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Prior studies obtained mixed conclusions on the relationship between firm exporting and pollution emissions, probably because the role of environmental regulation has been ignored in this relationship. This study focuses on whether the abatement effect of exporting is related to the stringency of environmental regulation. To avoid measurement bias in the environmental regulation stringency faced by firms, we use the two control zones policy implemented in China to reduce sulfur dioxide (SO2) emissions as a natural experiment to distinguish the difference in the SO2 regulation stringency faced by different firms. Empirical results show that Chinese manufacturing firms can significantly reduce their SO2 emissions intensity by exporting, but the abatement effect of exporting occurs only in the firms regulated by the two control zones policy. This result confirms for the first time that the abatement effect of exporting stems from the incentives of stringent environmental regulations. Further analysis shows that the abatement effect of exporting is realized mainly through firm investment in source control technologies rather than in end-of-pipe treatment technologies. The findings of this study suggest that stringent environmental regulations are important for emerging and developing countries to achieve environment-friendly exports. [ABSTRACT FROM AUTHOR]

Scientific and technological revolutions have given rise to a new generation of general-purpose intelligent manufacturing technology represented by industrial robots, which have become the emerging growth engine in many countries worldwide, leading to significant improvements in productivity and innovation. However, it remains unclear whether the industrial robot adoption can help address the increasingly severe environmental issues. This study investigates the impact of imported industrial robots on the pollutant emission intensity of Chinese manufacturing enterprises using micro panel data from 1998 to 2013. Our findings suggest that the industrial robot adoption leads to a significant reduction in SO 2 emission intensity at the enterprise level. These results remain robust even after conducting various robustness checks, addressing endogeneity concerns and adjusting matching strategies. Furthermore, our investigation reveals three channels through which robot adoption reduces SO 2 emission intensity: technological progress spillover, clean energy transition, and improvement in end-of-pipe treatment. By providing micro-level evidence on the environmental impacts of industrial robots, this study contributes to our understanding of the positive environmental externality associated with the diffusion of imported intelligent technology across nations and offers valuable insights for the sustainable development of emerging economies. [ABSTRACT FROM AUTHOR]

Air-borne pollutants in particulate matter (PM) form, produced either physically during industrial processes or certain biological routes, have posed a great threat to human health. Particularly during the current COVID-19 pandemic, effective filtration of the virus is an urgent matter worldwide. In this review, we first introduce some fundamentals about PM, including its source and classification, filtration mechanisms, and evaluation parameters. Advanced filtration materials and their functions are then summarized, among which polymers and MOFs are discussed in detail together with their antibacterial performance. The discussion on the application is divided into end-of-pipe treatment and source control. Finally, we conclude this review with our prospective view on future research in this area.

The present investigation focused on End-of-pipe treatment of secondary treated coke-oven wastewater to remove cyanide, phenol, ammoniacal-N, nitrate and fluoride using earthen tea pot (ETP), a local market waste. The effect of parameters like adsorption time (0–10 h), particle size (1–3 mm) and adsorbent dose (10–30 gL−1) was tested for removal of pollutants from synthetic BOD treated coke-oven wastewater (SBTCW) and maximum removal was obtained as cyanide (95.46 ± 0.004%), phenol (99.70 ± 0.005%), ammoniacal-N (47.88 ± 6.31%), nitrate (61.03 ± 2.12%), and fluoride (92.35 ± 0.09%) at adsorption time 10 h, particle size 1 mm and adsorbent dose 10 gL−1. Kinetic study showed that the fluoride removal data fit satisfactorily to the Pseudo 2nd order kinetic model, whereas the Pseudo 1st order model was found to be fitted well to the kinetic data of all other pollutants. Adsorption isotherm study portrayed that the Freundlich isotherm model holds good to represent equilibrium data for the removal of pollutants. Response Surface Methodology (RSM) was used to optimize the removal efficiencies of all five pollutants. The optimum removal condition as shown by RSM study was contact time: 7.3 h, and initial concentrations (ICs) of cyanide, phenol, ammoniacal-N, nitrate and fluoride are 0.71, 10, 400, 100 and 10.1 mgL−1, respectively, and the removal of five pollutants (cyanide, phenol, ammoniacal-N, nitrate and fluoride) were predicted as 40.58%, 90.00%, 41.63%, 96.00% and 45.29%, respectively. Artificial Neural Network model was developed based on experimental points which indicated that the model can calculate abatement of five different pollutants for various operating conditions with reasonably high accuracy. Genetic Algorithm was then used to optimize the removal process of the five pollutants. Regeneration study was conducted to assess the efficacy of the regenerated adsorbent in next cycle of the End-of-pipe treatment of SBTCW. Finally, real secondary treated coke-oven wastewater was collected and treated with the present adsorbent. • End-of-pipe treatment of secondary treated coke-oven wastewater was studied. • Earthen tea pot was used for simultaneous removal of five pollutants. • Response Surface Methodology was used to optimize the removal process. • Artificial Neural Network was used to model the adsorptive removal. • Genetic Algorithm was used to optimize the removal of all five pollutants. [ABSTRACT FROM AUTHOR]

