Spent coffee ground (SCG) is a main byproduct of the coffee industry and has been revalorized as a source of value-added products. The direct application of SCG as a soil amendment has drawn much attention in recent years as a more environmentally sustainable option. In this work, a comprehensive review of studies on the agricultural application of SCG is presented. The aims of this review were (1) to summarize the impacts of raw SCG on soil health and to identify the factors limiting its direct soil use, (2) to outline methods that are often used to upgrade SCG for soil application, and (3) to highlight the potential of SCG and its derivatives as a biocontrol agent and biofertilizer. The results indicate that raw SCG could improve certain soil health attributes, but plant growth is often limited owing to its phytotoxicity and induced N immobilization. To eliminate phytotoxicity, composting, vermicomposting, and thermochemical treatments have been employed but to a limited extent. SCG and its derivatives may be used as biocontrol agents for weeds, soil-borne pathogens, and pests. Novel bio-organic fertilizers based on SCG have also been developed. Future research should focus on the long-term effects of SCG and its derivatives as soil amendments under real scenarios and the underlying mechanisms, particularly the soil–plant–microorganism interactions.

Adsorptive atmospheric water harvesting systems (AWHs) represent an innovative approach to collecting freshwater resources from the atmosphere, with a hygroscopic agent at their core. This method has garnered significant attention due to its broad applicability, strong recycling capacity, and sustainability. It is being positioned as a key technology to address global freshwater scarcity. The core agent’s hygroscopic properties play a crucial role in determining the performance of the AWHs. This article provides a comprehensive review of the latest advancements in hygroscopic agents, including their adsorption mechanisms and classifications. This study of hygroscopic agents analyzes the performance and characteristics of relevant porous material composite polymer composites and plant composites. It also evaluates the design and preparation of these materials. Aiming at the problems of low moisture adsorption and desorption difficulty of the hygroscopic agent, the factors affecting the water vapor adsorption performance and the method of enhancing the hygroscopic performance of the material are summarized and put forward. For the effect of hygroscopic agents on the volume of water catchment devices, the difference in density before and after hygroscopicity is proposed as part of the evaluation criteria. Moisture absorption per unit volume is added as a performance evaluation criterion to assess the effect of hygroscopic agents on the volume of water collection equipment. The article identifies areas that require further research and development for moisture absorbers, exploring their potential applications in other fields and anticipating the future development direction and opportunities of moisture-absorbing materials. The goal is to promote the early realization of adsorptive atmospheric water harvesting technology for large-scale industrial applications.

Ficus pumila L. has been used as a functional plant for a long time in East Asia, especially its fruits, as a dietary component in Japan and parts of China. A series of bioactive compounds, including phenolic acids, flavonoids, terpenoids, alcohols, and steroids, have been extracted from the stems, leaves, flowers, and fruits of Ficus pumila L. Accumulated studies have demonstrated that Ficus pumila L. has multiple therapeutic activities, including antioxidant, anti-inflammatory, antibacterial, antitumor, hypoglycemic, and cardiovascular protective effects. Moreover, Ficus pumila L. has extensive applications, such as in the food industry and ecological city construction. Herein, we summarize the latest knowledge about the bioactive compounds and therapeutic activities of Ficus pumila L., and its applications in the food industry and ecological city construction are also discussed. We hope that this comprehensive review can attract more attention to Ficus pumila L. and be helpful for its further applications.

