A PLS model for predicting rejection of trace organic compounds by nanofiltration using treated wastewater as feed

Two studies were performed with a time interval of about a year with different wastewater matrices and age of membranes. For different VRFs, but in the same study, the model produced consistent predicted rejections. For the same VRF, but in the different studies, the regression lines were almost parallel, but with a deviation of about 7% for the predicted values. Most of the compounds were within the 95% prediction interval. The model also proved to be able to predict rejection using data from the literature. This confirms that the predictive PLS model can estimate the rejection albeit, with limitations. Generally the proposed predictive rejection model is most likely valid but the model coefficients need to be determined for each individual WWTP or wastewater reuse facility.