This paper shows that manufacturer traceability triggers environmental standard diffusion from highly to weakly regulating countries, driving local companies to meet environmental regulation requirements. The paper aims to explain firms' environmental performance by using product differentiation as an indicator for manufacturer traceability. The findings show that differentiated goods sold to international markets prompt local firms to meet environmental regulation requirements and produce positive pressure to go beyond local compliance levels. However, when traceability is low, as in the case of undifferentiated goods, trade with global markets does not tend to create incentives for environmental investment. The study examines firms in the emerging economy of India. [ABSTRACT FROM AUTHOR]

The electrolytic aluminum plays an irreplaceable role in the Chinese national economy. The large amount of fluorine flue gas produced by it contributes to tremendous pressure on the environment. When the concentration of PFCs in the environment reaches a certain value, it will cause damage to the central nervous system and liver of human body. The treatment method of perfluorocarbon (PFCs) is mainly based on source or end-of-pipe control, with the former having low emissions and low energy consumption and the latter having high removal rate. However, reviews of the formation mechanism and influencing factors of PFCs has seldom been conducted. Therefore, it is very important to comprehensively understand the formation mechanism and treatment status of PFCs, finding effective and rational processing technologies in the electrolytic aluminum industry for realizing effective control. This paper provides a more systematic review of the micro-formation mechanism of PFCs, pollutant source management, and ultimate pollution and carbon reduction. Each technology research progress and influencing factors in terms of material properties and process conditions are analyzed in recent years. This review aims to provide some references for subsequent related research in PFCs treatment and purification in electrolytic aluminum flue gas. [Display omitted] • The micro-formation mechanism of perfluorocarbons (PFCs) is analyzed. • The advantages and disadvantages of source and end technologies are discussed. • The vital impact of PFCs emission reduction on global climate change is emphasized. • The future research prospects of solid waste used to treat PFCs is explained. [ABSTRACT FROM AUTHOR]

Facilitating pollution reduction in manufacturing enterprises is crucial for implementing the new development concept and achieving sustainable, environmentally friendly growth. This research delves into the influence of digital inputs on pollution emission reduction in Chinese manufacturing enterprises. The study utilizes a combination of the World Input-Output Database, the Chinese Industrial Enterprises Database, and the Chinese Industrial Enterprises Pollution Emission Database covering the period from 2000 to 2012. The findings reveal that digital inputs make a significant contribution to pollution reduction in Chinese manufacturing enterprises. Specifically, digital software inputs and foreign digital factor inputs display more pronounced effects on pollution reduction. The analysis of the mechanism reveals that the pollution reduction effects of digital inputs in manufacturing enterprises can be attributed to several effective mechanisms: the enhancement of energy efficiency, technological innovation, and servitization, as well as the crowding-out effect of pollution control investment. The former mechanisms demonstrate a promoting effect, while the latter exhibits an inhibiting effect. The impact of digital inputs on pollution reduction in manufacturing enterprises displays heterogeneity, with a more significant emission reduction effect observed in industries facing higher environmental regulatory intensity, digitization-unrelated industries, non-state-owned firms, and firms with higher levels of financing constraints. These findings offer empirical evidence and serve as a policy foundation for promoting digital transformation and achieving green economic development in China. [Display omitted] • The findings reveal a significant positive effect of digital inputs on pollution reduction. • Digital inputs reduce pollution by improving energy efficiency, promoting technological innovation, and facilitating servitization. • The investment in pollution control is diminished as a result of digital inputs. • The promotion effect of digital inputs on pollution reduction exhibits heterogeneity across different enterprises. [ABSTRACT FROM AUTHOR]

