连续式离子分离系统(ISEP)在水杨酸生产废水处理中的应用

采用连续式离子分离系统 (ISEP)处理水杨酸生产废水 ,结果表明 ,该系统对水杨酸生产废水有良好的处理效果。当进水CODCr为 180 0 0— 2 0 0 0 0mg/L时 ,经一步吸附处理 ,出水CODCr可实现达标排放 ,苯酚、水杨酸去除率接近10 0 % ,脱附液中高浓度苯酚、水杨酸等资源可有效回收利用     

Toxicological and biochemical responses of the earthworm Lumbricus rubellus to pyrene, a non-carcinogenic polycyclic aromatic hydrocarbon

The effects of the polycyclic aromatic hydrocarbon (PAH) pyrene on earthworms were investigated in contact and soil tests. In addition to measuring toxic effects on survival and reproduction, Ethoxyresorufin-o-deethylase (EROD) activity and catalase activity were also studied as possible biomarkers of toxic stress. The survival data indicated that LC₅₀ values were 0.0068 mg/ml for the contact test, and 283 mg/kg in the soil test. Cocoon production rate was significantly reduced compared to controls at 160, 640 and 2560 mg/kg in the soil test. No EROD activity could be detected in preliminary studies using control and exposed animals from the contact test, so this assay was not used to the soil test. Catalase activity was shown to be significantly lower at 640 mg/kg in the soil test compared to all other treatments and the control. When compared to toxicological data for other soil invertebrates, Lumbricus rubellus has an intermediate sensitivity in respects of survival and a lower sensitivity for reproductive effects, although the soil used in this study had a higher organic content than previous studies, meaning that the sensitivity of this species may be underestimated in comparison to previous published data for other soil invertebrates.     

Nitrogen species in drinking water indicate potential exposure pathway for Balkan Endemic Nephropathy

This study explored two hypotheses relating elevated concentrations of nitrogen species in drinking water and the disease Balkan Endemic Nephropathy (BEN). Drinking water samples were collected from a variety of water supplies in both endemic and non-endemic villages in the Vratza and Montana districts of Bulgaria. The majority of well water samples exceeded US drinking water standards for nitrate + nitrite. No statistically significant difference was observed for any of the nitrogen species between villages classified as endemic and non-endemic. Other constituents (sodium, potassium and chloride) known to be indicators of anthropogenic pollution were also found at elevated concentrations and all followed the order wells > springs > taps. This ordering coincides with the proximity of human influences to the water sources. Our results clearly establish an exposure pathway between anthropogenic activity and drinking water supplies, suggesting that the causative agent for BEN could result from surface contamination.     

AB法A段污泥减量试验研究

针对AB法A段剩余污泥量大的问题,采用臭氧和超声波对A段污泥减量效能进行了对比试验研究.结果表明:(1)将相当于传统A段剩余污泥量的污泥,进行2 h臭氧接触氧化后,再回流至A段反应器,其平均污泥产率系数为0.0328 kg MLSS/kg COD·d;(2)采用超声波对A段进水作用0.5 h,其平均污泥产率系数为0.0246 kg MLSS/kg COD·d.A段采用上述2种方法减量后几乎无剩余污泥产生,同时对A段反应器中的污泥活性和出水水质的影响较小,从经济上考虑臭氧法具有优势.     

Method for comparing the capture efficiency of benthic sampling devices

Traditional comparisons between the capture efficiency of sampling devices have generally looked at the absolute differences between devices. We recommend that the signal-to-noise ratio be used when comparing the capture efficiency of benthic sampling devices. Using the signal-to-noise ratio rather than the absolute difference has the advantages that the variance is taken into account when determining how important the difference is, the hypothesis and minimum detectable difference can be made identical for all taxa, it is independent of the units used for measurement, and the sample-size calculation is independent of the variance. This new technique is illustrated by comparing the capture efficiency of a 0.05 m² van Veen grab and an airlift suction device, using samples taken from Heron and One Tree lagoons, Australia.     

