Long-term evolution of carbonaceous aerosols in PM2.5 during over a decade of atmospheric pollution outbreaks and control in polluted central China

Against the backdrop of an uncertain evolution of carbonaceous aerosols in polluted areas over the long term amid air pollution control measures, this 11-year study (2011-2021) investigated fine particulate matter (PM2.5) and carbonaceous components in polluted central China. Organic carbon (OC) and elemental carbon (EC) averaged 16.5 and 3.4 μg/m3, constituting 16 and 3 % of PM2.5 mass. Carbonaceous aerosols dominated PM2.5 (35 and 27 %) during periods of excellent and good air quality, while polluted days witnessed other components as dominants, with a significant decrease in primary organic aerosols and increased secondary pollution. From 2011 to 2021, OC and EC decreased by 53 and 76 %, displaying a high-value oscillation phase (2011-2015) and a low-value fluctuation phase (post-2016). A substantial reduction in high OC and EC concentrations in 2016 marked a milestone in significant air quality improvement attributed to effective control measures, especially targeting OC and EC, evident from their decreased proportion in PM2.5. Primary OC (POC) in winter exhibited the most pronounced reduction (8 % per year), and the seasonal disparities in PM2.5 and carbonaceous components were reduced, showcasing the effectiveness of control measures. Contrary to the more pronounced reduction of EC, which decreased in proportion to PM2.5, secondary OC (SOC) in PM2.5 exhibited an increasing trend. Along with rising OC/EC, SOC/OC, and SOC/EC ratios, this indicates a growing prominence of secondary pollution compared to the decrease in primary pollution. SOC shows an increasing trend with NO2 rise (r = 0.53), without O3 promoting SOC. Positive correlations of SOC with SO2, CO (r = 0.41, 0.59), also highlight their influence on atmospheric conditions, oxidative capacity, and chemical reactions, indirectly impacting SOC formation. The implementation of precise precursor emission reduction measures holds the key to future efforts in mitigating SOC pollution and reducing PM2.5 concentrations, thereby contributing to improved air quality.

Synergistic disparities of pollution reduction and carbon mitigation in the industrial chain: Evidence from China's industrial sector

The synergistic enhancement of pollution reduction and carbon mitigation (PRCM) is an inevitable requirement for China's ecological civilization construction. Existing studies primarily focus on macro-level research, and there is a relative lack of research specifically addressing the micro-level of industrial chains. Based on non-competitive IO tables, this study employed the structural path decomposition analysis method to analyze the synergistic disparities of the PRCM industry chain and its driving factors. The findings reveal: (1) The crucial emission industrial chains for CO2, SO2, and PM show a high overlap degree, accounting for 46.67 %, 46.67 %, 60.00 %, 50.00 %, and 56.67 % during 2002-2020. The PRCM industrial chains are operating at a low synergistic level, with proportions of only 13.33 %, 23.33 %, 20.00 %, and 16.67 %. PRCM exhibits a "similar origin with different paths" phenomenon. (2) China's carbon mitigation policies can reduce pollution, whereas pollution reduction policies have limited carbon mitigation effects. (3) The emission control effect is the primary disparate factor in PRCM synergy, while other factors exhibit consistent impact direction to three emissions. The study's conclusions and corresponding policy suggestions hold significant theoretical and practical implications for relevant authorities to systematically plan synergistic emission reduction pathways and establish targeted synergistic policies.

Fiscal policy, green finance, and low carbon transformation nexus: a novel study unleashing the synergistic effects of carbon reduction and pollution in China

Under the simultaneous demands of combating environmental pollution and decreased carbon emissions, it is critical to investigate the combined effect of agricultural contamination reduction and fiscal policy carbon reduction to support and promote green agriculture and low-carbon transformation. Based on provincial panel data of 2007 to 2020 in China, this paper employs the spatial Dubin model to empirically examine the pollution reduction and carbon reduction effects of fiscal policies supporting agriculture, as well as calculating the synergistic effect of pollution reduction and carbon reduction. Our study's findings reveal that non-point source agricultural pollution and agricultural carbon emissions have a tendency of growing and subsequently reducing, such as increasing from 2007 to 2015 and decreasing from 2016 to 2020. Second, results demonstrate that agricultural carbon emissions and agricultural pollution have a positive geographical dependency in each province, and fiscal policies supporting agriculture have high-high and low-low spatial clustering features. Furthermore, fiscal policies that promote agriculture can lower local agricultural carbon emissions and pollution while also having a considerable beneficial spillover impact on neighboring provinces. According to the study findings, the fiscal policy for supporting agriculture has a negative pollution reduction impact and a positive synergistic effect, resulting in a synergistic effect of agricultural pollution reduction and carbon reduction. The outcomes of this study can serve to promote carbon-reduction measures and provide recommendations for future policy development.

Synergetic benefits of pollution and carbon reduction from fly ash resource utilization-Based on the life cycle perspective

Synergetic reduction of pollution and carbon is a key strategy for the fundamental improvement of ecological and environmental quality and carbon neutrality. Solid waste resource utilization can reduce the secondary pollution caused by conventional solid waste disposal and presents evident environmental potential. Based on the comparable system boundaries, this study adopts life cycle assessment (LCA) to compare the environmental impact of three fly ash utilization paths. The synergy index is then defined according to six environmental impact indicators to quantitatively evaluate the synergetic effects of carbon emission and pollutant reduction. The results confirm the possibility of fly ash resource utilization for synergetic pollution and carbon reduction and demonstrate the synergetic emission reduction potential of the solid waste resource utilization supply chain. This study is both an application of the life cycle assessment model in the solid waste utilization and disposal field and provides insight into the pathway of pollution and carbon reduction in China.

