Main Pollution Sources Research Articles

Characteristics of marine litter on Russian High Arctic islands under modern conditions

The study used data on the pollution of the coastline of the Russian Arctic National Park with marine litter to examine its composition and determine its origins. Marine litter is shown to accumulate on the islands of the Russian Arctic despite the absence of garbage patches in the Arctic Ocean. The analysis identified plastic as the main type of marine litter polluting the coasts. Monitoring also helped to identify the main source of pollution—fishing. The obtained results can be used to develop a plan designed to prevent industrial and consumer waste from reaching the coasts of islands.

Biogeochemical behavior, health risk assessment and source identification of antimony and arsenic in soil from a legacy antimony smelter in Gansu, Northwest China

The study of the contamination patterns and characteristics of Sb and As in the soils of the legacy contaminated sites of antimony smelters is important for the redevelopment and utilization of industrial sites. In this study, 13 heavy metals were determined in the soil and plants of an antimony smelter in Gansu Province to study the biogeochemical behavior, health risk, and pollution source. The results showed that the Nemerow index of Sb (728) exceeded the value of As (43.6) by 17.6 times, and the average geoaccumulation index (Igeo) of Sb and As were 10.1 and 1.97, respectively, categorized as extremely and moderately contaminated classes. Compared to As, Sb had a larger proportion of oxidizable fraction and a smaller proportion of reducible fraction (Fe/Mn oxides), suggesting that Sb possessed a higher content of organic matter and sulfide forms. Even though the bioaccumulation factor (BAF) for As was about 10 times higher than that for Sb, the accumulation of Sb in plants was not negligible. For the USEPA model, the mean hazard quotient (HQ) values of As by oral ingestion, dermal absorption, and inhalation accounted for 99.0%, 0.97%, and 0.0002% of the total, and 54.2%, 45.3%, and 0.51% for MEEPRC model, respectively. There were significant positive correlations between Sb, As, Zn, Se, Cd, and Ba (P < 0.05). The results of the source identification analysis revealed that antimony smelting, solid waste pollution, and natural origin were identified as the main pollution sources. The principal component analysis (PCA) and positive matrix factorization (PMF) methods differed by more than 20% in the analysis of the contribution of antimony smelting activities and solid waste pollution sources, suggesting the differences in the models themselves and in the uncertainty parameters chosen during the application.

CONTENT OF HEAVY METALS IN THE PHYTOMASS OF THE NATURAL MEADOWECOSYSTEMS OF VINNYTSIA REGION UNDER GENERAL BACKGROUND POLLUTION AND AS A RESULT OF ANTHROPOGENIC TRANSFORMATION OF LAND

Meadows as plant ecosystems of the Forest-Steppe zone are secondary in origin. They were formed on the site of indigenous (primary) vegetation types – forest or marsh ecosystems – after being transformed by humans to meet the needs of agriculture or livestock. In ancient times, the areas that are now occupied by meadows were mostly covered by forests or swamps. With population growth and livestock development, these forests were cut down, swamps drained, and the land was used for agricultural production as pastures and hayfields. Meadows on the plains of former forest or marsh ecosystems are unstable dynamic phytocoenoses in different stages of succession. Therefore, dominant species' botanical composition and projective cover change rapidly, requiring constant human intervention to maintain their high productivity. Following the principles of sustainable development, one of the most urgent tasks is to provide the population with a sufficient amount of high-quality and safe food of both plant and animal origin. It is known that the quality and safety of food products are directly dependent on the environmental conditions of food raw material production. Vegetation of natural fodder lands is an important element of livestock production, which is characterized by low cost compared to cultivated lands. However, in some areas, natural fodder lands undergo a strong anthropogenic load in technogenesis, leading to soil contamination with various toxicants, particularly heavy metals such as Pb, Cd, Zn, and Cu. The main sources of pollution of natural fodder lands are industry, motor vehicles, chemicalisation of the crop production sector, and others. Under such conditions, the use of phytocoenoses as feedstock for both domestic and wild animals increases the risk of heavy metals entering their bodies, which threatens the production of safe and high-quality products, and contaminated soils may be withdrawn from agricultural use. The study aimed to determine the levels of accumulation of Pb, Cd, Zn, and Cu in the ecosystems of natural fodderlands under different anthropogenic loads in the conditions of Eastern Podillia in Vinnytsia region.

