Proof-of-concept investigation of an integrated multi-effect and forced-circulation adsorption water treatment system

초록

Water scarcity and increasing environmental concerns have intensified interest in developing energy-efficient water treatment and resource recovery technologies. Adsorption water treatment has demonstrated high water recovery as an effective concentration step for mature landfill leachate, contributing to both freshwater production and valuable resource recovery. However, despite its high water recovery potential, adsorption water treatment yields relatively low freshwater production and requires a large footprint compared with other treatment processes, limiting its large-scale applicability. To overcome these constraints, the present study proposes a proof-of-concept of a multi-effect and forced-circulation adsorption water treatment system. The proposed system integrates adsorption water treatment with a multi-effect evaporator to enhance freshwater yield and a forced-circulation separator to ensure stable concentration and crystallization under high-concentration conditions. A thermodynamic model was developed based on systematic adsorption isotherms and kinetic studies of silica gel and applied to pilot-scale system design. Experimental validation under various operating conditions yielded a maximum relative error below 7.5%. The system achieved a maximum specific daily water production of 33 m3/t·d at 65 °C hot water temperature and 4 bar motive steam pressure (152 °C), approximately four times that of the conventional adsorption water treatment system. By integrating medium-grade waste heat (100–400 °C), the specific energy consumption and footprint were reduced by approximately 55.1% and 38.4%, respectively, compared with conventional adsorption water treatment. The findings suggest that the proposed multi-effect and forced-circulation adsorption water treatment system has the potential to improve the energy efficiency and productivity of adsorption-based water treatment systems. wastewater reuse.

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