沿海地区海盐和大气污染物反应的致酸作用

The Mechanism of Reaction between Sea Salt with AtmosphericPollutants to Acidify Rainwater in Coastal

着重研究全球沿海地区海盐和大气污染物ＳＯ２、ＮＯｘ反应的致酸作用．通过资料分析发现：海盐和大气污染物反应的致酸存在临界浓度，在低气溶胶浓度的大气中，海盐和大气污染物反应致酸的ＳＯ２的临界浓度为０．００４３ｍｇ／ｍ３．海盐和大气污染物反应的致酸存在３种类型：火山排放ＳＯ２和海盐反应致酸，降水中过量氯与Ｈ＋浓度呈正相关，过量氯对Ｈ＋浓度最大贡献可达５０％；外来输送ＳＯ２、ＮＯｘ和海盐反应的致酸，过量氯对Ｈ＋浓度最大贡献达７９％，过量氯对Ｈ＋浓度平均贡献在３０％—５０％；局地人为排放ＳＯ２和海盐反应致酸，过量氯对Ｈ＋浓度最大贡献为２９％．

It was focused on discussing the reaction between sea salt with atmospheric pollutants to acidify rainwater in coastal.It was found that there is a critical concentration for the reaction between sea salt with atmospheric pollutants to acidify rainwater in coastal.The critical concentration is only 0.0043mg/m^3 in low aerosol concentration coastal.There are three types of mechanism for the reaction to acidify rainwater.First,SO_2 emitting from volcano reacts with sea salt to acidify rainwater.The excess chloride is positively relative to H^+ concentration.The maximum contribution to H+ ion occupies 50% from excess chloride.The second,SO_2,which is transported,reacts with sea salt to acidify rainwater.The maximum contribution to H^+ ion occupies 79% from excess chloride.The average value occupies 30%—50% for excess chloride to contribute to H^+ concentration.The third mechanism is the local emission SO_2、HCl and the reaction between sea salt with SO_2 to acidify rainwater.The maximum value occupies 29% for excess chloride to contribute to H^+ concentration.