Higher Water Yield Research Articles

Forest Management under Climate Change: A Decision Analysis of Thinning Interventions for Water Services and Biomass in a Norway Spruce Stand in South Germany

Climate change is producing threats to forests’ capacity of regulating water regimes. Therefore, thinning strategies can be applied to mitigate climate change impacts more efficiently by providing more spaces for trees to utilize resources e.g., water and nutrients. This study examined the effects of different thinning intensities and intervals on water characteristics and biomass growth of a 75-year-old Norway spruce (Picea abies) stand in the Black Forest, Germany. Here we used a water and management sensitive update of the process-based forest growth model 3PG, 3PG-Hydro. We applied light (10%), moderate (30%), and heavy thinning (50% intensity) in the interval of 10, 25, and 50 years of the management period. We simulated growth with climate change scenario RCP 8.5 data from 1995 to 2065. We analyzed the effects of the different thinning regimens on biomass, evapotranspiration as well as water yield. Thinning intensity and interval as well as their interaction have significant influence on production of stand biomass and water yield for all thinning regimes applied (p < 0.05). However, there is no significant difference (p > 0.05) in accumulated biomass (thinned biomass added to the stand biomass) between the applied thinning regimes. Light thinning in a long interval (50 years) produced highest stand biomass among the applied thinning regimes. Furthermore, the prediction showed that accumulated water yield increased with increasing thinning intensity. Our study concludes that repeated moderate thinning at intermediate intervals results in a high water yield without losing biomass production.

Experimental and Theoretical Assessment of Water Sorbent Kinetics.

The kinetics of water adsorption in powder sorbent layers are important to design a scaled-up atmospheric water capture device. Herein, the adsorption kinetics of three sorbents, a chromium (Cr)-based metal-organic framework (Cr-MIL-101), a carbon-based material (nanoporous sponges/NPS), and silica gel, have been tested experimentally, using powder layers ranging from ∼0 to 7.5 mm in thickness, in a custom-made calibrated environmental chamber cycling from 5 to 95% RH at 30 °C. A mass and energy transfer model was applied onto the experimental curves to better understand the contribution of key parameters (maximum water uptake, kinetics of single particles, layer open porosity, and particle size distribution). Open porosity (i.e., the void-to-particle ratio in the sorbent layer) shows the highest influence to improve the kinetics. Converting the sorbent kinetics data into a daily yield of captured water demonstrated (i) the existence of an optimal open porosity for each sorbent, (ii) that thinner layers with moderate open porosity performed respectively better than thicker layers with high open porosity, and (iii) that high maximum water uptake and fast single-particle kinetics are not necessarily predictive of high daily water yield.

Biomass:polystyrene co-pyrolysis coupled with metal-modified zeolite catalysis for liquid fuel and chemical production

Biomass and waste polystyrene plastic (ratio 1:1) were co-pyrolysed followed by catalysis in a two-stage fixed bed reactor system to produce upgraded bio-oils for production of liquid fuel and aromatic chemicals. The catalysts investigated were ZSM-5 impregnated with different metals, Ga, Co, Cu, Fe and Ni to determine their influence on bio-oil upgrading. The results showed that the different added metals had a different impact on the yield and composition of the product oils and gases. Deoxygenation of the bio-oils was mainly via formation of CO2 and CO via decarboxylation and decarbonylation with the Ni–ZSM-5 and Co–ZSM-5 catalysts whereas higher water yield and lower CO2 and CO was obtained with the ZSM-5, Ga–ZSM-5, Cu–ZSM-5 and Fe–ZSM-5 catalysts suggesting hydrodeoxygenation was dominant. Compared to the unmodified ZSM-5, the yield of single-ring aromatic compounds in the product oil was increased for the Co–ZSM-5, Cu–ZSM-5, Fe–ZSM-5 and Ni–ZSM-5 catalysts. However, for the Ga–ZSM-5 catalyst, single-ring aromatic compounds were reduced, but the highest yield of polycyclic aromatic hydrocarbons was produced. A higher biomass to polystyrene ratio (4:1) resulted in a markedly lower oil yield with a consequent increased yield of gas.