Introducing new green machining technology to enhance process performance and reduce environmental pollution in the metal processing industry

The pursuit of enhanced cooling and lubrication methods for machining processes that are energy-efficient, environmentally friendly, and cost-effective is receiving significant attention from both academia and industry. The reduction of CO2 emissions is closely tied to electrical and embodied energy consumption. This study introduces a novel LN2 oil-on-water (LNOoW) cooling/lubrication (lubricooling) approach for the machining of Ti-6Al-4V alloy. Machinability aspects, energy-related aspects, environmental-related aspects, and economic aspects are measured and compared. More specifically, surface quality, electrical energy, cutting forces, and tool wear were measured in machinability aspects. Similarly, specific total energy and specific cumulative Energy Demand (S_CED), specific carbon emission, and production costs were measured to investigate the energy and environmental and economic aspects, respectively. The LNOoW provided the best machinability results compared with other approaches. Result found that LNOoW produced 37.5% better surface quality, removed 159.17% more material, and reduced 50.56% specific cutting energy and 53.63% specific costs as compared to traditional dry cutting conditions. The 39% increment in specific carbon emissions observed in the LN2 oil-on-water (LNOoW) approach in comparison to the dry-cutting method can be mitigated through the implementation of sustainable practices in the production of liquid nitrogen (LN2). The information provided in this study serves as a valuable resource for the development of environmentally friendly machining processes. The study also helps get the sustainable development goals (SDGs) of the United Nations.

How environmental decentralization affects the synergy of pollution and carbon reduction: Evidence based on pig breeding in China

Reducing pollution and carbon is essential to achieve China's goal of "carbon peaking and carbon neutrality"; however, the collaborative paths of pollution and carbon reduction remain vague and worth exploring. This paper analyses panel data from 30 provinces in China from 2002 to 2017 to determine the impact of environmental decentralization on the synergy of pollution and carbon reduction in pig farming. The result shows that environmental decentralization has a significant 'carbon reduction effect' and 'pollution reduction effect' on pig farming; it is also conducive to promoting the synergistic effect of reducing pollution and carbon emissions through supporting environmental facilities and industrial organisations. Various types of environmental decentralization have significant differences in the synergy of pollution and carbon reduction. The scale of pig breeding plays a positive regulatory role in the impact of environmental decentralization on the synergy of pollution and carbon reduction while showing regional heterogeneity. This research is crucial for advancing the green transformation of pig breeding.

Economic growth targets and green technology innovation: mechanism and evidence from China

Economic growth target management is a government behavior that the authorities formulate at a specific time and direct the allocation of resources. Despite the importance of socio-economic development, economic growth targets have caused some potential hazards to the environment that cannot be ignored. Using a panel dataset of 278 prefecture-level cities in China over the period 2004-2019, the study employed a two-way fixed effects model to verify the inhibition effect of economic growth targets on green technology innovation (GTI). The results indicated that economic growth targets and hard constraints tended to have a significantly negative effect on GTI. More importantly, the results of the mediation effect test suggested a positive correlation between economic growth targets and the government fiscal expenditures and market segmentation, and both mediators played an intermediary role in the influence of economic growth target constraints restraining GTI. Other findings showed that the economic growth targets of prefecture-level cities had different impacts on GTI, which resulted from the different resource endowments, geographic locations, or periods. Overall, the results suggest that policymakers should lower the economic growth targets and use soft constraints to set them. The conclusions of this paper are applicable to policymakers not only in China but also other economies that regularly set economic growth targets.

Does the Emission Trading Scheme achieve the dual dividend of reducing pollution and improving energy efficiency? Micro evidence from China

Resolving the negative externality of environmental pollution has always been a concern in both the theoretical and practical space. To stimulate enterprises to participate in environmental governance actively, China has implemented a series of environmental regulation policies. The Emission Trading Pilot Scheme (ETPS) is an example of such policies implemented to ensure the gradual transition toward marketization. From a micro-enterprise perspective, the study examines how this policy achieves the dual effects of reducing emissions and promoting energy efficiency. We further explore potential channels through which this policy influences the dual effects. We empirically find ETPS to reduce the pollution emissions of enterprises significantly. However, the pollution reduction effect is mainly achieved by encouraging enterprises to strengthen cleaner production rather than through end governance. In addition to bringing environmental dividends, we observe ETPS to improve fossil energy efficiency by about 7.5% indirectly. We conclude by urging policy makers and participants to optimize energy structures and adjust intermediate input as they serve as significant pathways through which ETPS can affect fossil energy efficiency. The ETPS can encourage enterprises to actively step out of their "comfort zone" of environmental governance to be viewed as an effective environmental regulation policy.

