添加Al粉对有机硅树脂涂层性能的影响

应用电化学方法研究了在有机硅涂料中添加不同含量的铝粉对其性能的影响.实验结果表明，添加5%和25%Al粉的有机硅涂层在相当长浸泡时间内保持优良的耐蚀性能.Al粉明显提高了304不锈钢的电化学反应电阻.添加Al粉的有机硅涂层的耐蚀性与其含量之间不是简单的线性关系.     

合作伙伴的可拓综合评价方法

为了客观、综合地评价合作伙伴,首先建立了一般合作伙伴综合评价参考体系,然后给出了形式化的合作伙伴综合评价物元模型。在此基础上提出了一种定性与定量相结合的合作伙伴可拓综合评价方法。该方法利用可拓理论对经典集合理论和模糊集合理论的语义进行扩展,通过关联度、合格度和优度计算,客观地给出了合作伙伴综合评价结果,并通过DRAGON项目的应用场景得到验证。最后,给出了该方法与层次分析法和模糊综合评价法的对比,说明了该方法能够有效保证综合评价的质量和效率。     

珠江水中有机物分子量分布及其去除研究

采用超滤膜分级方法考察了常规混凝、高锰酸钾和粉末活性炭预处理等工艺对珠江水中各级分子量有机物的去除效果。结果表明,珠江水中有机物以分子量小于1kDa的小分子有机物为主,各级分子量有机物TOC和UV254具有良好的相关性。常规混凝工艺主要去除大分子有机物,且去除率随分子量的减小而降低。高锰酸钾预处理能够全面提高各级分子量有机物的去除效果;粉末活性炭主要吸附中小分子有机物,对各级分子量有机物的去除效果与常规混凝成互补。     

巴渝古镇有机更新探析——以酉阳龙潭古镇吴家院子为例

针对目前巴渝古镇更新所面临的问题,提出在有机更新的基本原则指导下,基于巴渝古镇原住居民生活需求进行小规模、渐进式的动态更新,强调古镇整体聚居环境的修复、居民社会网络的延续、更新的经济性等,并以酉阳龙潭古镇吴家院子为例,探讨巴渝古镇传统建筑组群空间的有机更新。     

Evaluation of UV/H2O2 treatment for the oxidation of pharmaceuticals in wastewater

Advanced oxidation treatment using low pressure UV light coupled with hydrogen peroxide (UV/H₂O₂) was evaluated for the oxidation of six pharmaceuticals in three wastewater effluents. The removal of these six pharmaceuticals (meprobamate, carbamazepine, dilantin, atenolol, primidone and trimethoprim) varied between no observed removal and >90%. The role of the water quality (i.e., alkalinity, nitrite, and specifically effluent organic matter (EfOM)) on hydroxyl radical (OH) exposure was evaluated and used to explain the differences in pharmaceutical removal between the three wastewaters. Results indicated that the efficacy of UV/H₂O₂ treatment for the removal of pharmaceuticals from wastewater was a function of not only the concentration of EfOM but also its inherent reactivity towards OH. The removal of pharmaceuticals also correlated with reductions in ultraviolet absorbance at 254 nm (UV₂₅₄), which offers utilities a surrogate to assess pharmaceutical removal efficiency during UV/H₂O₂ treatment.     

Bio-diatomite dynamic membrane reactor for micro-polluted surface water treatment

This work investigated the feasibility of treating micro-polluted surface water for drinking water production with a bio-diatomite dynamic membrane reactor (BDDMR) at lab-scale in continuous-flow mode. Results indicate that the BDDMR was effective in removing COD_Mn, DOC, UV₂₅₄, NH₃-N and trihalomethanes' formation potential (THMFP) at a hydraulic retention time (HRT) of 3.5 h due to its high concentrations of mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS). The removal of pollutants was mainly ascribed to microbial degradation in BDDMR because the dynamic membrane alone was much less effective in pollutant removal. Though the diatomite particles (5-20 μm) were much smaller in size than the aperture of the stainless steel support mesh (74 μm), microorganisms and their extracellular polymer substances could bind these particles tightly to form bio-diatomite particles which were completely retained by the support mesh. The analysis of molecular weight (MW) distribution by gel permeation chromatography (GPC) shows that the BDDMR could effectively remove the hydrophilic fraction of dissolved organic materials present in the raw water.     

