Characterization of Total-Phosphorus (TP) Pretreatment Microfluidic Chip Based on a Thermally Enhanced Photocatalyst for Portable Analysis of Eutrophication

Abstract

To minimize conventional total-phosphorus (TP) analysis systems, TP pretreatment microfluidic chip is proposed and characterized in this paper. Phosphorus (P) is one of the most important elements in ecosystem but it causes the eutrophication due to its overdose. TP analysis systems are increasingly receiving attention as a means to prevent eutrophication. Even though conventional TP analysis systems have high accuracy and sensitivity, they are not frequently utilized outside the laboratory because of their bulky size, complicated pretreatment processes, long response times, and high cost. Thus, there is a growing need to develop portable TP analysis systems. The microfluidic chip in this study is proposed with the aim of simplifying and minimizing TP analysis by replacing the conventional pretreatment process with a new method employing a thermally enhanced photocatalytic reaction that can be applied directly to a microfluidic chip of small size. The fabricated TP pretreatment microfluidic chip with thermally enhanced photocatalyst (TiO2) was optimized compared to the conventional pretreatment equipment (autoclave). The optimum pretreatment conditions using the proposed chip were pretreatment time of 10 min and temperature of 75 °C. The optimized pretreatment process using the proposed microfluidic chip showed similar performance to the conventional pretreatment method, even with shorter pretreatment time. The shorter pretreatment time and small size are advantages that enable the TP analysis system to be minimized. Therefore, the proposed TP pretreatment microfluidic chip based on thermally enhanced photocatalytic reaction in this study will be utilized to develop a portable TP analysis system.

Changes in Physicochemical Indicators of Water Resulting from River Activities. Case Study in Nida Valley, Poland

“…The Shapiro-Wilk test revealed the normal distribution of all indicators. Total phosphorus (TP) encompasses all kinds of phosphorus, including organophosphate and mineral phosphate (Dong et al, 2019). Phosphates in water primarily stem from metals in parent rocks or pollution due to fertilizers, sewage, production waste, and human activities (Zanini et al, 1998;Krapac et al, 2002).…”

Photocatalytic Oxidization Based on TiO2/Au Nanocomposite Film for the Pretreatment of Total Phosphorus (TP)

“…Before preparing the microchannel, a PDMS mold was developed using a 6 in Si substrate using the photolithography method [19]. The fabrication processes of the PDMS mold and PDMS are illustrated in Figure 4a.…”

“…The principle of the photocatalytic reaction of TiO2 [28] can be explained as follows: The alternative TP pretreatment method involves a portable and inexpensive LOC device prepared using micro-electro-mechanical system technology [19][20][21]. Using the principle of photocatalysis, a K 2 S 2 O 8 oxidizing agent is used to pretreat phosphorus-containing compounds and transform them into PO 4 3− under UV (365 nm) light irradiation.…”

A Study on TiO2 Surface Texturing Effect for the Enhancement of Photocatalytic Reaction in a Total Phosphorous Concentration Measurement System

“…Since the injected samples are made of different materials, it is rather difficult to mix the solution, but when the temperature rises, the airflow inside the chamber is generated and facilitates the mixing of the solution. In addition, according to the Maxwell-Boltzmann distribution, the increase in the temperature causes the probability of reaction for the activation energy in the molecules to increase and leads to higher TiO2 photocatalyst efficiency [36]. Figure 4 is a cross-sectional view of the total phosphorus monitoring device.…”