An analysis of the correlation between polycyclic aromatic hydrocarbons (PAHs) and economic parameters demonstrates that the total population, gross domestic product, coal consumption, petroleum, temperature, and day consumption significantly affect PAH concentrations in Dianchi Lake, Yunnan province, China. An artificial neural network (ANN) model was developed to predict the trend in PAH concentrations in the sediments of Dianchi Lake over the next 10 years based on current indicators of economic development. The ANN model estimated the concentration of PAHs from 1980 to 2014. The model was evaluated using available observations for the historical trends; concentrations of PAHs in the sediments of Dianchi Lake are calculated to be at 2128.1 ng/g in 2025 and are expected to decline up to 1044.3 ng/g by 2030. These concentrations are considered relatively high because of their impacts on the health of people and aquatic organisms and the development of surrounding industries. We show the importance of the socioeconomic and climate factors in increasing the pollution levels. Our results could support the local government to formulate effective measures to reduce the pollution levels in the lake.

Choosing pollution control instrument is an important environmental policy decision. Carbon taxes and subsidies for emissions reductions are two commonly used environmental policies. In practice, the government may be restricted to use only one policy instrument. In this paper, we compare the social welfare effect between policies of a carbon tax and a subsidy. We show that as the marginal environmental damage of the high carbon product increases, the control instrument should change from a subsidy policy to a carbon tax policy. It also turns out that Bertrand competition does not always incur a higher social welfare than Cournot competition when the government intervenes with a pollution control policy.

Very little work has determined the relative importance of uncontrolled environmental factors for affecting fish biology, and how these might influence gillnet catches. This study addresses this deficit for an important Southeast Asian cyprinid (Barbonymus schwanenfeldii). Fish were caught monthly for 12 months using gillnets of three different mesh sizes, each of which was deployed in duplicate at the surface of one of three randomly selected sites in Lake Kenyir, Malaysia, concurrent with determining various environmental parameters and the abundance of phytoplankton (chlorophyll–a). Results indicated that growth co-efficient of B. schwanenfeldii was positively influenced by dissolved oxygen and negatively influenced by total inorganic nitrogen, whereas an opposite result was observed in case of the hepatosomatic index of fish. Water turbidity was a limiting factor only for small fish (mean total length: 15.74±1.10 cm). B. schwanenfeldii could best be caught during the period of high phytoplankton abundance or at the location of high phytoplankton density in the water. Water temperature negatively influenced the gillnet catches of the fish. The remaining environmental factors such as water depth, pH, and phosphate had a weak and insignificant influence (P >0.05) on the biology and gillnet catches of fish. The observed results can be very useful for the ecological monitoring and conservation plans for this species in relation to climate change. Furthermore, the utility of the similar data for other species would be useful not only for regional but also for international fishery by optimizing catches considering environmental conditions.

There are obvious differences between different types of environmental regulation, which are manifested in different environmental protection tendencies and goals, and there are also significant differences in policy implementation. Therefore, it is an urgent empirical problem to quantitatively evaluate the impact of heterogeneous environmental regulation on the upgrading of industrial structures. Therefore, on the basis of measuring the level of industrial structure upgrading, this paper empirically tests the impact of heterogeneous environmental regulation on industrial structure upgrading. The results show that the upgrading level of China’s industrial structure increased year by year from 2000 to 2018. The three types of environmental regulatory measures have effectively promoted the upgrading of the industrial structure, and the market-incentive environmental regulation (MER) has a significantly higher role in the advancement of the industrial structure than the command-controlled environmental regulation (CER) and the voluntary public participation environmental regulation (VER). With the improvement of regional economic development level, the three types of environmental regulation have gradually become more prominent in promoting the upgrading of industrial structure. In the mechanism test, it is found that technological innovation has a partial mediating effect in the process of CER affecting the upgrading of industrial structure, MER and public VER have a complete mediating effect, while foreign direct investment (FDI) has only a partial mediating effect in the process of the three types of environmental regulation affecting industrial advancement, and there is no mediating effect in the process of influencing the rationalization of industrial structure.

The reuse of human wastes as biofertilizer resources offers a new option for meeting the growing demand for food and addressing poor soil productivity. Feces and black water are ubiquitous human wastes that usually require proper treatment, such as composting and anaerobic digestion, to remove potentially harmful substances before they can be applied as fertilizers. As an effective treatment technology for livestock farming wastes, the ectopic fermentation bed system (EFS) provides a new means of treating human waste and producing organic fertilizer from decomposed filler. Therefore, the objective of this study was to evaluate and compare the nutrient content and fertilizer potential of decomposed fillers obtained after EFS treatment of human feces and black water under different application conditions. The results showed that the application of fillers increased the yield of pakchoi by 3.60⁓29.32% and nutrient uptake by 8.09⁓83.45% compared to the CK, which could effectively promote the growth of pakchoi. This approach also improved the quality of pakchoi and enhanced soil fertility, and differences were observed in the effects of different kinds and application amounts of fillers. Soil EC was the soil property that had the greatest effect on the growth characteristics of pakchoi in this study. These findings help to better clarify the agronomic value of human wastes, but the effects of long-term filler application need to be further explored.