Territorially ecological restoration zoning and optimization strategy in Guyuan City of Ningxia, China: Based on the balance of ecosystem service supply and demand

Scientifically identifying the territorially ecological restoration zoning is a vital prerequisite for implementing ecological restoration projects and enhancing environmental quality. Based on remote sensing data, we syste-matically assessed supply and demand for ecosystem service and their relationship in Guyuan City, China by using the InVEST model, coordination degree model, and spatial autocorrelation analysis. We carried out territorially ecological restoration zoning by coupling the ecosystem service supply and demand. Furthermore, the corresponding optimization strategies were put forward according to the regional characteristics of natural resources and socio-economic development. The results showed that the areas with high water yield, carbon storage, soil conservation and habitat quality were mainly located in the southern part of Guyuan City. The areas with high population density, economic development level and high ecological demand were mainly located in the central urban area and the location towns of the county government. The spatial mismatch of supply and demand for ecosystem services in Guyuan City was dominant, as indicated by the fact that the areas with high ecological supply having low ecological demand and low ecological supply having high ecological demand. The average coordination index was 0.5, indicating that the relationship between ecological supply and ecological demand was basically coordinated. Based on the diffe-rences between supply and demand of ecosystem services and regional natural geographical pattern, the administrative township units in Guyuan could be classified into six ecological restoration zonings: key ecological restoration area, potential ecological restoration area, ecological economic reconstruction area, characteristic agricultural development area, ecological core protection area, and ecological industry construction area. Different management strategies were proposed to provide scientific support for ecological restoration.

Indium-Mediated Reformatsky Reaction of Iododifluoro Ketones with Aldehydes: Preparation of α,α-Difluoro-β-hydroxyketone Derivatives in Water

AbstractIndium can efficiently mediate the Reformatsky reaction of iododifluoroacetylketones with aldehydes to afford the corresponding α,α-difluoro-β-hydroxyketones in high yield in pure water This reaction has excellent substrate suitability and functional group selectivity and provides an efficient approach for the synthesis of bioactive molecules containing the α,α-difluoro-β-hydroxyketone pharmacophore.

«Зелені» та соціальні інвестиції як інструмент забезпечення водної безпеки населених пунктів України.

The article suggests a scientific base for using «green» and social bonds to solve environmental problems in water supply systems; numerous facts that encourage using social investment tools in the high-yield water sector are revealed. In particular, preconditions for intensifying economic activity in the construction field are appearing, as it is obvious that a constant threat of shelling faced by our country changes the requirements for all living conditions, and water supply systems as well. Emphasis is placed on the assumption that if the green bond market in Ukraine is implemented and developed, it will help to create a multiplier for attracting funds to implement various environmental projects and to increase guarantees for investors injecting funds in such projects. Both negative and positive factors of using social investment to modernize water supply systems in Ukraine are identified. It is concluded that it is necessary to intensify the development of the regulatory framework for «green» and social investment in order to offset the trend of debt accumulation among enterprises operating water supply systems in Ukrainian settlements, so that such enterprises could become monopolists in the market.

Modeling the supply, demand, and stress of water resources using ecosystem services concept in Sirvan River Basin (Kurdistan-Iran)

AbstractWater resources modeling can provide valuable information to planners. In this respect, water yield is an ecosystem service with significant roles in the sustainability of societies and ecosystems. The present study aimed to model the supply and demand of water resources and identify their scarcity and stress in the Sirvan river basin. For this purpose, we employed the ecosystem services concept as new thinking in earth sciences and using soil, climate, and land use data. Firstly, the Landsat satellite images of 2019 were prepared after different corrections, and the land use map was produced. Then, precipitation, evapotranspiration, root restricting layer depth, and evapotranspiration coefficients of the land uses were prepared and modeled in the InVEST 3.8.9 software environment. The findings indicated that the water yield in this river basin is 5,381 million m3, with sub-basins 5, 11, and 1 having the highest water yield per year and sub-basin 2 having the lowest water yield. Moreover, sub-basins 5 and 11 had the highest water consumption. Based on the estimated water scarcity and stress index, sub-basin 8 has experienced water scarcity and sub-basin 4 water stress. We conclude that applying the InVEST Water Yield model to assess water resource status at the basin and sub-basins level can provide suitable results for planning.

