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Enormous wastewater discharges have significantly impeded the sustainable development. As several economic belt has been formed in China, systematic analysis of multi-regional wastewater metabolic system is required for advancing wastewater mitigation effectively and efficiently. In this study, a distributive environmental input-output model (DEIO) is developed for the Yangtze River Economic Belt (YREB) to provide bases for supporting sustainable development from inter-regional and inter-sectoral perspectives. The discharges and flows of wastewater and related pollutants (i.e., chemical oxygen demand (COD) and ammonia nitrogen (AN)) among sectors and regions are analyzed to providing solid bases for wastewater management within the YREB. The results show that the industrial wastewater mitigation in YREB is desired urgently. The industrial wastewater discharges in Jiangsu and Zhejiang provinces are numerous, while Hunan and Yunnan provinces are more inclined to suffer from serious COD and AN pollution. In addition, the manufacture of food, tobacco, chemical materials, and pharmaceutical are the typical sectors with a large amount of direct wastewater discharge, and the tertiary industry is ranked at the first in indirect wastewater discharge. According to the analysis, the implementation of the “Supply-side Structure Reform” and the “Replace Subsidies with Rewards” policy can benefit the wastewater mitigation in the YREB.

Small modular reactor (SMR) is an emerging clean technology that is expected to help decarbonize power systems and mitigate climate change in the future. However, previous SMR siting methods were unable to take the multi-complexities of the power system into account. To deal with such a shortage, a factorial optimization-based SMR siting (FOSS) model is developed in this study. The main advantage of the developed FOSS model is its capability of comprehensively examining the SMR siting issue within a general electricity-system framework under multi-complexities. The optimized SMR siting schemes and power-systems transition plans can be then provided. The developed approach was applied to the power systems in Saskatchewan, Canada. The results indicate that replacing conventional coal-fired plants with SMRs can be a beneficial alternative to promote GHG mitigation and meet the growing power demand. The SMR deployment would enable a transition to a low-carbon power system in Saskatchewan with at least 65.6% emissions reduction by 2045 from 2018 level. Factorial and scenario-based analysis can provide policy makers with reference points to formulate specific decarbonization policies of power systems. The FOSS model can be adapted for electricity systems in different countries and this research provides a promising way to promote a transition towards long-term sustainability in global energy systems.

Long-chain perfluoroalkyl acids (PFAAs) such as perfluorodecanoic acid (PFDA) are toxic, persistent organic pollutants. This study investigated the harmful effect of PFDA on mouse primary nephrocytes and its mechanism at cellular and molecular levels. Cellular results showed that PFDA exhibited nephrotoxicity with decreased cell viability and increased apoptosis. The increase of intracellular reactive oxygen species (ROS) content and the decrease of intracellular superoxide dismutase (SOD) activity were significant (p 0.01) when PFDA concentration exceeded 10 μM. Additionally, the molecular results indicated that PFDA bind with Val-A98 in the surface of Cu/Zn-SOD by a 3.11 Å hydrogen bond driven by Van der Waals' force and hydrogen bonding force, which triggered the structural changes and decreased activity of Cu/Zn-SOD. Altogether, the intracellular oxidative stress is the main driver of nephrocyte apoptosis; and the interaction of PFDA and Cu/Zn-SOD exacerbated the oxidative stress in nephrocytes, which is also a nonnegligible reason of cytotoxicity induced by PDFA. This study represented a meaningful method to explore the toxic effect and mechanism of xenobiotics at cellular and molecular levels. The findings have implications for revealing the clearance of long-chain PFAAs in vivo.