Recovery of Flared Natural Gas with High CO&lt;sub&gt;2&lt;/sub&gt; Content Using SOFC CHP System: Feasibility Study for Neem-Field, Sudan

Flared natural gas emissions are one of the main sources of environmental pollution and global warming. To recover this gas, the presence of impurities like CO2 in high concentrations forces oil producers to escape from investing in such intensive processing. Several implementations of no flaring methods have been reported in the literature, however, there have been limited concerning the bulk-CO2 natural gases. This research developed an innovative idea for the use of the SOFC CHP system to recover flared bulk-CO2 associated gas of Neem-Field in Western Sudan. The exergy of the system and the performance of the SOFCs are investigated in this paper, in addition to environmental and economic analysis. The simulation (Cycle-Tempo©) results demonstrate that the proposed system can generate 1 MW electrical power and 0.068 MW thermal energy with efficiency approached 43.3% (based on LHV). The exergy analysis showed that 38% of system losses occurred in the air preheaters. Instead of conventional gas-burning, recovering the flared gas reduced the equivalent CO2 GHGs emissions by 80%. Overall, the novel solution found to be environmentally friendly, and economically appealing with a total capital investment estimated to be US$1.175 million and a cost of electricity (COE) of 4.07 cents per kWh.

Remarkable contamination characteristics, potential hazards and source apportionment of heavy metals in surface dust of kindergartens in a northern megacity of China

It is essential to understand the impact of heavy metals (HMs) present in the surface dust (SD) of kindergartens on children, who are highly sensitive to contaminated dust in cities in their growth stage. A study was conducted on 11 types of HMs present in the SD of 73 kindergartens in Beijing. This study aims to assess the pollution levels and sources of eleven HMs in Beijing’s kindergartens surface dust (KSD), and estimate the potential health risks in different populations and sources. The results indicate that Cd has the highest contamination in the KSD, followed by Pb, Zn, Ni, Ba, Cr, and Cu. The sources of these pollutants are identified as industrial sources (23.7%), natural sources (22.1%), traffic sources (30.4%), and construction sources (23.9%). Cancer risk is higher in children (4.02E-06) than in adults (8.93E-06). Notably, Cr is the priority pollutant in the KSD, and industrial and construction activities are the main sources of pollution that need to be controlled. The pollution in the central and surrounding areas is primarily caused by historical legacy industrial sites, transportation, urban development, and climate conditions. This work provides guidance to manage the pollution caused by HMs in the KSD of Beijing. Environmental implicationChildren within urban populations are particularly sensitive to pollutants present in SD. Prolonged exposure to contaminated SD significantly heightens the likelihood of childhood illnesses. The pollution status and potential health risks of HMs within SD from urban kindergartens are comprehensively investigated. Additionally, the contributions from four primary sources are identified and quantified. Furthermore, a pollution-source-oriented assessment is adopted to clearly distinguish the diverse impacts of different sources on health risks, and the priority pollutants and sources are determined. This work holds pivotal importance for risk management, decision-making, and environmental control concerning HMs in KSD.

Identifying sources and transformations of nitrate in different occurrence environments of carbonate rocks using a coupled isotopic approach (δ15N, δ18O, 87Sr/86Sr) in karst groundwater system, North China

