Project's information

Project's title Research on the treatment of some heavy metal ions in water by apatite ore and modified apatite ore
Project’s code VAST07.02/20-21
Research hosting institution Institute for Tropical Technology
Project leader’s name Dr. Nguyen Thu Phuong
Project duration 01/01/2020 - 31/12/2021
Project’s budget 600 million VND
Classify Excellent
Goal and objectives of the project

The objectives of the project are purifying and modifying apatite ore in order to apply to adsorb some heavy metal ions in wastewater, orient in application in environment treatment.

Main results

Scientific results:
- Đã nghiên cứu khả năng xử lý Pb2+ của quặng apatit và so sánh với quặng apatit tinh chế. Quặng apatit có khả năng xử lý Pb2+ với điều kiện thích hợp như sau: hàm lượng 3 g/L, thời gian 60 phút, dung lượng hấp phụ cực đại 11,26 mg/g. Quặng apatit tinh chế có khả năng xử lý Pb2+ tốt hơn so với quặng ban đầu.
- Apatite ore was purified and modified to hydroxyapatite. The results show that the initial ore has the main component of fluorapatite, a specific surface area of 3.97 m2/g, the particles do not have a uniform particle size. After purification, the main component is still fluorapatite with the specific surface area increases to 36.62 m2/g, and the particle size is smaller and more uniform. After modification, the specific surface area increases to 100.79 m2/g, the particles have nanometer size and are uniform with the main component of hydroxyapatite.   
- The Pb2+ adsorption ability of apatite ore was studied and compared with purified apatite ore. Apatite ore can adsorb Pb2+ with suitable conditions as follows: a dose of adsorbent of 3 g/L, contact time of 60 minutes, and maximum adsorption capacity of 11.26 mg/g. Purified apatite ore can adsorb Pb2+ better than original apatite ore.
- The suitable adsorption conditions for some heavy metals ions were found: In the case of Pb2+ 50 mg/L: a dose of adsorbent of 0.2 g/L, 40 minutes, pH from pH0 (4) to neutral pH. For Cd2+ 30 mg/L: dose of modified apatite of 1 g/L, 30 minutes, pH from pH0 (5.545) to neutral pH. With Cu2+ 30 mg/L: dose of adsorbent of 0.6 g/L, 45 minutes, pH from pH0 (5.625) to neutral pH. In the case of Fe3+ 50 mg/L: dose of material of 0,2 g/L, 80 minutes, pH from pH0 (2.65) to neutral pH. The effect of the initial concentration of heavy metal ions from 10 to 1000 mg/L to adsorption capacity at room temperature shows that adsorption is suitable with the Langmuir adsorption isotherm model. The maximum adsorption capacity of Pb2+, Cd2+, Cu2+ and Fe3+ are 341.3 mg/g; 43.94 mg/g; 69.59 mg/g and 1092.7 mg/g, respectively. The adsorption follows a pseudo-second-order kinetic model and is an endothermic and spontaneous process. After Pb2+ adsorption, modified apatite ore has the phase of Pb10(PO4)6(OH)2 showing the completely replace of calcium ions in structure by Pb2+ ions. In the case of Fe3+, there is the appearance of the FeOOH phase. With Cd2+ and Cu2+, the material has a hydroxyapatite phase.
- The adsorption ability of a mixture of heavy metal ions and wastewater of material was investigated. The material has contemporaneous adsorption ability for heavy metal ions with the order:  Pb > Fe > Cu > Cd. The material can treat real wastewater, in detail plating, craft village, and mine wastewater.

Novelty and actuality and scientific meaningfulness of the results

The process to modify apatite ore (a huge material source in nature) to hydroxyapatite was shown and research on the treatment ability of material toward some heavy metal ions. The simple modified process with the dissolution of apatite ore by HNO3 and precipitation by NH3 leads to obtaining a material with a specific surface area increase 25 times compared with the initial ore. The obtained material can adsorb some heavy metal ions such as Pb2+, Cu2+, Cd2+, Fe3+, Cr3+, Co2+, Zn2+.

Products of the project

- Scientific papers in referred journals (list):
1. Phuong Thu Nguyen, Xuyen Thi Nguyen, Trang Van Nguyen, Thom Thi Nguyen, Thai Quoc Vu, Huy Trung Nguyen, Nam Thi Pham, Thanh Mai Thi Dinh, Treatment of Cd2+ and Cu2+ ions using modified apatite ore, Journal of Chemistry, 2020, 6537197, doi: 10.1155/2020/6527197 (SCIE).
2. Nguyen Thu Phuong, Cao Thi Hong, Nguyen Thi Thuy, Nguyen Thi Xuyen, Nguyen Thi Thom, Pham Thi Nam, Nguyen Thi Thu Trang, Do Thi Hai, Dinh Thi Mai Thanh, Research on the adsorption of Pb2+ by apatite ore and purified apatite ore, Vietnam Journal of Science and Technology, 59 (6), 2021, 745-761 (VAST 2).
- Other products (if applicable):
01 procedure of purification and modification of apatite ore with high efficiency.
50 g of the product of purified and modified apatite ore which have heavy metal adsorption ability in the water.
01 procedure of treatment of some heavy metal ions in water by purified and modified apatite ore with an efficiency above 80%.
Education: 2 masters and 1 student follow the direction of the project.

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