Assessment of coordinative relationship between comprehensive ecosystem service and urbanization: A case study of Yangtze River Delta urban Agglomerations, China

Understanding the coordinative relationship between urbanization and ecosystem services (ESs) has a great significance in sustainable development in urban agglomeration. In this paper, InVEST model was firstly used to assess the spatio-temporal evaluation of four types of ESs (water yield, carbon storage, soil retention and nitrogen export) in the Yangtze River Delta Urban Agglomerations (YRDUA) of China from 2000 to 2020. Then comprehensive evaluation index system of urbanization was established from the multi-dimensions of economy, population and land to analyze the urbanization level during the study period. Finally, a comprehensive ecosystem service (CES) index was developed to explore the coordinative relationship between ESs and urbanization by using coupling coordinating degree model (CCDM). The results revealed that: 1) Urbanization has led to greatly land use/ land cover change, which caused the degradation of carbon storage and water purification, and the improvement of water yield and soil retention. The higher water yield and nitrogen export mainly clustered around urban areas, while higher carbon storage and soil retention were distributed in forest-rich cities in the Zhejiang and the southern of Anhui. There were positive correlations between different ESs. And the CES of cities in the YRDUA had deteriorated during the study period. 2) The urbanization levels of almost all cities showed an overall upward trend, with Shanghai the highest urbanization, followed by Nanjing and Hangzhou, and rapid urban expansion mainly occurred in developed urban areas. 3) The coordinative relationship between CES and urbanization in the YRDUA was always in mild incoordination, showing an obvious spatial distribution pattern of “higher in the south, but lower in the north”. The coordinative relationship between CES and urbanization in most cities in the north of YRDUA has not achieved coordination development, with the state of moderate or mild incoordination, while the cities in the south has attained coordination development, with the state of primary or even superior coordination. Therefore, our study suggested that differentiated urban space management and control policies should be made for the YRDUA to improve the overall coordinative relationship between CES and urbanization.

Pine savanna restoration on agricultural landscapes: The path back to native savanna ecosystem services

Restoration of savanna ecosystems within their historic range is expected to increase provision of ecosystem services to resident human populations. However, the benefits of restoration depend on the degree to which ecosystems and their services can be restored, the rate of restoration of particular services, and tradeoffs in services between restored ecosystems and other common land uses. We use a chronosequence approach to infer multi-decadal changes in ecosystem services under management aimed at restoring fire-dependent pine savannas, including the use of frequent prescribed fire, following abandonment of row-crop agriculture in the southeastern U.S. We compare ecosystem services between restored pine savannas of different ages and reference pine savannas as well as other common land uses (row-crop agriculture, improved pasture, pine plantation, unmanaged forest). Our results suggest that restoring pine savannas results in many improvements to ecosystem services, including increases in plant species richness, perennial grass cover, tree biomass, total ecosystem carbon, soil carbon and C:N, reductions in soil bulk density and predicted erosion and sedimentation, shifts from soil fungal pathogens to fungal symbionts, and changes in soil chemistry toward reference pine savanna conditions. However, the rate of improvement varies widely among services from a few years to decades. Compared to row-crop agriculture and improved pasture, restored savannas have lower erosion, soil bulk density, and soil pathogens and a higher percentage of mycorrhizal fungi and ecosystem carbon storage. Compared to pine plantations and unmanaged forests, restored pine savannas have lower fire-prone fuel loads and higher water yield and bee pollinator abundance. Our results indicate that restoration of pine savanna using frequent fire provides a broad suite of ecosystem services that increase the landscape's overall resilience to climate change. These results are likely relevant to other savannas dominated by perennial vegetation and maintained with frequent fire.

Control of differential diagenesis of tight sandstone reservoirs on the gas–water distribution: A case study on the Upper Paleozoic He 8 Member in the northern Tianhuan depression of the Ordos Basin

The sandstone reservoirs in the Upper Paleozoic He 8 Member in the northern Tianhuan depression of the Ordos Basin are vastly different and feature particularly complex gas–water distributions. Scanning electron microscopy, fluorescence, Raman spectroscopy inclusions, relative permeability analysis, and nuclear magnetic resonance were utilized in this study based on core data, identification statistics, and various thin-section microscope measurements. Samples from the Upper Paleozoic He 8 Member in the northern Tianhuan depression were collected to study the characteristics of reservoir heterogeneity and gas–water distribution, which were controlled by differential diagenesis. The results indicate that compaction and dissolution are the two most important factors controlling reservoir heterogeneity. Large differences in diagenesis–accumulation sequences and pore structure characteristics affect reservoir wettability, irreducible water saturation, and gas displacement efficiency, thereby controlling the gas–water distribution. The He 8 Member is a gas reservoir that is densified because of accumulation. Reservoirs can be divided into three types based on the relationship between diagenetic facies and gas–water distribution. Type I is characterized by weak compaction, precipitate or altered kaolinite cementation, strong dissolution of diagenetic facies, and high porosity and permeability. This type is dominated by grain-mold pores and intergranular dissolution pores and produces gas reservoirs with high gas yield. Type II is characterized by medium-strength compaction, altered kaolinite or chlorite cementation, weak dissolution of diagenetic facies, and medium porosity and permeability. This type is dominated by residual intergranular pores, a few residual intergranular pores, and dispersed dissolution pores, producing gas reservoirs with low gas yield. Type III is characterized by medium-strength compaction, altered kaolinite cementation, and medium-strength dissolution of diagenetic facies. This type is dominated by kaolinite intercrystal pores and dispersed dissolution pores, producing gas reservoirs with high water yield.