Effects of fertilizer application on phthalate ester pollution and the soil microbial community in plastic-shed soil on long-term fertilizer experiment

Due to the use of agricultural film, the pollution of phthalate esters (PAEs) in plastic-shed soils has attracted increasing attention. In this study, we used watermelon as a planting system and investigated the effects of organic fertilizer and chemical fertilizer application on the degradation of PAEs by evaluating soil nutrients and soil bacterial communities in plastic-shed soil. The dibutyl phthalate (DBP) concentration in the organic fertilizer soil was only 58.2% in the zero-fertilization control (CK) soil, but the concentrations of monohexyl phthalate (MEHP) and mono-n-butyl ester (MBP), the metabolites of PAEs, were found to be higher. The concentration of MBP is ten times that of DBP. The results showed that fertilization, especially the application of organic fertilizers, had a significant effect on the degradation of PAEs. There were specific biomarkers in different fertilization treatments. Among the microbiome community, Planifilum had the highest relative abundance in the organic fertilizer (OF) soil, and the highest proportion of Thermodesulfovibrionia was detected in the chemical fertilizer (CF) soil. These biomarkers were significantly correlated with PAEs and their metabolites. The relative abundance of Thermomonosporaceae was significantly positively correlated with DBP. Planifilum and Thermaerobacter, which significantly increased in organic fertilizer soil, showed a significant negative correlation with DBP and a significant positive correlation with MBP. The relative abundances of Planifilum and Geobacillus were elevated in the OF soil and may be able to co-metabolize soil nitrogen and PAEs. PAEs and their metabolites in soils had significant effects on soil microbes, as did the soil nutrients including available phosphorus (AP), alkali-hydrolysable nitrogen (Alkali-N), and organic matter (OM). Our research provides scientific support for the use of fertilizers to reduce PAE contamination but also warns of the potential risks of PAE metabolites.

Plant growth promoting strain Bacillus cereus (RCS-4 MZ520573.1) enhances phytoremediation potential of Cynodon dactylon L. in distillery sludge

Elevated levels of physico-chemical pollution including organic pollutants, metals and metalloids were detected in distillery sludges despite of the anaerobic digestion treatment prior to disposal. The concentrations of the metals were (in mg kg^-1): Fe (400.98 ± 3.11), Zn (17.21 ± 0.54), Mn (8.32 ± 0.42), Ni (8.00 ± 0.98), Pb (5.09 ± 0.43), Cr (4.00 ± 0.98), and Cu (3.00 ± 0.10). An invasive grass species, Cynodon dactylon L., demonstrated its ability to remediate the distillery waste sludge (DWS) in the field study. All the physico-chemical parameters of the sludge significantly improved (up to 70-75%) in the presence of Cynodon dactylon L. (p < 0.001) than the control with no plant growth. The highest phytoremediation capacity was associated with the uptake of Fe in the root and shoot. Sludge samples collected near the rhizosphere also showed lower amount of organic compounds compared to control sludge samples. Metal resistant Bacillus cereus (RCS-4 MZ520573.1) was isolated from the rhizosphere of Cynodon dactylon L. and showed potential to enhance the process of phytoremediation via plant growth promoting activities such as production of high level of ligninolytic enzymes: manganese peroxidase (35.98 U), lignin peroxidase (23.98 U) and laccase (12.78 U), indole acetic acid (45.87(mgL^-1), phosphatase activity (25.76 mg L^-1) and siderophore production (23.09 mg L^-1). This study presents information on the performance of Cynodon dactylon L., an abundant invasive perennial grass species and its associated plant growth promoting rhizobacteria demonstrated good capacity to remediate and restore contaminated soil contained complex organic and inorganic pollutants, they could be integrated into the disposal system of distillery sludge to improve the treatment efficiency.

Vegetable wastes as a bio-additive for low-salt preservation of raw goat skin: An attempt to reduce salinity in leather manufacture

Preservation or curing of hides/skins is performed as the primary step of leather processing to conserve them from putrefaction. Normally preservation is carried out using common salt (NaCl), which is discharged in the soak liquor contributing to ~ 70%, of total dissolved solids (TDS) load of entire leather manufacturing. In an attempt to reduce the TDS and chlorides, phyto-based preservation using garlic peel (Allium sativum) and white onion peel (Allium cepa) was carried out. Different concentrations of salt in combination with garlic peel and white onion peel were applied on freshly flayed goat skins based on its green weight and compared to control (40% salt). Sensory evaluation of the preserved skin was done by assessing different parameters like hair slip, putrefaction and odour. Estimation of hydroxyproline (HP) release, moisture content and microbial load were carried out at regular intervals. Skins that remained in good condition for 14 days were further processed into leather and properties were examined which were found comparable to the conventionally cured skins. Hence, this cleaner curing technique helps in reducing the TDS and chlorides in the effluent, thus controlling the pollution caused by tanneries through sustainable leather processing.

Environmental regulation, import trade, and green technology innovation

To further clarify the relationship between environmental regulation and green technology innovation and discuss how environmental regulation affects green technology innovation through import trade, this paper analyzes the impacts of environmental regulation and import trade on green technology innovation and the transmission effect of import trade based on panel data for 30 provinces in China for 2008 to 2017. The results show that (1) environmental regulation first plays a role in promoting green technology innovation and then restrains it, and import trade can significantly promote green technology innovation; (2) under the constraints of stronger environmental regulations, import trade has a significantly positive effect on green technology innovation; and (3) environmental regulation can further enhance the technology spillover effects of import trade in regions with high absorptive capacity and regions with high levels of R&D investment. This paper analyzes the impact of environmental regulation on green technology innovation from the perspective of import trade and makes up for the deficiencies of existing research. It also lays a foundation for scholars to study the relationship between environmental regulation and green technology innovation in the midst of heterogeneous government regulation capabilities and industries in the future.

