributary and sampling station. The two main patterns observed were a steady increment of the metal concentration along all the campaigns in the samples collected in the Galindo River and a seasonal variation in the Nerbioi-Ibaizabal River, with higher metallic content during summertime and lower content during wintertime.     

超临界络合萃取铅的研究进展

本文综述了超临界络合萃取铅的研究进展 ,介绍了几类络合剂 ,以及温度、压力和基质及基质修饰剂等因素对萃取效率的影响。