5%NaCl盐雾环境对铝合金铆接防护结构性能影响研究

目的研究2024铝合金在5%NaCl盐雾环境下的腐蚀疲劳性能。方法开展2024铝合金5%NaCl盐雾环境下的腐蚀疲劳试验,采用"疲劳加载-腐蚀环境"交替循环的试验模式,通过试验测试铝合金铆接结构在5%NaCl盐雾环境下的腐蚀疲劳寿命值,分析不同疲劳载荷大小对铝合金连接结构的腐蚀疲劳寿命影响。结果 5%NaCl盐雾环境对于铝合金铆接结构疲劳寿命有较大影响,疲劳载荷对防护涂层防护性能和腐蚀疲劳载荷的滞后效应等两方面影响,0.25P破坏载荷相较于0.3P破坏载荷,涂层防护作用影响更小,低载锻炼效应更强,腐蚀疲劳寿命降低量更少。结论 2024铝合金铆接结构耐腐蚀性能与结构载荷和防护涂层特性有重要关系。     

我国大气环境下大型钢结构的长效防护

论述了喷涂Zn、Al及Zn鄄Al合金涂层的防护性能,列举了它们在不同环境条件下的腐蚀试验结果及数据,介绍了一些工程实例中采用金属喷涂层进行防护的效果及防护寿命。此外还介绍了氟碳树脂涂层在我国典型的高辐射太阳能和沿海地区环境下的优秀耐候性能。在上述工作基础上,推荐了关于大型钢结构高效、长效防腐措施的2种建议方案,其防腐蚀寿命可达15～20年以上。     

特种化工废水的生物毒性、抑制性研究

某厂特种有机废水 ,含季铵盐和羟乙基纤维素。研究表明 ,他们在浓度分别超过 1 2 0 mg/L和 2 2 0 mg/L时 ,呈现生物毒性或抑制性 ,且随浓度增高而严重影响废水生化处理效果。当水样中季铵盐浓度小于 1 2 0 mg/L,羟乙基纤维素浓度小于 2 2 0 mg/L时 ,它们不具生物毒性 ,可作为营养物质被微生物利用。废水动态模拟试验表明 ,进水 CODCr30 0 0 mg/L的废水 ,用接触厌氧—好氧生化法能使出水达到当地排放标准。     

耐盐降解苯乙酸类菌株A1(Arthrobacter sp.A1)的分离和特性研究

从处理含盐（NaCl浓度为0．77mol/L）苯乙酸生产污水的耐盐活性污泥中分离到一株节杆菌（Arthrobacter sp.A1）。该菌株能在NaCl浓度为0．1mol/L－2．0mol/L，以苯乙酸为唯一碳源的基础培养基中生长，或在NaCl浓度为0mol/L－2.4mol/L的完全培养基中生长，并能适应急剧的盐浓度变化，对其它常见的低价态无机盐份如KCl、MgCl2、（NH4）2SO4、Na2SO4、CaCl2也具有较强的耐受性，而对高价态无机盐份和重金属盐则耐受性不强。在不同的NaCl浓度下，菌株A1细胞内的QAC（季胺化合物）、游离氨基酸和K^ 含量与盐浓度的升高成正比关系。     

我国东部七省生态系统对酸沉降的相对敏感性

讨论了影响亚热带生态系统对酸沉降敏感性的生态因子，提出了敏感性等级划分的指标体系，根据大量资料编制了我国东部７省１市生态系统对酸沉降相对敏感性分区图。结果表明，在研究区域内生态系统的敏感性有相当大的差别，极敏感区和敏感区面积占全区总面积的１／３以上，主要分布在福建、浙江、江西３省。     

喷雾增湿塔用离心式雾化器的设计

在分析各种运行参数对雾化效果影响的基础上 ,介绍了喷雾增湿塔用离心式雾化器的选型与放大设计的方法。     

水喷淋法控制煤尘的研究

水喷淋法是连续采煤过程中广泛应用的一种有效的除尘方法。由于煤是憎水性物质，使水喷淋的除尘效率受到一定的限制。本研究表明，粉尘的粒径影响极大，粒径越小的煤尘，界面张力对它的影响相对就越大，其捕集效率就越低，使用表面活性剂的效力也就越明显。当尘粒极微小时，其斯托克数亦很小，使动能小于穿透功（Ｅｋ＜Ｗ），惯性碰撞不再是支配性的捕集作用机理，尘粒与水滴之间的界面作用要受到许多其他参数的控制。在不同的操作条件下，许多作用力互相竞争，起着各种各样的协同作用。喷淋水中含有电解质会降低煤尘捕集效率，含盐量的多少是一个不可忽视的因素。阳离子表面活性剂可以提高憎水性煤尘的捕集效率，但是，喷淋水中的电解质会干扰离子型表面活性剂的效力。     

The Role of a Salt Marsh Plant on Trace Metal Bioavailability in Sediments. Estimation By Different Chemical Approaches * (7 pp)

