Analysis of Acid Rain Characteristics and Related Meteorological Conditions in Dalian

The variation characteristics of acid rain and the relationship between the formation of acid rain and meteorological conditions were analyzed based on the observation data and meteorological records collected from acid rain observation station in Dalian over 2006-2009.The results showed that Dalian was one of the regions with strong acid rain in northern China,with the frequency of 66% and pH value of 3.49.The acidity was the strongest in fall and weakest in spring;and the maximum and minimum frequencies were in summer and in winter respectively.Frequency of acid rain was inversely proportional to wind speed and concentration of inhalable particles in Dalian;acid rain occurred easily in foggy weather due to the steady stratification and abundant moisture;continuous precipitation did not mean the reduction of acidic material in the air,and the rainfall with increased acidity in the second day accounted for 42% in continuous precipitation cases.

降雨pH对煤矸石中重金属和SO_(4)^(2-)释放行为的影响

以高硫煤矸石为研究对象,采用静态淋溶试验探究在模拟降雨pH分别为2、3、5、7的条件下,煤矸石中重金属Mn、Cu、Zn和SO_(4)^(2-)的释放规律及动力学行为。结果表明,酸性条件更有利于重金属和SO_(4)^(2-)释放,随时间增加表现为先快速释放后逐渐稳定的趋势。在降雨pH为3时,重金属Mn、Cu、Zn的累积释放量最大,分别达到60.40、29.11、5.86 mg/kg。在降雨pH为2时,SO_(4)^(2-)的累积释放量最大,达到了25027.27 mg/kg。动力学结果表明,重金属释放由界面化学反应控制,而SO_(4)^(2-)由固体膜层界面和扩散混合控制,且在重金属与SO_(4)^(2-)释放的过程中产生大量H^(+),使淋出液pH<1.52。本研究结果可以从污染物源头释放的角度为煤矸石堆场重金属及SO_(4)^(2-)污染防控和监管提供理论依据。

酸雨和SO_2对蔬菜生长和产量的影响

应用开顶式熏气装置,以油菜和白菜为材料,分别将其暴露于模拟酸雨(pH2.8—5.6)和模拟酸雨与0.1ppmSO_2环境中,测定单独污染与复合污染对蔬菜生长反应和产量的影响。结果表明,酸雨(pH2.8)和酸雨(pH4.6)与0.1ppmSO_2复合处理均对LAR有明显抑制,LAR最多可减少37.5%。模拟酸雨(pH2.8,3.6)使蔬菜减产1.4—8.7%,而模拟酸雨与SO_2复合污染可使蔬菜产量减少7.9—28.9%(P<0.05)。

烟草BY-2细胞生长和呼吸对不同类型酸雨的响应

为了直观探究不同类型酸雨对植物生理生长的影响,以烟草Bright Yellow-2(BY-2)细胞为试验材料,模拟不同p H值(1.5、2.5、3.5、4.5、5.5)下硫酸型酸雨(SAR)、硝酸型酸雨(NAR)及混合型酸雨(MAR),以期了解其对烟草BY-2细胞干重和呼吸的影响。研究表明,在不同酸度下,烟草细胞干重均低于对照,细胞呼吸出现紊乱变化,说明不同p H下的酸雨对细胞均有伤害,BY-2细胞的干重和呼吸有不良反馈,且不同酸度的伤害程度不一,强酸(p H值为1.5)下对细胞迫害性最强。因此,不同类型酸雨对植物有迫害性,迫害性大小为SAR>NAR>MAR。

玉溪市中心城区酸雨变化趋势分析

以 1991年至 2 0 0 0年实测数据为依据 ,揭示了玉溪市中心城区