scholarly journals Fuel park wastewater monitoring with UV-Vis spectra and partial least squares models

2008 ◽  
Vol 27 (1) ◽  
pp. 19
Author(s):  
Nídia D. Lourenço ◽  
José C. Menezes ◽  
Helena M. Pinheiro ◽  
David Diniz
Keyword(s):  
Least Squares ◽  
Partial Least Squares ◽  
Mean Squared Error ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Original Dataset ◽  
Calibration Models ◽  
Wastewater Quality ◽  
On Line ◽  
Determination Of Parameters

In the context of the high application potentials for on-line and in-line measurements in wastewater quality monitoring, UV-Vis spectrophotometry has received recent attention. In the present work the development of Partial Least Squares (PLS) calibration models for the fast determination of parameters legally required at the discharge of a fuel park wastewater treatment plant was attempted using UV-Vis spectra and the corresponding standard analytical values. A PLS model was developed and validated for Chemical Oxygen Demand (COD) determination with 3.8 mg O2/l RMSEP (root mean squared error of prediction). The models developed for 5-day Biochemical Oxygen Demand (BOD5) and Total Suspended Solids (TSS) were validated (3.5 mg O2/l and 2.9 mg/l RMSEP, respectively), but presented some predictive limitations mainly attributed to the narrow interval of concentration values present in the original dataset.

Use of reflectance spectroscopy to estimate the organic carbon and CaCO3 contents of soils

2012 ◽  
Vol 61 (2) ◽  
pp. 277-290 ◽  
Author(s):  
Ádám Csorba ◽  
Vince Láng ◽  
László Fenyvesi ◽  
Erika Michéli
Keyword(s):  
Organic Carbon ◽  
Least Squares ◽  
Partial Least Squares ◽  
Partial Least Squares Regression ◽  
Mean Squared Error ◽  
Reflectance Spectroscopy ◽  
Least Squares Regression ◽  
Root Mean Squared Error ◽  
Squared Error

Napjainkban egyre nagyobb igény mutatkozik olyan technológiák és módszerek kidolgozására és alkalmazására, melyek lehetővé teszik a gyors, költséghatékony és környezetbarát talajadat-felvételezést és kiértékelést. Ezeknek az igényeknek felel meg a reflektancia spektroszkópia, mely az elektromágneses spektrum látható (VIS) és közeli infravörös (NIR) tartományában (350–2500 nm) végzett reflektancia-mérésekre épül. Figyelembe véve, hogy a talajokról felvett reflektancia spektrum információban nagyon gazdag, és a vizsgált tartományban számos talajalkotó rendelkezik karakterisztikus spektrális „ujjlenyomattal”, egyetlen görbéből lehetővé válik nagyszámú, kulcsfontosságú talajparaméter egyidejű meghatározása. Dolgozatunkban, a reflektancia spektroszkópia alapjaira helyezett, a talajok ösz-szetételének meghatározását célzó módszertani fejlesztés első lépéseit mutatjuk be. Munkánk során talajok szervesszén- és CaCO3-tartalmának megbecslését lehetővé tévő többváltozós matematikai-statisztikai módszerekre (részleges legkisebb négyzetek módszere, partial least squares regression – PLSR) épülő prediktív modellek létrehozását és tesztelését végeztük el. A létrehozott modellek tesztelése során megállapítottuk, hogy az eljárás mindkét talajparaméter esetében magas R2értéket [R2(szerves szén) = 0,815; R2(CaCO3) = 0,907] adott. A becslés pontosságát jelző közepes négyzetes eltérés (root mean squared error – RMSE) érték mindkét paraméter esetében közepesnek mondható [RMSE (szerves szén) = 0,467; RMSE (CaCO3) = 3,508], mely a reflektancia mérési előírások standardizálásával jelentősen javítható. Vizsgálataink alapján arra a következtetésre jutottunk, hogy a reflektancia spektroszkópia és a többváltozós kemometriai eljárások együttes alkalmazásával, gyors és költséghatékony adatfelvételezési és -értékelési módszerhez juthatunk.

scholarly journals Estimation of water quality by UV/Vis spectrometry in the framework of treated wastewater reuse

2017 ◽  
Vol 76 (3) ◽  
pp. 633-641 ◽  
Author(s):  
Erwan Carré ◽  
Jean Pérot ◽  
Vincent Jauzein ◽  
Liming Lin ◽  
Miguel Lopez-Ferber
Keyword(s):  
Wastewater Reuse ◽  
Reclaimed Water ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Treated Wastewater ◽  
Water Production ◽  
Least Squares Regression ◽  
Complementary Method ◽  
Original Dataset ◽  
Treated Wastewater Reuse

The aim of this study is to investigate the potential of ultraviolet/visible (UV/Vis) spectrometry as a complementary method for routine monitoring of reclaimed water production. Robustness of the models and compliance of their sensitivity with current quality limits are investigated. The following indicators are studied: total suspended solids (TSS), turbidity, chemical oxygen demand (COD) and nitrate. Partial least squares regression (PLSR) is used to find linear correlations between absorbances and indicators of interest. Artificial samples are made by simulating a sludge leak on the wastewater treatment plant and added to the original dataset, then divided into calibration and prediction datasets. The models are built on the calibration set, and then tested on the prediction set. The best models are developed with: PLSR for COD (Rpred2 = 0.80), TSS (Rpred2 = 0.86) and turbidity (Rpred2 = 0.96), and with a simple linear regression from absorbance at 208 nm (Rpred2 = 0.95) for nitrate concentration. The input of artificial data significantly enhances the robustness of the models. The sensitivity of the UV/Vis spectrometry monitoring system developed is compatible with quality requirements of reclaimed water production processes.

Optimization of Partial-Least-Squares Calibration Models by Simulation of Instrumental Perturbations

1997 ◽  
Vol 69 (16) ◽  
pp. 3391-3399 ◽  
Author(s):  
Frédéric Despagne ◽  
Désiré-Luc Massart ◽  
Onno E. de Noord
Keyword(s):  
Least Squares ◽  
Partial Least Squares ◽  
Calibration Models

scholarly journals Inovatividade, envolvimento, atitude e experiência na adoção da compra on-line

2011 ◽  
Vol 51 (6) ◽  
pp. 568-584 ◽  
Author(s):  
Abrão Caro ◽  
José Afonso Mazzon ◽  
Barbara Caemmerer ◽  
Matthias Wessling
Keyword(s):  
Theory Of Planned Behavior ◽  
Least Squares ◽  
Partial Least Squares ◽  
Planned Behavior ◽  
On Line

Este trabalho procura analisar as inter-relações entre a inovatividade, o envolvimento, a atitude dentro do modelo Theory of Planned Behavior (TPB) decomposto desenvolvido na psicologia social, e a experiência com a Internet com o processo de adoção da compra pela internet. Foi elaborado um modelo integrativo que possibilitasse explicar a relação entre esses fatores e a compra pela internet, e foi desenvolvida uma pesquisa de campo considerando uma amostra não probabilística de estudantes. Foi utilizado o método multivariado de modelagem de equações estruturais, aplicado por meio da técnica Partial Least Squares (PLS) para a verificação, explicação e comparação das relações entre os construtos. Os resultados mostram que a intenção da compra pela internet é diretamente influenciada pela atitude e pela inovatividade, e a atitude é influenciada pelo envolvimento. Não foi encontrada relação entre a experiência com a internet e a compra pela internet.

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