油田高盐浓度废水对其生化处理的影响

根据油田压裂液废水中的盐浓度对生化处理系统的影响,对生化处理系统中活性污泥的生物学变化规律进行了实验研究。结果表明:当废水中盐浓度低于2.5×104mg/L时,废水生化处理系统对COD的去除率可稳定在92%左右,污泥活性良好;当废水中盐浓度达到2.5×104mg/L时,污泥活性开始受到抑制,COD去除率急剧下降(稳定在80%左右);当盐浓度达到3.5×104mg/L时,COD去除率下降到60%左右;当废水中盐浓度达到6.0×104mg/L时,污泥活性系统趋于崩溃。     

Trihalomethane formation potential of filter isolates of electrolyte-extractable soil organic carbon

Certain organic C moieties of soil origin in drinking source waters of Sacramento-San Joaquin Delta (Delta) can react with chlorine to form trihalomethanes (THMs) during the disinfection process. Isolation and characterization of them and quantitation of their THM formation potential (THMFP) is necessary for developing effective strategies to reduce their influxes in Delta waters and for removing them during drinking water treatment. In this study, organic C from two Delta soils was extracted using deionized H(2)O and four Na- or Ca-based electrolytes of varying electrical conductivity values. Extracts were filtered into particulate, colloidal, fine colloidal, and soluble organic C for quantitation and THMFP determination. Results suggested that <1.5% of soil organic C was electrolyte-extractable. The soluble organic C fraction from both soils dominated in quantity and THMFP. Electrolyte effects were cation dependent. Sodium-based electrolytes at either conductivity level did not significantly decrease extractable organic C (EOC) or THMFP compared with deionized H(2)O. In contrast, Ca-based electrolytes reduced EOC and THMFP by >50% even at 1 dS m(-1). Further increase in Ca concentration did not significantly decrease EOC or THMFP. Most reduction in EOC and THMFP by Ca-based electrolytes occurred with the fractions other than the soluble organic C. Results suggested that under natural soil leaching and runoff conditions, the majority of THMFP is associated with organic C of <0.025 mum in diameter. Further molecular characterization of the fractions with high THMFP may help understand the nature of chlorine-reactive organic C from Delta soils.     

发展绿色建筑是可持续发展的必然选择

本文在总结绿色建筑概念及其涵义的基础上,论述了发展绿色建筑的意义,提出了推进绿色建筑发展的措施。     

A grey multi-objective programming approach for sustainable land-use in the Miyun Reservoir basin, China

Miyun Reservoir is the most important water source to Beijing City. Land-use of the basin plays a great role in the protection of water resources. Hence a sustainable land-use planning is required to optimize land-use structure and protect water resources in the basin. Based on the complete land-use system analysis in Miyun, a grey multi-objective programming to basin land-use(GMOPBLU)model was developed and applied to land-use planning. Two alternatives were produced and analyzed by means of interactive adjustment and scenano analysis. The results showed the GMOPBLU model is a valuable approach for basin land-use planning.     

A new approach of drawing airport noise contours on computer based on Surfer

Noise contours are used to describe the extent of airport noise pollution and to plan land use around airports. The LWECP, (weighted equivalent continuous perceive noise level) recommended by ICAO( International Civil Aviation Organization) is adopted as airport noise rating parameter in this paper. With the help of various mathematical models in the software Surfer, noise contours can be drawn automatically by the completed program in Visual C Code. Corrections for thrust, velocity, atmospheric temperature, humidity and lateral ground attenuation are also considered in the new method, which can improve the efficiency of drawing contours. An example of its use for drawing noise contours of an airport in Zhejiang Province of China is proposed and the predictions and the measurements show agreements well.     

梁式桥震害及其影响因素分析

为了研究梁式桥的震害及其影响因素,基于近年来国内外几次大地震中梁式桥震害调查资料,对梁式桥震害现象进行分类并分析其原因,从地震烈度、建设年代、结构体系、地震次生地质灾害等4个方面对桥梁震害的影响分别进行了分析,得到了关于梁式桥地震破坏影响因素、破坏机理等方面的认识。     

Distribution,source, and ecological risk assessment of PAHs among size and density fractions in contaminated sediments from the Yellow River of Henan section

This study investigated particle size and density distributions of polycyclic aromatic hydrocarbons (PAHs) in two surface sediments (JZ and KF), collected from the Yellow River of Henan section, China. The concentrations of Σ₁₅PAHs ranged from 35.6 to 45862?ng g^?1 dry wt, which were greatly elevated in coarse particles and low-density fractions. The Σ₁₅PAHs concentrations in low-density fractions were 533 (JZ) and 996 (KF) times higher than those in the corresponding high-density fractions. However, due to relatively less quantities of low-density fractions (0.27–2.33%), most of the PAHs were contributed by the high-density components. For both sediments, the influence factors of PAHs source in the environment were very complex, more so than the level of TOC and BC content. JZ sediment was dominated by 4-ring to 6-ring PAHs (61.5–75.1%), while, 2-ring to 3-ring PAHs were abundant in KF samples (39.8–72.6%). Ratios of specific PAHs reflected PAHs among the size- and density-fraction of each sediment may be contaminated by mixed of pyrolytic and petrogenic origin. Additionally, ecological risk assessment of PAHs suggested that total toxic equivalent values of PAHs in the low-density fractions were much higher than those of the corresponding high-density fractions in the studied area.     

Characterization of modified Alternanthera philoxeroides by diethylenetriamine and its application in the adsorption of copper(II) ions in aqueous solution

Environmental Science and Pollution Research - By a simple and convenient method of using epichlorohydrin as linkages, a novel Alternanthera philoxeroides (AP) derivative modified with...     

国内外有机废液的焚烧处理技术

介绍了国内外高浓度有机废液的焚烧处理装置,即液体喷射焚烧炉,回转窑焚烧炉,泡流化床焚烧炉和循环流化床焚烧炉,阐述了各种焚烧炉的工作特点,通过比较出,鼓泡流化床和循环流化床焚烧炉在环保方面具有突出的优点。     

长江源区草地植被退化对土壤持水能力影响

选择长江源区的格尔木市唐古拉山镇作为研究区,通过野外实地采样与室内测试分析相结合,在分析草地植被不同退化阶段和不同土层深度下土壤持水能力特征的基础上,探讨了草地植被退化对土壤持水能力影响。结果表明：（1）在相同草地植被退化阶段,毛管持水量、饱和含水量和田间持水量随土层深度变化的特征基本一致;在相同土层深度上,毛管持水量、饱和含水量和田间持水量随草地植被退化的特征也大体相同。（2）在相同草地植被退化阶段,土壤持水量总体上随土层深度增加而减少,特别是在未退化阶段,10~20 cm土层的毛管持水量、饱和含水量和田间持水量比0~10 cm土层分别减少了12.38%、33.73%和7.64%。（3）在相同土层深度上,土壤持水量总体上随草地植被退化而减少,特别是在0~10 cm土层,轻度退化阶段的毛管持水量、饱和含水量和田间持水量比未退化阶段分别减少了41.52%、59.95%和27.03%。（4）土壤持水量与土壤容重、总碳、有机质和总氮显著相关,它在草地植被不同退化阶段和不同土层深度下的变化可能与地表覆被状况、植物根系数量和分布特征所引起的土壤容重、有机质等变化有关。研究可深化对草地植被退化与土壤持水能力相互关系的理解和认识,并为长江源区生态环境和水资源状况研究提供参考依据。 关键词： 土壤持水能力;草地植被退化;长江源区;影响