城市生活垃圾渗透系数测试研究

采用常水头测渗实验，对不同压实密度和水力梯度下的新鲜垃圾与陈垃圾的渗透系数进行测试，根据达西定律求得渗透系数值。由于垃圾的不均匀性、小颗粒的运动和大孔隙沟道流的形成和改变，实验初始阶段渗透系数值先增大至峰值，然后缓慢降低直至趋于稳定。实验稳定后，新鲜垃圾压实密度为0．75—0．95t／m^3时，渗透系数值约为1．26E-03～1．43E-03cm／s。陈垃圾在压实密度分别为1．2和1．4t／m^3时，渗透系数为8．29E-04和1．35E-04cm／s。     

A combined radical and non-radical oxidation processes for efficient degradation of Acid Orange 7 in the homogeneous Cu(II)/PMS system: important role of chloride

Environmental Science and Pollution Research - Trace copper ion (Cu(II)) in water and wastewater can trigger peroxymonosulfate (PMS) activation to oxidize organic compounds, but it only works under...     

反渗透海水淡化水的消毒

反渗透海水淡化是解决水资源危机的一项重要技术。反渗透海水淡化水在饮用水生产过程中需进行消毒以解决微生物污染问题。采用次氯酸钙、二氧化氯和紫外线3种消毒方法,考察了反渗透海水淡化水和自来水的消毒效果,比较了对主要水质指标如pH、硬度和碱度的影响及余氯和余ClO2的衰减性。结果表明,二氧化氯消毒速率最快,次氯酸钙消毒对水质的影响最大,而紫外线的消毒效果最为稳定。可为反渗透海水淡化水的进一步利用提供依据。     

水中氰化物突发性污染事故应急监测方法研究

旨在研究现场快速测定水中的氰化物。运用比色分析的朗伯 比尔定律和真空工艺设计 ,将复杂繁琐的实验室测试方法和操作程序有机地融合在测试管中。该测试管具有快速、简便和价格低廉等特点 ,测定范围为 0 0 0 5— 0 2 0mg/L。     

Mercury pollution in a mining area of Guizhou,China: Fluxes over contaminated surfaces and concentrations in air,biological and geological samples

A dynamic flux chamber has been used to estimate fluxes of mercury over different types of surfaces in an abandoned open‐cut mine of Tongren prefecture, Guizhou province, China during spring and summer of 1996. The highest fluxes were obtained over cinnabar slag and contaminated soils, whereas the emissions above cinnabar ore were substantially lower. These fluxes was scaled up to estimate the contribution of mercury emissions to air from mercury wastes, compared to anthropogenic activities in the province of Guizhou, China. Atmospheric mercury concentrations measured were enhanced in the mining area (<1.3 μg m^‐3) compared to regional background sites (1.8–5.1 ng m^‐3). The spreading of mercury was estimated by using biological and geological samples. Moss bags have been employed to estimate long‐time dry‐ and wet‐deposition to this area.     

Structural effect on photocatalytic degradation of metallised azo dyes in aqueous TiO2 suspension

Three metallised azo dyes were investigated under TiO₂‐photocatalytic and photosensitised conditions in aqueous buffering solutions. The degradation follows apparent first‐order kinetics. The size and strength of intramolecular conjugation determine the light‐fastness of the investigated dyes. Compared with ¹O₂ produced in photosensitised process, the more powerful *OH radicals in TiCO₂ photocatalytic process are highly reactive towards the investigated azo dyes. And as a result, the TiO₂‐photocatalysis makes little less distinction in the degradation kinetic data of the azo dyes compared with the photosensitised degradation of them.     

