Pollutant Concentrations Research Articles

Effects of Human Activities from the Indo-Gangetic Plain on the Air Quality in the Foothills of the Himalayas

The relationship between surfaces that measure climatic parameters and the mass concentration of various air pollutants across the Indo-Gangetic Plain (IGP) and Himalayan foothills is investigated using three separate stations. In an industrial area of Delhi, a residential area of Shimla, and a residential area of Hisar, the simultaneous measurement of mass concentrations of air pollutants such as NO2, SO2, RSPM, and SPM, as well as the impact of surface meteorological parameters on their distributions, are investigated for the study period of January 2005 to December 2012. The seasonal variations in air pollutants were also examined. Additionally, a regression analysis between the daily mass concentration of air pollutants and metrological parameters has been carried out. The correlation coefficients between climatic factors and air pollutants were found to be positive with the exception of the correlations between wind direction and SO2 and visibility and NO2. Additionally, the time series of AOD and ASMF, two MODIS-derived daily and monthly mean columnar aerosol parameters, are examined over Delhi, Hisar, and Shimla from 2005 to 2012. The maximum and minimum AOD values for Delhi, Hisar, and Shimla, respectively, are 2.3 and 0.08, 3.5 and 0.09, and 2.6 and 0.06. However, at all three locations, ASMF fluctuated between 0 and 1. The highest values of AOD were observed in the months of June and August, with a pattern of increasing values from January to June and a pattern of decreasing values from August to December. While an increasing pattern was seen during the post-monsoon and winter months, ASMF was found to diminish from February up to April or May. A back-trajectory analysis of the air mass is used to examine the effects of the observed increased air pollution from the IGP over the Himalayan city of Shimla. The trajectories (23%) passing over the IGB in a southeasterly direction were seen to have an impact on Shimla.

Temporal analysis of eutrophication and water toxicity in the Jundiaí Mirim river basin, São Paulo State, Brazil

Natural and anthropogenic pressures generate numerous negative impacts on the physical and biotic environment of the watersheds. Such impacts cause risks to the water security of the basins, due to the increase in consumption, concentration of pollutants and siltation of water bodies. The objective of this research was to perform a temporal analysis of eutrophication and water toxicity in the Jundiaí Mirim River Basin (BHJM), in the state of São Paulo, Brazil. The methodology was based on the analysis of data published in public reports, including the Trophic State Index (TSI) and the Quality Index for the Protection of Aquatic Life (QIAF), in the period from 2017 to 2022. The results indicate eutrophication along the water bodies of the basin, inferring about the discharge of domestic sewage and carried fertilizers. The QIAF was influenced by high concentrations of Lead and Mercury, above those recommended for Class 1 rivers by the Brazilian federal legislation.

Long term emission and simulation on air quality from residential coal burning in China

Abstract Residential coal burning (RCB) is a notable contribution source of airborne pollution in China. To address this, a suite of control policies has been implemented, leading to a shift in the energy structure and a limitation in pollution emission within RCB sector. This study presents emission inventories for SO2, NOx, CO, and PM2.5 from RCB between 2010 and 2020, utilizing both published and measured emission factors (EFs). Furthermore, the emission amounts of pollution in year 2030 and 2050 were projected. Since 2010 to 2020, emission of pollution from RCB sector has demonstrated a noticeable decreasing trend, especially in policy priority regions. The emission amounts in policy priority regions are at a similar level to those in the South region. The most substantial reductions were observed in the Beijing-Tianjin-Hebei (BTH) region, with decreases of 69.8%, 74.2%, 74.8%, 79.8% 60.6% for SO2, NOx, CO, PM2.5 and BC respectively. Finally, the updated emission data used to calibrate the emission in GEOS-Chem model and to simulated national particle and gas pollution concentration in heating season emitted from RCB for year 2020 and 2030. The simulation results demonstrate a migration in the emission intensity center in the Northeast region. For SO₂, NO₂ and PM2.5, the RCB contribution decreased from 3.1, 18.3 and 19.9 μg/m³ in 2020 to 1.8, 11.6 and 9.8 μg/m³ in 2030, respectively. The SO2, NO2 and PM2.5 impact from RCB was -0.03 to 0.29, 0.61 to 7.04 and 1.2 to 2.9 μg/m3 on average in 2030 which shown a minor impact on ambient pollution in BTH region during heating season.

Enhancing urban air quality prediction using time-based-spatial forecasting framework.