Karst water as the vital water supply source is an increasingly serious problem suffering from NO3− pollution. Identifying sources and transformations is the key to effectively controlling diffuse NO3− pollution. In this study, 25 karst groundwater samples were collected from the Xujiagou karst groundwater system in June 2023, and chemical variables and stable isotopes (δ15N, δ18O, 87Sr/86Sr) were determined in different occurrence environments of carbonate rocks (exposed, covered, and buried carbonate rock areas). The results showed that the karst groundwater is dominated by nitrification. Human activities have affected the water quality of karst groundwater. The nitrate concentration ranged from 5.69 to 124.22 mg/L, and 4 % exceeds the quality indexes of class III water in China's standard for groundwater quality (20 mg/L as NO3−-N). NH4+ in fertilizer, manure and septic waste, and soil N were the main sources of nitrate pollution in the karst groundwater system. The distribution of NO3− sources is closely related to land-use types. Soil N (72.2 %) became the dominant nitrate source in the exposed area due to the small amount of urban land and the large distribution of forest and grassland. There were more cultivated land and large agricultural activities in the covered area, NH4+ in fertilizer (59.1 %) contributes the most to NO3− sources. The buried area dominated by urban land, the influence of human activities (densely population and agricultural production activities) caused the highest concentration and coefficient of variation of nitrate in this area, and manure and septic waste (64.2 %) were the most to NO3− sources. This study can provide an important scientific basis for the protection of karst groundwater, and provide theoretical support for the treatment of karst groundwater pollution sources in the “monoclinic paraclinal” strata in northern China.

Physico-chemical characterization of Lake Togbadji

This study focused on the physico-chemical characterization of Lake Togbadji, located in southwestern Benin. The methodological approach followed was as follows: literature review, sampling and in-situ measurements, analysis of collected samples, and data processing. Parameters such as pH, temperature, dissolved oxygen, TDS, and ORP were determined in-situ, while color, TSS, and other parameters were analyzed in the laboratory. The obtained results were subjected to descriptive statistics, the Wilcoxon test for two samples to determine the impact of different locations on the abundance of microbiological contaminants, and Principal Component Analysis (PCA) using R software version 3.5.0 to group pollution parameters according to different levels and sources of contamination. From our results, it was found that the main sources of pollution in Lake Togbadji are runoff water, various wastewater discharges from artisanal activities, livestock farming, and open defecation. On a physico-chemical level, the recorded levels do not suggest pollution of the lake.

The effect of mechanical action on the release of microplastic fibers during washing

The release of microplastic fibers (MPFs) during washing is the main source of microplastic pollution in water environment. Mechanical action is the principle factor affecting the release of MPFs during washing. In order to better understand the effect of washing mechanical action on the release of MPFs, a washing simulation device was designed to study the effects of abrasion action, hydrodynamic flow action and beating action on the release of MPFs. The results show that there is a certain amount of floating MPF in the fabric due to the production process. The floating MPFs can be released in large quantities even though the mechanical action is weak, accounting for about 28% of the total MPF release. In addition, the release of secondary MPFs increases with the mechanical action. The increase of the abrasion times between fabric and fabric has the most significant effect on the release of MPFs. Compared with 60 abrasion times, the number of MPFs increased by about 16% and the average length decreased by 40% when abrasion was 5000 times. This study enhances the understanding of how mechanical action during washing affects the release of MPFs. This emphasizes the impact of floating MPFs, as well as the need to optimize the washing process to reduce the emission of MPFs.

Development of machine-learning-based models for identifying the sources of nitrate and fluoride in groundwater and predicting their human health risks

AbstractThis research aimed to identify the main sources of groundwater pollution and assess the non-carcinogenic human health risk resulting from nitrate and fluoride contamination. These goals were achieved by employing unsupervised and supervised machine algorithms, including principal component analysis (PCA) and multilayer perceptron artificial neural networks (MLP-ANN). Thirty-seven groundwater samples were analyzed for twelve physical and chemical parameters, including pH, EC, TDS, TH, Cl, F, SO4, NO3, Ca, Mg, Na, and HCO3, and the initial investigation indicated that except for Cl, F, Ca, and Mg, all the parameters are above the guidelines of the World Health Organization (WHO). PCA indicated that mineral dissolution is the main source of F, while high NO3 concentration primarily resulted from agricultural operation due to extensive use of nitrogen and calcium-based fertilizers. Consequently, the non-carcinogenic human health risk (HHR) for children and adults is evaluated based on NO3 and F. The conventional approach for assessing HHR is time-consuming and often associated with errors in calculating hazard quotients (HQ) and hazard indices (HI). In this research, MLP-ANN is suggested to overcome these limitations. In the MLP-ANN modeling, the data were divided into two parts training (80%) and validation (20%), with NO3 and F concentration as inputs and HQ and HI as outputs. The performance of the resulting models was tested using root mean square error (RMSE) and coefficient of determination (R2). The model provided a satisfactory result with a maximum RMSE of 4% and R2 higher than 97% for training and validation. As a result, obtained HIs suggested that 97.3% of the groundwater samples in the study area are suitable for human consumption. The non-carcinogenic HHR is successfully assessed using machine learning algorithms, and the results have led to the conclusion that this approach is highly recommended for effectively managing groundwater resources.

