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Heavy metal pollution in rivers and lakes arising due to rapid economic development has been extensively studied by various countries due to its direct impact on ecological health and human well-being. However, there is a lack of comprehensive and systematic reviews addressing the current research status of this subject. In this study, we conducted a visual metrological analysis of the literature from 2001 to 2021 using the Web of Science (WoS) and China National Knowledge Infrastructure (CNKI) citation databases. The results show that studies conducted in other countries initially outnumbered those in China; after 2010, China emerged as the foremost contributor. Furthermore, both the WoS and CNKI databases indicate active engagement of Chinese researchers through a significant proportion of published papers on metal research, with prominent contributions coming from institutions such as the Chinese Academy of Sciences (CAS) and University CAS. Nevertheless, Chinese research institutions still have relatively low total paper citation numbers and have yet to establish themselves as key players in international scientific research efforts. Additionally, core authors from different countries share substantial similarities in their research directions and focuses. Consistent research hotspots regarding heavy metals in rivers and lakes were identified across both databases, including heavy metal pollution, adsorption, human activities, water quality, and sediment. [ABSTRACT FROM AUTHOR]

Qinghai Lake is the largest inland saltwater lake in China, with a drainage area of 29,661 km2. This study sought to conduct an ecological and human health risk assessment of metals and heavy metals, including copper, as well as investigate their concentration, distribution, and source distribution. In terms of seasonal variation, the increases in Fe, Cr, As, Pb, and Hg were relatively large, and the spatial distribution of metals presented a three-level stepped distribution trend, gradually increasing from east to west. By further exploring the source and migration path of pollutants, our study found that the source of metals in the sediments of Qinghai Lake is mainly controlled by five rivers entering the lake. Enrichment factor (EF) calculations indicated that the metal accumulation or enrichment capacity of the three central points in Qinghai Lake Basin was strong. Interestingly, the enrichment capacity of Cu and Zn was the strongest among all metals but occurred at low and medium concentration levels, respectively. The Igeo and E r i ecological risk assessment results indicated that the individual metals posed little to no ecological risks to the Qinghai Lake Basin. However, the multi-element environmental risk comprehensive index (RI) indicated that Hg (RI = 147.97) represented a slight ecological hazard, Mn (RI = 181.13) posed moderate ecological hazards, and Zn (RI = 386.66) posed strong ecological hazards. The human health risk assessment results showed that the heavy metals in the surface sediments of Qinghai Lake currently do not pose a threat to human health. This information may facilitate the implementation of more stringent monitoring programs in the aquatic ecosystem by the relevant regulatory authorities. [ABSTRACT FROM AUTHOR]

Achieving decarbonization and industrial transformation in typical energy-dependent regions is a crucial step in mitigating regional climate change. This study constructed a factorial carbon policy equilibrium effect model (FCEE) that integrated input–output analysis, a computable general equilibrium model, factorial analysis, multi-regional input–output, and ecological network analysis. This work explored the internal impact of a composite carbon tax policy that considered the endogenous driving forces of the socioeconomic system on Shanxi Province, a typical energy-dependent region in China, as well as the cascading external effects on China's major economic circles. A significant interaction was found between carbon tax policy, production efficiency progress, and emission efficiency progress, confirming advantage of the composite policy in terms of the environmental–economic benefits. In contrast to common stereotypes, the composite climate policy will promote the clean transformation of the energy structure and gross domestic product growth, and water scarcity in Shanxi Province will be alleviated under the energy–water nexus mechanism. Relying on complex cross-regional networks, China's economic inequality will be indirectly eased. The economic driving forces of the Yangtze River, Chengdu-Chongqing economic circles, and Shanxi Province will be strengthened, promoting system stability and sustainability. It is recommended that Shanxi Province implement a moderate carbon tax policy while improving production efficiency; the intensity of emissions technology reform can be flexibly adjusted according to actual needs. This study provides evidence to support the implementation of climate policy, which is of great significance for other similar regions looking to solve the dilemma of sustainable development. [Display omitted] • The results reverse the stereotype of climate policy in energy-dependent regions. • A factorial carbon policy equilibrium effect model was developed. • Complex internal and external effects of composite climate policies were uncovered. • Composite climate policy will enhance China's economic circles and overall system. • Sustainable transformation of the resource–environment–economic system is feasible. [ABSTRACT FROM AUTHOR]

