Separation of COD, Sulphate and Chloride from Pharmaceutical Wastewater using Membrane Integrated System:Transport Modeling towards Scale-Up

Abstract The effluent from the pharmaceutical industries is a serious threat to the environment because of the existence of high chemical oxygen demand, ionic Chloride and Sulphate concentrations. To bring down the pollutant level as per environmental safe discharge regulations, a nanofiltration based semi pilot based system is proposed to recover clean water in continuous mode from pharmaceutical effluent. The experimental results were validated by the newly developed mathematical model, used for the transportation of molecules through nanofiltration membrane. Such mathematical approach was constructed on the basis of Extended Nernst–Planck equation which was further linearized and applied for the simulation. Effects of governing parameters like operating pressure, feed flow rates across membrane surface, constituents of feed solutions, solution pH and operational time on membrane solute rejection and solvent flux were analysed. It was found that the model predicted results corroborated extremely well with the experimental results with less relative error ( 99%) and Willmott-d-index (>98%), generating a steady state clean water flux of 110 L/m2h at 12 bar operating pressure and at a cross flow rate of 750 L/h with more than 98% rejection to active pharmaceutical ingredients, chemical oxygen demand and other toxic molecules. Economic assessment with Scale-up shows that the proposed system is promising in producing clean water at a low cost (US 0.89 $/m3) by purifying pharmaceutical wastewater.