Topic
Formazine
About: Formazine is a research topic. Over the lifetime, 18 publications have been published within this topic receiving 134 citations. The topic is also known as: formazin.
Papers
TL;DR: Process conditions such as temperature and concentration have been systematically investigated by turbidity probe measurements and Photon Density Wave (PDW) spectroscopy, revealing an influence on the temporal formazine formation onset.
Abstract: Turbidity measurements are frequently implemented for the monitoring of heterogeneous chemical, physical, or biotechnological processes. However, for quantitative measurements, turbidity probes need calibration, as is requested and regulated by the ISO 7027:1999. Accordingly, a formazine suspension has to be produced. Despite this regulatory demand, no scientific publication on the stability and reproducibility of this polymerization process is available. In addition, no characterization of the optical properties of this calibration material with other optical methods had been achieved so far. Thus, in this contribution, process conditions such as temperature and concentration have been systematically investigated by turbidity probe measurements and Photon Density Wave (PDW) spectroscopy, revealing an influence on the temporal formazine formation onset. In contrast, different reaction temperatures do not lead to different scattering properties for the final formazine suspensions, but give an access to the activation energy for this condensation reaction. Based on PDW spectroscopy data, the synthesis of formazine is reproducible. However, very strong influences of the ambient conditions on the measurements of the turbidity probe have been observed, limiting its applicability. The restrictions of the turbidity probe with respect to scatterer concentration are examined on the basis of formazine and polystyrene suspensions. Compared to PDW spectroscopy data, signal saturation is observed at already low reduced scattering coefficients.
24 citations
TL;DR: A micropumping multicommutation manifold to perform turbidity determinations in waters is described, based on the use of a combination of hydrazine sulfate and hexamethylenetetramine to obtain an external standard of nephelometric turbidity units (NTU), which could compare the absorbance measurements at high wavelengths for samples with a calibration line obtained from a concentrated formazine standard diluted on-line.
22 citations
Journal Article•
TL;DR: The multiplicative scatter correction method affected by the turbidity of the water sample spectra calibration test can correct water samples spectral affected by turbidity and improve the quality of COD spectroscopy detection SNR, but also for providing an efficient data conditioning regimen for establishing an accurate of the chemical measurement methods.
Abstract: Eliminating turbidity is a direct effect spectroscopy detection of COD key technical problems. This stems from the UV-visible spectroscopy detected key quality parameters depend on an accurate and effective analysis of water quality parameters analytical model, and turbidity is an important parameter that affects the modeling. In this paper, we selected formazine turbidity solution and standard solution of potassium hydrogen phthalate to study the turbidity affect of UV--visible absorption spectroscopy detection of COD, at the characteristics wavelength of 245, 300, 360 and 560 nm wavelength point several characteristics with the turbidity change in absorbance method of least squares curve fitting, thus analyzes the variation of absorbance with turbidity. The results show, In the ultraviolet range of 240 to 380 nm, as the turbidity caused by particle produces compounds to the organics, it is relatively complicated to test the turbidity affections on the water Ultraviolet spectra; in the visible region of 380 to 780 nm, the turbidity of the spectrum weakens with wavelength increases. Based on this, this paper we study the multiplicative scatter correction method affected by the turbidity of the water sample spectra calibration test, this method can correct water samples spectral affected by turbidity. After treatment, by comparing the spectra before, the results showed that the turbidity caused by wavelength baseline shift points have been effectively corrected, and features in the ultraviolet region has not diminished. Then we make multiplicative scatter correction for the three selected UV liquid-visible absorption spectroscopy, experimental results shows that on the premise of saving the characteristic of the Ultraviolet-Visible absorption spectrum of water samples, which not only improve the quality of COD spectroscopy detection SNR, but also for providing an efficient data conditioning regimen for establishing an accurate of the chemical measurement methods.
21 citations
TL;DR: Compared the correction effects and COD prediction results of first-to-fourth order derivative spectra, the proposed method was verified to provide theoretical basis of direct derivative method and reduce blindness in the order determination.
20 citations
26 Jul 2017
TL;DR: In this paper, a simple and cost effective procedure to measure water turbidity with image processing is presented, where water samples were first placed inside a dark cabin before digital images of the samples were captured with smartphone camera.
Abstract: This paper demonstrates a simple and cost effective procedure to measure water turbidity with image processing. Water samples were first placed inside a dark cabin before digital images of the samples were captured with smartphone camera. The red, blue and green (RGB) images were processed to obtain greyscale images, which later converted to mean greyscale index (MGI). A total of 27 formazine samples were prepared and tested to develop a calibration equation relating MGI and nephelometry turbidity unit (NTU) with regression value of R2 = 0.96. This procedure is only valid for the range of turbidity between 0 and 100 NTU. The total cost of this procedure, excluding the smartphone, was only RM16.20 which is much less than the cost of commercial turbidimeters and other proposed cost-effective counterparts.
17 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2020 | 4 |
| 2019 | 1 |
| 2017 | 2 |
| 2016 | 1 |
| 2014 | 2 |