A Review of Upcycling Technologies for Functional Materials Used in Water Treatment Using Waste-Derived Ceramic Precursors

Abstract

As climate change, urbanization, and industrialization intensify, the demand for sustainable and high-performance water treatment materials is increasing. At the same time, large amounts of agricultural, marine, livestock, and industrial wastes, including rice husk, biomass ash, seashells, fish bones, eggshells, fly ash, and blast furnace slag, are often disposed of or reused in low-value applications, causing additional environmental burdens. This review summarizes recent advances in converting waste-derived resources into ceramic precursors and upcycling them into functional materials for water treatment. Silica-, calcium-, and aluminosilicate-based precursors are compared in terms of chemical composition, phase characteristics, impurities, compositional variability, pretreatment, and conversion processes. Their applications as membrane supports, ceramic membranes, porous adsorbents, and geopolymer-based materials are also discussed. The reviewed studies show that material performance is strongly influenced by amorphous/crystalline phases, glassy structure, impurity distribution, thermal history, and forming or sintering conditions, rather than by major component content alone. Membrane-type materials require controlled pore structures and mechanical stability, while adsorbent-type materials depend on active surfaces and reactive phases. Remaining challenges include compositional heterogeneity, impurity control, high-temperature processing costs, long-term stability, leaching risks, and real wastewater applicability. Future research should focus on precursor standardization, low-energy processing, hybrid structural design, and long-term practical evaluation to promote the commercialization of waste-derived ceramic materials for water treatment.