Development of calcium-modified biochar for enhanced phytoremediation of human-induced salt pollutants (HISPs).

Soil salinization is a major environmental hazard that limits land availability. Human-induced salt pollutants (HISPs) are regularly presented in large quantities on the contaminated site (such as brine leakages and salt-water spills), causing a devastating shock with high salt stress to the ecosystem. For instance, Saskatchewan resulted in a 48% drop in wheat production and a 0.3% decline in provincial GDP. As the calcium-modified biochar can potentially ameliorate the negative effects of HISPs on plants and improve the plant, phytoremediation with calcium-modified biochar can have increased detoxification of hazardous pollutants from sites. Therefore, the objective of our study was to develop a biochar-assisted phytoremediation employing diverse approaches to calcium modification for the sustainable removal of HISPs. The co-pyrolyzed calcium biochar achieved a remarkable removal rate of 18.06%, reducing salinity from 9.44 to 7.81 dS/m. During a 90-day long-term phytoremediation, the overall reduction rate of calcium-modified biochar stimulated the germination and growth of Thinopyrum ponticum. The result of post-treatment further indicated that co-pyrolyzed biochar with Ca transferred salt into the plant compared to Ca-coated biochar, which only immobilized HISPs on its surface. These results offer two different treatment approaches for diverse situations involving HISPs contamination, addressing current in-situ spills and providing a calcium-related biochar technology for further research in desalination.

Spotlight on the vertical migration of aged microplastics in coastal waters.

Coastal waters are complex and dynamic areas with unique environmental attributes that complicate the vertical migration of microplastics (MPs). The MPs that enter coastal waters from diverse sources, including terrestrial, riverine, oceanic, and shoreline inputs undergo various aging pathways. In this study, the variations in the physiochemical characteristics of MPs undergoing various aging pathways and their vertical migration under dynamic conditions subjected to the effects of different MP characteristics and coastal environmental features were comprehensively explored. Opposite effects of aging on the vertical migration of hydrophobic and hydrophilic MPs were observed, with aging appearing to promote the dispersion of hydrophobic MPs but enhance the vertical migration of hydrophilic ones. The positive role of salinity and the negative role of humic acid (HA) concentrations on MP vertical migration were identified, and the mechanisms driving these effects were analyzed. Notably, intense turbulence not only promoted the floating of positively buoyant MPs but also reversed the migration direction of negatively buoyant MPs from downward to upward. Aging-induced changes in MP characteristics had a limited effect on MP vertical migration. The inherent characteristics of MPs and the surrounding environmental features, however, played major roles in their vertical migration dynamics. ENVIRONMENTAL IMPLICATION: Microplastics (MPs) have emerged as a significant global environmental concern and the coastal zones are the hotspots for MP pollution due to their high population density. This study comprehensively investigated the variations in the physiochemical characteristics of MPs undergoing various aging pathways. Their vertical migration patterns under dynamic conditions subjected to the effects of different MP characteristics and coastal environmental features were revealed. The roles of turbulence and MP density in their migration were identified. The findings of this study have important implications for understanding the transport and determining the ecological risks of MPs in coastal waters.

Unveiling the Vertical Migration of Microplastics with Suspended Particulate Matter in the Estuarine Environment: Roles of Salinity, Particle Properties, and Hydrodynamics.

The estuary is an energetic area connecting the inland, river, and ocean. The migration of microplastics (MPs) in this highly complex area is tied to the entire ecosystem. In this study, the effects of cohesive SPM (clay) and noncohesive SPM (sand) on the vertical migration of positively buoyant MPs, polyethylene (PE), and negatively buoyant MPs, polytetrafluoroethylene (PTFE), in the estuarine environment under hydrodynamic disturbances were investigated. The settling of positively buoyant MPs was more reliant on the cohesive SPM compared to the settling of negatively buoyant MPs. Moreover, MPs interacting with the SPM mixture at a clay-to-sand ratio of 1:9 settled more efficiently than those interacting with clay alone. A significant positive correlation was observed between MP settling percentage and the salinity level. MP settling percentage was significantly negatively correlated with fluid shear stress for both types of MPs, meanwhile, negatively buoyant MPs were able to resist greater hydraulic disturbances. In the low-energy mixing state, for both types of MPs, the settling percentage reached about 50% in only 10 min. The resuspension process of MPs under hydrodynamic disturbances was also uncovered. Additionally, the migration and potential sites of MPs were described in the context of prevalent environmental phenomena in estuaries.

