Thi Tuyet Nhung Hoang’s scientific contributions

Long An High School in Tan An, Long An, Vietnam, undertook a study to examine the generation and physical composition of solid and plastic waste. The study sampled 899 individuals, including officers, students, and teachers. Solid waste was classified into five primary categories and established three subcategories for plastic waste. The results showed that the average daily waste generation rate at Long An High School is 0.13 kg per student, including out-boarders who generate 0.028 kg per student, and boarding and part-boarding students who generate 0.18 kg/person/day. This rate is marginally lower than the waste generation rates observed in households. The analysis of plastic waste at the school indicated that it comprised 31% (35.65 kg/day) of the overall refuse generated. Boarding and part-boarding pupils generate a daily plastic waste generation rate of 0.055 kg, while out-boarders generate 0.01 kg per person. Long An Specialized High School receives recyclable plastic (46.5%), nylon bags (35.3%), and non-biodegradable polystyrene (foam delivery packaging) (18.2%) as its primary waste materials. Due to their lack of classification, these wastes are challenging to recycle. In terms of refuse generation per capita, male students produce 0.17 kg per male per day, while female students generate 0.15 kg per female per day, on average. Male students have an average discharge of 0.051 kg/male/day, which is 0.039 kg/female/day higher than female students' average discharges. In the case of plastic No. 6 (foam delivery boxes), male pupils emit three times more than female students.

Drinking water for residents who live in flood area is the concern of the government and environmental management. Using natural coagulants to transform flood water into potable water in order to reduce the number of chemical coagulants (aluminum salt) that have a negative impact on human health. The results of the flocculation procedure using agricultural residue extracts, dragon fruit branches (DFBE) and avocado seeds (ASE), did not meet the Vietnamese standard for the provision of potable water. Using DFBE and ASE as coagulation aides improves the flocculation efficacy of alum in high turbid water (150 to 175 NTU) and low turbid water (20 to 30 NTU). The ratio of ASE to Alum was determined to be 1/6 for high-turbidity water and 0.2 for low-turbidity water. The ratio of DFBE/Alum was determined to be greater than 1/3 for high turbidity water and less than 0.2 for low turbidity water. This ratio is also evaluated for a portable, simple, and user-friendly water filter that is suitable for flood-prone residents. Combining natural coagulation aides with Alum in water flocculation satisfies the Vietnamese standard with DFBE for sources with high turbidity and ASE for sources with low turbidity. This demonstrates the utility of natural coagulation aids derived from agricultural residues for water purification in flooded areas.