A GIS-based moving window analysis of landscape pattern in the Beijing metropolitan area,China

Quantifying landscape pattern and its change is essential for monitoring and assessment of ecological consequences of urbanization. Using the GIS-based land-use data for 2002, we combined moving window analysis along an urban-rural gradient and around the urban centre with landscape metrics to quantify the spatial pattern of urbanization in Beijing. The results of moving window analysis along the urban-rural gradient indicated that, for class-level metrics, the spatial pattern of urbanization could be quantified using landscape metrics, different land-use types exhibited distinctive spatial signatures, and, for landscape-level metrics, the increase in urbanization in the metropolitan Beijing region has resulted in dramatic increases in patch density (PD), edge density (ED), and patch and landscape shape complexity, and sharp decreases in the largest and mean patch size (MPS), agriculture land-use type, and landscape connectivity. The results of moving window analysis around the urban centre showed that the direction of urbanization could be quantified using the class-level metrics, and landscape-level metrics indicated similar results to gradient analysis. In general, moving window analysis showed that the increasingly urbanized landscape became compositionally more diverse, geometrically more complex, and ecologically more fragmented.     

The abatement of major pollutants in air and water by environmental catalysis

This review reports the research progress in the abatement of major pollutants in air and water by environmental catalysis. For air pollution control, the selective catalytic reduction of NO _x (SCR) by ammonia and hydrocarbons on metal oxide and zeolite catalysts are reviewed and discussed, as is the removal of Hg from flue gas by catalysis. The oxidation of Volatile organic compounds (VOCs) by photo- and thermal-catalysis for indoor air quality improvement is reviewed. For wastewater treatment, the catalytic elimination of inorganic and organic pollutants in wastewater is presented. In addition, the mechanism for the procedure of abatement of air and water pollutants by catalysis is discussed in this review. Finally, a research orientation on environment catalysis for the treatment of air pollutants and wastewater is proposed.     

Removal of sulfadiazine from aqueous solution on kaolinite

The adsorption of sulfadiazine onto kaolinite clay as an alternative adsorbent was examined in aqueous solution, hnpacts of the contact time, pH, temperature, ionic strength and coexistent surfactants on the adsorption process were evaluated. The pH significantly influenced the adsorption process, with adsorption being promoted at lower pH due to the cation exchange mechanism. Decreasing ionic strength in the solution was favorable for adsorption, and the addition of cationic and anionic surfactants had negative effects on the adsorption capacity of sulfadiazine on kaolinite. Kinetic experiments showed that the adsorption followed the pseudo-second-order model. The equilibrium adsorption was well described by both Freundlich and Dubinin-Radushkevich （DR） models. According to the DR model, the adsorption mechanism was determined by cationic exchange and weak physical forces. The thermodynamic study showed that sulfadiazine adsorption onto kaolinite was a sponta- neous and endothermic reaction.     

Factors influencing sexual cannibalism and its benefit to fecundity and offspring survival in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae)

Sexual cannibalism is hypothesized to have evolved as a way to obtain a high-quality meal, as an extreme mate choice or as a consequence of female aggressive spillover. Here, we examined underlying factors likely to influence sexual cannibalism in the wolf spider Pardosa pseudoannulata (Bösenberg & Strand, 1906) from China, including mating status, female egg-laid status, female hunger level, female adult age and mate size dimorphism. The results showed that about 10 % of P. pseudoannulata virgin females cannibalized the approaching males before mating and that 28 % of P. pseudoannulata virgin females immediately cannibalized the males after mating. No incidents of sexual cannibalism during copulation were observed. Before mating, previously mated females and starved females tended to engage in significantly higher rates of attacks compared to virgin and well-fed females. Females that had laid egg sacs tended to engage in a significantly higher rate of attacks and sexual cannibalism than virgin females before mating. Regardless of pre- or post-mating, there was a strong positive relationship between mate size dimorphism and the occurrence of sexual cannibalism. We also tested the effects of sexual cannibalism on the fecundity of cannibalistic females and the survival of their offspring. Our results indicated that sexual cannibalism affected positively the offspring survival of cannibalistic females, but not fecundity. Our findings support the hypothesis that sexual cannibalism has evolved as an adaptive component of female foraging strategy and that it benefits offspring survival as a result of paternal investment.