Water rights trading planning and its application in water resources management: A water-ecology-food nexus perspective.

Nexus approach provides an effective perspective for implementing synergetic management of water resources. In this study, an interval two-stage chance-constrained water rights trading planning model under water-ecology-food nexus perspective (ITCWR-WEF) is proposed to analyze the interaction between water trading and water-ecology-food (WEF) nexus, which fills in the water resources management gaps from a novel nexus perspective. ITCWR-WEF incorporates hydrological simulation with soil and water assessment tool (SWAT), water rights configuration with interval two-stage chance-constrained programming (ITCP), and multi-criterion analysis with Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). The developed ITCWR-WEF is applied to a real case of Daguhe watershed, which has characteristics of water scarcity, food producing areas and fragile ecosystem. Initial water rights allocation is addressed before the trading. Mechanisms analysis is designed to reveal mutual effect of water rights trading and WEF nexus. Optimal water management scenario is identified through multi-criterion analysis. Results reveal that the mechanism of water rights trading with WEF nexus under low constraint-violation risk level of water availability and environment capacity is recommended to promote the rational water resources allocation to balance the economic goals, water environment and water supply security, as well as ecological and food water demand guarantees.

Prolonged drying impedes the detachment of microplastics in unsaturated substrate: Role of flow regimes.

The detachment of microplastics (MPs) from porous media under different moisture conditions and flow regimes has garnered limited attention within the research community. The present study investigates the detachment of MPs from porous media under wet and dry conditions combined with steady and transient flow. For both the wet and dry conditions, the increase in flow rates is found to decrease the detachment of hydrophobic polyethylene of two sizes and of hydrophilic polymethylmethacrylate. Intermittent flow is found to result in effluent peaks and a higher rate of MP detachment compared to steady flow. The ionic strength of inflow drops in a stepwise manner, leading to abrupt peaks followed by a tail corresponding to the arrival of each ionic strength front. Each step increase in flow rate leads to a steep peak followed by slow release over several pore volumes. Although transient flow facilitates the detachment of MPs, drying significantly impedes the detachment of MPs irrespective of flow regime. Ultraviolet weathering of MPs for 60 days weakens the inhibition effect of drying on hydrophilic polymethylmethacrylate, facilitating their detachment. Furthermore, the release of MPs decreases markedly with an increase in air-drying duration from 0 h to 72 h. Hydrus-1D two-site kinetic models are used to successfully simulate time-dependent processes, implying that drying heightens the energy barrier for MPs to detach. Our analysis confirms the significance of moisture in determining the remobilization of MPs, providing valuable insights concerning the fate of MPs in unsaturated substrate under prolonged drought conditions.

A Taguchi-STIRPAT input-output model for unveiling the pathways of reducing household carbon emissions under dual-carbon target-A case study of Fujian province.

