自控水力截齿增大块率的声发射实验研究

通过对岩石破裂过程中声发射活动的实验探测，证明自控水力截齿在一定的水力参数和截割条件下，对岩样的潜在损伤范围及实际破碎沟槽宽度都明显大于同样截割条件下的普通截齿，从而为采掘机械应用少截齿配置方案以提高块率提供了一条可行的技术途径。     

基于可靠度约束的高层建筑结构优化设计

本文以文献中提出的结构体系可靠度分析的最弱失效模式法为基础,充分考虑结构体系的造价和结构的损失期望与结构体系可靠度的关系,以及结构构件的可靠度约束,提出了结构体系目标可靠度的优化决策方法;基于优化决策的结果,提出了结构体系的最优设计准则;最后,依所提出的最优设计准则,实现了高层建筑基于构件和结构可靠度约束的结构优化设计。     

CT4-35钻井废水处理剂的研制及应用

CT-35是一种高效的钻井废水处理剂，与其它常用药剂相比，该混凝剂对处理高浓度钻井废水特别是处理难度很大的磺化类废水有明显的优势。介绍了CT4-35研制、生产工艺，用它处理现场钻井废水的情况。现场使用表明：利用CT4-35处理钻井废水，COD的去除率可达85％以上，浊度去除率为100％，处理后出水呈中性（PH6～8），色度小于原水样的1／10，出水清澈透明，并且产生的污泥量少。通过对处理前、后出水的水质分析，证明其中无药剂残留。     

瀑布沟水电站的主要环境问题

本文简要介绍了瀑布沟水电站的工程情况，工程地区的环境特点，以及兴建该工程带来的主要环境影响，包括自然环境，生物环境和社会环境的影响及其评价结论。     

新型类Fenton催化剂用于酸性红B染料废水处理的研究

为了解决Fenton试剂反应前后需要调节pH值、催化剂不能重复利用的问题,本实验以酸性红B溶液作为模拟染料废水,探索以硫铁矿烧渣作为非均相催化剂进行类Fenton反应的催化活性,研究了H2O2投加量、催化剂投加量、pH值、反应时间对酸性红B去除效果的影响。在双氧水(H2O2质量分数为30%)投加量为30 mL/L、催化剂投加量为30 g/L、pH值在1~11范围内,反应4 h,浓度为200 mg/L的酸性红B去除率均达到95%以上,且反应后pH值在中性范围。实验结果表明,该非均相类Fenton反应体系对pH的适用范围广,且催化剂易于沉淀分离,反应数次后依然保持较高催化活性,能重复利用。     

电吸附技术的新进展

阐述了电吸附技术的原理及特点,介绍了双电层模型的发展,综述了活性炭电极、活性碳纤维电极、碳气凝胶电极、碳纳米管电极及复合电极的制备工艺以及电吸附技术在咸水淡化和去除水中污染物方面的最新应用,并对以后的研究方向提出了建议。     

序批式膜生物反应器(SMBR)处理生活污水的研究

实验模拟生活污水,考察了连续式膜生物反应器(continuous membrane bioreactor,CMBR)和序批式膜生物反器(sequencing batch membrane bioreactor,SMBR)的膜污染和污染物去除效果.结果表明CMBR和SMBR出水COD的平均浓度分别为15.42 mg/L和...     

Release of hexachlorocyclohexanes from historically and freshly contaminated soils in China: implications for fate and regulation

Hexachlorocyclohexanes (HCHs) were produced and used in large quantity worldwide and are common soil pollutants. In this study, desorption of α-HCH and γ-HCH from two soil samples collected from a historical pesticide plant in Tianjin, China, was examined. As a comparison, desorption of freshly sorbed γ-HCH was examined, using five typical Chinese soils. Strong resistant desorption was observed for both historically contaminated and freshly contaminated soils, and desorption results were well modeled with a biphasic desorption isotherm. The unique thermodynamic characteristics associated with the desorption-resistant fraction indicated that physical constraint within soil organic matrices was likely the predominant mechanism controlling resistant desorption. Resistant desorption could have significant effects on fate and exposure of HCHs in soil environment. More accurate biphasic desorption models that take into account of the resistant desorption can be used to facilitate regulating, management and remediation of HCH-contaminated sites.     

Combined effect of adsorption and biodegradation of biological activated carbon on H2S biotrickling filtration

In order to evaluate the combined effect of adsorption and biodegradation of H(2)S on activated carbon surface in biotrickling filtration, four laboratory-scale biofiltration columns were operated simultaneously for 120h to investigate the mechanisms involved in treating synthetic H(2)S streams using biological activated carbon (BAC). The first three columns (A, B, C) contained a mixture of activated carbon and glass beads, with the carbons (BAC or virgin activated carbon (VAC)) and conditions (with or without liquid medium recirculation) differentiated. The last column (D) used 100% glass beads with liquid medium recirculation. Air streams containing 45ppmv H(2)S were passed through the columns at 4s of gas retention time (GRT) and liquid flow rate was set at 0.71mlmin(-1). Column D got its breakthrough in 3min of operation, indicating a negligible contribution of glass beads to the adsorption of H(2)S. The removal efficiency (RE) of Columns B and C using VAC dropped quickly to 30% within the first 8h, and afterwards continued to drop further but slowly. Column A using BAC stayed at 25% of RE throughout the operation time. A thorough investigation of the H(2)S oxidation products, i.e., various S species in both aqueous (recirculation media) and solid phases (BAC and VAC), was conducted using ICP-OES, IC, XRF, and CHNS elemental analyzer. BAC demonstrated a better performance than columns with adsorption only. Water film was found to enhance H(2)S removal. The percentage of sulphate in the total sulphur of the BAC system improved to twice of that of VAC system, indicating sulphate is the main product of H(2)S biofiltration. The observed pH drop in BAC system double confirmed that the presence of biodegradation in the biofilm over carbon surface did profound effect on the oxidation of H(2)S, compare to the systems with adsorption only.     

Oasis land-use change and its environmental impact in Jinta Oasis, arid northwestern China

Land use change resulted in land degradation is a focus of research on global environmental changes and plays a significant role in the stability and economic development of oases in arid regions of China. Jinta Oasis, a typical oasis of temperate arid zone in northwestern China, was investigated to assess land-use change dynamics during 1988–2003 with the aid of satellite remote sensing and GIS, and to explore the interaction between these changes and oasis environment. Six land-use types were identified, namely: cropland, forestland, grassland, water, urban or built-up land, and barren land. The results indicate that cropland, urban/built-up land, and barren land increase greatly by 30.03, 13.35, and 15.52 km², respectively; but grassland and forestland areas decrease rapidly by 58.06, and 1.76 km², respectively. These results also show that obvious widespread changes in land-use occur within the whole oasis over the study period and result in severe problems of environmental degradation (i.e. land desertification, decline of groundwater, and vegetation degeneracy).