Alternative assessment of machine learning to polynomial regression in response surface methodology for predicting decolorization efficiency in textile wastewater treatment.

Journal: Chemosphere
PMID:

Abstract

This study investigated the potential of machine learning (ML) as a substitute for polynomial regression in conventional response surface methodology (RSM) for decolorizing textile wastewater via a UV/HO process. While polynomial regression offers limited adaptability, ML models provide superior flexibility in capturing nonlinear responses but are prone to overfitting, particularly with constrained RSM datasets. In this study, we evaluated decision tree (DT), random forest (RF), multilayer perceptron (MLP), and extreme gradient boosting (XGBoost) models with respect to a quadratic regression model. Our observations indicated that the ML models achieved higher R values, demonstrating better adaptability. However, when provided with additional data, the polynomial regression displayed a moderate predictability, whereas MLP and XGBoost exhibited indications of overfitting, while DT and RF remained robust. Both ANalysis Of VAriance (ANOVA) and SHapley Additive exPlanations (SHAP) analyses consistently emphasized the significance of operational factors (HO concentration, reaction time, UV light intensity) in decolorization. The findings underscore the need for cautious validation when substituting ML models in RSM and highlight the complementary value of ML (particularly SHAP analysis) alongside conventional ANOVA for analyzing factor significance. This study offered significant insights into replacing polynomial regression with ML models in RSM.

Authors

  • Jin-Kyu Kang
    Department of Marine Environmental Engineering, Gyeongsang National University, Gyeongsangnam-do, 53064, Republic of Korea.
  • Youn-Jun Lee
    Department of Energy Systems Research, Ajou University, Suwon, 16499, Republic of Korea.
  • Chae-Young Son
    Department of Environmental and Safety Engineering, Ajou University, Suwon, 16499, Republic of Korea.
  • Seong-Jik Park
    Department of Bioresources and Rural System Engineering, Hankyong National University, Anseong, 17579, Republic of Korea. Electronic address: parkseongjik@hknu.ac.kr.
  • Chang-Gu Lee
    Department of Energy Systems Research, Ajou University, Suwon, 16499, Republic of Korea; Department of Environmental and Safety Engineering, Ajou University, Suwon, 16499, Republic of Korea. Electronic address: changgu@ajou.ac.kr.