Combining algae cultivation and wastewater treatment for biofuel production is considered the feasible way for resource utilization. An updated comprehensive techno-economic analysis method that integrates resources availability into techno-economic analysis was employed to evaluate the wastewater-based algal biofuel production with the consideration of wastewater treatment improvement, greenhouse gases emissions, biofuel production costs, and coproduct utilization. An innovative approach consisting of microalgae cultivation on centrate wastewater, microalgae harvest through flocculation, solar drying of biomass, pyrolysis of biomass to bio-oil, and utilization of co-products, was analyzed and shown to yield profound positive results in comparison with others. The estimated break even selling price of biofuel ($2.23/gallon) is very close to the acceptable level. The approach would have better overall benefits and the internal rate of return would increase up to 18.7% if three critical components, namely cultivation, harvest, and downstream conversion could achieve breakthroughs.

The development of digital financial inclusion has added a new vitality to economic growth, and environmental regulation is an important tool to achieve sustainable economic growth. Therefore, whether there is a synergistic effect between these two factors of economic growth is a topic worth exploring. This paper uses the space econometric model and threshold model to explore the impact of digital financial inclusion and environmental regulation on regional economic growth using panel data from 30 Chinese provinces, collected between 2011 and 2019. The research results prove that the development of digital financial inclusion and the improvement in the intensity of environmental regulation have a significant direct promotion effect and negative spatial spillover effect on regional economic growth. Moreover, the two have a significant synergistic effect on regional economic growth. A panel threshold analysis showed that, with the improvement in the level of digital financial inclusion, the regression coefficient of environmental regulation changed from negative to positive, which played a significant role in promoting regional economic growth. The heterogeneity analysis found that digital inclusive finance in eastern regions of China plays a greater role in promoting the economy, whereas environmental regulation in the central region plays a greater role in promoting the economy. The synergy between the two in the central region greatly promotes economic development. When digital inclusive finance is used as the threshold variable, environmental regulation in eastern and western regions has a single-threshold effect on regional economic development. Based upon these research results, this paper proposes that a coordination mechanism between digital financial inclusion and environmental regulation should be established to give full play to their synergies in sustainable economic growth.

In the past 40 years, China's rapid industrialization has resulted in remarkable social progress and regional economic prosperity but also has caused problems, such as excessive resource consumption and environmental pollution. Ecological efficiency is an important indicator of whether economic efficiency and environmental efficiency are balanced. Exploring ecological efficiency is vital for achieving sustainable development, as technological innovation, industrial structure upgrading, and ecological efficiency are probably related. However, there has been little research on the relationships among them. In this study, we used the super‐efficiency slacks‐based model (SBM) involving undesirable output to calculate the ecological efficiency of 30 provinces in China from 2008 to 2017. We found that China's ecological efficiency has risen, fallen, then fluctuated, and that there were significant spatial differences. Then, we used 3 spatial econometric models for comparative analysis, which revealed that the independent effects of technological innovation on ecological efficiency was significant and negative; however, technological innovation demonstrated a strong positive effect in tandem with industrial structure upgrading, and industrial structure always had a positive effect on ecological efficiency. On this basis, we added the cross‐item of technological innovation, and industrial‐structure upgrades had a significant and positive impact on ecological efficiency, which was significantly greater than the independent effect of technological innovation and industrial‐structure upgrades. To explore the mechanism of industrial‐structure upgrading and technological innovation on regional ecological efficiency, we set the first 2 as threshold variables. We found that there is in fact a threshold effect of technological innovation and industrial‐structure upgrading on ecological efficiency due to the mismatch of periods. These results provide a theoretical rationale for China to formulate strategies to improve ecological efficiency. Integr Environ Assess Manag 2021;17:852–865. © 2020 SETAC

Environmental regulation is a crucial tool for controlling environmental pollution. Digital finance is essential for the development of green finance. The relationship between environmental regulation and digital finance concerning environmental pollution is an issue worth exploring. This paper uses the spatial econometric model and the panel threshold model to empirically analyze the impact of environmental regulation and digital financial inclusion on environmental pollution using panel data from 30 Chinese provinces between 2011 and 2019. It mainly discusses the independent impact and synergy of environmental regulation and digital inclusive finance on environmental pollution. The research results show that the improvement of the intensity of environmental regulation and the development level of digital-inclusive finance can effectively alleviate the problem of environmental pollution. Moreover, environmental regulation and digital inclusive finance can coordinately control environmental pollution. A panel threshold analysis shows that as the intensity of environmental regulation increases, digital financial inclusion will reflect the function of environmental governance. Similarly, with the development of digital financial inclusion, environmental regulation has shown a significant inhibitory effect on environmental pollution. The results of a heterogeneity analysis show that the intensity of environmental regulation in the eastern region has a significant inhibitory effect on environmental pollution. Digital financial inclusion in the central region shows a strong environmental governance function. The intersection of environmental regulation and digital financial inclusion has shown a significant synergistic governance effect in the eastern region. Therefore, the government gives full play to the functions of environmental regulation and digital inclusive finance environmental governance to achieve coordinated governance of environmental pollution.

China is in a strategic phase of an industrial green transformation. Industrial air pollution is a key environmental target for governance. Because import trade is a core channel through which advanced environmental protection technology is absorbed, the question of whether technology spillovers brought about by import trade can reduce industrial air pollution emissions is a topic worth exploring. This paper uses a generalized spatial two-stage least-square (GS2SLS) model to explore the impact of import trade technology spillovers on industrial air pollution emission intensities using panel data from 30 provinces and cities between 2000 and 2017. Economic scale, industrial structure, and technological innovation are used as intermediary variables to test whether they play mediating effects. The results show that: (1) capital and intermediate goods technology spillovers directly reduce industrial air pollution emission intensity and (2) import trade technology spillovers indirectly reduce emission intensities by expanding economic scale, optimizing industrial structure, and enhancing technological innovation through mediating variables. Furthermore, industrial structure optimization and technological innovation have the largest mediating effects on industrial SO2, while economic expansion has the most significant mediating effect on industrial smoke and dust. The mediating effects of technology spillovers from intermediate goods exceed those of capital technology spillovers. Finally, industrial air pollution emission intensity demonstrates both spatial agglomeration and time lag effects. Environmental regulations and energy structure are shown to increase industrial air pollution emissions, while urbanization and foreign direct investment reduce industrial air pollution. Based upon these research results, some pertinent policy implications are proposed for China.