VIETNAM NATIONAL UNIVERSITY, HANOI VNU UNIVERSITY OF SCIENCE FACULTY OF ENVIRONMENTAL SCIENCES Lê Thi Thuy ASSESSMENT OF ACID RAIN PROGRESS IN HANOI CITY DURING THE PERIOD OF 2008-2018 Submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Environmental Sciences (Advanced Program) Hanoi - 2020 VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAMVNU NATIONAL UNIVERSITY, UNIVERSITY HANOI OF SCIENCE FACULTYVNU UNIVERSITY OF SCIENCE OF ENVIRONMENTAL SCIENCES FACULTY OF ENVIRONMENTAL SCIENCES Lê Thi Thuy Lê Thi Thuy ASSESSMENT OF ACID RAIN PROGRESS ASSESSMENT OFDURING IN HANOI CITY ACID RAIN THEPROGRESS PERIOD OF IN HANOI CITY DURING 2008-2018THE PERIOD OF 2008-2018 Submitted in partial fulfillment of the requirements for the degree of SubmittedBachelor in partialoffulfillment Science inofEnvironmental the requirements Sciences for the degree of Bachelor of (Advanced Science in Environmental Program) Sciences (Advanced Program) Supervisor Supervior : DrPham : Dr. PhamThi ThịThu ThuHa Ha Hanoi - 2020 Hanoi - 2020 ACKNOWLEDGEMENT Foremost, I would like to express my sincere gratitude to my supervisor Dr. Pham Thi Thu Ha, Faculty of Environmental Sciences – University of Science, Vietnam National University, Hanoi. I feel fortunate and honored to have had her as my supervisor.
It was her expertise and experience that provided me with practical knowledge, comments, and support during the thesis writing process. I would like to thank Acid Deposition Monitoring Network in East Asia system for providing data. I am most in debt to the households, the district and commune authorities who were most collaborative in completing the data, and in providing discussion opportunities on the results. I am grateful to the lecturers of the Faculty of Environmental Sciences from VNU University of Science, Vietnam University for teaching and conveying a lot of professional knowledge to me during my studies.
Last but not least, I would like to thank my family and friends, whose kindness, encouragement and support are with me against all the odds. Hanoi, September 2020 Student Lê Thị Thuy LIST OF ABBREVIATIONS AIRMoN : Research Monitoring Network AF : Anthropogenic factor AP : Acidify potential CF : Crust fraction DS : Dry season EANET : East Asia Acid Deposition Monitoring Network EEC : European Economic Community EDGAR : The Electronic Data Gathering, Analysis, and Retrieval system EFs : Enrichment factors HYSPLI : Hybird Single Partical Lagrangian Integrated Trajectory model MDN : mercury deposition network NAD/NTN : The National Atmospheric Deposition Program VWM volume - weighted mean NP : Neutralize potential NF : Neutralization factor NSS : non-sea salt RS : Rain season SSF : Sea spray fraction SMK : Seasonal MannKendall LIST OF ABBREVIATIONS INTRODUCTION. The concept of rain water. Oveview of dosmestic and worldwide researches.
In the world. Overview of area. The economic growth in Hanoi. MATERIAL AND REARCH METHODS.
Scope of study. Collection and synthesis of secondary data method. Field investigation and survey method. Calculation method of acid rain characteristics and data processing.
Annual volume - weighted mean precipitation concentrations. Wet deposition flux. Marine and crustal enrichment factors. Non-parametric test method Seasonal Mann-Kendall.
Calculate pAi index. RESULT AND DISCUSSION. Annual volume - weighted mean precipitation concentrations. pH of rain water.
Seasonal variation of the chemical composition. Assessment on wet deposition trend. Monthly deposition of ions. Trend of ions deposition.
Trend of ions concentration. Wet deposition rates of major ions. Source assessment for different ionic component. 43 CONCLUSION AND RECOMMENDATION.
52 LIST OF FIGURES Figure 1. This image illustrates the pathway for acid rain in our environment. Administrative map of Hanoi city [11]. Hanoi climate graph [10].
Chemical composition percentages of rainwater in Hanoi. Frequency distribution of the pH values of rainwater in Hanoi during the sampling period. Frequency distribution of the pH values of rainwater in Ho Chi Minh. Frequency distribution of the pH values of rainwater in Hoa Binh.
Frequency distribution of the pH values of rainwater in Yen Bai. VWM of major ions in rain season and dry season in Hanoi during 2008-2018 (µmol L-1). The trend of wet deposition of ions over the months in Hanoi between 2000-2018. The average multi annual wet flux depositions (mmol m-2y-1) of major ions at the studied sampling site.
41 LIST OF TABLES Table 1. Seasonal variations of the VWM concentrations of the major ions in the rainwater from Hanoi (µmol L-1). The average value of ion deposition, the level of change in deposition, the Sen’s slope, significance level p at Hanoi station during the period from 2000-2018. Level of change in concentration and precipitation by year (%) in Hanoi from 2000-2018.
Pearson correlations matrix for the ion concentrations in rainwater of Hanoi. The value of neutralization factor (NF) of rainwater from Hanoi and other areas in Vietnam. The value of neutralization factor (NF) of rainwater from Hanoi and other areas in Vietnam. Enrichment factors relative to seawater and soil for rainwater constituents in Hanoi in 2008-2018.