Air quality forecasting plays a pivotal role in environmental management, public health and urban planning. This research presents a comprehensive approach for forecasting the Air Quality Index (AQI). The proposed Time-Based-Spatial (TBS) forecasting framework is integrated with spatial and temporal information using machine learning techniques on data collected from a wide range of cities. The TBS employs Convolutional Neural Networks (CNNs) to capture spatial dependencies based on normalized latitude and longitude coordinates of the cities. Simultaneously, time series model, specifically the ARIMA (AutoRegressive Integrated Moving Average)was employed to capture temporal dependencies using pollutant concentration readings over time. The dataset included information such as date, time, pollutant concentrations and AQI was further preprocessed and divided into training and testing sets. The CNN was configured to utilize the normalized latitude and longitude grid, while the ARIMA model concurrently processed the pollutant concentrations. The model was trained on the training dataset, and a 6hour forecast is generated for each test instance. The outcomes demonstrate the TBS model's ability to accurately predict AQI values. The integration of CNNs and time series model allowed for an clearer and deeper understanding of geographical and pollutant concentration factors that contribute to air quality variations.

Simulation Study of Groundwater Polluted by Landfill Leachate in Subsidence Areas

The subsidence caused by mining was used as domestic waste landfill, due to the lack of anti-seepage treatment at its bottom, the internal leachate not only contaminated the surface water, but also the goaf groundwater continuously. Therefore, taken the Datong landfill in Huainan, Anhui Province as an example, the similar simulation test was chosen to simulate the temporal variation of the concentration of pollutants in the goaf. The formed mechanism of leachate pollution of groundwater was also discussed. The results show that the leachate still caused serious pollution to groundwater after the closure of the landfill. Pollutants in groundwater mainly move from west to east under the action of convection-dispersion and adsorption. In the process of pollutant migration and diffusion from west to east, it is controlled by the boundary of the aquifer in the goaf, resulting in a large accumulation of pollutants at the end of the goaf and causing the high concentration of pollutants. In addition, due to the influence of geological environment in goaf, the pollution rate and concentration are constantly changing. The results of the test provide some reference for the groundwater remediation and treatment in the coal mine subsidence area.

Facile synthesis of MIL-100(Fe) adsorbents for boosting organic dye removal.

Highly effective MIL-100(Fe) adsorbent material was successfully synthesized from (NH4)2Fe(SO4)2·6H2O and H3BTC precursors under mild conditions. Characteristics regarding crystal structure, functional groups, elemental composition, surface morphology, specific surface area, and surface charges revealed the formation of pure and microporous MIL-100(Fe) adsorbent with a super surface area (1916.26 m2/g). The results showed that the adsorption of tartrazine organic dye was affected by adsorption time, solution pH, adsorbent dosage, pollutant concentration, and temperature. The adsorption kinetics was best described by a pseudo-second-order model with a coefficient of determination R2 = 0.999. The Toth and Langmuir models best fitted to the experimental data, showing a maximum adsorption uptake of 104.913 mg/g, which is much better than many other adsorbents. The thermodynamic parameters revealed the adsorption process of tartrazine on MIL-100(Fe) material was exothermic, spontaneous, and mainly controlled by chemical adsorption. The desorption and reuse ability of the material was effectively performed by using ethanol (98%), which showed an adsorption efficiency still remained at 88% after five adsorption cycles. This work provides an environmentally friendly synthesis of MIL-100(Fe) material with high adsorption efficiency and opens up opportunities to develop new materials for organic dye treatment in water.

Impact of monthly air pollution and weather conditions on cardiorespiratory mortality in Portuguese Metropolitan Areas

This study analyses cardiorespiratory mortality rates (CARDIO) and their association with air pollutants - particulate matter with aerodynamic diameters lower of equal to 10 or 2.5 (µm) (PM10, PM2.5), carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3) - and meteorological variables (temperature, humidity, wind speed, direction) in the Lisbon (LMA) and Porto (PMA) metropolitan areas from 2011 to 2020. Monthly analyses reveal regional patterns and seasonal variations. The results show that PMA had a higher average CARDIO rate (202.94 [Deaths per 100 000]) compared to LMA (169.70 [Deaths per 100 000]). Linear and Poisson regression, contingency tables, correspondence analysis and Pearson’s chi-squared tests confirmed significant associations between low temperature and wind speeds, high pollutant concentrations, and increased mortality. Lower temperature (≤ 13 [°C]) and wind speed (≤ 2.5 [m/s]) were consistently associated with increased CARDIO in both regions. High pollutant levels, particularly PM10 (≥ 24 [µg/m³]) and NO2 (≥ 24 [µg/m³]), were also associated with higher CARDIO rates. Additionally, high PM2.5 and CO levels were linked to increased CARDIO in LMA. The seasonal Mann-Kendall test showed no significant trend in CARDIO for LMA, but a statically significant increasing trend of 2.14 [Deaths per 100 000]) per month for PMA. This study shows the importance of mid-term exposure standards and emphasises the need for multifactorial assessments of air quality and meteorological impacts on health, as regional differences in pollutant dynamics and meteorological conditions may significantly impact cardiorespiratory mortality in urban areas.