Polychlorinated biphenyls (PCBs) were determined in sediment samples collected from the Turag River, Dhaka city, Bangladesh. This river provides critical ecological services to agriculture, industry, and transportation. However, it is one of the most polluted rivers surrounding the capital city. This study analyzed six PCB congeners (PCB 10, PCB 28, PCB 52, PCB 138, PCB 153, and PCB 180) by GC-ECD at 9 sampling sites in two different seasons. The total concentrations of PCBs in studied samples varied from 344 to 0.217 ng/g dw and 10.6 to 1.68 ng/g dw in Monsoon-season and Dry-season, respectively. The paramount contributor-congener to the total PCBs was PCB 180, and it was found at all the study sites. The ecological risk assessment indicated a high potential risk in the Monsoon-season ([Formula: see text]= 277) and low potential risk in the Dry-season ([Formula: see text]= 25.7). Sediment quality guideline quotients (SQGQs) showed that PCBs in the Monsoon-season would cause “no” or “moderate” biological effects on organisms at every site except site-5 (S5) (high biological effects), while no adverse ecotoxicological effect was observed in the Dry-season. Considering both probable effect level (PEL) and threshold effect level (TEL), the new sediment quality guideline quotient (NSQGQ) showed that in the Dry-season PCB contamination would cause “moderate” biological effects. At the same time, in the Monsoon-season, the findings remained consistent with the findings of SQGQ. This study looked at the PCB contamination scenario in the Turag River sediments for the first time and allowed for a comparison with other rivers worldwide.

This paper studies the effects of financial development, economic growth, and climate-related financial policies on carbon emissions for G20 countries. The focus is particularly on financial policies implemented to scale up green finance and address climate-related financial risks from 2000 to 2017 and represent this paper’s value added. The empirical results obtained by relying on the panel quantile regression approach indicate that the impacts of the different explanatory variables on carbon emission are heterogeneous. Specifically, the effect of the stock of short-term financial policies on carbon emissions is negative, and its effect becomes smaller at higher quantiles. The stock of long-term policies also shows significant negative coefficients, but its impact is stronger for higher quantiles. No significance is reported for the lowest quantile. Financial development contributes to improving environmental quality, and its impact is larger in higher emission countries. Energy consumption increases carbon emissions, with the strongest effects occurring at higher quantiles. Our results also support the validity of the EKC relationship and positive effects of GDP and population on high carbon emissions levels. Estimation results are robust to alternative model specifications and after controlling for the role played by adopting international climate change mitigation policies as proxied by the adoption of the Kyoto Protocol.

China VI standard proposed higher requirements for durability of heavy-duty diesel vehicles emissions. Previous research which took advantages of both on-board sensors and big data approach to get the NOx deterioration factor was rather scarce. This paper used big data approach to study the deterioration of engine out NOx emission based on 254,622 km operation data getting from the on-board sensors or ECUs (Electronic Control Unit). Meanwhile, a formula for on-board NOx correction for ambient humidity and temperature had been fitted. The analyses revealed that the engine out NOx deterioration factor (DF) of the maximum weight steady-state condition was about 1.005 after 254,622 km durability test; as for transient conditions, the DF was not more than 1.092 during 254,622 km durability test. For a same steady working condition, the engine out NOx mass flow (g/h) was negatively linearly correlated with absolute humidity (Ha) (R² = 0.997). If Ha was lower than 12 g/kg, Ha almost had no effect on engine out NOx concentration (ppm). Otherwise, there was also a negatively linear relationship between them (R² = 0.978). It is hoped that the methods and conclusions of this paper could provide some enlightenment for future NOx emission deterioration research.

The coronavirus disease 2019 (COVID-19) is an ongoing pandemic with high morbidity and mortality rates. Current epidemiological studies urge the need of implementing sophisticated methods to appraise the evolution of COVID-19. In this study, we analysed the data for 228 days (1 May to 15 December 2020) of daily incidence of COVID-19 cases for a district level analysis in the region of Jammu and Kashmir in the northern Himalayan belt of India. We used a deep learning-based incremental learning technique to model the current trend of COVID-19 transmission and to predict the future trends with 60-day forecasting. The results not only indicate high rates of morbidity and mortality but also forecast high rise in the incidence of COVID-19 in different districts of the study region. We used geographic information system (GIS) for storing, analysing, and presenting the spread of COVID-19 which provides key insights in understanding, planning, and implementing mitigating measures to tackle the current spread of the pandemic and its possible future scenarios. The existing disparity in health care facilities at district level is shown in relation to the spread of disease. The study results also highlight the need to upgrade health care infrastructure in the study region to control the current and future pandemics. These results could be useful for administration and scientific community to develop efficient short-term and long-term strategies against such diseases.

Groundwater resources can be artificially augmented by managed aquifer recharge especially in arid and semi-arid areas. Unlike most of the existing results which focus only on impervious aquifer base and assume perfect hydraulic connection between aquifer and adjacent stream, the present study addresses the recharge process in a more realistic case of leaky aquifer interacting with semipervious streambank. The mathematical model relies on 2D linearized Boussinesq equation with Robin boundary condition accounting for hydraulic resistance owing to semiperviousness of the streambed. The method of Green’s function offers an integral representation of hydraulic head in semi-infinite aquifer domain in response to time-varying recharge from a rectangular basin. Hydrological components of groundwater recharge are derived taking into account volumetric rates of leakage, mound storage, and outflow to adjacent stream. Hypothetical test cases illustrate how sum of these components exactly counterbalances the volumetric rate of recharge received by the aquifer at each instant of time, and this is in full conformity with the expected mass balance at aquifer scale. The most influential parameters affecting the model outputs are identified through sensitivity analysis. Furthermore, interaction of pumping wells with groundwater mound is examined. Performance of the present results is assessed against numerical counterparts from finite element method, and extremely good agreement is found for temporal mound peaks.