This study develops a novel Taguchi-STIRPAT input-output (TSIO) model for exploring pathways to reduce carbon emission from the perspective of household consumption, through incorporating input-output model (IOM), Taguchi design (TD), and STIRPAT model. TSIO can not only identify the main factors (carbon emission intensity, consumption structure, per capita consumption, and population) and evaluate their effects on indirect household carbon emissions (IHC), but also predict IHC from a long-term perspective to achieve the dual-carbon target. TSIO is then applied to Fujian province (China), where multiple scenarios related to multiple factors with multiple levels are examined. Results reveal that (i) among all sectors, the highest contributors to IHC are residence (RES), followed by food, cigarettes, and drinks (FCD), and transport and communication (TC); it is suggested that the government can consider market mechanism to control these high-carbon emission consumption behaviors; (ii) the decline in the share of RES consumption has the largest effect on rural and urban IHC; the share of RES consumption is considered to be a key factor in predicting carbon emissions; (iii) under the optimal scenario, IHC would peak in 2025 and decrease to 10.07 × 106 ton in 2060; this scenario can effectively mitigate household carbon emissions by reducing carbon emission intensity and the share of RES consumption; at the same time, it can ensure a sustained increase in per capita consumption. The results unveil the pathways of household carbon reduction under the dual-carbon target in Fujian province and suggest the local government should adopt policies (such as taxation and financial incentives) to limit residential consumptions with high carbon emission intensity.

Regional bioethanol supply chain optimization with the integration of GIS-MCDM method and quantile-based scenario analysis.

This study presents a novel decision-support framework for the bioethanol supply chain network planning and management under uncertainties. Under the holistic framework, the most suitable sites for biorefineries are first screened out by adopting a GIS-based multi-criteria decision-making approach. Then, a mixed-integer linear programming model combined with quantile-based scenario analysis is developed to determine the strategic planning (i.e. locations and size of biorefineries) and tactical management (i.e. biomass purchasing, feedstock transportation, bioethanol production, and product delivery) under uncertainties. The model can effectively search for reliable solutions under uncertainties and achieve tradeoff solutions with the consideration of decision makers' risk tolerance. The proposed framework is demonstrated through a case study in China. It is suggested to build seven biorefineries with a capacity of 100 million liters in Zhumadian city. Utilizing 41% of local agricultural residues could satisfy the bioethanol requirement in the transportation sector under the E20 policy. However, the estimated production cost of bioethanol in Zhumadian is very high, about 1.11 $/L, which makes it lose cost advantage in the fuel market. Thus, currently, effective subsidies, mandatory energy substitution policies, along other environmental regulatory measures are desired to promote the bioethanol industry development.

Multi-objective optimisation model of a low-cost path to peaking carbon dioxide emissions and carbon neutrality in China.

A low-cost path system for achieving carbon neutrality in China was modelled using multi-objective programming by integrating industrial production, electric power, heating, transportation, and forest carbon sequestration. We aimed to minimise the total system cost, CO2 emissions, and air pollutants. The constraints included China's targets of peaking CO2 emissions before 2030; achieving carbon neutrality before 2060; ensuring industry, power, heating, and transportation supplies; promoting green energy; and implementing emission control. The model accounted for industries with high coal consumption, such as steel and chemical industries. Various power sources were considered, including coal-fired, nuclear, wind, and solar energy. Forest carbon sink and carbon capture and storage technologies were employed to achieve the emission reduction goals. The model, which was validated using available research data, offered cost-effective path schemes and exhibited high validity. Our findings emphasise the importance of structural adjustments and emission control, with electric power, heating, and transportation sectors showing higher feasibility and providing greater contributions to achieving carbon neutrality than other industries. Conversely, industrial transformation in sectors such as iron and steel, chemical, and construction materials had low feasibility and limited contribution. The modelling outcomes provide valuable insights for developing low-cost, carbon emission-targeted transportation structures in China's complex system. The results presented here demonstrate the global applicability of this method in contributing to plans aimed at meeting key carbon reduction targets.

Salinity-mediated water self-purification via bond network distorting of H2O molecules on DRC-surface.

High salinity has plagued wastewater treatment for a long time by hindering pollutant removal, thereby becoming a global challenge for water pollution control that is difficult to overcome even with massive energy consumption. Herein, we propose a novel process for rapid salinity-mediated water self-purification in a dual-reaction-centers (DRC) system with cation-π structures. In this process, local hydrogen bond networks of H2O molecules can be distorted through the mediation of salinity, thereby opening the channels for the preferential contact of pollutants on the DRC interface. As the result, the elimination rate of pollutants increased approximately 32-fold at high salinity (100 mM) without any external energy consumption. Our findings provide a novel technology for high-efficiency and low-consumption water self-purification, which is of great significance in environmental remediation and even fine chemical industry.