Simultaneous sludge minimization, pollutant and nitrogen removal using integrated MBBR configuration for tannery wastewater treatment

An advanced operational configuration of anoxic-aerobic moving bed biofilm reactors (AMOMOX process) was experimentally demonstrated to achieve simultaneous sludge yield minimization, pollution and nitrogen removal. The AMOMOX experimentation witnessed considerable variation in process parameters while feed operation changed from synthetic wastewater to real tannery influent. The strict maintenance of operational strategies resulted prominent removal of TCOD, SCOD, ammonia nitrogen and total nitrogen higher upto 93.5%, 94.8%, 95.2% and 88.7% respectively. The nourishment of filamentous microbiota and purposeful promotion of cell-lysis effectively sustained sludge yield restriction. Here, the sludge yield (Y_obs) lowering upto 0.51 gVSS/gCOD ultimately turned an overall sludge minimization of 46.8% compared with a parallel-run conventional activated sludge treatment. The observations were further supported by sophisticated instrumental imaging, thermogravimetric analysis and batch digestion test of the sludge pool. The experimental Y_obs and corresponding solids retention showed consensus with the reported correlation model and, thus, a modified correlation was tested.

Do carbon emissions impact Nepal's population growth, energy utilization, and economic progress? Evidence from long- and short-run analyses

Greenhouse gases are the major issues globally leading to climate change and increased pollution of the atmosphere. CO₂ emissions have divergent effect to the environment that also causes the economic performance of any country. The main motive of this analysis was to expose the influence of CO₂ emission on population growth, fossil fuel energy consumption, economic progress, and energy usage in Nepal by using time series data ranging from 1971 to 2019, and data stationarity was checked with the help of unit root tests. An autoregressive distributed lag (ARDL) method with cointegration test was employed to adjudicate the variable dynamics with short- and long-run evidence. Furthermore, variable causality was tested through the Granger causality test. Study findings show that during long-run analysis that fossil fuel energy consumption and energy utilization has constructive affinity with carbon dioxide emission that exposed the p-values (0.0000) and (0.1065) correspondingly, while population growth and economic progress uncovered an inimical relation to CO₂ emission. Similarly, the outcomes via short-run analysis also show that fossil fuel energy consumption and energy utilization have productive relation with CO₂ emission which shows the p-values (0.0000) and (0.1317), while population growth and economic progress demonstrate an adverse influence to CO₂ emission. The causality test results also validate a unidirectional linkage among variables. In attempt to participate in the global fight to clean up the atmosphere, the Nepali government and officials must take new measures to reduce CO₂ emissions.

Pretreatment of industrial wastewater by natural flotation: application to pollution reduction from vegetable oil refinery wastewaters

The objective of this study is to evaluate the effectiveness of the natural flotation process in reducing pollution with reasonable investment and operating costs of an industrial effluent of refining vegetable oils. Flotation tests were carried out in separating funnels and in drums of 30 l. The results obtained have shown that the volume of sludge produced during flotation is related to the pollutant load of the wastewater studied (process wastewater and acidic wastewater). The sludge volume is respectively 600, 12, and 120 ml/l for heavy, light, and medium loads respectively. Therefore, it is essential to find an effective way to remove oils and greases from polluted waters. Natural flotation eliminates on average 88% of COD for acid wastewater and 50% for process wastewater. However, the reduction of BOD5 showed 28 and 43% respectively for acid wastewater and process wastewater. In addition, the yield of fats and oils, TSS, and turbidity varies around 85%, 45%, and 88% respectively for acidic wastewater, while for process wastewater, elimination yields vary around 58%, 46%, and 46% respectively for the grease and oil parameters, the MES, and the turbidity. Flotation allows the elimination of 10659 Kg/day of greases and oils for process wastewater while it eliminates 5765 Kg/day for acidic wastewater. This reduces the cost of treatment related to chemicals and energy. Reducing pollution of wastewater by natural flotation could therefore help reduce the costs of treating wastewater, and recycling would then be more attractive for this purpose for the company.

Experimental investigation on solar-powered ejector refrigeration system integrated with different concentrators

The objective of the work is to analyse and to improve the efficiency of solar-powered ejector refrigeration system integrated with flat-plate collector and Scheffler concentrator. The Scheffler concentrator of 2.7 m² and flat-plate collector of 5 m² collecting area are coupled with the storage tank of 15 l capacity. The developed system was designed for a potential replacement of conventional 1-ton room air conditioner with much reduced electrical energy consumption. The system was built based on two key subsystems namely 'Scheffler concentrator-based vapour system' and 'ejector-based cooling system'. The pilot effort showed promising results with the probability of energy-saving potential as near 70 to 80% over conventional air conditioners.

