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1、河海大学本科毕业论文一、 中文翻译：城市环境土壤污染的原因 广泛的灰尘沉积，主要是工业排放造成的。这是存放在干燥的条件和悬浮颗粒物。这些颗粒物大小各不相同。不到10微米的可吸入颗粒物含量指定是最适合人类健康的危险界限。部分的水泥粉尘和粉煤灰可能超过该值，但也有一些小于10微米的微粒一般像石棉粉尘粒度因烟油发电厂而得的。应该注意的是较小的悬浮物，是高浓度的污染物，其吸附能力的增强污染越严重。 污染颗粒物可由户外运进入房间。在那里，一旦积尘发生，尤其是当窗户在白天开放时候。令人感兴趣的是、花园土壤和屋尘浓度比较。在英国已经发现镉，铜，铅，锌值在屋尘大于其在相关的花园（桑顿1991年）。 市区粉尘的
2、形成可能起着重要作用，特别是在干旱和半干旱地区，那里干燥的环境下占主导地位，而且灰尘是土壤潮湿气候条件形成的重要部分。例如，在汉诺威（德国）52万人口的城市，一个在50年内5-8厘米的巨大积累的粉尘（瑞光和霍克2005年）。当灰尘发展和沉积技术没有任何过滤系统，巨大的沉积层厚度可以达到在一个在哈雷（德国）煤炭厂加工的情况。 城市地区的一个重要特点是经常暴露地表，你永远无法发现在林地和草场和在长期内裸土的百分比大部分是是私人花园和冬季拨款，运动场，墓地，拆迁和建筑工地，废弃和废弃，主要是工业用地，废物堆，铁路路基，和储存地点，在那里发生永久性的尘埃沉积（桑顿1991年）。在城市和工业区设密封网站
3、的影响，以及，因为灰尘容易渗透到路面的石头之间的缝隙，卵石以及铁路路堤，不断填补起来。据推测灰尘会在人行道上横向运动，并最终在下坡（瑞光和霍克2005年）集中。 这是合乎逻辑的期望，城市土壤表明不是因为它们靠近潜在污染源的如农村地区高污染水平。大城市如纽约，二千三百二十万居民（美国）遭受多种污染源，如工业排放的同时，对交通的影响，存款技术性基板等，在如下降铜，镍，铅含量，发现随着进入农村地区距离市中心（曼哈顿）以外的城市。虽然在曼哈顿铅值超过130毫克公斤表土- 1的测量，在50-60公里的值下降到约40毫克公斤- 1的距离，并在该120-130公里的距离约30毫克公斤-1（Pierzynsk
4、i等。2005年）。在北半球的发达国家城市到农村梯度经常被发现。图3.3介绍了五个相对较小的美国城镇的铅浓度。城市草坪的污染程度相对比较高，这将由附近，暴露于高浓度的空气污染城市环境的预期。空气污染是重工业以及化石燃料的有关金属气溶胶的燃烧。该调查称草坪靠近房屋和公园。高级别并没有被限制到上层的视野和森林地板。可能是蚯蚓，蚂蚁（生物扰动）的活性在腐植表土和底土的矿物长期混合作用，导致污染物如铅（见6.3节）易位。二、 英文原文：Causes of Soil Contamination in the Urban EnvironmentExtensive dust deposition is ma
5、inly caused by industrial emission. It is deposited in dry conditions and as suspended particulate matter. The size of particulate matter varies. The fraction of less than 10 m designated as respirable particulate matter is most dangerous for human health. A portion of cement dust and fly ash may ex
6、ceed that value, but there are some kinds of particulate matter with a general size distribution of less than 10 m like asbestos dust and smoke derived from oil-fired power stations. It should be borne in mind that the smaller the suspended matter is the higher the contaminant concentration is due t
7、o the enhanced sorption capacity. Contaminated particulate matter can be transported from outdoors into rooms. There, a dust accumulation occurs, particularly if windows remain opened during daytime. Of interest is the comparison between garden soil and house dust concentration. In England it has be
8、en found that the Cd, Cu, Pb and Zn values were larger in house dust than in the associated gardens (Thornton 1991). Dust formation in urban areas may play an important role, in particular in arid and semi-arid regions, where dry conditions dominates, but also in humid climates dust is of importance
9、 for soil formation. For instance, in the city of Hanover (Germany) with a population of 520,000, an enormous accumulation of 58 cm within 50 years was observed (Burghardt and Hke 2005). When dust development and deposition occurred without any filter technique systems, the deposited layer can reach
10、 enormous thickness as observed in vicinity of a coal processing factory in Halle (Germany) with its 230,000 inhabitants (Fig. 3.2). One important feature of urban areas is the often exposed land surface you can never discover in woodland and pasture and over long periods percentages of bare soils a
11、re private gardens and allotments in wintertime, playing fields, cemeteries, demolition and building sites, derelict and disused, mostly industrial land, waste heaps, railway embankments, and storage sites, where permanent dust deposition occurs (Thornton 1991). In urban and industrial areas sealed
12、sites are influenced as well, since dust may easily penetrate into gaps between pavement stones, cobbles as well as railway embankments, constantly filling them up. It is supposed that dust will be laterally transported on the pavement stones and ultimately concentrated in gaps downslope (Burghardt
13、and Hke 2005). It is logical to expect that urban soils show higher contamination levels than the rural areas because of their proximity to a number of potential pollution sources. Big cities like New York (USA) with 23,200,000 inhabitants are affected by several contamination sources, for instance
14、simultaneous industrial emission, impact of traffic, deposits of technogenic substrates, etc. Consequently, a decline in e.g. Cu, Ni and Pb concentrations was found with increasing distance from the city centre (Manhattan) into the rural district outside of the city. While in Manhattan Pb topsoil va
15、lues of more than 130 mg kg1 were measured, at a distance of 5060 km the values decreased to about 40 mg kg1, and at a distance of 120130 km to about 30 mg kg1 (Pierzynski et al. 2005). The urban-to-rural gradient has frequently been found in developed countries of the northern hemisphere. Figure 3.
16、3 presents the lead concentrations of five relatively small towns in the United States. The contamination level of the urban lawn is comparably high, as would be expected by the vicinity and exposure to high levels of air pollution in urban environments. The air pollution is related to metallic aero
17、sols from heavy industry as well as combustion of fossil fuel. The investigations referred to lawns close to houses and in parks. The high level has not to be restricted to the upper horizons and forest floors. The activity of earthworms and ants (bioturbation) may play a role in the long-term mixing of the humic topsoil and the mineral subsoil, causing translocation of contaminants like Pb (Craul 1992) (see Section 6.3).4