Studying the ultrasound-assisted extraction of phosphate in soil using the portable ultrasonic equipment UTR 200

• Grant number: 25/04704-0
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: June 19, 2025
• End date: August 01, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Arnaldo Alves Cardoso
• Grantee: Stella Sales Macedo
• Supervisor: Francisco Javier Pena Pereira
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Institution abroad: Universidade de Vigo, Spain
• Associated to the scholarship: 24/08182-5 - Determination of Labile Phosphorus in Soil: A Low-Cost Proposal Using Digital Images, BP.IC

Abstract

This is a request for a Research Abroad (BEPE) to be developed in collaboration with Prof. Dr. Francisco Javier Pena Pereira; University of Vigo Spain. The initial part of the IC project proposal, which was developing a method for determining phosphate using digital images of the reaction product between phosphate and the reagent, has already been well resolved. The second part, extracting phosphate from soil using a portable ultrasound (US) bath, is currently being studied. The results obtained so far are pretty promising. However, we believe that a more complete study could enrich the results and the researcher's training. The suggestion is to work within the concept of ultrasound-assisted pretreatment of solid samples in the context of green analytical chemistry. Prof. Pena Pereira has vast experience in this subject, as evidenced by his articles and books. This proposed project uses ultrasound-assisted extraction such as the UTR200 (Hielscher), which could complement the work developed with the ultrasound bath used at UNESP. The UTR200 is a high-power equipment operating with 200 watts of power at 24 kHz. This high power makes it highly effective in extraction processes. With the ability to work with small volumes (1 mL or less), the UTR200 presents a promising option for extracting available phosphorus from soil. The UTR200 allows for modifying more experimental variables than those in a conventional bath, such as ultrasound power, time, position, and wave amplitude. The proposal is to initially carry out a variable selection design using the Box-Behnken or Central Composite Design, well-known experimental planning techniques that allow for the optimization of processes. The understanding of the relationship between variables, thereby identifying the parameters that have the most significant impact on the extraction of phosphate from the soil. This approach aims not only to improve the efficiency of the extraction process but also to evaluate the feasibility of using portable ultrasonic equipment, such as the UTR200, to determine phosphate in soil in situ, using smartphones as detection and analysis tools.