Goal, Scope and Background The presence or absence of vegetation can condition sediment characteristics. The main aim of this work was to investigate the influence of the sea rush Juncus maritimus on metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) availability to organisms living on or in estuarine sediments, from Douro River (NW Portugal), by comparing the characteristics and chemical behaviour of rhizosediments (collected within the plant assemblage) and those of sediment (collected around the plant). In order to evaluate whether and how sediment characteristics condition the role of plants on metal availability, sandy and muddy sediments colonised by J. maritimus were studied in parallel. Methods Metal availability was estimated by enzymatic digestion with pepsin (ED), which may provide an estimate of metal availability to organisms living at estuarine sediments. Nevertheless, since no consensus exists yet on the most suitable methodologies to estimate metal bioavailability in sediments, two more conventional approaches, BCR sequential extraction (SE) and AVS/SEM model, were also used, in parallel, and the information these approaches provided was compared with that provided by ED. Total-recoverable metal contents were determined by atomic absorption spectrophotometry after sediment digestion using a high-pressure microwave system. Results and Discussion Plants could concentrate metals around its roots and rhizomes. In addition, they were capable of oxidizing (release of oxygen by the roots) the anaerobic medium surrounding their roots in muddy sediment (reducing AVS). As sulphide oxidation renders metals (Cd, Cu, Ni, Pb and Zn) into more soluble forms, according to the AVS/SEM model, metals from muddy sites would be more available in rhizosediment than in sediment. The SE approach led to a similar conclusion. Nevertheless, the results provided by ED pointed at opposite conclusion, particularly for Cd and Zn, indicating less availability at rhizosediments than in the surrounding sediment. ED results were interpreted as a consequence of an enrichment of the rhizosediment in organic ligands exuded by the roots or liberated by dead plants. The effect of complexation of metals by organic compounds, which ED could not decompose/dissolve, seemed to overcome that caused by sediment oxidation. In general, a comparison of the information about metal availability by ED, SE, AVS/SEM, showed that it did not always match and in few cases it was even contradictory. Conclusion and Outlook Therefore, a thorough evaluation of the metal availability in sediments requires a combination of different chemical approaches, so as to take into consideration differences in ways of organism exposure (interstitial water and/or ingestion of sediment particles). - * The basis of this peer-reviewed paper is a presentation at the 9th FECS Conference on 'Chemistry and Environment', 29 August to 1 September 2004, Bordeaux, France.     

对淮安市盐化工循环经济发展的探析

主要对江苏淮安盐化工循环经济发展的现状，发展的必要性、可行性及可操作性进行了分析研究，并对加快淮安盐化工循环经济发展提出了几点建议。     

Temporal and spatial relationships in fine particle strong acidity, sulphate, PM1O, and PM2.5 across multiple canadian locations

The Canadian Acid Aerosol Measurement Program (CAAMP) was established in 1992 to gain a better understanding of the atmospheric behaviour of fine particle strong acidity (“acid aerosols”) and to facilitate an assessment of the potential health risks associated with acid aerosols and particles in general. During 1992. 1993 and 1994, annular denuder and filter measurements were taken at four sites in Ontario, two in Quebec, three in the Atlantic Provinces and one in the greater Vancouver area. Mean fine particle sulphate concentrations (SO₄²⁻) were highest in southern Ontario (annual average ranged from 40–70 nmol m⁻³), lowest at a site in the Vancouver area (average = 16 nmol m⁻³) and second lowest in rural Nova Scotia. However, mean fine particle strong acid concentrations (H⁺) were geographically different. The highest mean concentrations were at the east coast sites (annual average of up to 30 nmol m⁻³). Acidities were lower in areas where the fine particle acidity experienced greater neutralization from reaction with ammonia. This included the major urban centres (i.e. Toronto and Montréal) and areas with greater amounts of agricultural activity, as in rural southern Ontario. On average, ambient concentrations of fine and coarse particle mass were larger in the urban areas and also in areas where SO₄²⁻ levels were higher. All the particle components were episodic. However, compared to SO₄²⁻ and fine particles (PM_2.5 or PM_2.1, depending upon inlet design), episodes of H⁺ tended to be less frequent and of shorter duration, particularly in Ontario. Saint John, New Brunswick, had the highest mean annual H⁺ concentration, which was 30 nmol m⁻³. H⁺ episodes (24 h concentration > 100 nmol m⁻³) were also the most frequent at this location. The high levels in Saint John were partially due to local sulphur dioxide sources and heterogeneous chemistry occurring in fog, which, on average, led to a 50% enhancement in sulphate, relative to upwind conditions.There was a substantial amount of intersite correlation in the day to day variations in H⁺, SO₄²⁻ , PM_2.5 and PM₁₀ (fine + coarse particles) concentrations, which is due to the influence of synoptic-scale meteorology and the relatively long atmospheric lifetime of fine particles. Sulphate was the most regionally homogenous species. Pearson correlation coefficients comparing SO₄²⁻ between sites ranged from 0.6 to 0.9, depending on site separation and lag time. In many cases, particle episodes were observed to move across the entire eastern portion of Canada with about a two-day lag between the SO₄²⁻ levels in southern Ontario and in southern Nova Scotia.