Tracing sulfate sources and transformations of surface water using multiple isotopes in a mining-rural-urban agglomeration area

Rapid urbanization and mining activities are exacerbating sulfate (SO42-) pollution in surface water, and the information on its sources and transformations is crucial for understanding the sulphur cycle in mining areas. In this study, the SO42- in the surface water of Huaibei mining area were monitored and the main sources of pollution and biogeochemical processes were identified using stable isotopes (δD, δ18O-H2O, δ34S-SO42- and δ18O-SO42-) and water chemistry. The results demonstrated the SO42- content in the Huihe River and Linhuan subsidence water area (SWA) is higher than that in other rivers and SWAs, which exceeded the environmental quality standard of surface water. The SO42- content of different rivers and SWAs showed seasonal differences, and the dry season was higher than the wet season. In addition, the SO42- in Tuohe River and Suihe River is primarily caused by urban sewage and agriculture activities, while in Zhonghu and Shuoxihu SWA is mainly contributed by natural evaporate dissolution. Notably, the input of SO42- in the Huihe River and Linhuan SWA caused by mining activities cannot be disregarded. The aerobic environment and isotopic fractionation of surface water indicate that sulfide oxidation is not the major cause of SO42- formation. This work has revealed the multiple sources and transformation mechanisms of SO42-, and provided a reference for the development of comprehensive management and effective remediation strategies of SO42- contamination in surface water around mining areas.

Highly efficient electromagnetic interference shielding composite with excellent superhydrophobic and photothermal/electrothermal effects

With the development of communication facilities, electromagnetic pollution has become more problematic in modern society. Outdoor electromagnetic devices such as signal stations and radar units are the main source of electromagnetic pollution. Therefore, it is urgent to develop electromagnetic interference (EMI) shielding composites for outdoor applications. Meanwhile, the accumulation of ice on the surfaces of these facilities often has serious effects, especially in winter and cold areas. To this end, the Polydimethylsiloxane/Graphite/Carbon black-Polydimethylsiloxane/Fe3O4@Multi-walled carbon nanotube-Aramid paper@Ag (PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP) laminated composite was prepared by combining spraying, scraping and electroless plating techniques to enable the coordination of EMI shielding and de-icing. Through the rational design of the absorbing and conducting layers, the PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP composite has a shielding effectiveness of 31.35 dB in the X-band and an ultra-high absorption coefficient (A) of 0.9. It is worth noting that, due to the rough structure and the low surface energy of the surface layer, the composite exhibits excellent superhydrophobicity (158° ± 1°). Importantly, the PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP composite exhibits stable electrothermal properties, with a fast response and high-speed de-icing capability. At 0.1 W/cm2 input electrical power, ice completely melts in 210 s. And the composite shows excellent photothermal properties, with the ice completely melts within 180 s at 1 sun. The composite also shows excellent self-cleaning properties and acid-alkali resistance. This multifunctional EMI shielding composite provides a new strategy for the safe and long-term use of all-weather outdoor devices.

A prediction model of dust accumulation on photovoltaic modules considering rainfall washing

AbstractThe power generation of the photovoltaic plant is related to the cleanliness of the photovoltaic modules. The accumulation of natural dust is the main source of pollution, which is affected by human activities and meteorological factors such as temperature, humidity, wind speed, and rainfall concentration in the current region. On the basis of particle swarm optimization (PSO) and the least‐squares support vector machine (LSSVM), the density of dust on photovoltaic modules was estimated. The authors proposed that the inertia weight decreased as a concave function to improve the efficiency of optimization and let the two positive constants change dynamically to improve convergence performance. The dust accumulation prediction model was established considering natural rainfall and the authors obtained the attenuation rate of the photovoltaic power output. Finally, the experiments in Hangzhou showed that the model can predict the density of accumulated dust quickly, which provides a theory for predicting PV power generation and managing the cleaning frequency.