A sector-disaggregated cross-regional emission analysis for carbon mitigation policies from production and consumption perspectives.

As one of the most challenging environment issues worldwide, climate change has posed a serious threat to habitat, species, and people's livelihoods. In this study, a sector-disaggregated cross-regional emission analysis model is developed to systematically analyze enviro-economic effects of sector-level carbon mitigation efforts from both production and consumption perspectives for supporting climate change-related policymaking. A special case study of Hubei Province, China, is conducted to demonstrate the potential benefits of its use in the climate change related policymaking field. The power generation sector has been disaggregated into five subsectors based on different power generation technologies to help investigate the potential of such technologies to carbon emission mitigations. The carbon mitigation policy scenarios from both industry optimization and demand substitute perspectives will further be explored to provide bases for decision makers to formulate the desired carbon mitigation policy aimed at different regions and sectors. Results indicate that dominant direct and indirect CO2 emissions in Hubei Province are from the Production and supply of fossil-fuel power sector and Construction sector, respectively. When industry optimization policies on the fossil-fuel power sector (in Hubei), there are significant effects on the CO2 emission mitigation whichever regions. Therefore, industry optimization policies are suggested for implementation in specific sectors with close intersectoral/interprovince trade contacts and significant emissions to achieve joint carbon emission mitigations.

Water Self-Purification with Zero External Consumption by Livestock Manure Resource Utilization.

Improper disposal of waste biomass and an increasing number of emerging contaminants (ECs) in water environment are universal threats to the global environment. Here, we creatively propose a sustainable strategy for the direct resource transformation of livestock manure (LM) into an innovative catalyst (Fe-CCM) for water self-purification with zero external consumption. ECs can be rapidly degraded in this self-purification system at ambient temperature and atmospheric pressure, without any external oxidants or energy input, accompanied by H2O and dissolved oxygen (DO) activation. The performance of the self-purification system is not affected by various types of salinity in the wastewater, and the corresponding second-order kinetic constant is improved 7 times. The enhanced water self-purification mechanism reveales that intermolecular forces between anions and pollutants reinforce electron exchange between pollutants and metal sites on the catalyst, further inducing the utilization of the intrinsic energy of contaminants, H2O, and DO through the interfacial reaction. This work provides new insights into the rapid removal of ECs in complicated water systems with zero external consumption and is expected to advance the resource utilization of livestock waste.

Development of iron-based biochar for enhancing nitrate adsorption: Effects of specific surface area, electrostatic force, and functional groups.

The problem of nitrate contamination in water has attracted widespread attention. Original biochar has a poor adsorption capacity for nitrate adsorption. Iron impregnation and acid protonation (base deprotonation) are common modification methods for biochar. In order to develop iron-mediated biochar containing multi-functional groups for enhancing nitrate adsorption, Fe-BC@H and Fe-BC@OH were prepared using a two-stage development process, including an iron-based carbon pyrolysis followed by acid protonation (or base deprotonation). The pseudo-second-order kinetic and Langmuir models can well describe the adsorption process which is a physicochemical complex monolayer adsorption. The data proved that Fe-BC@H (9.35 mg/g NO3--N) had a stronger adsorption capacity than Fe-BC@OH (2.95 mg/g NO3--N). Surface morphologies, functional groups, and mineral compositions of Fe-BC@H and Fe-BC@OH were analyzed through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Characterization results showed that acid protonation can further improve the specific surface area (SSA), pore volume, and Zeta potential of Fe-based biochar, providing more adsorption sites for nitrate and enhancing the electrostatic force between nitrate and biochar. However, these effects were suppressed through base deprotonation. In addition, acid protonation can significantly increase the type and number of functional groups of biochar to enhance the chemisorption of nitrate. Such results suggested that the acid protonation can further improve the adsorption capacity of Fe-based biochar for nitrate, while base deprotonation had an inhibitory effect on that of Fe-based biochar. Overall, this study reveals that specific surface area, electrostatic force, and functional groups are crucial effects of the nitrate adsorption on acid/base modified biochar.

