Acid Deposition in the Tuscan Appennines During the Dry Period 1988-89

The typical parameters of acid precipitation are evaluated in the forest of Vallombrosa (Tuscan Appennines) during the dry period 1988-89. Individual rain events (dry and wet deposition) were sampled in a clearing of the forest and below the canopy of an evergreen tree as well as a deciduous broadleaf tree.

In atmospheric precipitation the pH values usually vary around 4.4, with neutralization in the hot season due to calcareous material from distant sources. Relatively large concentrations of Pb and Cd are found in rain, but only in a small amount in canopy leachate. Aluminium, manganese and iron are more significantly washed off than Pb and Cd.     

Fractionation of Cu, Pb and Zn in certified reference soils SRM 2710 and SRM 2711 using the optimized BCR sequential extraction procedure

Sequential extraction of metals from solid media is a common analytical tool used in environmental and exploration geochemistry. A number of procedures exist, but without harmonization and standardization, meaningful comparisons are tenuous without baseline data. A newly developed, standardized sequential extraction procedure (optimized BCR) was applied to two contaminated certified reference soils from Montana, US (SRM 2710 and SRM 2711) for Cu, Pb and Zn. Four operationally defined fractions were isolated, acid extractable, reducible, oxidizable, and residual (by aqua regia). Fraction-specific concentrations, percentages and recoveries for Cu, Pb and Zn were used to explore differences between the optimized BCR procedure and three other sequential extraction schemes with published data for SRM 2710 and 2711 (i.e. Tessier scheme, Geological Survey of Canada scheme and the original BCR scheme). Results indicate significant differences between the four schemes, even for schemes that are closely associated (i.e. the original and optimized BCR schemes). Order-of-magnitude fraction-specific concentration differences were observed, especially for Pb in the reducible fraction. Differences between schemes are worrisome because trends varied between metals, between fractions and between reference soils. These data reinforce the need for increased adoption of standardized sequential extraction procedures and further examination of different solid media.     

酸雨防治迫切性浅析

文章从水体，植物，建筑群，人体健康等几个方面，详细讨论了酸雨防治的迫切性，通过对宜宾，桂林，宁波等几个的酸 雨调查监测进行综合分析，对我国，尤其是宁波地区的酸雨污染现状提出了看法，并结合地形各种因素对酸雨的防治对策进行了一些探讨。     

酸沉降破坏材料造成的经济损失的估算研究

酸沉降对材料的破坏和其经济损失估算是国际上酸沉降研究领域听一个重要课题，国内在经方面的研究较少，文章通过对“两广酸沉降破坏材料造成的经济损失的估算”研究，提出了了一套较实用的经济损失估算方法。     

酸雨对种子萌发影响的实验研究

采用ＰＨ值２．５、３．０、３．５、４．５的酸雨处理小麦种子，观察种子的萌发率、平均萌发天数和萌发势。结果表明：酸雨对种子的萌发率和平均萌发无显著影响，但对种子萌发势有显著影响。     

抛丸处理在钢铁冷锻加工中的应用

钢铁冷锻加工中的磷化工序一般采用酸洗法去除毛坯上的氧化膜。现介绍用抛丸处理工艺替代酸洗方法,可以大幅度减少工业污染,降低生产成本,提高工艺质量。     

BP神经网络在降水酸度预测中的应用

本文利用南昌市城市大气中SO2、NOX、TSP等浓度数据及降尘数据建立了BP神经网络的降雨酸度预测模型，结果表明：BP神经网络的预测模型不仅能较好地反映致酸因素与降水酸度的相互关系，而且预测精度也高于多元回归等模型。     

酒石酸淋洗过程中土壤重金属解吸动力学特征

采用批处理淋洗的方法,研究了酒石酸淋洗修复张士污灌区土壤过程中镉、铅、铜、锌4种重金属离子解吸动力学特征。结果表明,酒石酸在12h条件下,达到对污染土壤中镉离子的最大去除率,铅、铜、锌3种重金属离子达到最大去除率则需要24h。4种重金属离子的解吸动力学过程可以用Elovich方程很好的描述,说明酒石酸去除重金属离子的过程是一种非均相扩散过程。此外,解吸速率曲线显示,反应初期相同时刻上酒石酸对铅离子的解吸速率最快,其次是铜和锌,最后是镉离子;反应后期同一时刻上铜和锌的解吸速率大于铅和镉。     

海洋气溶胶对沿海地区降水组成的贡献

以青岛地区为对象，对沿海地区大气气溶海洋因子对降水组成的贡献，进行了研究分析。结果表明，１）夏季受海洋影响要比冬季明显得多；（２）降水中主要的碱性物质，不论是夏季或冬季，９９％来自大陆气溶胶，海洋的影响可忽略；（３）海洋影响的程度和离海边的距离有关，离海愈远，受海洋影响就愈小，离海愈近，受其影响就愈大。     

Assessment of the maximum allowed acid deposition load at current stage in China

Soil acidification caused by acid deposition has been significant in some forests in southern China. We present an approach for assessing the current stage maximum allowed load (SML) of acid deposition for terrestrial system in the country. The main idea was that soil base cation exchange as a finite buffer to acidity was included in the soil acidity mass balance calculation at current acidification stage. We calculated the SML for five forests in southern China. The usual critical loads for the same forests were also calculated by the steady state mass balance model for comparison. The results showed that the SML is a more tolerant limit than the critical load for the forests with soils not acidified seriously at current stage. However, the SML become a more stringent limit to acid deposition when the forest soils have acidified seriously to very low base cation saturation. In this case the SML assessment is beneficial for the soils recovering from a serious acidified state. Based on a national scale database, the SML mapping for non-agricultural soil system in China was carried out.