Process assessment, integration and optimisation: The path towards cleaner production

This contribution starts from the broad perspective of the global material cycles, analysing the main resource and pollution issues world-wide from the viewpoint of the disturbances to these cycles caused by human activities. The issues are analysed in the light of the currently developing COVID-19 pandemic with the resulting behavioural and business pattern changes. It has been revealed in the analysis of previous reviews that there is a need for a more comprehensive analysis of the resource and environmental impact contributions by industrial and urban processes, as well as product supply chains. The review discusses the recent key developments in the areas of Process Integration and Optimisation, the assessment and reduction of process environmental impacts, waste management and integration, green technologies. That is accompanied by a review of the papers in the current Virtual Special Issue of the Journal of Cleaner Production which is dedicated to the extended articles developed on the basis of the papers presented at the 22nd Conference on Process Integration for Energy Saving and Pollution Reduction. The follow-up analysis reveals significant advances in the efficiency and emission cleaning effects of key processes, as well as water/wastewater management and energy storage. The further analysis of the developments identifies several key areas for further research and development - including increases of the safety and robustness of supply networks for products and services, increase of the resources use efficiency of core production and resource conversion processes, as well as the emphasis on improved product and process design for minimising product wastage.

A model for evaluating green credit rating and its impact on sustainability performance

The development of economic activities and social progress index leads to the governmental considerations for the environmental challenge's issues. The Green Credit Policy (GCP) in China for manufacturing, as a part of a sustainable finance package, initiatives restrictions with suppliers to reduce harmful pollution for the environment. The study mainly validates the impact of GCP on manufacturing for diminishing the emerged pollution to the environment. The study develops Neutrosophic Multiple-Criteria Decision-Making Framework (N-MCDMF) according to neutrosophic theory and various MCDM methods of grey relational analysis (GRA), analytic network process (ANP), the Decision-Making Trial and Evaluation Laboratory technique (DEMATEL), and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to support the decision-makers with highly systematic procedures in the uncertain and inconsistent environmental conditions. The N-MCDMF evaluates the conditions of GCP and recommends the optimal Supply Chain Management (SCM) in manufacturing alternatives. A case study is presented for the validation of the issues of applicability and flexibility for the proposed N-MCDMF. The results obtained from the implementation of the N-MCDMF indicates the applicability and flexibility of the proposed approach. In addition, results show that SCM in manufacturing can provide more cooperation for the environment to reduce harmful pollution and to attain sustainability for achieving motivations under the restrictions of GCP.

Diurnal and temporal changes in air pollution during COVID-19 strict lockdown over different regions of India

Lockdown measures to contain COVID-19 pandemic has resulted in a considerable change in air pollution worldwide. We estimate the temporal and diurnal changes of the six criteria air pollutants, including particulate matter (PM2.5 and PM10) and gaseous pollutants (NO2, O3, CO, and SO2) during lockdown (25th March - 3rd May 2020) across regions of India using the observations from 134 real-time monitoring sites of Central Pollution Control Board (CPCB). Significant reduction in PM2.5, PM10, NO2, and CO has been found in all the regions during the lockdown. SO2 showed mixed behavior, with a slight increase at some sites but a comparatively significant decrease at other locations. O3 also showed a mixed variation with a mild increase in IGP and a decrease in the South. The absolute decrease in PM2.5, PM10, and NO2 was observed during peak morning traffic hours (08-10 Hrs) and late evening (20-24 Hrs), but the percentage reduction is almost constant throughout the day. A significant decrease in day-time O3 has been found over Indo Gangetic plain (IGP) and central India, whereas night-time O3 has increased over IGP due to less O3 loss. The most significant reduction (∼40-60%) was found in PM2.5 and PM10. The highest decrease in PM was found for the north-west and IGP followed by South and central regions. A considerable reduction (∼30-70%) in NO2 was found except for a few sites in the central region. A similar pattern was observed for CO having a ∼20-40% reduction. The reduction observed for PM2.5, PM10, NO2, and enhancement in O3 was proportional to the population density. Delhi's air quality has improved with a significant reduction in primary pollutants, however, an increase in O3 was observed. The changes reported during the lockdown are combined effect of changes in the emissions, meteorology, and atmospheric chemistry that requires detailed investigations.

Effect of plant hedgerows on agricultural non-point source pollution: a meta-analysis

Eutrophication has been a critical environmental issue due to soil nitrogen (N) and phosphorus (P) loss in runoff from agricultural lands. Plant hedgerow is an important measure to prevent soil erosion and reduce agricultural non-point source pollution (NPSP). In the present study, we searched 3683 research papers on plant hedgerows published from 1980 to March 2020. After screening, we used 53 effective papers on plant hedgerows for the meta-analysis by using Stata 15.1. The results showed that plant hedgerows significantly increased soil organic matter (SOM) (standardized mean difference (SMD) = 1.46; 95% confidence interval (CI) = 1.12-1.80 > 0), total N (TN) (SMD = 1.33; 95% CI 0.98-1.68 > 0), total P (SMD = 0.73; 95% CI 0.26-1.20 > 0), alkali N (SMD = 0.86; 95% CI 0.52-1.21 > 0), available P (SMD = 1.28; 95% CI 0.75-1.81 > 0) and readily available potassium (K) (SMD = 1.20; 95% CI 0.75-1.65 > 0) concentrations but exhibited no significant effects on soil total K concentration (SMD = 0.17; 95% CI - 0.13-0.47 < 0). Plant hedgerows showed a greater effect on SOM increase than soil N, P, and K, and soil TN increase than the available state, but the opposite trend was observed for P and K. This meta-analysis can clarify the influence of plant hedgerows on soil nutrients and provide ideas for the prevention and control of agricultural NPSP.