Spatial heterogeneity of ecosystem services and their trade-offs in the Hengduan Mountain region, Southwest China

Spatial heterogeneity, which is one of the basic characteristics of ecological and geographical elements, is substantial in mountainous areas. Research on ecosystem services (ESs) increasingly considers spatial heterogeneity in environmental management-related decision-making. This study quantified the dominant ESs and ES trade-offs for the Hengduan Mountain region in Southwest China. The spatial heterogeneity was analyzed by introducing gradients of elevation, vegetation cover, and land cover. The results showed that, in addition to inverse changes in ESs, ES change rates were important for ES trade-offs. Further, land cover was identified as the main factor influencing the spatial heterogeneity of the majority of ES trade-offs. Specifically, the net primary productivity (NPP), carbon storage (C), and habitat quality (HQ) all showed inverted U-shaped trends along the elevation gradient and HQ increased thereafter, water yield (WY) presented an overall decline but increased in high-altitude areas, and soil conservation (SC) exhibited a fluctuating trend. The change rate of SC was slower than that of NPP, C, and HQ, which led to changes in the trade-offs between SC and other ESs along the elevation gradient. The higher WY in built-up land and higher HQ in forests were the main reasons for higher trade-offs. The low trade-off for unused land was attributed to the limited levels of several ESs. Along the vegetation gradient, WY first decreased then increased, whereas all other services showed increasing trends. The limited promotion effect of vegetation on SC was the primary reason for increased trade-offs. Therefore, more attention should be devoted to improving SC via engineering measures. Furthermore, vegetation degradation on unused land should be prevented to maintain SC and reduce the trade-offs among ESs.

Study on the process of simultaneous desalting and boron removal from seawater

Two new combined technologies, reverse osmosis (RO) + electrodeionization (EDI) and reverse osmosis (RO) + ion exchange (IE), were studied for simultaneous desalination and boron removal of seawater. The results show that the RO system has excellent desalination performance under the experimental conditions, and can provide stable desalination rate for the subsequent processes of the two combined schemes. The boron concentration in water has little effect on the desalination rate of RO system, and the boron removal rate of RO system is between 47% and 50%, which provides a good early treatment for the subsequent process. The blank experiment shows that the salinity has little effect on the boron removal rate of RO-EDI equipment, and the boron removal rate is more than 93%, which has excellent and stable boron removal performance, but the water yield of RO-EDI equipment is low (less than 60%). The RO-IE system has a high water yield (> 70%), but the equipment has poor adaptability to influent boron concentration and salinity. The results of effluent water show that the boron concentration of raw water by RO-EDI combined process can be adapted to a wider range, and the influence of salinity is less. Considering comprehensively, RO-EDI process has more advantages and broad application prospects.

Photovoltaic-multistage desalination of hypersaline waters for simultaneous electricity, water and salt harvesting via automatic rinsing

