Measuring Microplastic Concentrations in Water by Electrical Impedance Spectroscopy
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsWater-3272817-peer
Title: Measuring Microplastics concentration in water by Electrical Impedance Spectroscopy
The paper “Stress of Soil Moisture and Temperature Exacerbates the Toxicity of Tire Wear Particles to Soil Fauna: Tracking the Role of Additives through Host Microbiota” aims to develop a rapid and reliable method for detecting and estimating the concentration of microplastics (MPs) in water effluents using electrical impedance spectroscopy (EIS) technology. The study aims to address the limitations of existing microplastic detection methods, such as being laborious, typically requiring offline processing, involving multiple steps, and expensive equipment. This research provides a new detection method: the application of EIS technology offers a novel approach for the rapid detection of microplastics, which is of great significance for environmental protection and water resource management. Therefore, it is necessary to consider the following suggestions before they can be published in the Water. Here are some suggestions for authors.
1. Electrochemical Impedance Spectroscopy (EIS) is a method for analyzing the electrical response of a system. Is this method used for detecting the concentration of microplastics? Is the method reliable and accurate?
2. Why were polyvinyl chloride (PVC) and polyethylene (PE) microplastic particles selected for the experiment, and how does Laser Diffraction Spectroscopy (LDS) evaluate particle size distribution? Are polystyrene (PS) and polyethylene terephthalate (PET) microplastic particles also suitable for this method?
3. The introduction should clearly state the purpose of this study, outlined in a structured, point-by-point manner.
4. Impedance primarily reflects the electrochemical properties of materials, such as conductivity and dielectric characteristics, while particle size is typically measured through geometric or optical methods, such as laser diffraction. Although impedance may be indirectly influenced by particle size, it cannot be used alone to precisely determine particle dimensions. Therefore, additional characterization methods are required for further validation.
5. The experiment was conducted under controlled conditions, which may not fully simulate the behavior of microplastics in natural environments. For example, it is recommended to consider factors such as water flow, temperature variations, and the presence of other chemicals in the experiment to assess their impact on EIS detection results.
6. The results indicate that pH has a significant effect on the surface charge of microplastic particles, which in turn affects the sensitivity of EIS detection. It is recommended that future research explore the mechanisms of surface charge variation of microplastic particles under different pH conditions, as well as how these changes influence EIS signals.
7. It is recommended to number the formulas used in the article and provide detailed definitions for each letter in the formulas.
8. Please provide a detailed description of the device depicted in Figure 1 and explain its operating principle. Additionally, Figures 2 to 9 need to be reformatted and their clarity and readability enhanced.
9. It is necessary to provide a more in-depth summary of the main findings and data of the study, while also highlighting the various limitations present in this research. Additionally, the significance of this study should be considered within a broader context.
Comments on the Quality of English Language
The English could be improved to more clearly express the research.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe study focuses on detecting and quantifying microplastics (MPs) in water, addressing the critical issue of plastic pollution. Traditional methods are often expensive, time-consuming, and not suitable for real-time analysis. This research introduces Electrical Impedance Spectroscopy (EIS) as a fast and reliable alternative for detecting MPs in water, using a submersible device that enables large-scale monitoring, such as in water treatment systems. EIS offers an innovative, real-time method, reducing the need for laborious laboratory processes. The submersible device simplifies direct water sampling, increasing applicability in real-world environments. The method is highly sensitive to MP concentration changes, particularly PVC, and shows that pH affects detection. Its sensitivity at neutral pH makes it ideal for wastewater treatment plants, where such conditions are common.
However, I recommend a major revision for this manuscript. Below are suggestions to enhance it:
1. 1. The abstract lacks crucial experimental details and key findings. Including specifics about the experimental setup, such as the types of microplastics tested, the concentration ranges, and the main results, would strengthen the abstract and provide a clearer overview of the study's significance and outcomes.
2. The Introduction requires substantial improvement, including more comprehensive literature reviews, clearer justification of the study's relevance, and a well-defined hypothesis. The section on "Classical Classification methods" lacks specific reasoning for the choice of method. It is recommended to refer to the articles at DOI: [https://dx.doi.org/10.30919/esee1233] (https://dx.doi.org/10.30919/esee1233), 10.30919/esfaf793; https://doi.org/10.1016/j.ceja.2024.100649, which provides a more detailed description of traditional methods for microplastic detection, along with their advantages and limitations. A comparative analysis of these methods will help justify the selection of the proposed method using Electrical Impedance Spectroscopy (EIS) and emphasize its practical significance for monitoring microplastics in real-world water systems.
3. Additionally, the selection of the specific types of microplastics used in the study (Polyethylene and Polyvinyl Chloride) should be justified. These polymers are among the most prevalent in environmental contamination due to their widespread use in various industries, such as packaging, construction, and consumer goods. Polyethylene (PE) and Polyvinyl Chloride (PVC) were chosen because they represent different densities and surface properties, which affect their behavior in water systems. Emphasizing this rationale will strengthen the study by highlighting that the chosen microplastics are representative of real-world pollutants commonly found in aquatic environments.
3. While the study presents a promising new approach, a comparative analysis with traditional methods, such as FTIR and Raman spectroscopy, would further strengthen the argument for EIS. Additionally, expanding the types of microplastics analyzed and assessing the impact of organic matter on EIS performance would increase the method’s robustness in diverse environmental conditions. The conclusion also needs improvement.
4. Another question why the final concentration of two types of MPs varies, is there any reason. Justify.
Comments on the Quality of English Language
Quality of English Language is good.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authorsaccept
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Editor,
The authors have addressed all the issues indicated by the Reviewer. I have no further comments on the manuscript; therefore, I recommend accepting the paper.