Inexact fuzzy-flexible left-hand-side chance-constrained programming for agricultural nonpoint-source water quality management.

In this study, an inexact fuzzy-flexible left-hand-side chance-constrained programming (IFLCCP) method is proposed for optimizing an agricultural nonpoint-source water quality management problem under uncertainty. The developed method can address complex uncertainties resulted from system fuzzy flexible under various level of decision-making requirements and randomness parameters appeared on the left-hand side of the constraints, and deal with the conflict between water quality protection and agricultural system economic development. The IFLCCP model is formulated through incorporating inexact left-hand-sided chance-constrained programming into interval fuzzy flexible programming framework. The decision schemes obtained by the IFLCCP are analyzed under scenarios at different confidence level of environmental constraint. The results demonstrate that the scale of crop planting and breeding industries reduces as the confidence coefficient of environmental constraint (1-pi) increases, in order to satisfy pollutant discharge constraints, which results in the reduction of the system net benefit from scenarios 1 to 3. Meanwhile, the interval control variables λ± are introduced for quantifying the degrees of overall satisfaction for the objective function and the constraints, which get optimal adjustment to guarantee the net benefit to be as close as possible to the upper bound. The IFLCCP is able to provide management schemes with high system benefits under different levels of acceptable environmental risk, taking full consideration of decision makers' environmental management requirements. This study is a new application of the IFLCCP model to agricultural water quality management problem, demonstrating its applicability to practical environmental problems with high complexity and uncertainty.

Removal of pharmaceutical and personal care products (PPCPs) by MOF-derived carbons: A review.

Nowadays, the increasing demand for pharmaceuticals and personal care products (PPCPs) has resulted in the uncontrolled release of large amounts of PPCPs into the environment, which poses a great challenge to the existing wastewater treatment technologies. Therefore, novel materials for efficient treatment of PPCPs need to be developed urgently. MOF-derived carbons (MDCs), have many advantages such as high mechanical strength, excellent water stability, large specific surface area, excellent electron transfer capability, and environmental friendliness. These advantages give MDCs an excellent ability to remove PPCPs. In this review, the effects of different substances on the properties and functions of MDCs are discussed. In addition, representative applications of MDCs and composites for the removal of PPCPs in the field of adsorption and catalysis are summarized. Finally, the future challenges of MDCs and composites are foreseen.

Correlation between Spatio-Temporal Evolution of Habitat Quality and Human Activity Intensity in Typical Mountain Cities: A Case Study of Guiyang City, China.

The acceleration of the urbanization process brings about the expansion of urban land use, while changes in land-use transformation affect the urban habitat quality, and land-use change brings a threat to regional sustainable development. Against such a backdrop, the assessment of land use on the habitat quality and the relationship between the intensity of human activities is becoming a hot spot in terms of the current land use coordinated with habitat quality. Based on the land-use data of Guiyang in 2000, 2005, 2010, 2015 and 2020, the spatial-temporal evolution characteristics of habitat quality in the study area, combined with the spatial correlation between human activity intensity and habitat quality, were hereby analyzed using the InVEST model. The impact of human activity intensity on habitat quality was correspondingly analyzed. The results show that: (1) From 2000 to 2020, the habitat quality level in Guiyang remained stable without drastic changes, but the changes showed hierarchical distribution and were scattered, mainly reflected in the urban expansion areas of the urban-rural fringe and the key areas of industrial development, and the ecological environment quality fluctuated in a small range. (2) From 2000 to 2020, the intensity of human activities in Guiyang was mainly affected by the relatively concentrated distribution, featuring obvious and significant changes. From 2010 to 2015, the high-impact area surrounded the Guanshan Lake New Area, and the regional habitat quality presented a downward trend. In 2020, the high-impact area of the main urban area and the key industrial development zone was expected to be formed, while the low-impact area was still distributed in forest areas with complex natural conditions. (3) From 2000 to 2020, there was a significant positive correlation between human activity intensity and habitat quality in Guiyang, and such a spatial correlation was weak from 2000 to 2005. The period from 2015 to 2020 witnessed the rapid development of urban construction in Guiyang, human construction activities continue to affect the urban habitat quality. The results show that the intensity of human activities on the promoting function of land use, and the dependencies between them should be considered at the same time, and that explorations on the influence of human activities on land-use intensity and habitat quality of space link are crucial to improving the efficiency of urban land use and ecological environment protection, as well as the coordination between land use and the sustainability of urban development.

