Assessing the Feasibility of Sustainable Materials to Boost the Sorption of Pharmaceutical Active Compounds When Included in Reactive Barriers in Soil Aquifer Treatment for Water Reuse

We evaluated the feasibility of five sustainable materials (clay, zeolite, biochar, compost, and woodchips) to be included in a reactive barrier intended to improve the removal of pharmaceutical active compounds (PhACs) during soil aquifer treatment (SAT). The potential of the five materials to sorb PhACs was assessed and compared to sand capacity through batch experiments. Materials with high organic carbon content (biochar, compost, and woodchips) exhibited a greater capacity to sorb PhACs than materials with a low organic carbon content (clay and zeolite). The ion speciation of the molecules is a major parameter controlling the fate and transport of PhACs during SAT operations. Anionic species are the ones with the highest risk of reaching the aquifer since they are generally less sorbed compared to cationic and neutral species. Experimental parameters such as contact time, solid:water ratio, and grain size had no a significant effect on the sorption of PhACs in the studied materials. The incorporation of biochar, compost, and/or woodchips into reactive barriers will promote the sorption of PhACs and will boost the ability of the SAT system to improve the quality of the recharged water.