Passive solar multistage stiller with heat localization has shown great potential in wastewater purification and seawater desalination due to its ultrahigh solar-to-vapor conversion ability. However, achieving high water yield with long stability remains a great challenge because of the salt clog. Here, we demonstrated a photovoltaic-multistage stiller (PV-MS) with excellent salt-rejecting ability, even when dealing with hypersaline waters. The solar energy is converted to electricity and heat by a commercial photovoltaic panel and the waste heat subsequently drives the passive multistage stiller. The capillary wick and the crystalized salt at the edge of the wick form a siphon channel and the crystalized salt was rinsed intermittently by the siphon action, thereby avoiding salt clog. Thus, we achieved simultaneous electricity, water and salt collection in the integrated photovoltaic-thermal utilization system with long-term stability. Under one sun, the water yield of a five-stage stiller was about 1.17 kg m −2 h −1 with electricity output of 97 W m −2 and salt collection of 1.02 kg m −2 d −1 when desalinating hypersaline NaCl solution of 170 g/L. We envision that such a technology can help full use of solar energy in desalinating high-salinity waters with long term stability and is greatly promising at the water-energy nexus. We presented a photovoltaic-multistage stiller system with long term stability via manipulating salt crystallization for desalinating hypersaline waters and electricity generation. • Photovoltaic-multistage stiller (PV-MS) with excellent salt-rejecting ability was developed. • The crystalized salt was rinsed intermittently by the siphon action, thereby avoiding salt clog in stiller part. • Desalinating of hypersaline NaCl solution of 170 g/L with passive solar multistage stiller was demonstrated. • PV-MS could harvest electricity, water and salt simultaneously with high stability.

High‐Yield and Low‐Cost Solar Water Purification via Hydrogel‐Based Membrane Distillation

AbstractAs an eco‐friendly means, solar water purification has attracted substantial research interest regarding material design, system engineering, and energy management. However, the low water yield and relatively high cost essentially restrict its practical potential. Here, a hydrogel‐based ultrathin membrane (HUM) is developed to synergistically coordinate facilitated vapor transfer and environmental energy harvesting for solar‐driven membrane distillation. The evaporation front is directly exposed to an airflow, which fundamentally eliminates the temperature polarization induced energy consumption. As such, the humidity of the output flow is significantly increased, and thus the vapor collection ratio rises to over 80% to achieve a high water yield of 2.4 kg m–2 h–1 under one sun without any energy recycling and cooling accessories. The HUM with a raw material cost of $0.36 m–2 offers a competitive potential cost of freshwater production of about $0.3–1.0 m–3. This work demonstrates a promising membrane distillation strategy based on sustainable energy toward both decentralized water purification and large‐scale water treatment.

Maize nitrogen management in soils with influencing water tables within optimum depth

AbstractThe central temperate Argentinean region is currently affected by rising water tables, allowing higher and more stable maize yields (Zea mays L) when they fluctuate within optimum depth. However, limited information was available for optimizing N management in these environments. Yield response to N rates was explored in soils with influencing groundwater (always <3.5 m depth), and different environment and management variables were examined to help explain differential yield responses across sites. A total of 15 rainfed experiments (site × year combinations) were conducted with five N rates (0–240 kg N ha−1) tested at two different timings (sowing and V7) in a factorial design. A consistent yield response to N rate was evident, increasing yields from 2,300 to 6,900 kg ha−1 across sites. Yields at maximum N levels ranged from 13,700 to 16,900 kg ha−1. Fertilization timing had a minor and inconsistent effect on yield across sites. At a maize grain/fertilizer N price ratio of 10, the economically optimal N rate ranged from 117 to 206 kg N ha−1. Soil N‐NO3 at sowing, previous crop, and apparent–indigenous N supply (INS) helped explain differential yield responses across sites, and response models for obtaining economic optimum rates considering the influence of these variables are provided. These results highlight the relevance of N rate, rather than timing, as a critical crop management decision in environments with high water availability and yield.

Agilyx, ExxonMobil set up plastic waste recycling JV.

Photodynamic antimicrobial therapy (PACT) is a powerful technic recommended to eliminate life-threatening pathogens that cause localized and superficial infections as pathogens cannot develop resistance to it. For this reason, new positively charged chalcone substituted zinc (3a) and indium (4a) metalated phthalocyanines (Pcs) were synthesized and were π-π interacted with detonation nanodiamonds (DNDs) nanoparticles to form new water soluble nanoplatfoms 3a@DNDs and 4a@DNDs. The conjugates generated high singlet oxygen quantum yields (ΦΔ) in water (1% DMSO, used for PACT studies) with values of 0.46 and 0.47 for 3a@DNDs and 4a@DNDs, respectively. Hence, they were tested for PACT against biofilms of S. aureus and E. coli, as well as their planktonic cells. The quaternized Pcs alone 3a and 4a as well as their nanoconjugates 3a@DNDs and 4a@DNDs were effective PACT agents with log10 CFU > 9 for E. coli and S. aureus. The quaternized derivatives were found to have higher ability to completely suppress both planktonic and biofilms of S. aureus and E. coli in vitro. Therefore, they could be used as appropriate photosensitive agents.

