Project's information

Project's title Determination of Glyphosate and its metabolite – aminomethylphosphonic acid (AMPA) in the Red River’s surface water. Proposing treatment technology for Glyphosate removal
Project’s code VAST07.04/20-21
Research hosting institution Hanoi University of Science & Technology
Project leader’s name Dr. Le Phuong Thu
Project duration 01/01/2020 - 31/12/2021
Project’s budget 600 million VND
Classify Excellent
Goal and objectives of the project

- Determination of residues of the herbicide Glyphosate and its metabolite AMPA in Red River’s surface water from Hanoi to Thai Binh.
- Production of biochar from agricultural by-products to treat Glyphosate and AMPA in the aquatic environment.


Main results

Theoretical results:
- Assessment of surface water quality of the Red River flowing from upstream through the downstream Thai Binh - Nam Dinh showed that residues of the herbicide Glyphosate and its metabolites were detected simultaneously in the river water with low concentration. The content of these substances varies considerably, depending on the time, area and weather of sampling, the hydrological features of the flow, and especially the control of the discharge sources into the river. The surface water environment in the areas is polluted mostly by organic substances and microorganisms exceeding the allowable threshold.
- Biochars derived from agricultural by-products including coir and rice husks have been successfully produced in large quantities, homogeneously after calcination, and then activated by different conditions: H2O, HNO3 and NaOH 10% and 25% at room temperature and high temperature (90oC). The biochars had a high specific surface area of 329.71 m2/g and 364.22 m2/g for coir fiber biochar (BC1) and rice husk biochar (BC2), respectively. All biochars have a micro and medium structure but in different amounts. The biochar obtained in this study may have a high adsorption capacity for small to large molecules. Both BC1 and BC2 showed good adsorption capacity for Glyphosate. However, BC2 has better adsorption performance than BC1. In addition, the study also successfully produced biochar from rice husks impregnated with TiO2 which exhibits good photocatalytic properties and effectively removes glyphosate from aqueous solution.
- The adsorption column was 2 mm thick glass tubes with an inner diameter of 2.8 cm and an effective length of 53 cm. One end of each glass tube is welded with a threaded mouth (outer diameter 4.5 cm, inner diameter 3 cm) with a plastic cap for adding materials to the tube and removing the material as well as helping to clean the tube after each experiment easily and effectively. The threaded mouth of the column also ensures that the liquid in the column cannot leak to the outside, facilitating the study of the effects of a large flow range on the column performance. The plastic cap is connected to an outlet pipe with an outer diameter of 5 mm and an inner diameter of 3 mm serving the connection to the water supply pipe. The other end of the glass tube is sealed with a hole disc and welded with a valve (outlet diameter 8 mm, inner diameter 5 mm). The perforated glass disc helps to the packing materials in the tube while ensuring efficient drainage of water out of the tube through the valve. The entire column materials including quartz, glass and Teflon resin which have good chemical inertness and can use for the study of many types of pollutants as well as under harsh experimental conditions (such as very low or very high pH).
Applied results:
- Biochar from rice husk and coir both have good Glyphosate adsorption capacity compared with different adsorbents, such as bamboo activated carbon, pea pods, modified clay sphere, and biochar wakame-derived activation. On the other hand, the biochar made in this study with a particle size of 1 – 2 mm for coir and 5 mm for rice husk is more eco-friendly and cost-effective than other adsorbents. Firstly, the granular nature of the adsorbent is useful because it can be easily separated after filtration and settling without generating sludge. Second, in terms of recycling, using agricultural by-products allows agricultural waste to be more valued to reduce environmental risks.
- The adsorption column system consists of 3 quartz columns connected in series representing one pre-column and two main treatment column. The system is directly connected to a dual-channel peristaltic pump with total capacity of 750 to 3000 mL/h. This system allows the treatment of two parallel systems at the same time with different material conditions and different pollutant sources, as well as allowing direct treatment of river water and no pre-filtration or pre-treatment is required.

Novelty and actuality and scientific meaningfulness of the results

In addition to using biochar from agricultural by-products as an adsorbent to remove persistent organic matter such as Glyphosate as well as other inorganic and organic impurities present in water, the study also introduced the first study on the synthesis of TiO2 supported on biochar derived from agricultural by-products. Due to the linkage between TiO2 and biochar, biochar from rice husks impregnated with TiO2 is a potential catalyst in the photodegradation of Glyphosate and difficult to treat organic pollutants.

Products of the project

Scientific papers in referred journals (list):
●    Preparation and Characterization of Biochar Derived from Agricultural By-Products for Dye Removal (Adsorption Science & Technology, 2021, 1 – 14.
●    On the Degradation of Glyphosate by Photocatalysis Using TiO2/Biochar Composite Obtained from the Pyrolysis of Rice Husk (Water, 13(23), 3326.
●    Removal of methylene blue from aqueous solution by biochar derived from rice husk (Vietnam Journal of Earth Sciences, 2022.
●    Nghiên cứu xử lý Glyphosate bằng quá trình hấp phụ trong hệ tháp chứa than sinh học từ vỏ trấu (Accepted by Journal of analytical sciences, 28(1), 2022)
Technological products (describe in details: technical characteristics, place):
- All products are stored in the Department of Applied Environmental Science, University of Science and Technology of Hanoi.
●    Data on Glyphosate residues and AMPA metabolites in Red River water samples from Hanoi to Thai Binh: 27 water samples corresponding to 27 sampling locations and two seasons of the year.
●    Biochar materials from rice husk and coir: amorphous structure with graphene layers, large specific surface area of 364.2 m2/g compared with 329.7 m2/g, and pore volume of 0.26 cm3/g compared with 0.17 cm3/g, for rice husk and coir biochar, respectively. The maximum adsorption solutions for Glyphosate and AMPA on both biochars were above 4 mg/g.
●    Glyphosate and AMPA adsorption column model with capacity ranging from 18 L/day to 72 L/day.
Other products (if applicable):
- The project supervised 01 master (GUST) and 01 bachelor (USTH) students.


In further studies, it is necessary to focus on (1) investigating other operating conditions, to determine the optimal conditions for Glyphosate degradation; (2) investigating the possibility of removing other pesticides and applications of other biochar from agricultural by-products; (3) examining the applicability of the process in actual wastewater treatment.

Images of project