Influence of key operating parameters and bio-fouling on simultaneous desalination of seawater & reduction of organic wastes from petroleum industrial wastewater

Bio-cathode microbial desalination cells are emerging technology that utilizes bioelectric potential from organic matter (petroleum refinery effluent) to enhance the desalination process along with the activity of microalgae (Scenedesmus abundans). In the present work, the system is assumed to be governed by interdependent key process variables such as salt concentration, anolyte concentration, and external resistance. Three different levels of salt concentration (5, 20 and 35 g L-1), anolyte concentration (250, 500 and 750 mg L-1), and external resistance (100, 560 and 1000 ohm) were analysed and optimized by the statistical and probabilistic tool such as Box Behnken design method and Genetic Algorithm to maximize the desalination performance. The optimized parameters such as salt concentration (35 g L-1), anolyte concentration (500 mg L-1), and external resistance (100 ohm) produced maximum desalination efficiency of 59.6%. The model also distinguished the influence of input parameters on the output responses such as significant responses (Salinity, Total dissolved solids, and Electrical conductivity) and non-significant responses (Chemical oxygen demand removal, power density, and algal growth). The model predicted the desalination efficiency with +/- 1.25% error. The high impact of bio-fouling was observed in Anion Exchange Membrane on comparison with Cation Exchange Membrane.

Automated summary

Bio-cathode microbial desalination cells utilize bioelectric potential and microalgae activity to enhance the desalination process. Statistical and probabilistic tools were employed to analyze and optimize key variables such as salt concentration, anolyte concentration, and external resistance, achieving maximum desalination performance. The model predicts desalination efficiency with a +/- 1.25% error.