Source contributions for different ionic constituents in rainfall measured in Hanoi in the period 2008 -2018. Comparison of pH and major ions concentration (in µmol L-1) at Hanoi with other areas in Vietnam. 52 INTRODUCTION In recent years, the problem of air pollution has become an urgent problem that all countries aim to solve, especially its consequences such as acid rain, the greenhouse effect,. Acid rain is one of the most serious consequences of air pollution.
Acid rain has caused serious harm to the environment, ecosystem and people. Currently, research on acid rain in many countries around the world is very methodical and organized. Many countries have laws regarding gas emissions that cause acid rain. [18] The atmospheric precipitation is an important means of scavenging pollutants from the atmosphere and this occurs either by wet or dry deposition.
Sulfur compounds and acids were already identified in the air and in rainwater during the 17th century; however, in the 19th century, there was an increase in rain acidity mainly due to anthropogenic emissions [42]. Acid rain has a pH lower than 5.6, the value expected on the equilibrium of pure water and atmospheric CO2. This decrease of pH values is basically caused by the presence of sulfuric, nitric and carboxylic acids, their main precursors being emissions of sulfur and nitrogen oxides, hydrocarbons and carboxylic compounds. These processes involve complex chemical reactions in the atmosphere [42, 43].
Rain is the most effective scavenging factor for removing particulate and dissolved organic gaseous pollutants from the atmosphere. The scavenging of the atmospheric pollutants affects the chemical composition and the pH of rainwater. The acidity level depends on the neutralization produced by certain rainwater components such as NH3, CaCO3 and hydroxide [25, 42, 43]. Rainwater composition plays an important role in scavenging soluble components from the atmosphere and helps us understand the relative contribution of different sources of atmospheric pollutants [25, 31, 42].
Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo 1 complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Acid deposition has serious human and property consequences such as damaging crops, reducing crop yields, destroying forests, threatening aquatic and terrestrial life, destroying architectural and construction works and seriously affecting human health [19]. In developing countries, with high economic growth and energy consumption, air pollution has become a socially significant issue that needs to be scientifically considered. Rainwater plays an important role in collecting dissolved components from the atmosphere, so the composition of the rainwater will provide information on the contributions of various sources to air pollution [21, 37].
Rapid economic development and increased energy demand have resulted in severe air pollution problems throughout Vietnam, and the increasing emissions of man-made acidic oxides of sulfur and nitrogen have led to the significant deposition of acid rain in Vietnam. Acid rain is one of the manifestations of acid deposition in the atmosphere. Rainwater washes pollutants from the air, so acid rain is considered a problem of environmental pollution, the main cause of SO2 and NOx emissions from various sources. Nearly one decade, the extent and magnitude of acid deposition in Vietnam and some Asian countries become apparently increasing.
More importantly, in Vietnam acid rain has been recorded in almost the city and some dramatic effects of acid rain on terrestrial plants have been investigated [14]. Vietnam is in the period of industrialization and modernization, so air pollution is becoming an urgent problem. The overexploitation of natural resources, development of industrial parks and urban areas without synchronous planning lead to increased degradation environmental quality. According to the annual Vietnam Environmental Status Report, the air environment around most urban centers and some industrial zones has been polluted, and thus its consequences will lead to acid rain [14].
Observed data from the national 2 monitoring network show that acid rain has occurred in some places and is increasing in quality (pH) and quantity (total ion concentration). Moreover, Vietnam is adjacent to an area with great potential for acid rain, the entire coastal area of China. Therefore, the effects of transboundary pollution from neighboring countries, especially from China, have further increased the risk of acid rain in the Northern provinces. Hanoi is a large industrial and economic area, which plays a leading role in the country's economy, so air quality will be influenced by waste from industrial development activities [10].
The urgent issue is to conduct acid rain studies to assess the current situation, the degree of influence and finally take practical measures to control the level of emissions of acid rain gases as well as its impact on the environment and the health of the population community in the research area. On that basis, we have conducted research on the topic: “Assessment of acid rain progress in Hanoi city during the period of 2008- 2018”. The objectives of research Assessment of acid rain progress in Hanoi city during the period of 2008 to 2018. This is the basis for making some recommendations to minimize air pollution leading to acid rain.
Research contents: The study assesses the progress of acid rain based on data of the EANET through contents such as: Annual volume-weight mean concentration of ions in rainwater, acid rain frequency, applying the non-parametric test method Seasonal Mann-Kendall (SMK) and estimating the Mann-Kendall slope (Sen's slope) to evaluate the tendency of acid deposition in rainwater (wet deposition), determining correlation coefficient, neutralization capacity, and determining the origin of the main ions in rainwater. The concept of rain water Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystems, as well as water for hydroelectric power plants and crop irrigation.
Definition of acid rain Acid rain, or acid deposition, is a broad term that includes any form of precipitation with acidic components, such as sulfuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms. This can include rain, snow, fog, hail or even dust that is acidic. According to EEC (European Economic Community), all precipitation rains of < 5.6 are considered acid rain. However, there is a difference in the regulation of limiting the pH of rain with each country.
For example, in the USA, the regulation of acid rain is rain with less than 5. Some Asia countries use pH < 5. It can occur in the form of snow, fog, and even dry material that settles to the Earth. [18] Acid deposition have 2 form which wet deposition and dry deposition.
Wet deposition is what we most commonly think of as acid rain.