Drinking water was produced from Marmara seawater by membrane distillation (MD). The best operating conditions were determined by batch experiments as: 0.45 μm PTFE, 30°C distillate temperature and temperature difference, and 270–360 L/h cross‐flow rates in feed‐distillate. Seawater desalination was carried out with 99.93% solute rejection and 17.2 L/m2h permeate flux in 66% concentration ratio by lab‐scale pilot system. Since the desalinated water contained no organic carbon, turbidity, and nitrate, it seemed to be very suitable for immediate service with quality of 7.3 pH, clear, odor‐free, 76.0 µS/cm, 47.1 mg TDS/L, <0.001 color, and 0.01 mg boron/L. The product water lacked of vital cations, especially Na+, K+, Ca2+, Mg2+ that are essentials for promoting osmotic balanced body liquid and healthy development. A holistic management approach towards satisfying specific water quality requirements in direct service of MD effluents to human consumption was proposed that jointly included in injecting into urban potable water, adding appropriate chemicals into the effluent, and mixing effluents with raw or concentrated seawater (1:250/1:1000 for Marmara seawater) or brackish natural waters under hygienic precautions.
Part of the book: Desalination
In the recent past years, micropollutants that are pharmaceutically active compounds (PhACs) have been used extensively and have been discovered in raw sewage, wastewater treatment plants, effluents, surface, and groundwater with concentrations from ng/L to several μg/L. Even though many of these compounds are still not determined online, monitoring technology improvements progressed. Today’s wastewater treatment plants are not constructed to remove these micropollutants yet. Conventional activated sludge processes are used in the treatment of municipal wastewater but are not specifically designed for the removal of micropollutants. The remaining pharmaceuticals mix into surface waters. At that stage, they can adversely affect the aquatic environment and may cause issues for drinking water production. As the conventional methods are insufficient for removing the micropollutants, other alternative treatment methods can be applied such as coagulation-flocculation, activated carbon adsorption (powdered activated carbon and granular activated carbon), advanced oxidation processes, membrane processes, and membrane bioreactor. It has been observed that membrane bioreactor (MBR) can achieve higher and more consistent micropollutants removal. The removal of micropollutants is based on physicochemical properties of micropollutants and the conditions of treatment. Due to recent technical innovations and cost reductions of the actual membranes, the membrane bioreactor takes attention. In this study, membrane bioreactor experiments for micropollutants in drinking use, wastewater, and surface waters were investigated in detail based on literature investigations, and the feasibility of this method was evaluated.
Part of the book: Wastewater and Water Quality