Wastewater treatment plants (WWTPs) play a critical role in the sustainable development of water resources due to its outstanding ability of removing pollutants from complex influent wastewater and generating clean and safe effluent. This paper innovatively adopted the meta-analysis method in view of published LCA studies to assess the energy use and environmental impacts of WWTPs during their life cycle. The search and screening process determined a useful data source with 54 LCA literatures covering 109 relevant case studies. The meta-analysis results revealed that, compared with other regions, the WWTPs in China have the higher intensity in terms of energy use, global warming potential (GWP), eutrophication potential (EP), acidification potential (AP), photochemical oxidation (PHO), freshwater ecotoxicity potential (FETP) and terrestrial ecotoxicity potential (TETP) categories, implying that the energy conservation and emission reduction strategies are necessary to wastewater treatment industry in China. Moreover, compared with A/A/O and CASS processes, the A/O process consumes less energy and results in lower GWP and AP intensity, but affects adversely the natural water-body protection due to undesirable treatment efficiency. Furthermore, the treatment capacities of medium and large scales (i.e. 5-20 × 104 m3/d) are most reasonable sizes for WWTPs since their intensity of energy use, GWP, EP and AP are under a relatively low level. Finally, a strict effluent discharge standard is highly recommended from the perspective of protecting aquatic environment, although it leads to a higher energy consumption. The findings of this study could provide valuable references for promoting healthy and sustainable wastewater treatment industry. • Meta-analysis was firstly explored for evaluating the energy use and EIs of WWTPs. • Data source included 54 LCA literatures covering 109 independent case studies. • Four physical characteristics associated with WWTPs were in-depth discussed. • Recommendations for design and reconstruction of WWTPs in the future were provided. [ABSTRACT FROM AUTHOR]

The water-energy nexus (WEN) system is a large-scale complex system that comes with diverse forms of risks owing to many challenges in the process of maintaining economic-resource-environmental sustainability. First, the rapidly increasing demand for water and energy subjects many regions to the high risk of water and energy shortages. Second, decision makers face difficulties in weighing system benefits and loss risks under a series of stricter water-energy policies. To handle the aforementioned dual risks of WEN, in this study we propose copula-based stochastic downside risk-aversion programming (CSDP) for regional water-energy management. CSDP integrates the superiority of the copula analysis method and downside risk-aversion programming into a framework, which can not only reveal the risk interactions between water resources and energy demand by using copula functions under different probability distributions, even previously unknown correlations, but also control economic risk, tackle systemic uncertainties, and provide an effective linkage between system stability and conflicting economic benefits. The proposed model was applied to a water-energy system case study in Tianjin City, China. Optimal solutions for various water resources and energy demand copulas associated with different scenarios and hierarchical risk levels were examined in the CSDP model. The results showed that water resources have a greater influence than energy on industrial structure adjustment in Tianjin, with consequent effects on system benefits, optimal output value schemes, and environmental protection strategies. In addition, the tertiary industry provides a new opportunity for economic growth based on a large amount of water-energy consumption, and its potential resources and water-air pollution risks also deserve extensive attention. [Display omitted] • A dual risk-aversion programming model for water-energy nexus was established. • Water-energy demand joint risk and systemic economic risk were addressed. • Optimization solutions of various joint-interaction scenarios were obtained. • The proposed model was applied to Tianjin City, China for industrial structure adjustment. [ABSTRACT FROM AUTHOR]