A simplified 137Cs transport model for estimating erosion rates in undisturbed soil

(137)Cs is an artificial radionuclide with a half-life of 30.12 years which released into the environment as a result of atmospheric testing of thermo-nuclear weapons primarily during the period of 1950s-1970s with the maximum rate of (137)Cs fallout from atmosphere in 1963. (137)Cs fallout is strongly and rapidly adsorbed by fine particles in the surface horizons of the soil, when it falls down on the ground mostly with precipitation. Its subsequent redistribution is associated with movements of the soil or sediment particles. The (137)Cs nuclide tracing technique has been used for assessment of soil losses for both undisturbed and cultivated soils. For undisturbed soils, a simple profile-shape model was developed in 1990 to describe the (137)Cs depth distribution in profile, where the maximum (137)Cs occurs in the surface horizon and it exponentially decreases with depth. The model implied that the total (137)Cs fallout amount deposited on the earth surface in 1963 and the (137)Cs profile shape has not changed with time. The model has been widely used for assessment of soil losses on undisturbed land. However, temporal variations of (137)Cs depth distribution in undisturbed soils after its deposition on the ground due to downward transport processes are not considered in the previous simple profile-shape model. Thus, the soil losses are overestimated by the model. On the base of the erosion assessment model developed by Walling, D.E., He, Q. [1999. Improved models for estimating soil erosion rates from cesium-137 measurements. Journal of Environmental Quality 28, 611-622], we discuss the (137)Cs transport process in the eroded soil profile and make some simplification to the model, develop a method to estimate the soil erosion rate more expediently. To compare the soil erosion rates calculated by the simple profile-shape model and the simple transport model, the soil losses related to different (137)Cs loss proportions of the reference inventory at the Kaixian site of the Three Gorge Region, China are estimated by the two models. The over-estimation of the soil loss by using the previous simple profile-shape model obviously increases with the time period from the sampling year to the year of 1963 and (137)Cs loss proportion of the reference inventory. As to 20-80% of (137)Cs loss proportions of the reference inventory at the Kaixian site in 2004, the annual soil loss depths estimated by the new simplified transport process model are only 57.90-56.24% of the values estimated by the previous model.     

昭通市民用型煤固硫脱硫实验研究

结合本地燃料煤特征、燃烧方式、固硫脱硫剂资源情况等,初步确定以生石灰为主固硫剂、窑泥巴为粘结剂,重点考察了固硫剂的适用温度、民用型煤固硫脱硫效果.     

Courtship and reproduction in<Emphasis Type="Italic"> Carybdea sivickisi</Emphasis> (Cnidaria: Cubozoa)

Courtship and fertilization events in cubozoans have received little attention from biologists, and much of what we know about these processes is based on conjecture or scant anecdotal evidence. I set out to describe these processes in the cubozoan Carybdea sivickisi by observing mature medusae in vitro. Mature adults engage in courtship during which spermatophores are transferred from the male to the female, who then inserts the gametes into her manubrium. Females accepted multiple spermatophores from multiple males, and only produced one embryo strand. This study also provides evidence that the presence of conspicuous velar spots on the females bell margin is a signal of sexual maturity, and that sexual maturity was not reached in either sex until individuals had a bell diameter of at least 5 mm.Communicated by R.J. Thompson, St. Johns     

Fix-Neyman model of illness-death processes

The concept of the life table originated in longevity studies of man, where it was always presented as a subject peculiar to public health, demography, and actuarial science. As a result, its development has not received sufficient attention in the field of statistics. Actually, the problems of mortality studies are similar to those of reliability theory and life testing, and they may be described in terms familiar to the statistically oriented mind. From a statistical point of view, human life is a random experiment and its outcome, survival or death, ss subject to chance. The life table systematically records the outcomes of many such experiments for a large number of individuals over a period of time. Thus, the quantities in the table are random variables subject to established statistical analysis. The purpose of this presentation is to discuss the life table from a statistical viewpoint.     

高温熔渣热资源回收技术发展及探讨

我国高温熔渣年产生量超过6亿t,其热资源价值巨大,但浪费情况严重。对干法粒化、化学法、冷却水余热利用、直接制备产品4种熔渣热能利用技术进行了论述探讨。熔渣热能回收技术的应用离不开熔渣资源利用,综合经济效益最大化是热能利用技术应用的关键因素。对于高温熔渣热回收技术建议如下:针对活性物料含量低的熔渣采用干法粒化、化学法进行热能回收;活性物料含量高的熔渣,在确保熔渣产品活性的条件下进行热能回收技术开发;因地制宜地进行冲渣冷却水余热利用;解决熔渣直接制备产品的关键工艺技术难点,提质降本;加强熔渣液固转变矿物结构变化过程的研究,实现固化渣的矿物组成调控。