Innovative technique for analysis of wastewater contaminants using hyperspectral imaging

Abstract

Accurate, fast, quantitative on-site analysis of wastewater is an environmental necessity. Therefore, we report a quantitative spectroscopic study in order to analyse organic contaminants in wastewater. For this purpose, two spectroscopy-based techniques were utilised and their results are compared. The first technique is ultraviolet/visible (UV/vis) spectrophotometry. This technique is a standard laboratory technique, however, it is inappropriate for working in the field. Besides, the analysis results of the standard laboratory technique display low accuracy in detecting small concentrations of wastewater contaminants such as methylene blue (< 20 ppm). Accordingly, there is a need for another technique to overcome the shortcomings of UV/vis spectrophotometry. Hyperspectral imaging (HSI) combines imaging and spectrometry. HSI works on-site since it is portable and easy to operate. The analysis of the data acquired by HSI showed a higher efficacy in accurately detecting both low (< 20 ppm) and high concentrations (> 50 ppm) of water contaminants such as methylene blue and methyl orange. For verification, Pearson correlation coefficients were computed between the concentration of contaminants and their absorbance for all the operating spectral bands. The results of the two techniques were statistically compared using Bland and Altman’s limit of agreement. This study showed that HSI is potentially a promising technique for the analysis of wastewater contaminants on-site.

Nano Modifications of Biochar to Enhance Heavy Metal Adsorption from Wastewaters: A Review

“…88,89 The fundamental benefit of the technique lies in its ability to perform analysis in a nondestructive manner at high sensitivity and with higher throughput which are critical to obtain accurate inferences regarding the concentration and spatial distribution of the heavy metal elements in soil matrix and water samples. 85 The EEMFS has the potential to compare and identify the dynamics and transformations of a chromophore in three dimensions with high sensitivity and without degradation of the test sample. 80 It can be utilized to discern the effect of heavy metal contamination in the soil and/or water sample.…”

“…Hyper-spectral spectroscopy/imaging methods include an array of remote-sensing enabled quantitative spectroscopic-microscopy analysis to obtain quick and sensitive on-site estimation of a variety of attributes such as occurrence of heavy metal in land, tailing pond water, groundwater, river water, wastewater, soil, and plant tissue. − However, now HSI has transcended from remote sensing to up-close spectroscopy imaging analysis of samples in situ or ex situ in research laboratories for heavy metal contaminated soil samples. , The fundamental benefit of the technique lies in its ability to perform analysis in a nondestructive manner at high sensitivity and with higher throughput which are critical to obtain accurate inferences regarding the concentration and spatial distribution of the heavy metal elements in soil matrix and water samples …”

“… 88 , 89 The fundamental benefit of the technique lies in its ability to perform analysis in a nondestructive manner at high sensitivity and with higher throughput which are critical to obtain accurate inferences regarding the concentration and spatial distribution of the heavy metal elements in soil matrix and water samples. 85 …”

Underwater hyperspectral imaging bioinspired by chromatic blur vision

“…Hyperspectral imaging is a technique for acquiring images in continuous narrow bands, which can be used to analyze the 'spectral fingerprint' and spatial distribution of large-scale detection objects [1,2]. It is widely used in satellite remote sensing [3], biomedical imaging [4,5], water contamination analysis [6] and other fields [7,8]. Its characteristic of high spectral resolution is not available in other types of photoelectric imaging [1-3, 9, 10].…”

A novel dual-path high-throughput acousto-optic tunable filter imaging spectropolarimeter

“…5,6 HSI has displayed a profound impact in a diversity of research fields including archaeology, wastewater monitoring, food industry, criminology, forensics, medicine and planetary remote sensing. [7][8][9][10][11][12][13][14] Nevertheless, the valuable information of HSI might disguise evidence of the presence of some species in a heterogeneous environment. 11,15,16 For such cases, a piece of auxiliary information might improve identification.…”