Formation of carbonaceous and nitrogenous disinfection by-products from the chlorination of Microcystis aeruginosa

Formation of carbonaceous disinfection by-products (C-DBPs), including trihalomethanes (THMs), haloacetic acids (HAAs), haloketones (HKs), chloral hydrate (CH), and nitrogenous disinfection by-products (N-DBPs), including haloacetonitriles (HANs) and trichloronitromethane (TCNM) from chlorination of Microcystis aeruginosa, a blue-green algae, under different conditions was investigated. Factors evaluated include contact time, chlorine dosages, pH, temperature, ammonia concentrations and algae growth stages. Increased reaction time, chlorine dosage and temperature improved the formation of the relatively stable C-DBPs (e.g., THM, HAA, and CH) and TCNM. Formation of dichloroacetonitrile (DCAN) followed an increasing and then decreasing pattern with prolonged reaction time and increased chlorine dosages. pH affected DBP formation differently, with THM increasing, HKs decreasing, and other DBPs having maximum concentrations at certain pH values. The addition of ammonia significantly reduced the formation of most DBPs, but TCNM formation was not affected and 1,1-dichloropropanone (1,1-DCP) formation was higher with the addition of ammonia. Most DBPs increased as the growth period of algal cells increased. Chlorination of algal cells of higher organic nitrogen content generated higher concentrations of N-DBPs (e.g., HANs and TCNM) and CH, comparable DCAA concentration but much lower concentrations of other C-DBPs (e.g., THM, TCAA and HKs) than did natural organic matter (NOM).     

Mineralization and biodegradability enhancement of natural organic matter by ozone-VUV in comparison with ozone, VUV, ozone-UV, and UV: Effects of pH and ozone dose

The increase in mineralization and biodegradability of natural organic matter (NOM) by ozone-vacuum ultraviolet (VUV) in comparison with ozone, VUV, ozone-ultraviolet (UV), and UV were investigated. The effects of operating parameters including pH and ozone dose were evaluated. Results showed that the mineralization rate of dissolved organic carbon (DOC) provided by the processes tested was in the following order: ozone-VUV > VUV > ozone-UV > ozone > UV. Among three pH studied (7, 9, and 11), pH 7 provided the highest DOC mineralization rate and biodegradability increase. A synergistic effect was observed when combining ozone with UV or VUV at pH 7 and 9 but not at pH 11. The oxidized NOM samples were separated into six fractions based on polarity (hydrophobic/hydrophilic) and charge (acid/neutral/base) to reveal NOM characteristic changes. Ozone-VUV was effective in mineralizing hydrophobic neutral and acid fractions. The hydrophilic neutral fraction was a major NOM fraction after oxidation (39-87%) and was contributed to by the biodegradable DOC produced during oxidation. High performance size exclusion chromatography results revealed that the combination of UV or VUV with ozone was more effective in the decomposition of high molecular weight compounds than ozone alone.     

Persistent organic pollutants in fish tissue in the mid-continental great rivers of the United States

Great rivers of the central United States (Upper Mississippi, Missouri, and Ohio rivers) are valuable economic and cultural resources, yet until recently their ecological condition has not been well quantified. In 2004-2005, as part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE), we measured legacy organochlorines (OCs) (pesticides and polychlorinated biphenyls, PCBs) and emerging compounds (polybrominated diphenyl ethers, PBDEs) in whole fish to estimate human and wildlife exposure risks from fish consumption. PCBs, PBDEs, chlordane, dieldrin and dichlorodiphenyltrichloroethane (DDT) were detected in most samples across all rivers, and hexachlorobenzene was detected in most Ohio River samples. Concentrations were highest in the Ohio River, followed by the Mississippi and Missouri Rivers, respectively. Dieldrin and PCBs posed the greatest risk to humans. Their concentrations exceeded human screening values for cancer risk in 27-54% and 16-98% of river km, respectively. Chlordane exceeded wildlife risk values for kingfisher in 11-96% of river km. PBDE concentrations were highest in large fish in the Missouri and Ohio Rivers (mean > 1000 ng g^− 1 lipid), with congener 47 most prevalent. OC and PBDE concentrations were positively related to fish size, lipid content, trophic guild, and proximity to urban areas. Contamination of fishes by OCs is widespread among great rivers, although exposure risks appear to be more localized and limited in scope. As an indicator of ecological condition, fish tissue contamination contributes to the overall assessment of great river ecosystems in the U.S.     

恢复·改建·延续——上海复兴中路642号改造设计回顾

近年来,由于对历史性建筑物的保护、利用、修复的要求不断提高,创造性的建筑细部设计已成为整个建筑设计的重要元素,恢复性的改建往往需要从细部体现出历史的延续性。