Measuring China's regional inclusive green growth

In response to the increasing pressure of global resource management and environmental issues and a slowdown in the related economic growth, China has proposed an inclusive green growth strategy based on coordination between society, the economy, and the environment. The alignment of resources with the socio-economic development goals is a key issue that must be addressed for inclusive green growth. A comprehensive directional distance function and slacks-based measure model are proposed to evaluate the inclusive green growth levels of 285 cities in China from 2003 to 2015. The Luenberger indicator is used to decompose the drivers of inclusive green growth. Our research shows that the main obstacle to China's inclusive green growth is the magnitude of technical change, which is not aligned with China's green development level. Hence, it is necessary to coordinate overall inclusive green growth levels using both technical and regional aspects. This research provides a reference not only for China's economic green development, but also for that of developing countries, enabling the coordination of economic development and environmental resource protection.

China's industrial gray water footprint assessment and implications for investment in industrial wastewater treatment

Industrial wastewater is the largest contributor of toxic pollutants and third-largest contributor of nutrients to bodies of water in China, and understanding the characteristics of such pollution is important for water pollution control. In this study, the industrial gray water footprint (GWF) of each industry sector in China's 31 provinces in 2015 was calculated to identify the pollution characteristics of industrial wastewater discharge and determine how to efficiently allocate investment to pollution reduction. We show that the total industrial GWF of China was 300 billion m³ in 2015 and that the major pollutants were petroleum pollutant (PP), ammonia nitrogen (NH₃-N), volatile phenol (VP), and chemical oxygen demand (COD). The water pollution level (WPL) was higher than 1 in Ningxia, Shanxi, Hebei, Tianjin, Shanghai, Henan, and Shandong, indicating that industrial pollution exceeded the carrying capacity of local water bodies in these seven regions. Given equivalent total investment, a scenario that takes the total reduction of the industrial GWF weighted by the WPL in each region as the investment target can better allocate funds to control industrial wastewater pollution in regions with high WPLs relative to a scenario in which investment targets the reduction of the unweighted total industrial GWF. For further industrial GWF reduction in regions with high WPLs, it is crucial to adjust the industrial structure and to upgrade relevant technologies.

Studies on the use of sodium polyacrylate (SPA) for low-salt animal skin preservation

Salt-based preservation is practiced for decades in the leather industry because of its versatility, cost-effectiveness, and availability. The salt removed from the soaking process causes significant pollution including organic and elevated total dissolved solids (TDS). Hence, a low-salt skin preservation method using commercial sodium polyacrylate with a reduced quantity of sodium chloride aiming to retain leather properties and pollution reduction was the principal focus of the study. Commercial sodium polyacrylate initially characterized for water absorption capacity along with structural and functional properties is confirmed by NMR and IR spectroscopic techniques. In preliminary experiments, the process parameters attained optimized conditions of sodium polyacrylate (SPA) quantity (5%), a minimal amount of salt (15%), and contact time (4 h) required for skin preservation. Besides, reusability studies after SPA recovery (95%) were applied to skins with an optimized quantity of SPA and salt subsequently stored for 15 days along with control (40% salt). The results revealed that SPA with low salt aided an adequate curing efficiency with a substantial reduction (> 65%) of TDS and comparable physical and organoleptic properties on par with the conventional method. Overall, SPA supported low-salt skin preservation reduces pollutant load (TDS) caused due to using of 40% sodium chloride in the conventional curing process.

High sorption of reactive dyes onto cotton controlled by chemical potential gradient for reduction of dyeing effluents

This research uses soybean oil/water dual-phase solvents system (SWDS) to achieve high dye fixation as well as minimal discharge of waste effluents. Reactive dyeings are one of the most serious pollution sources and few dyeing technologies developed could successfully reduce the generation of toxic substances without decreasing dyeing qualities. Through a remarkable increase in chemical potential of dyes in dyeing medium, SWDS remarkably increased the dye concentration in the internal solvent phase. As a result, % exhaustion of dye was 100%, and % fixation of dye was up to 92% in SWDS. Final discharges of dyes and salts from SWDS were decreased by 85% and 100%, respectively, compared to that from the conventional aqueous system. More than 99.5% of initially added biodegradable soybean oil could be recycled for reactive dyeing without treatments. Furthermore, SWDS could be readily applied in jet-dyeing machines on a pilot scale. Via the reuse of soybean oil, SWDS could save up to $0.26 per kg of fabric compared to aqueous dyeings in terms of materials cost.

Air pollution reduction in China: Recent success but great challenge for the future

China's rapid economic growth has caused severe air pollution, raising serious concerns about the growing evidence of its negative health, environmental, and economic impacts. Consequently, the Chinese government has implemented a number of policies and measures to reduce air pollution. Relying on published information over the last three decades in China, we analyzed trends in air pollutant emissions (SO₂ and NO_x) and concentrations of particulate matter (PM) and ozone (O₃). During the past decade, SO₂ and NO_x emissions had declined throughout China and concentrations of PM_2.5 and PM₁₀ had considerably decreased in most cities, but average reported 90th MDA8 O₃, M7, and AOT40 O₃ for 31 capital cities showed an increasing trend between 2013 and 2017. Despite progress in air pollution reduction and an increasing number of "clear sky" days, PM concentrations throughout China remain higher than the World Health Organization guidelines, and urban smog and haze remain a major threat to human health and the environment. Thus far, significant emission reductions have occurred largely through robust administrative power, especially when emission reductions were tied to the performance evaluations and promotion of government officials. Similar to most already-industrialized nations, China is now shifting away from SO₂-dominated to NO_x- and O₃-dominated air pollution. Existing technologies and improved operations of existing control equipment appear unlikely to achieve sufficient reductions in NO_x and O₃ pollution. Considering the complex relationship between O₃, NO_x, VOCs, weather, and socio-economic changes in China, it is necessary to increase research on impacts of increasing ozone on plants and to adopt novel technologies and implemented to further reduce air pollution to levels that will protect human health and the environment.

