Optimising wastewater treatment solutions for the removal of contaminants of emerging concern (CECs): a case study for application in India

The aim of this study was to produce optimal wastewater treatment solutions to calculate the removal of different CECs found in developing countries. A new methodology was developed for a decision support tool (WiSDOM), which focuses on producing treatment solutions suited to treating water for reuse to Indian Water Quality Standards. WiSDOM-CEC analyses the removal of CECs through different treatment solutions and was also used to evaluate the performance of each treatment train solution in terms of removal of conventional pollutants using multi-objective optimisation and multi criteria decision analysis. Information was collected on different CECs across different regions of India, and the removal of eighteen different CECs through 42 wastewater treatment unit processes for five different regions of India was analysed. Comparisons between similar categories of CECs, such as non-steroidal anti-inflammatory showed that emerging contaminants all react differently to individual treatment options. For example, the removal of Ibuprofen (IBP) and Naproxen (NPX) varied from >80% and 0%, respectively, for a solution in Karnataka involving sedimentation, submerged aerated filter, ultra-filtration and Nano filtration. In Tamil Nadu results ranged from 36.8% to 72% for Diclofenac, 10.7% to 66.5% for IBP and 0% for NPX.