Towards low-carbon domestic circulation: Insights from the spatiotemporal variations and socioeconomic determinants of emissions embedded within cross-province trade in China.

For a country like China with unbalanced development pattern among provinces, domestic circulation (i.e., cross-province trade) is important for the long-term stability and prosperous development of economic market. However, with the rapid advance of integration of domestic regional economy, while expanding the internal market scale and deepening the provincial division of labor network for promoting the economic growth, the carbon emissions embedded within the cross-province traded products and services cannot be underestimated. Under the background of climate-trade dilemma, it is necessary to exploring the spatiotemporal variations and socioeconomic determinants of provincial "invisible" carbon emissions for a better understanding of trade-induced eco-environmental effects. To that end, this study developed an environmental-economic system model through integrating the environmentally extended multiregional input-output method and weighted average structural decomposition analysis technique to explore the trade-related emissions at the provincial level and generate the mitigation-management strategies for decisionmakers. Overall, more than half the emissions were embedded within cross-province goods and services trade over the whole study period. Furthermore, the distribution of traded emissions showed obvious spatial heterogeneity and great unbalance was existed between provincial imports and exports. Among all provinces, carbon surplus provinces were always more than deficit ones and the trading patterns of approximately 65% regions remained unchanged during 2007-2017. Remarkably, the emissions trading pattern undergone transition from carbon deficit to carbon surplus in provinces like Henan, Hubei, Guizhou, and so on. Conversely, provinces like Jilin, Shanghai, and Xinjiang showed opposite change. With the prevalence of online payment and electronic commerce in the future, the central and sub-national government could consider launching a pilot project for the design and creation of personal carbon consumption account in the carbon surplus provinces such as Guangdong, Henan, and Jiangsu. Meanwhile, for the provinces with larger carbon exports, it is necessary to establish the horizontal high technical transfer channels and vertical compensation mechanisms such as financial subsidies for improving the low-carbon production level. Our findings provided a holistic depict of national traded emissions at the provincial level, highlighting the importance of cross-province emission effect in exploring ways to promote the low-carbon transition of domestic circulation and fulfill the high-quality development of 'dual circulation' new pattern and successful achievement of 'double carbon' solemn commitment.

Exploring the embodied carbon flow interactive relationships in China from an ecological network perspective: a model framework and application at provincial level.

Energy-related carbon emissions take a large proportion in China, and the interregional trade caused by provincial disparities has led to significant differences in carbon footprint (CF) and embodied carbon flows among provinces that make great bottlenecks for the balance of economic development and carbon mitigation. In this study, we developed an embodied carbon flow-based ecological network (ECFEN) model with economic trade and emission data through combining the multi-regional input-output model and ecological network analysis approach. The developed ECFEN model was applied to 30 provinces in China to quantify the interprovincial flow of carbon embodied in final goods and services and identify the ecological utility (competitive, exploitative, and exploited) and control/dependence relationships between different regions. The main findings can be summarized as follows: Firstly, Jiangsu had the highest total CF with amount of 906 Mt, which was approximately 24.5 times than that of Hainan (37 Mt). Especially, the local CF in Shandong was the largest among all of the provinces with an amount of 683 Mt. Secondly, 13 pairs of embodied carbon flow paths exceeded 20 Mt, and the remarkable embodied carbon flowed from resource-oriented regions (e.g., Inner Mongolia, Shanxi, Hebei) to economically developed eastern coastal provinces and municipalities (e.g., Jiangsu, Guangdong, Beijing, Chongqing). Metallurgy and electricity, water, and gas contributed 30-80% of the total embodied carbon import and export for each province. Thirdly, the exploitative and exploited relationship dominated the ecological relationship between provinces. Meanwhile, the resource-oriented regions played the role of controllers while economically developed provinces were dependents. On the one hand, the central government could take vertical compensation measures such as financial subsidies for major exporter and controllers. On the other hand, it is necessary to take horizontal technical transfer especially from economically developed southeast coastal provinces to western underdeveloped inland area. The obtained results and policy implications are expected to provide reasonable insights for decision-makers to formulate carbon mitigation strategies under the domestic circulation strategy.