Training artisanal miners: A proposed framework with performance evaluation indicators

Worldwide, approximately 30 million people depend directly on artisanal mining of many different minerals to provide for themselves and their families. However, poverty and a lack of education and training keep artisanal miners trapped in a cycle of rudimentary practices, which generate both environmental and health impacts. As the needs and motivations of artisanal miners are often ignored, previous attempts to deliver training projects have resulted in little sustained success. A successful training project for artisanal miners should be site-specific, including implementation of a thorough evaluation plan to monitor progress of the project's initiatives through established indicators. Frequently, training projects are restricted to the specifications of the funding donor, instead of designing initiatives that adequately reflect the realities of the context in which the training will take place. Furthermore, it is imperative that any training project uses a bottom-up approach that incorporates knowledge garnered from the successes and mistakes of previous projects. In this study, after analysis of previous and current training efforts, the attributes of a successful training project were outlined, including the importance of training champions within artisanal miner communities, drawing effectively on government support, and providing simple, affordable and profitable techniques to improve productivity and reduce environmental impacts. In addition, a framework with performance indicators was mapped out to show how a successful training project could be designed, implemented, monitored and evaluated, including the need to incorporate inclusive consultation, cultural sensitivity and consistently applied protocols into every step of the project. Instead of instructing practitioners on what the training should cover, the framework outlines how a training project's design can be informed by the needs of a particular mining sector. Ultimately, this kind of framework can serve as a template for practitioners working in diverse sectors around the world.

A Monte Carlo-based integrated model to optimize the cost and pollution reduction in wastewater treatment processes in a typical comprehensive industrial park in China

Wastewater generated from an industrial park is usually characterized by large volumes, variation in composition, and high pollutant concentrations, and is generally toxic and difficult to biodegrade. Wastewater treatment at an industrial park includes several stages, namely, pretreatment inside factories (F-WWTPs), centralized wastewater treatment (C-WWTP), and reclaimed wastewater treatment (R-WWTP), during which the treatment efficiencies are mutually restricted. Therefore, water pollution control in industrial parks is extremely challenging. In this study, models, including those for pollutant reduction and operating costs, were established considering the F-WWTPs, C-WWTP, and R-WWTP stages at an industrial park. A Monte Carlo model was used to simulate the treatment and solve the above-mentioned models. Consequently, the characteristic values, including the extent of pollutant reduction, concentration of pollutants in the effluent, and operation costs, were predicted under optimal operating conditions of the wastewater treatment system. The established model was verified and applied to industrial park A in the Tianjin Economic-Technological Development Area in China. Based on the comparison of the above-mentioned optimization values with the sampled values as well as the theoretical analysis, the status of the wastewater treatment system in the industrial park was quantitatively evaluated to diagnose pertinent issues. Additionally, optimization and reformation strategies were proposed. Therefore, the established model can achieve optimization of pollution reduction and operation costs for the entire industrial park, thus contributing to industrial wastewater pollution control and water quality improvement.

Development of a system dynamics model for polycyclic aromatic hydrocarbons and its application to assess the benefits of pollution reduction

A dynamic multimedia transport (DMT) model for polycyclic aromatic hydrocarbons (PAHs) was constructed using the system dynamics software STELLA to simulate the transmission and flow of PAHs in different media. Humans are primarily exposed to PAHs via ingestion. Thus, this study used the DMT model to simulate the concentrations of PAHs in food media and the human body and assess the risk of harm to humans. On the basis of the hypothesis of PAH reduction in the Taiwanese steel industry, two scenarios were used (cases I and II), and integration indicators such as the Air Resource Co-Benefit Model of air pollutants, greenhouse gases, and PAHs reduction was established for the cost-benefit analysis of the reduction scenarios. This study not only established Taiwan's PAHs dynamic multimedia transmission model successfully but also performed a reduction scenario on the steel industry. In the year 2025, the total costs for cases I and II will be USD 690 and USD 694 million per year, respectively, and the total benefits will be USD 492 and 1669 million per year, respectively. Therefore, case II is preferable to case I in terms of benefit ratio (2.40 vs. 2.35, respectively).

