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Membrane-based reverse electrodialysis (RED) can convert the salinity gradient energy between two solutions into electric power without any environmental impact. Regarding the practical application of the RED process using natural seawater and river water, the RED performance depends on the climate (temperature). In this study, we have evaluated the effect of the feed solution temperature on the resulting RED performance using two types of pilot-scale RED stacks consisting of 200 cell pairs having a total effective membrane area of 40 m2 with different intermediate distances (200 µm and 600 µm). The temperature dependence of the resistance of the solution compartment and membrane, open circuit voltage (OCV), maximum gross power output, pumping energy, and subsequent net power output of the system was individually evaluated. Increasing the temperature shows a positive influence on all the factors studied, and interesting linear relationships were obtained in all the cases, which allowed us to provide simple empirical equations to predict the resulting performance. Furthermore, the temperature dependence was strongly affected by the experimental conditions, such as the flow rate and type of stack, especially in the case of the pilot-scale stack.

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Conventional wastewater treatment methods are not efficient in treating wastewaters contaminated with volatile hydrocarbons such as benzene, toluene and xylenes (BTX). The aim of this study is to enhance the efficiency of an extractive membrane bioreactor (EMBR) in treating toluene contaminated wastewater by usage of pure culture of Alcaligenese faecalis. Toluene was used as a model of toxic contaminant because of its wide presence in wastewaters contaminated with petrol derivatives. The Haldane kinetic model adequately described the dynamic behavior of the toluene biodegradation by the strain of A. faecalis over a wide range of initial toluene concentrations (50-1,000 mg L(-1)) with kinetic constants micro(max) = 0.066 h(-1), k(s) = 91.7 mg/L and k(I) = 278.2. Overall mass transfer coefficient has been measured and described as resistance in the series model. No biofilm formed on the exterior surface of the membrane; however in previous works the layer of the biofilm on the exterior surface of the membrane acts as a mass transfer resistance. A mathematical model was developed to predict the pollutant concentration profile along the tube side of the membrane modules.

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