An approach to using the AQI components in urban air pollution sources identifying

Problem statement. The fact that the air we breathe is polluted is well known. There are many sources of pollution, especially in big cities. Various sensors are installed to monitor pollutants in the air. One of the global systems for registering the concentration of pollutants in urban air is AQI. Air quality monitors collect data of five major air pollutants – ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide, that then convert to the Air Quality Index. And although the sensors themselves are not capable of reducing pollution in the air, based on the data they provide, it is possible to create indicative maps of urban pollution. Such mapping of urban areas will enable authorities to develop and implement plans to improve the most dangerous areas, as is already done in other countries. But there are still no such maps for Kyiv. Study objective is to analyse the air quality index in Kyiv, identify the main source of atmospheric pollution and to visualize urban air pollution. Methodology involves data analysis from 15 sensors of the AQI worldwide network. We analyzed the concentration of 5 main air pollutants contributed to the common Air Quality Index for a certain period in Kyiv and its surroundings. Knowing the exact coordinates of each sensor and the results of their measurements, we drew a map of air pollution in Kyiv using OriginPro 8.1 software and images from the Google maps. Research results. It was determined that the largest contribution to the Air Quality Index is made by the fine particulate matter emissions. We determined that the morning sensor data on the amount of dust in the air is the most informative. It is known transportation is one of the main sources of PM2.5 in the city. Our map clearly shows that the area with the highest AQI value coincides with a major road junction on the north-west outskirts of the city. Thus, atmospheric pollution in Kyiv is mainly determined by the amount of fine dust in the air. Further research will be aimed at identifying the relationship between the amount of PM2.5 in the air and the morphological parameters of indicator plants. Scientific novelty of the research. We showed for the first time that air pollution does not coincide with the official sources of atmospheric pollution given by the Kyiv Bureau of Technical Supervision. We also presented new approach to draw up-to-date, representative, and accurate pollution maps that can be submitted to the representatives of environmental services and other interested parties. Such investigations are of great importance as they can give the opportunity to the government to take real actions on pollutants reducing.

Use Unio Tigridis as a Bioindicator of Heavy Metal Contamination in the Diwaniyah River

The current study aims to estimate the concentrations of lead and cadmium in the water of the Diwaniyah River, based on investigation and study of the concentrations of these elements within the body of the vital indicator, where this organism will be taken from 4 different stations with varying distances to know the concentrations and compare them with the national determinants. The study showed that the main sources of pollution the water of the Diwaniyah River is due to the river’s passage within the city center and the discharge of sewage into it directly and in the role of a treatment agent and throwing waste of all kinds and the increase of human activities in the center, which causes an increase in the concentration of pollutants, including heavy elements. Highly efficient treatment units to reduce pollutants that are disposed directly into the river water, as well as increasing the environmental awareness of the population.

Acoustic Over-Exposure in the Institutional Land Use of Calabar Metropolitan Area, Cross River State, Nigeria

Every tertiary institution is meant to be a centre of excellence in terms of academic activities as well as an enabling environment to achieve such. However, many of these academic settings have turned into activity hubs of varying natures of land uses, which daily generate high acoustic levels. The study comparatively assessed noise levels across the two major tertiary institutions in Calabar metropolis, Nigeria. The objectives were to identify institutional sources of noise, perform a comparative analysis of noise levels across tertiary institutions in Calabar metropolis, as well as render viable measures for reducing the incidence and effects of noise levels in tertiary institutions within Calabar metropolis. Sound level data were acquired using BK Precision 732 Digital Sound Level Meters. Analysis was done using the Analysis of Variance (ANOVA) technique. From the test, the ‘F’ value calculated (2.74) is greater than the ‘F’ tabulated (1.86), which implies that there is a significant variation in noise levels within the University of Calabar and the University of Cross River State. Observations show that generator noise, socio-economic activities, extracurricular activities within tertiary institutions, traffic within and outside the school premises, and business outlets within the study locations are the main sources of noise pollution within the institutions. It was therefore recommended that university authorities should zone/allocate land uses to activities that are similar to each other so as to avoid land use conflicts and incompatibilities. Moreover, land uses that are not compatible with the university environment should be eliminated. University authorities should help reduce the total number of generating sets within the school premises by allocating one generating set which will serve all business operations within the school premises, and such should be away from lecture venues and other offices.

