Abstract：
The chemical composition of acid rain and its impact on lake water chemistry in Chongqing, China, from 2000 to 2020 were studied in this study. The regional acid rain intensity is affected jointly by the acid gas emissions and the neutralization of alkaline substances. The pH of precipitation experienced three stages of fluctuating decline, continuous improvement, and a slight correction. Precipitation pH showed inflection points in 2010, mainly due to the total control actions of SO2 and NOx implemented in 2011. The total ion concentrations in rural areas and urban areas were 489.08 µeq/L and 618.57 µeq/L, respectively. The top four ions were SO42-, Ca2+, NH4+ and NO3-, which accounted for more than 90% of the total ion concentration, indicating the anthropogenic effects. Before 2010, SO42- fluctuated greatly while NO3- continued to rise; however, after 2010, both SO42- and NO3- began to decline rapidly, with the rates of -12.03 µeq/(L·year) and -4.11 µeq/(L·year). Because the decline rate of SO42- was 2.91 times that of NO3-, the regional acid rain has changed from sulfuric acid rain to mixed sulfuric and nitric acid rain. The lake water is weakly acidic, with an average pH of 5.86, and the acidification frequency is 30.00%. Acidification of lake water is jointly affected by acid deposition and acid neutralization capacity of lake water. Acid deposition has a profound impact on water acidification, and nitrogen (N) deposition, especially reduced N deposition, should be the focus of future research.
摘要：
重庆市酸雨的化学成分及其对湖泊水化学的影响,中国,这项研究从2000年到2020年进行了研究。区域酸雨强度受酸性气体排放和碱性物质中和的共同影响。沉淀的pH值经历了三个波动下降阶段,持续改进,轻微的修正。2010年降水pH出现拐点,主要是由于2011年实施了SO2和NOx的总量控制措施。农村地区和城市地区的总离子浓度分别为489.08µeq/L和618.57µeq/L，分别。前四个离子是SO42-，Ca2+,NH4+和NO3-，占总离子浓度的90%以上，表明人为影响。在2010年之前，SO42-波动较大，而NO3-继续上升；然而，2010年后，SO42-和NO3-开始迅速下降，比率为-12.03µeq/(L·年)和-4.11µeq/(L·年)。因为SO42-的下降速率是NO3-的2.91倍，区域酸雨已从硫酸雨转变为硫酸和硝酸混合雨。湖水是弱酸性的，平均pH值为5.86,酸化频率为30.00%。湖水的酸化受到湖水的酸沉降和酸中和能力的共同影响。酸沉降对水酸化有深远的影响，和氮（N）沉积，特别是减少N沉积，应该是未来研究的重点。
