An order determination method in direct derivative absorption spectroscopy for correction of turbidity effects on COD measurements without baseline required

Hu, Yingtian; Zhao, Dongdong; Qin, Yali; Wang, Xiaoping

doi:10.1016/j.saa.2019.117646

Cited by 15 publications

(7 citation statements)

References 12 publications

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“…The theory of Mie scattering (IMie) is complex. In general, the relation between the intensity of Mie scattering and the incident wavelength can be simplified as given by equation ( 4), where the intensity of Mie scattering is inversely proportional to the k th power of the wavelength [25], where k is a variable parameter. It should be clear that when k = 4, the equation is identical to that for Rayleigh scattering.…”

Section: Rayleigh and Mie Theoriesmentioning

confidence: 99%

Light-scattering in absorption spectra: a literature survey of examples and corrections

Taniguchi,

Lindsey

2024

Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications XV

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Absorption spectroscopy is a simple yet robust method for qualitative and quantitative analysis. The technique is most commonly applied for molecules in solution that absorb light in the ultraviolet (UV), visible (Vis), and/or near-infrared (NIR) spectral region. The presence of the particles of size comparable to or greater than the wavelength of light can cause scattering. The contribution from light scattering can overwhelm intrinsic absorption especially in the shorter wavelength, UV regions, which impedes accurate analysis. The problem of light scattering is common in absorption spectroscopy. To compensate for the alterations caused by light scattering, various correction methods have been applied over the years. The chief correction methods are based on Rayleigh or Mie light-scattering theory. Displayed here are >40 spectra drawn from spectroscopy and photochemistry journals published over 7 decades (since the 1950s) that illustrate the lightscattering problem. The displays include >25 spectra beset by light scattering and 15 examples wherein spectral corrections have been applied. The present survey of the scope of the light-scattering problem in absorption spectroscopy (200-1000 nm) serves as a prelude to the development of a systematic calculational module for spectral correction.

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Section: Rayleigh and Mie Theoriesmentioning

confidence: 99%

Light-scattering in absorption spectra: a literature survey of examples and corrections

Taniguchi,

Lindsey

2024

Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications XV

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“…Peer review dibawah tanggung-jawab Jurusan Teknik Sipil Universitas Lampung. urangi intensitas cahaya yang masuk ke dalam air karena merupakan partikel yang berhamburan [6].…”

Section: Pendahuluanunclassified

Peningkatan kualitas air dengan meggunakan sistem filtrasi pada pengolahan air baku

Rizki

2021

RJITS

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Air baku merupakan air tanpa pengolahan. Instalasi pengolahan dengan material filter alami digunakan untuk mengurangi kekeruhan dan sedimentasi. Penelitian ini bertujuan menganalisis kualitas air baku, kombinasi susunan filter dan menganalisis prospek pengembangan instalasi pengolahan air untuk masyarakat. Sampel diambil pada bulan oktober 2019-januari 2020 di Desa Bernung, Kecamatan Gedong Tataan. Pada penelitian ini digunakan material filter kerikil, pasir kuarsa, arang, ijuk dan zeolite. Dari lima material filter yang digunakan, material ijuk yang paling baik menurunkan parameter TDS dengan nilai 209.5 mg/liter, sedangkan zeolite yang paling efektif menurunkan nilai parameter TSS dan turbidity dengan nilai 0.0490 mg/liter dan 4.61 NTU. Instalasi pengolahan air dalam studi ini dapat diterapkan untuk daerah dampak bencana banjir maupun kekeringan, dan dikhususkan untuk wilayah pedesaan dengan ekonomi menengah ke bawah karena mudah dan ekonomis.

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“…The COD solution (100 mg/L) was prepared by dissolving 0.02125 g potassium hydrogen phthalate in deionized water and diluting to 250 mL. COD standard solutions whose values were 1, 2, 3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31, and 32 mg/L, and were prepared by appropriate dilution. In addition, the NTU (nephelometric turbidity unit) standard (7027-1984 ISO) was used to determine the water turbidity.…”

Section: Samples Preparation and The Measurement Of Uv-vis Absorbance...mentioning

confidence: 99%

“…Although the absorbance at 546 nm is simple for turbidity compensation, the accuracy of COD detection with compensation is not satisfactory. Hu et al used the fourth derivative method to remove turbidity interference [13]. The fourth-order derivative method has the advantage of no baseline and reduces the signal strength of COD, resulting in the reduction of signal-to-noise ratio, finally affecting the accuracy of COD detection.…”

Section: Introductionmentioning

confidence: 99%

A Novel Hybrid Strategy for Detecting COD in Surface Water

Gui-ping

et al. 2020

Applied Sciences

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The prediction of chemical oxygen demand (COD) by ultraviolet–visible absorption spectrum is a common method. Many researchers use the absorbance at the characteristic wavelength to establish COD prediction models. However, selecting the characteristic wavelength is a problem. In this paper, the extreme values of absorption spectrum change rate, was proposed as a new characteristic parameter to determine the characteristic wavelengths. On this basis, a novel hybrid strategy for detecting COD in surface water was proposed. We first proposed to combine the first derivative method with the permutation entropy method (FDPE) to determine the characteristic wavelengths. Then we used partial least square (PLS) to establish a COD prediction model. Experimental results demonstrated the linear correlation coefficient (R2) of the FDPE_PLS was above 0.99 without turbidity interference. Secondly, a dual-wavelength method (DWM) was proposed to determine the turbidity values. The DWM used slopes of absorbance values at 400 nm and 600 nm to predict the turbidity values. Compared with the single-wavelength method, the DWM improves the measurement accuracy of turbidity. Finally, a new turbidity compensation method was proposed to compensate for the interference in the first derivative spectrum. After compensation, FDPE_PLS can predict COD concentrations accurately, whose R2 was 0.99.

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An order determination method in direct derivative absorption spectroscopy for correction of turbidity effects on COD measurements without baseline required

Cited by 15 publications

References 12 publications

Light-scattering in absorption spectra: a literature survey of examples and corrections

Light-scattering in absorption spectra: a literature survey of examples and corrections

Peningkatan kualitas air dengan meggunakan sistem filtrasi pada pengolahan air baku

A Novel Hybrid Strategy for Detecting COD in Surface Water

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