Research on the Performance Evaluation of Agricultural Non-point Source Pollution Prevention and Control in Anhui Province

Agricultural and rural pollution control is a key and difficult issue in the revitalization of rural ecology in China, and agricultural non-point source pollution, as the main source of pollution, is of the utmost importance. Building a performance audit system for agricultural non-point source pollution prevention and control is beneficial for measuring the degree of agricultural non-point source pollution prevention and control, identifying constraints, and is of great significance for agricultural non-point source pollution prevention and control. This article selects Anhui Province as the research object, and based on the PSR model of environmental resource management, constructs an agricultural non-point source pollution performance evaluation system. On the basis of this evaluation system, the entropy weight TOPSIS method is used to empirically investigate the agricultural non-point source pollution prevention and control data in Anhui Province from 2017 to 2021, and corresponding suggestions are proposed based on the specific analysis results.

Spatial variation and factors associated of solid fuel use in Ethiopia a multilevel and spatial analysis based on EDHS 2016

Cooking and heating using solid fuels, such as dung, wood, agricultural residues, grass, straw, charcoal, and coal, is a main source of household air pollution. This indoor combustion encompasses a diversity of health detrimental pollutants, especially for people from low-income countries like Ethiopia since solid fuels are accessible easily at a lesser cost. Limited studies done showing factors affecting in choosing fuel type and no study, which revealed spatial heterogeneity of solid fuel used based on such nationally representative data. Therefore, this study, aimed at investigating spatial variation and determinants of solid fuel use in Ethiopia. This study was done using the data from the Ethiopian Demographic and Health Survey 2016, a national representative sample (16,650) households were included. Spatial and Multi-level logistic regression analysis was done by considering the DHS data hierarchal nature. Variables in the final model with a p-value < 0.05 were reported as significant predictors of using solid fuel. All analyses were done using ArcGIS V.10.7.1 and STATA V.14 software. The finding of this study revealed that 90.8% (95% CI (87.9%, 91.2%)) of households depend on solid fuel for cooking. Based on the final model ;Male household head (AOR 1.38, 95% CI (1.12–1.71)), age of household head (AOR 1.61, 95% CI (1.20, 2.17)), and 1.49 (OR 1.49, 95% CI (1.12, 1.99)) respectively for the age classes of < 30, and 30–40, education attainment no education (OR 3.14, 95% CI (1.13, 8.71)) and primary education (AOR 2.16, 95% CI (2.78, 5.96), wealth index Poorest (AOR 11.05, 95% CI (5.68, 15.78)), Poorer (OR 5.19, 95% CI (5.43, 13.19)), Middle (OR 3.08, 95% CI (2.44, 8.73)), and Richer (OR 1.30, 95IC (1.07, 13.49)) compared to richest, and not accessibility of electricity (AOR 31.21, 95% CI (35.41, 42.67)), were individual-level factors significantly associated with using solid fuel. Community-level factors like households found at large city (AOR 2.80, 95CI (1.65, 4.77)), small city (AOR 2.58, 95% CI (1.55, 4.32)) town (AOR 4.02, 95% CI (2.46, 6.55)), and countryside (AOR 14.40, 95% CI (6.23, 21.15)) compared households found in capital city, community level media exposure (AOR 6.00, 95% CI (4.61, 7.82)) were statistically predictors in using solid fuel for cooking. This finding revealed that a large proportion of households in Ethiopia heavily depend on biomass, especially wood, for cooking. There was a greater disparity on solid fuel use for cooking in Ethiopia. Implementing major policy interventions should be introduced to reduce solid fuel use for cooking and inequalities in accessing clean fuel in Ethiopia.

