Development of a predictive environmental model for wastewater from industrial paper production using multivariate analysis technique

Abstract

Wastewater from papermaking provides an important environmental challenge. Improved understanding of industrial paper production through the set of material inputs used and their interactions with the process itaelf may lead to the ability to predict the change in wastewater loadings. It should lead as well to the root causes of wastweater load gencration that should be managed in order to prevent upsttien of the wastewater treatment system. The identification and derivation of these relationships between material supplied and wastweater load is the focus of this work. The mathematical multivariate technique consisting of factor analysis (FA) and multiple regression analysis (MRA) was used to develop a model that not only characterizes the interrelationships omong the material input variables (pulps, chemicals, water, and electric power) but also leads to the prediction of the relationships between wastewater generation and production conditions. The models were developed based on measurable data obtained form a papermaking facility during January, 2001 to September, 2002 for the three major classes of paper products from the study site (Gypsum face liner board, GF; Gypsum back liner board, GB; and Duplex coated board, DP) It was found that the contaminants from the feed stock, poor control of addition of chemicals and poor retention of fines and filler, and too frequent change over of paper grade including scheduling of machine operations between paper mackhine and wastepaper plant contribute greatly to high wastewater loads, namely suspended solids, total dissolved solids, biological oxygen demand, and chemical oxygen demand. Various management responses for wastewater control were suggested based on the findings from this model development.