To curb the increasing pollutant emissions that have accompanied rapid economic growth, China implemented a mandatory emissions control system since the 11th Five-Year Plan (FYP) period, and the emission reduction targets have been met and even exceeded. This article explores how China achieved its emissions reduction targets by systematically identifying the main emission reduction pathways, including both the environmental and economic factors, and evaluates the contribution of each factor using structure decomposition analysis. A study of the two key controlled pollutants, industrial sulfur dioxide (SO 2 ) and chemical oxygen demand (COD), during the 11th FYP period showed that (i) changes in the end-of-pipe treatment and pollutant generation coefficient were the dominant contributors to emissions reduction. The power and metal smelting sectors played important roles in SO 2 abatement, while the paper products and food products sectors were important in COD reduction; (ii) changes to the input coefficient increased overall emissions although there was a decrease in SO 2 emissions in 2007–2010 mainly due to input structure improvements in the construction sector; (iii) the trade effect largely offset the domestic emission reduction effects, although the trade effect declined during the study period; (iv) domestic demand was the main factor increasing domestic emissions; domestic investment changes (especially in the construction sector) were the major contributor to increases in SO 2 emissions, and final consumption changes (especially consumption in the food production sector) were the main contributor to the increase in COD emissions. The results yield important implications for China's pollution emissions control policies. [ABSTRACT FROM AUTHOR]

There is a need for simple, maintenance-free technologies for removing nitrogen (N) from aquaculture effluents. Denitrifying woodchip bioreactors have been used successfully to remove nitrate-N (NO 3 -N) from ground and surface waters and may potentially be applied to dilute aquaculture effluents as well. Real-life applicability in commercial, outdoor fish farms including practical start-up issues such as e.g. time till stable performance and potential leaching are, however, unknown to the industry. This case study consequently investigated the temporal performance of a woodchip bioreactor (12.5 m 3 ) during start-up. The bioreactor was operated end-of-pipe at a commercial, outdoor rainbow trout ( Oncorhynchus mykiss ) farm in Denmark operated at low recirculation intensity. Applying an empty bed contact time (EBCT) of 5 h, the specific objectives of the study were to resolve: i) how fast the bioreactor would start to remove NO 3 -N; ii) how fast steady state was achieved; iii) which NO 3 -N removal rates could be attained at the relatively low effluent temperature (∼8 °C) and iv) to which extent any concomitant leaching of phosphorous (P), ammonia or organic matter would occur. In- and outlet grab samples were obtained every 6 h until the bioreactor was in steady state (2 weeks) followed by weekly 24 h pooled samples for another 3 weeks (5 weeks in total). Additional grab samples were obtained from 9 sampling ports within the bioreactor on 3 consecutive days during steady state. Samples were analyzed for dissolved nutrients (total N, nitrate, nitrite, ammonium, total phosphorous, ortho-phosphorous, BOD 5 and COD). In addition, oxygen, temperature and pH were logged every 30 min while sampling and alkalinity were measured once a week. Removal of NO 3 -N started immediately and remained stable at 7.06 ± 0.81 g NO 3 -N/m 3 /d (n = 6) throughout the sampling period. Increased effluent NO 2 -N concentrations (peaking at 1.14 mg NO 2 -N/l after 4–5 days) were transiently observed during the initial 11 days. After that, the woodchip bioreactor was largely in steady state with respect to N-balances corroborated by a close match between filtered total-N (TN diss ) and NO 3 -N removal rates. Measurements within the bed showed that the majority of the influent dissolved oxygen (DO) was consumed within the first part of the bioreactor and that NO 3 -N removal thereafter proceeded gradually with distance within the bed. Leaching of non-structural, dissolved organic compounds were observed just after startup, causing a short-term (1 week) increase in effluent concentrations of COD, BOD 5 , P and ammonium. Additional measurements carried out until 147 days after start-up showed that the woodchip bioreactor continued to remove TN diss at an average removal rate of 7.81 ± 0.82 g N/m 3 /d, and that the initial leakage of P stopped altogether. In summary, the study demonstrated that woodchip bioreactors can effectively remove NO 3 -N from dilute aquacultural effluents at low temperatures and commercial conditions and that stable performance is achieved within a few weeks. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) pollution is a great challenge for air environment management. However, macro quantitative research on VOC control technologies (VOCTs) evolution and global knowledge transfer is still lacking. Therefore, we analyzed the 6,636 global patents for VOCTs from 1961 to 2020 in the Derwent Innovation Index database to give a quantitative study, by using patent analysis methods such as text mining and technology life cycle analysis. The results showed that global patents surged from 2014 to 2018, and China held the most patents, followed by the US. Chinese 2013–2017 intensive atmospheric environment governance policy was the main possible reason for the sharp increase of VOC patents. However, very few Chinese patents were transferred. On the contrary, the US was the most important source country for transferred patents, and its main overseas markets were Europe, followed by China. Up to now, absorption and adsorption were the most mature technologies, accounting for 51% of the end-of-pipe patent. Biodegradation and membrane separation patents were active in transfer, indicating their high demand in the global market, so they may be promising technologies in the future. These findings enrich the literature on the evolution and transnational diffusion of VOCTs, and help policy-makers, scholars, and company managers better understand future research directions and the demands of the international market. [Display omitted] • Global 6,636 patents in 1961–2020 on VOCTs were evaluated quantitively. • The U.S. had the strongest VOCTPs market ties with Europe, followed by the U.S. with China. • Over half (51%) of the VOCTPs for end-of-pipe focused on adsorption and absorption. • The technologies of biodegradation and membrane separation were promising directions. [ABSTRACT FROM AUTHOR]