In response to the challenge of resource recycling, this review investigates the removal of phytotoxicity from agricultural waste for its application as a growing media component. Agricultural waste typically exhibits high phytotoxicity due to the presence of substances such as phenols, organic acids, ammonia, nitrogen, and heavy metals. These substances hinder seed germination and plant growth, posing a significant barrier to the use of agricultural waste as a growing media component. Thus, it is imperative to mitigate or eliminate phytotoxicity before effectively utilizing agricultural waste. This review rigorously analyzes an extensive array of recent studies, scrutinizing diverse technologies for the mitigation of phytotoxicity in agricultural wastes. The methods investigated include the four most common methods—composting, heat treatment, washing, and aging, and a recently introduced method, ammonium incubation. Each method was assessed considering its underlying principles, effects in application, and respective advantages and disadvantages. This review suggests that successful phytotoxicity mitigation in agricultural waste hinges on reducing the content or activity of phytotoxic substances. Moreover, this study emphasizes that future phytotoxicity mitigation efforts should aim for economic efficiency while maximizing the preservation of the original material volume and weight. This study offers insightful guidance for technical professionals aiming to mitigate the phytotoxicity of agricultural waste, thereby fostering sustainable agricultural practices.

Biostimulants can enhance horticultural crop production. However, their application in hydroponically grown lettuce is still limited, and information regarding their relative efficacy is lacking. A greenhouse trial was conducted to address this issue. Five nutrient solution treatments were evaluated on two lettuce cultivars: butterhead and red oak-leaf. The treatments included a half-strength modified Hoagland solution (Hs-H); a full-strength modified Hoagland solution (Fs-H); and Hs-H supplemented with 50 mg L⁻¹ fulvic acid (FA), 334 mg L⁻¹ seaweed extract (SE), or 5 mL L⁻¹ gamma polyglutamic acid (PGA). The results indicated that the shoot biomass observed after biostimulant supplementation was significantly greater than or comparable to that observed with Fs-H. Nutrient solutions supplemented with SE and PGA led to a greater increase in the root biomass than that realized with Hs-H and Fs-H treatments. The Hs-H + FA treatment resulted in the lowest root-to-shoot ratio on a fresh weight basis among all treatments. The nitrate concentration in the shoot was significantly reduced following biostimulant supplementation compared to that realized with Fs-H and Hs-H treatments. Nutrient solutions supplemented with SE and PGA also decreased soluble sugar concentrations compared to that achieved using Hs-H and Fs-H treatments. FA and SE improved nutrient uptake for both cultivars, but PGA had a minimal effect on nutrient uptake. The two cultivars varied in their responses to biostimulant supplementation with regard to biomass, quality traits, and nutrient uptake. This study supports using fulvic acid and seaweed extract, rather than γ-PGA, in hydroponic lettuce production systems.

Bismuth-based photocatalytic materials have been widely used in the field of photocatalysis in recent years due to their unique layered structure. However, single bismuth-based photocatalytic materials are greatly limited in their photocatalytic performance due to their poor response to visible light and easy recombination of photogenerated charges. At present, constructing semiconductor heterojunctions is an effective modification method that improves quantum efficiency by promoting the separation of photogenerated electrons and holes. In this study, the successful preparation of an In₂O₃/Bi₂WO₆ (In₂O₃/BWO) II-type semiconductor heterojunction composite material was achieved. XRD characterization was performed to conduct a phase analysis of the samples, SEM and TEM characterization for a morphology analysis of the samples, and DRS and XPS testing for optical property and elemental valence state analyses of the samples. In the II-type semiconductor junction system, photogenerated electrons (e⁻) on the In₂O₃ conduction band (CB) migrate to the BWO CB, while holes (h⁺) on the BWO valence band (VB) transfer to the In₂O₃ VB, promoting the separation of photoinduced charges, raising the quantum efficiency. When the molar ratio of In₂O₃/BWO is 2:6, the photocatalytic degradation degree of rhodamine B (RhB) is 59.4% (44.0% for BWO) after 60 min illumination, showing the best photocatalytic activity. After four cycles, the degradation degree of the sample was 54.3%, which is 91.4% of that of the first photocatalytic degradation experiment, indicating that the sample has good reusability. The XRD results of 2:6 In₂O₃/BWO before and after the cyclic experiments show that the positions and intensities of its diffraction peaks did not change significantly, indicating excellent structural stability. The active species experiment results imply that h⁺ is the primary species. Additionally, this study proposes a mechanism for the separation, migration, and photocatalysis of photoinduced charges in II-type semiconductor junctions.