Pollution and energy reduction strategy in soft drink industries

The present study was conducted on soft drink industry with the objective to reduce wastewater pollution through end-of-pipe treatment and controlling energy loss through steam pipeline insulation approach. For this purpose, the main operation and manufacturing steps were examined. Wastewater was analyzed for 10 physicochemical parameters. Among these parameters, total dissolved solids (TDS), total suspended solids (TSS) and chemical oxygen demand (COD) were above their permissible level of Pakistan national environmental quality standards (Pak NEQS). For wastewater treatment, sedimentation, flocculation, coagulation and adsorption were tested. The active study reduces the pollution load up to 48%. After treatment, all the parameters were below the Pak NEQS level. To reduce the energy loss and economic benefits, the steam pipeline system was galvanized using glass wool, sheet and paper. Through galvanizing, 91.4% of energy was recovered and reduced an extra cost of 91.5%. The net saving of energy and cost are 312 GJ and114098 Rs/year, respectively. The study recommends end off pipe treatment and insulation of bare pipeline system for soft drink industries.

The impact of highway base-saturation flow rate adjustment on Kuwait's transport and environmental parameters estimation

Traditional transportation systems' management and operation mainly focused on improving traffic mobility and safety without imposing any environmental concerns. Transportation and environmental issues are interrelated and affected by the same parameters especially at signalized intersections. Additionally, traffic congestion at signalized intersections has a major contribution in the environmental problem as related to vehicle emission, fuel consumption, and delay. Therefore, signalized intersections' design and operation is an important parameter to minimize the impact on the environment. The design and operation of signalized intersections are highly dependent on the base saturation flow rate (BSFR). Highway Capacity Manual (HCM) uses a base-saturation flow rate of 1900-passenger car/h/lane for areas with a population intensity greater than or equal to 250,000 and a value of 1750-passenger car/h/lane for less populated areas. The base-saturation flow rate value in HCM is derived from a field data collected in developed countries. The adopted value in Kuwait is 1800passengercar/h/lane, which is the value that used in this analysis as a basis for comparison. Due to the difference in behavior between drivers in developed countries and their fellows in Kuwait, an adjustment was made to the base-saturation flow rate to represent Kuwait's traffic and environmental conditions. The reduction in fuel consumption and vehicles' emission after modifying the base-saturation flow rate (BSFR increased by 12.45%) was about 34% on average. Direct field measurements of the saturation flow rate were used while using the air quality mobile lab to calculate emissions' rates.

Optimization of RDM-UF for alfalfa wastewater treatment using RSM

Rotating disk membrane (RDM) module with ultrafiltration (UF) was an effective alternative method to treat alfalfa wastewater and realize protein recovery and agricultural irrigation water production. A scientific investigation has been conducted to comprehend the effect of operation conditions (feed flow rate, shear rate, transmembrane pressure (TMP), and temperature) on alfalfa wastewater treatment with RDM-UF by central composite response surface methodology (CCRSM). First, the filtration behaviors of three types of UF membranes (PES20, UH030P, and PES50) were studied to select the optimized membrane (UH030P). Then, the effects and interactions of four operation conditions were studied and fitting models were established, while data on pollution reduction and protein recovery, membrane fouling behavior, and energy cost evaluation were collected. Furthermore, the optimized operation conditions calculated by CCRSM were Q = 60 L h^-1, γ = 220 × 10³ s^-1, TMP = 5.61 bar, and T = 25 °C. In addition, the concentration test was conducted with these parameters. This work may contribute to the potential application of RDM for membrane wastewater treatment. Graphical abstract Schematic diagram of UF process for alfalfa wastewater treatment and resource recovery.

Atmospheric pollution reduction effect and regional predicament: An empirical analysis based on the Chinese provincial NOx emissions

Atmospheric pollution emissions have become a matter of public concern in recent years. However, most of the existing researches on NOx pollution are from the natural science and technology perspective, few studies have been conducted from an economic point, and regional differences have not been given adequate attention. This paper adopts provincial panel data from 2006 to 2013 and the LMDI model to analyze the key driving factors and regional dilemmas of NOx emissions. The results show that significant regional disparities still exit on NO_x emissions and its reduction effect 27 provinces didn't accomplish their corresponding reduction targets. Economic development factor is the dominating driving factor of NO_x emissions during the study period, while energy efficiency and technology improvement factors offset total NO_x emissions in the majority of provinces. In addition, the industrial structure factor plays a more significant role in reducing the NO_x emissions after 2011. Therefore, the government should consider all these factors as well as regional heterogeneity in developing appropriate pollution mitigating policies. It's necessary to change NOx emissions control attitude from original key areas control to divided-zone control, not only attaches great importance to the reduction of the original key areas, but also emphasizes the new potential hotspots with high NO_x emissions.

How China achieved its 11th Five-Year Plan emissions reduction target: A structural decomposition analysis of industrial SO2 and chemical oxygen demand

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 (SO₂) 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 SO₂ 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 SO₂ 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 SO₂ 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.

Reduction of spatial distribution of risk factors for transportation of contaminants released by coal mining activities

It is reported that water-energy nexus composes two of the biggest development and human health challenges. In the present study we presented a Risk Potential Index (RPI) model which encapsulates Source, Vector (Transport), and Target risks for forecasting surface water contamination. The main aim of the model is to identify critical surface water risk zones for an open cast mining environment, taking Jharia Coalfield, India as the study area. The model also helps in feasible sampling design. Based on spatial analysis various risk zones were successfully delineated. Monthly RPI distribution revealed that the risk of surface water contamination was highest during the monsoon months. Surface water samples were analysed to validate the model. A GIS based alternative management option was proposed to reduce surface water contamination risk and observed 96% and 86% decrease in the spatial distribution of very high risk areas for the months June and July respectively.