Abstract: Vanadia–titania oxidation catalysts are highly regarded for the abatement of persistent air pollutants including aromatics, chlorinated aromatics, furans and dioxins in gas effluents. Molybdenum and tungsten oxides are recognized as efficient promoters enhancing the efficiency of vanadia-based catalysts. Classical approaches for the preparation of promoted catalysts involve multi-step processes. Here, binary and ternary mixed oxide xerogels are formed in one step by nonhydrolytic condensation reactions of chloride precursors in non-aqueous medium. Calcination was applied to provoke the migration of active and promoting oxides toward the surface, leading to well-spread vanadium, molybdenum and tungsten oxide species on the surface of anatase particles. The resulting catalysts are mesoporous and their composition is precisely controlled, confirming the versatility and reliability of the preparation route. The samples perform well in the deep oxidation of benzene and chlorobenzene, chosen as model volatile organic compounds (VOC). The performances of ternary catalysts systematically exceed those of binary V2O5-TiO2, highlighting the promoting effect of WO3 and MoO3. [ABSTRACT FROM AUTHOR]

Leather is a unique material unmatched in properties by synthetics. Leather making is an environmentally challenged process. Tanning is the key process that renders stability to the skin matrix against microbial degradation, heat, sweat etc. Chromium(III) has been used widely in tanning for the excellent properties that it renders to the leather along with simplicity of operation. The reported toxicity of chromium compounds coupled with poor uptake of chromium during tanning process has challenged the continued use of this process. Problems associated with tanning have been classified as avoidable, controllable and unavoidable. Technological developments in avoidance and control of pollution in leather processing have come forth. There are both in-plant and end-of-pipe treatment solutions. This paper surveys the development of technologies that have rendered the tanning process eco-sustainable. A call for further understanding of the chemistry of tanning and need for cross-fertilization of ideas is made for enabling the greening of the tanning industry. [Copyright &y& Elsevier]

Geopolymer is a new type of inorganic polymer materials synthesized by reaction of natural mineral or industrial aluminosilicate solid wastes with aqueous solution of alkali-activator under the curing condition of room temperature or below 100 °C. Many research results demonstrated that the chemical structure and physical properties strongly depended on the raw material chemical composition and preparation conditions. Even though geopolymer as new construction material has been extensively investigated in recent years, the essential brittleness still limits it as commercial building material for the application in the field of municipal engineering. Hence, it was urgent for researchers to explore some alternative approaches. Recently, a number of studies reported that the geopolymers were used as various catalysts for environmental governance. The present review described the latest progresses on the synthesis techniques of the geopolymer-based catalysts in detail, and then focused on the current applications in the environmental governance from the view of source control and end-of-pipe treatment, in which the source control included hydrogen generation, biodiesel production and other heterogeneous catalysis, and the end-of-pipe treatment contained photocatalytic degradation of dye wastewater and gas purification. It is considered that the geopolymer is a promising candidate for recycling of industrial solid waste and developing cost-effective heterogeneous catalysts for environmental governance. Image 1 • The synthesis technologies of geopolymer-based catalysts are summarized in detail. • This paper focuses on geopolymer-based catalysts for environmental governance. • The applications were described based on source control and end-of-pipe treatment. • Mechanisms of photocatalytic dye degradation and H 2 yield are diagrammatized. • Geopolymer as eco-friendly catalyst has the characteristics of resource recycling. [ABSTRACT FROM AUTHOR]