Simulation of landfill leachate treatment systems involving self-designed disk tube reverse osmosis (DTRO) model integrated with mechanical vapor recompression (MVR)

Abstract

Four landfill leachate treatment systems involving self-designed disk tube reverse osmosis (DTRO) module integrated with mechanical vapor recompression (MVR) were established in Aspen Plus. To assess the treatment efficiency and the economic feasibility of landfill leachate treatment techniques, simulation of leachate treatment by four systems were conducted, and the corresponding recovery rate Y, removal rate Rt, energy consumption and operating cost were obtained. Results indicate that for the two-stage DTRO system, the optimal operational pressures in compliance with emission standards are 5.6 MPa in the first stage and 3.5 MPa in the second stage. Adding an MVR system to further treat the membrane concentrate (MC) can greatly reduce the pollutant recharge and the energy consumption of the DTRO system. When Y in MVR is not strictly required, the single-stage MVR system is the most energy-saving one. When a high Y (≥80 %) is required, the series double-stage MVR system affords the highest energy-efficiency, offering a 3.14 % lower operating cost, a 3.27 % lower unit COD removal cost, and a 7.29 % lower unit water production cost as compared to the single-stage MVR system.