Recently an article was published by Tracey Reeves at John Hopkins University titled, “Flaw Found in water treatment method”. His article got my utmost attention as I currently work for an engineering company that designs separation units concerning many wastewater treatment applications. To design a complete process, we are presented with a list of contaminants and the required process conditions. The system is proved to work efficiently and achieve the desired removal efficiency of the contaminants until the water quality remains consistent.

Wastewater entering the WWTP contains numerous type of organic and inorganic micropollutants which are considered as trace chemicals, present at concentrations from µg/L to pg/L. WWTP often use methods to oxidize them and turn them into less harmful chemical products, called “transformation products”. If the system fails to operate at the desired process conditions, creating barriers for the reaction or mass transfer to occur, then the likelihood of the undesired product in the effluent stream increases. Also, another factor that plays a major role in the design of water treatment methods is the water quality. Engineers need to know what is coming inside the system to choose the best treatment method for its removal. The latter stresses the need to develop appropriate sampling strategies and effective models that predict the fate of micropollutants in WWTP as the water travels through a treatment stage. One such sampling strategy to quantify the removal of contaminants at each stage of the treatment is fractionated approach.

Nowadays, industries are pressed to abide by many environmental regulations before a chemical process has been put into effect. The Environmental Quality Control has placed a ban on only a few of the many thousand MP’s (micropollutants). This leads to a un-monitored release of MP’s in the receiving water. They must define an effluent target so that the model-based optimizations of MP removal can occur in WWTP. To create awareness and stress on the importance of removal, a composite biological toxicity index should be created for the concentration of individual MP’s throughout thee WWTP.