Life cycle assessment of ammonia/hydrogen-driven marine propulsion

Marine fuels are the main sources of pollution from shipping industry. Hydrogen and ammonia have been suggested to be alternative fuels for shipping as these two fuels do not emit carbon dioxides in the combustion process. This study employed life cycle assessment method to compare the environmental performance of propulsion systems using hydrogen and ammonia as marine fuels to fossil fuels. 2-stroke and 4-stroke engines of tankers using fossil fuels were chosen as base case scenarios. Alternative scenarios using ‘green’ and ‘blue’ hydrogen and ammonia with the support of pilot fuel were then compared to the base case scenarios. While the performance of the coming combustion concepts for hydrogen and ammonia engines are still unknown, preliminary estimations were used in this study. The results showed that hydrogen and ammonia could substantially reduce the global warming potential, compared with the fossil fuel scenarios. Hydrogen and ammonia are also expected to be highly effective in cutting down the particulate matter and the emission of black carbon.

Acoustic Over-Exposure in the Institutional Land Use of Calabar Metropolitan Area, Cross River State, Nigeria

Every tertiary institution is meant to be a centre of excellence in terms of academic activities as well as an enabling environment to achieve such. However, many of these academic settings have turned into activity hubs of varying natures of land uses, which daily generate high acoustic levels. The study comparatively assessed noise levels across the two major tertiary institutions in Calabar metropolis, Nigeria. The objectives were to identify institutional sources of noise, perform a comparative analysis of noise levels across tertiary institutions in Calabar metropolis, as well as render viable measures for reducing the incidence and effects of noise levels in tertiary institutions within Calabar metropolis. Sound level data were acquired using BK Precision 732 Digital Sound Level Meters. Analysis was done using the Analysis of Variance (ANOVA) technique. From the test, the ‘F’ value calculated (2.74) is greater than the ‘F’ tabulated (1.86), which implies that there is a significant variation in noise levels within the University of Calabar and the University of Cross River State. Observations show that generator noise, socio-economic activities, extracurricular activities within tertiary institutions, traffic within and outside the school premises, and business outlets within the study locations are the main sources of noise pollution within the institutions. It was therefore recommended that university authorities should zone/allocate land uses to activities that are similar to each other so as to avoid land use conflicts and incompatibilities. Moreover, land uses that are not compatible with the university environment should be eliminated. University authorities should help reduce the total number of generating sets within the school premises by allocating one generating set which will serve all business operations within the school premises, and such should be away from lecture venues and other offices.

Analysis of emission characteristics and driving forces of air pollutants and GHG from coal-fired industrial boilers in China

Coal burning is considered to be the main anthropogenic source of air pollutants, which can cause serious environmental pollution. As one of the important coal burning sources, coal-fired boilers have become the important challenges of the policy of “carbon peaking” and “carbon neutrality” of Chinese government. In this paper, the emission inventory of air pollutants (TSP, SO2, NOX, VOCs), and greenhouse gases (GHG, including CO2, CH4, N2O) from coal-fired industrial boilers (CFIB) from 2006 to 2020 are established by using the “bottom-up” emission factor method. Besides, Kaya identical equation and Logarithmic mean Divisia index (LMDI) model are used to quantify the driving forces of the changing tendency in pollutants emission based on five driving factors, which include pollution production coefficient (f), control technology level (β), economy (GOV), industrial energy intensity (e) and coal consumption structure of industrial boilers (s). Combined with existing relevant policies, the future emission tendency of air pollutants and GHG in 2025 and 2030 is projected. The result shows that policy adjustment has a significant impact on pollutant emission trends. In 2020, emissions of TSP, SO2, NOX, VOCs and GHG from CFIB in China are 679.5 kt, 644.7 kt, 603.9 kt, 40.7 kt and 4.4 × 105 kt CO2e, respectively. Control technology level is the main factor to the emission reduction of SO2 and TSP, which has caused a decrease of 4278.6 kt and 3337.3 kt in emissions of SO2 and TSP compared to those of 2006 respectively, while the influencing effect on NOX, GHG and VOCs was relatively weak. In addition, in the scenario of improved control technology, pollutant emissions could be reduced by 62.6%–94.9% until 2030.