1. Full name: Han Thi Ngan                                2. Sex: Female

3. Date of birth: 19/02/1979                                4. Place of birth: Bac Ninh

5. Decisions

- Decision No. 2556/QĐ-ĐHKHTN dated July 26, 2017 of the University of Natural Sciences on the recognition of the PhD student:

- Decision No. 3304/QĐ-ĐHKHTN dated September 28, 2017 of the University of Natural Sciences on the recognition of the dissertation title and the PhD student’s supervisor.

6. Changes in the academic process: None

7. Dissertation title: Study on acid rain assessment in the territory of Viet Nam through rainwater monitoring data in the period 2005-2018

8. Major: Environmental Science                                    9. Code: 9440301.01

10. Supervisor: Prof. Dr. Hoang Xuan Co

11. Summary of the new findings of the dissertation

- This is a study in which the most updated series of data on acid rain in Viet Nam in the longest period before 2019 has been used.  It has shown the correlation between ions in rainwater in 23 hydrological stations and the rainwater monitoring data of the Department of Meteorology, Hydrology and Climate Change. Based on the calculation of the NFi acid neutralization coefficient of 4 cation, it is determined that Ca2+ ions are the main contributor to the acid neutralization process in rainwater, followed by Mg2+ ions, NH4+ ions, and finally K+. From that point, it explains the decrease tendency of the acid level in rainwater (the tendency of H+ concentration decreases by 1.31%/year) in case the dust concentration containing the cations in the air increases.

- The PhD student has evaluated the concentration tendency, the deposition tendency, and the level of change of ions in rainwater as well as pointing out the similarity between the tendency of concentration and the tendency of ions deposition with the similarity (either increase or decrease) is from 69.37% to 86.11%.

12. Practical applicability

- The research results and the calculations obtained in the disertation with the overall view and argument about acid rain in recent years will be an important reference for managers, scientists, and future research projects.

- The research results are the scientific basis for the planning and supplementation of air quality monitoring stations.

- The solutions put forward in the dissertation provide managers and experts in the field of environmental monitoring with reference in order to make optimal decisions or solutions in environmental protection generally and in coping with acid rain particularly.

13. Further research directions

- Study assess monitor netwwork and the quality of wet deposition data.

- Study to develop a database of emission inventory for Viet Nam to serve the researches on air pollution and air pollution forecasts as well as its possibilities of affecting acid rain in the territory of Viet Nam.

- Do research on determining the origin of air pollution in Vietnam, how many percent are from the localities, from neighboring areas, from neighboring countries.

- Research more deeply on the harmful effects of acid rain as well as its beneficial effects on such fields as agriculture, industry etc.

- Do researches to determine the origin of air pollution in Viet Nam, which comes from the localities, neighboring areas, and neighboring countries.

- Research more deeply on the harmful effects of acid rain as well as its beneficial effects on such fields as agriculture, industry etc.

14. Dissertation-related publications:

[1] Han Thi Ngan, Hoang Xuan Co, Le Van Linh, Tran Thi Dieu Hang (2019), "Evaluation of the tendencies of chemical constituents in rainwater in Viet Nam by the Seasonal Mann-Kendal non-parametric test method", Journal of Environment, Topic III, pp.101-107.

[2] Han Thi Ngan, Hoang Xuan Co, Le Van Linh, Dam Duy An (2019), "Assessment of seasonal evolution of acid deposition (wet deposition) in Viet Nam in the current period", Journal of Environment, Issue IV, pp.71-79.

[3] Nguyen Thi Kim Anh, Le Van Quy, Le Van Linh, Nguyen Truong Giang, Nguyen Van Tien, Hoang Thi Van, Nguyen Phuong Nhung, Han Thi Ngan (2019), "Research on wet deposition tendencies at stations on the EANET network of Viet Nam in the period 2000-2018”, Journal of Climate Change Science, No. 12, pp.83-87.

[4] Han Thi Ngan, Hoang Xuan Co, Nguyen Manh Khai, Pham Thi Thu Ha, "Study on acidity and neutralizing ability of ions in the chemical composition of rainwater", VNU Journal of Science, (There was confirmation of acceptance for publication No. 39 /TCKH dated April 12th, 2021 by VNU Journal of Science).