## 1 _Applied sciences_
### Editorial
The traditional treatments of simple stacking and landfills not only had low value added but also wasted valuable space resources. At the same time, in the manufacturing process of buildings, people are increasingly interested in reducing energy consumption and minimizing negative effects on the environment. Therefore, many researchers are working hard to employ these solid wastes as sustainable building materials for green buildings and components. Spherical fly ash is a typical industrial solid waste from coal combustion. The excellent pozzolanic activity of fly ash enables it to partially substitute Portland cement and to produce low-carbon concrete [7; 8]. Moreover, fly ash can also be an alternative to non-renewable laterite soil in the manufacture of unfired bricks [9]. [PERSON] et al. proved the feasibility of preparing new road base material via iron tailing (mixing solid residues left after valuable minerals have been extracted from the ones) with natural soil and adding a certain amount of cement and soil agent [10]. It is worth noting that municipal waste usually contain high levels of organic substances, which is different from industrial waste. An effective and popular pre-treatment is incineration before use as a building material. [PERSON] and [PERSON] [11] used the bottom ash of municipal solid waste in combination with other types of industrial waste to produce artificial aggregates with a cold-bonding pelletizing technique. [PERSON] et al. [12] used the incinerator bottom ash of municipal waste and waste glass to produce foaming ceramics with impressive thermal properties and mechanical properties. The above studies have shown that both industrial and municipal waste have great potential as building materials, and the promotion of solid waste is key to achieving sustainable construction. For wastewater and exhaust gas, which contain heavy metal ions and other harmful substances, the key to treatment is the removal of harmful pollutants and contaminants before they are discharged into nature. Compared to traditional treatment materials such as metal oxides, clays, mesoporous silicas, and zeolites, byproducts derived from agricultural waste have dual environmental significance: the effective removal of pollutants and the high-value utilization of agricultural wastes. [PERSON] et al. [13] synthesized a green, efficient, and stable Pd@biochar nanocatalyst from corn husk wastes, which electrochemically reduces hazardous Cr (VI) in industrial wastewater to less toxic Cr (III). [PERSON] et al. [14] compared the performance of carbon-based adsorbents prepared via carbonization and pyrolysis for removing metal cations and found that the adsorbents obtained via pyrolysis exhibited the highest adsorption capacity. [PERSON] et al. [15] used modified rice husk char to remove gaseous mercury, SO\({}_{2}\), and NO of exhaust gas, and they found that the rice husk char adsorbent impregnated with ammonium bromide has excellent mercury removal performance. In addition to agricultural waste, protein nanofibers, carbon nanotubes, graphene, and other materials can also purify wastewater and exhaust gas. The challenges involved in developing materials for the removal of hazardous components include the need to reduce manufacturing costs, simplify the synthesis pathway, and introduce appropriate manufacturing and modification strategies to tailor absorption properties. Waste is usually composed of several complex components that vary in composition and proportions from batch to batch. Improper treatment may cause great regional ecological environment risks and jeopardize human life and health. Traditional solid waste source identification methods (i.e., manual identification and X-ray diffraction) can quantitatively or qualitatively accurately determine the chemical composition of solid waste materials but typically requires skilled technicians or expensive equipment [16]. Therefore, effective waste collection, identification, and treatment are crucial for effective waste management.