Photocatalytic disinfection for point-of-use water treatment using Ti3+ self-doping TiO2 nanoparticle decorated ceramic disk filter.

The challenge from pathogenic infections still threatens the health and life of people in developing areas. An efficient, low-cost, and abundant-resource disinfection method is desired for supplying safe drinking water. This study aims to develop a novel Ti3+ doping TiO2 nanoparticle decorated ceramic disk filter (Ti3+/TiO2@CDF) for point-of-use (POU) disinfection of drinking water. The production of Ti3+/TiO2@CDF was optimized to maximize disinfection efficiency and flow rate. Under optimal conditions, the log reduction value (LRV) could reach up to 7.18 and the flaw rate was 108 mL/h. The influences of environmental factors were also investigated. Natural or slightly alkaline conditions, low turbidity, and low concentration of humic acid were favorable for the disinfection of Ti3+/TiO2@CDF, while co-existing HCO3- ions and diatomic cations (Ca2+ and Mg2+) exhibited the opposite effect. Furthermore, the practicability and stability of Ti3+/TiO2@CDF was demonstrated. Ti3+/TiO2@CDF showed high disinfection efficiency for E. coli and S. aureus under a range of concentrations. Long-term experiment indicated that Ti3+/TiO2@CDF was stable. The underlying disinfection mechanisms were investigated and concluded as the combination of retention, adsorption, and photocatalytic disinfection. The developed Ti3+/TiO2@CDF can provide an effective and reliable disinfection tool for POU water treatment in remote area.

An interval two-stage fuzzy fractional programming model for planning water resources management in the coastal region - A case study of Shenzhen, China.

In this study, an interval two-stage fuzzy fractional programming (TFFP) method is developed to facilitate collaborative governance of economy and water resources. Methods of interval programming, fuzzy programming, two-stage programming, and fractional programming are integrated within a general system optimization framework. The main contribution of TFFP is simultaneously addressing various uncertainties and tackling trade-offs between environmental and economic objectives in the optimized schemes for water resources allocation. A case study of a highly urbanized coastal city (i.e., Shenzhen) in China is provided as an example for demonstrating the proposed approach. According to the results, industrial sectors should receive 34.8% of total water supply, while agricultural sectors should receive 1.5%. For the spatial allocation of water resources, Bao An, Long Gang, and Fu Tian districts should be allocated 21.6%, 20.5%, and 14.8% water to promote the economic development. The discharge analysis indicates that chemical oxygen demand (CODcr) and total phosphorus (TP) would be key pollutants. Moreover, the optimized seawater desalination volume would be negligibly influenced by price, while the upper bounds of desalination would be increased with the raising acceptable credibility levels in the period of 2031-2035. Analysis of desalination prices also reveals that the decision-makers should increase the scale of desalination in the period of 2021-2025. In addition, the effectiveness and applicability of TFFP would be evaluated under economic maximization scenarios. The result showed that the economic maximization scenario could obtain higher economic benefits, but it would be accompanied by a larger number of pollutant discharges. It is expected that this study will provide solid bases for planning water resources management systems in coastal regions.