Enhanced photo-ablation effect of positively charged phthalocyanines-detonation nanodiamonds nanoplatforms for the suppression of Staphylococcus aureus and Escherichia coli planktonic cells and biofilms

Photodynamic antimicrobial therapy (PACT) is a powerful technic recommended to eliminate life-threatening pathogens that cause localized and superficial infections as pathogens cannot develop resistance to it. For this reason, new positively charged chalcone substituted zinc (3a) and indium (4a) metalated phthalocyanines (Pcs) were synthesized and were π-π interacted with detonation nanodiamonds (DNDs) nanoparticles to form new water soluble nanoplatfoms 3a@DNDs and 4a@DNDs. The conjugates generated high singlet oxygen quantum yields (ΦΔ) in water (1% DMSO, used for PACT studies) with values of 0.46 and 0.47 for 3a@DNDs and 4a@DNDs, respectively. Hence, they were tested for PACT against biofilms of S. aureus and E. coli, as well as their planktonic cells. The quaternized Pcs alone 3a and 4a as well as their nanoconjugates 3a@DNDs and 4a@DNDs were effective PACT agents with log10 CFU > 9 for E. coli and S. aureus. The quaternized derivatives were found to have higher ability to completely suppress both planktonic and biofilms of S. aureus and E. coli in vitro. Therefore, they could be used as appropriate photosensitive agents.

Ionic liquid enables highly efficient low temperature desalination by directional solvent extraction

Seawater desalination plays a critical role in addressing the global water shortage challenge. Directional Solvent Extraction (DSE) is an emerging non-membrane desalination technology that features the ability to utilize very low temperature waste heat (as low as 40 °C). This is enabled by the subtly balanced solubility properties of directional solvents, which do not dissolve in water but can dissolve water and reject salt ions. However, the low water yield of the state-of-the-art directional solvent (decanoic acid) significantly limits its throughput and energy efficiency. In this paper, we demonstrate that by using ionic liquid as a new directional solvent, saline water can be desalinated with much higher production rate and thus significantly lower the energy and exergy consumptions. The ionic liquid identified suitable for DSE is [emim][Tf2N], which has a much (~10×) higher water yield than the currently used decanoic acid. Using molecular dynamics simulations with Gibbs free energy calculations, we reveal that water dissolving in [emim][Tf2N] is energetically favorable, but it takes significant energy for [emim][Tf2N] ions to dissolve in water. Our findings may significantly advance the DSE technology as a solution to the challenges in the global water-energy nexus.

Molecular Cages Self‐Assembled by Imine Condensation in Water

AbstractSelf‐assembly by imine condensation in aqueous media is a formidable task because of the labile nature of imines in the presence of water. Here, by taking advantage of multivalence and ligand preorganization, basket‐shaped triscationic cage molecules are self‐assembled in high yields in both water and organic solvent, by condensing a hexaformyl and bisamine. These cages, especially the chiral ones, are stable or inert in aqueous solution, that is, no decomposition was observed upon dilution, precipitation, or exposure to competitive amines or aldehydes. Such water‐compatibility allows the hosts to take advantage of the hydrophobic effect to accommodate hydrophobic guests. The chiral cage S‐23+ selectively binds and distinguishes one of two enantiomers, opening up opportunities for applications such as chiral compound separation. Chiral narcissistic self‐sorting and sergeants‐and‐soldiers effects occur during cage formation when two amino precursors are involved in self‐assembly.

Molecular Cages Self-Assembled by Imine Condensation in Water.

Self-assembly by imine condensation in aqueous media is a formidable task because of the labile nature of imines in the presence of water. Here, by taking advantage of multivalence and ligand preorganization, basket-shaped triscationic cage molecules are self-assembled in high yields in both water and organic solvent, by condensing a hexaformyl and bisamine. These cages, especially the chiral ones, are stable or inert in aqueous solution, that is, no decomposition was observed upon dilution, precipitation, or exposure to competitive amines or aldehydes. Such water-compatibility allows the hosts to take advantage of the hydrophobic effect to accommodate hydrophobic guests. The chiral cage S-23+ selectively binds and distinguishes one of two enantiomers, opening up opportunities for applications such as chiral compound separation. Chiral narcissistic self-sorting and sergeants-and-soldiers effects occur during cage formation when two amino precursors are involved in self-assembly.