In this study, rice husk was used as a precursor to prepare activated carbon using steam as a physical activation agent. Steam can be used to activate for almost all raw materials. This activation method was followed of the initial carbonization step. The study also investigated the effects of preparation parameters on the adsorption capacity of iodine (I) and methylene blue (MB). These parameters included the range of temperature and time in the carbonization and activation. The initial carbonization, done at temperatures up to 500°C in 60 min., was a highly exothermic process where the temperature was strictly controlled. The creation of the internal surface was done during the activation step with steam at temperatures 800 °C in 30 min., for which the BET (Brunauer, Emmett and Teller) specific surface area was up to 710.8 m 2 /g. Besides, the I and MB adsorption capacity of the activated carbon were the best that reached 866.0 ± 6.5 and 217.9 ± 1.0 mg/g, respectively, while the I and MB adsorption capacity of carbonization step only reached 311.7 ± 3.4 and 28.7 ± 0.8 mg/g, respectively. The entire synthetic procedure was simple, environmental-friendly and economical-effectively. The application prospect of the activated carbon prepared in this work was much more promising due to its high adsorptive capacity.

Surface modification of activated carbon (AC) could be done through different methods in order to modify their specific physical and chemical properties to facilitate metals removal from wastewater. Three methods were used to modify the rice husk AC (RHAC) including the use of (1) HNO3, (2) dithizone and (3) the combination of HNO3 with dithizone. These modification agents were increased its affinity towards the desired pollutant. The modification methods demonstrated the effective process for the metal ions adsorption capability and the removal of them from water. For Ni2+ and Cd2+ adsorption, RHAC was modified by HNO3 giving the best adsorption capacity in comparison with using dithizone or the combination of HNO3 with dithizone. That adsorption was reached 17.23 mg/g for Ni2+ and 29.61 mg/g for Cd2+. Additionally, the surface area, which was characterized by BET (Brunauer–Emmett–Teller) of RHAC, was 710.8 m2/g and DA micropore volume was 0.447 (cm3/g). Especially, the only modified RHACs had the peak of N-H functional group by using Fourier transform infrared spectrum (FTIR). Besides, the only RHAC modification by HNO3 had peak of C=O. That significantly contributed to increase the metal ions adsorption capacity of RHAC.

Tóm tắt -Trái quách là một loại cây ăn quả có hàm lượng dinh dưỡng cao, có khả năng bảo vệ gan, chống lại hoạt động của các vi khuẩn gây bệnh, chữa lành vết thương và ngăn sự phát triển của các khối u. Nghiên cứu bước đầu thực hiện nhằm tìm ra phương pháp tiền xử lí và nồng độ rượu ngâm thích hợp cho sản phẩm. Kết quả cho thấy quách tươi sau khi thu hoạch 2-3 ngày được rửa, để ráo, tiến hành xử lí trái bằng cách đập nứt vỏ, cho vào keo thủy tinh ngâm với rượu Xuân Thạnh 40 o . Sau ba tháng ngâm, sản phẩm có độ cồn là 19,8 o , độ Brix là 12,1 o Bx, và hàm lượng phenolic tổng số là 2,016 mg GAE/L. Từ khóa: trái quách, nồng độ rượu ngâm, tổng polyphenol.Abstract -Wood apple (Limonia acidissima L.) is a fruit with a high nutrition content, which can protect the liver, resist pathogenic bacteria, heal wounds and prevent the development of tumors. Initial research was conducted to find out the appropriate pretreatment and alcohol concentration for the end product. The results showed that fresh wood apples were sufficiently ripe 1,2,3 Trung tâm Công nghệ Sau thu hoạch, Khoa Nông nghiệp -Thủy sản, Trường Đại học Trà Vinh 2-3 days after harvesting, which were then washed, dried, individual apples were quartered and soaked in a glass jar containing Xuan Thanh wine (alc/vol = 40%) for 3 months. Thereafter, the wine sample exhibited a 19.8% alcohol concentration, 12.1 o Brix, and had a total phenolic compound (TPC) of 2.016 mg GAE/L.

Yogurt is a food product fermented from milk by Streptococcus thermophilus (S. thermophilus) and Lactobacillus bulgaricus (L. bulgaricus), which is very good for health. This study focuses on the evaluation of the ratio of condensed milk / Non-sugar fresh milk from 1/1.5 - 1/2 - 1/2.5, the ratio of the puree of soursop pulp added (5-25%), the fermentation temperature (from 41 to 47 oC) and fermentation time (from 6 to 8 hours) on the fermentation ability of yogurt in order toidentify the suitable fermentation condition for producing yogurt with the best sensory quality and the suitable sour taste. Additionally, this study also  investigates the effect of temperature and time of the fermentation process on the quality of yogurt. The results showed that, with the ratio of condensed milk / Non-sugar fresh milk = 1/2, the sensory properties of yogurt were very good. Besides, with the added puree of 5% and fermentation temperature of 44 oC within 7 hours, the sensory quality of yogurt was the best (with the point of 4.7/5 by the quality description scale) and the Donic degree of the product reached 86.3 that was suitable for yogurt (70 to 90 oD)