Developing an efficient strategy for managing nutrients in less-developed lake watersheds that can balance the need for socioeconomic progress with the protection of aquatic ecosystems has become an urgent research subject for achieving sustainable development. This paper improves the optimization method for environmental and economic management of lake watersheds proposed in our previous research. A spatiotemporal optimization method based on a coupling model consisting of the Soil and Water Assessment Tool, system dynamics model, and objective programming model was applied to an agricultural non-point source (ANPS) pollution control program and a rural sewage treatment program at the Yilong Lake watershed as a case study. A simulation evaluation showed that the efficiency of the previous scheme was significantly improved after conducting spatiotemporal optimization. This scheme was dynamic and distributed, demonstrating an annual and high-resolution control program that can provide a basis for the precise management of ANPS. Although it still requires improvement, a framework for coupling simulation and two-step optimization was achieved in this study., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Estuarine areas are not only the main gathering point for human sewage but also the place where one-way and two-way fluids interact, thus forming a complex and changeable geochemical physical field. Here, heavy metals (HMs) are adsorbed and desorbed due to physical, chemical, and biochemical processes. However, the adsorption and desorption behavior of HMs in the aquatic environment is complex, and physicochemical processes occurring in the estuarine sediment-water interface control the direction and boundaries of the system. This study analyzed the migration and distribution of HMs in rivers and lakes, and established a Bayesian network model to quantitatively understand the impact of nutrients and key environmental factors on the adsorption-desorption behavior of HMs in lake and estuaries, as well as the competitive relationship between environmental factors. The influence of environmental factors and the occurrence of HMs are both important model inputs. Our findings indicated that the migration risk of Cd in Qinghai Lake was high. Environmental factors such as Cation exchange capacity (CEC), Organic matter (OM), Soluble fluoride (SFL), and pH play the most important role in the adsorption and desorption of HMs. Our findings also indicated that the exchange and activity of HMs in sediments were much higher than in the overlying water. The organic matter content was the most complex environmental factor affecting HMS adsorption and desorption at the water-sediment interface. Additionally, the mass concentration of dissolved oxygen (DO) has a linear relationship with bioavailable HMs in river and lake sediments, but has no linear relationship with the concentration of water-soluble HMs. Interestingly, there are synergistic effects between environmental factors, which directly or indirectly affect the release of bioavailable HMs. However, it is important to determine whether the effects of different environmental factors on the exchange of bioavailable HMs are negative or positive. Our findings suggested that Bayesian network (BN) signals (positive or negative) could provide insights into the transfer direction of metals in the water-sediment interface., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Many lake basins are facing the challenge of mitigating water shortage and water pollution while maintaining economic growth. Existing planning method for water pollution control often focus on how to alleviate water pollution effectively at the lowest cost, but rarely pay attention to the dynamic feedback and synergy effects between water pollution abatement, water conservation and social economy. This article proposes a method which consists of system dynamics model (SDM), Soil and Water Assessment Tool (SWAT) and objective programming model (OPM). It could be used to create insights on basin-wide water problems from a systematic perspective. The case study on Yilong Lake Watershed evaluates the proposed measures in existing local planning, calculates the optimal scheme, and discusses issues including the uncertainty of effectiveness, choice between recycling sewage and transferring outside, and the necessity of restricting food processing industry. This method could be improved on the simulation of social and industrial economy, the simulation of water cycle, and the spatial planning., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Making clear of the background values of different watersheds is an important mission for water resource management and assessment. The background values of the virgin forested watershed with less human activities sometimes have high COD values. In order to investigate this issue, this study take the Tangwang River watershed as a study case, analyzing the monitoring data of COD, BOD, and DO from the year of 2014 to 2018, and taking the water samples in the wet, normal, and dry season of 2019 to make clear the relationships between COD and DOM, the composition, and source of DOM. The non-degradation and terrigenous source DOM contributed to the most of COD values through the fitting analysis. The DOM in the Tangwang River mostly consisted of the humic-like acid and fulvic-like acid. Along with the river, the concentration of DOM had a little decrease, but the composition of DOM did not change obviously, so that the DOM coming from the virgin forest did not degrade in the river, and the river water only had the dilution effect with the tributaries fed in spatially. The organic matters in the virgin forest were easily washed away, so that the DOM concentration had an increase in the wet season temporally. The background COD values of the small virgin forested watershed were usually high as for the leaching effects of the organic matters from the forest, which was worthy noted when conducting the management project of this kind of watershed, in order to adjust measures to local conditions., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

A bibliometric method was used to evaluate the global scientific publications about sulfur oxides and nitric oxides released by coal-fired flue gas and vehicle exhaust from 1995 to 2018 and to provide insights into the characteristics of the articles and tendencies that may exist in the publications. Performance of publications, research tendency, and hotspots were analyzed. The article number had an explosive growth in 2004 and, then, began to grow steadily. China had an absolutely advantage in publication quantities; however, America had a leading position considering publication cited times. The simultaneous removal of mercury, particulate matter, and CO 2 was a research hotpot in sulfur oxide and nitric oxide control process; oxidation, absorption, and catalytic reduction were the central control methods that had the most strength in relation with sulfur dioxide and nitric oxide. Considering the study of traditional flue gas pollutant control method (limestone-gypsum method, selective catalytic reduction, etc.) was perfection, it was speculated that adsorption by ionic liquid, electricity charging, advanced oxidation progress, and multi-pollutant removal, simultaneously, would be the new research orientation in flue gas pollutant control. One of the hot points of controlling the vehicle exhaust was the application of the "green energy" biodiesel; lots of keywords concerning human health suggested that quite a lot studies were focused on the health hazard brought by sulfur oxides and nitric oxide.