Purification mechanism of emergent aquatic plants on polluted water: A review.

Nitrogen and phosphorus inputs to surface water bodies lead to a decline in water quality and a disruption in the balance of aquatic ecosystems. Emergent aquatic plants were widely used for their high efficiency in removing nitrogen and phosphorus from surface waters. However, there was a lack of systematic analyses on the purification of surface waters by emergent aquatic plants, and the mechanism of differences in nitrogen and phosphorus removal by different plants needs to be further revealed. By preferentially selecting emergent aquatic plants, the removal effects of 15 selected aquatic plants on five pollutant indicators (total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus, and chemical oxygen demand) were analyzed at different concentrations, and the characteristics of the removal of pollutants by different aquatic plants were explored. At the same time, combined with the morphology and synergistic action of microorganisms, in-depth research on the purification mechanism of water bodies by emergent aquatic plants was conducted. Differences were found in the purification of different water-supporting aquatic plants for different concentrations of pollutants. The comprehensive evaluation results of the membership function showed that the combined purification ability of Acorus calamus, Cyperus involucratus, Iris pseudacorus and Typha orientalis was better for the conventional pollutants. This study provides an important reference for the preferential selection of emergent aquatic plants to enhance water pollution purification and further promote the progress of ecological water treatment technology.

Visible light-driven copper vanadate/biochar nanocomposite for heterogeneous photocatalysis degradation of tetracycline: Performance, mechanism, and application of machine learning.

Water pollution caused by antibiotics is considered a major and growing issue. To address this challenge, high-performance copper vanadate-based biochar (CuVO/BC) nanocomposite photocatalysts were prepared to develop an efficient visible light-driven photocatalytic system for the remediation of tetracycline (TC) contaminated water. The effects of photocatalyst mass, solution pH, pollutant concentration, and common anions on the TC degradation were investigated in detail. Analytical techniques indicated that the CuVO exhibited a nanobelt-like structure with a uniform distribution on the wrinkled biochar surface. The XRD spectrum confirmed that the as-prepared nanomaterial was composed of Cu3V2O7(OH)2·2H2O. Meanwhile, XPS analysis revealed that copper was present in two forms: monovalent and divalent, while vanadium remained pentavalent. The CuVO/BC exhibited excellent stability and high visible light photocatalytic activity towards TC degradation over a wide pH range. The presence of SO42-, H2PO4-, CO32-, and citric acid inhibited the degradation process due to the consuming of photogenerated h+ and •OH, while Cl- enhanced the efficiency of photocatalytic reactions due to generating chlorine oxidizing species. The CuVO/BC showed lower electron-hole recombination rate, more effective separation of photogenerated carriers, lower charge transfer resistance, and higher visible light absorption capacity comparing to pure CuVO by the addition of BC, thus improving the overall photocatalytic performance. In terms of oxidation mechanism, the EPR test and quenching experiment revealed that the contribution of the active species to the degradation of TC followed the order h+ > 1O2>•OH>•O2-. Through the application of machine learning models to analyse the influencing factors of photocatalytic processes, it was discovered that the GBDT model exhibited optimal reliability for the photocatalytic system, and the simulation results were in agreement with the experimental findings.

Exposure-crossover observations of air pollution after large-scale fireworks in two Korean megacities, Seoul and Busan: Empirical evidence toward sustainable festivals.

Firework burning can significantly contribute to emissions of ambient air pollutants such as particulate matters (PM), which might pose serious public health concerns. Nevertheless, environmental research and public health attention to this matter are limited in many countries, particularly in Korea where firework festivals remain popular in megacities. This study aimed to examine temporal and spatial patterns of ambient air pollution during large-scale firework festivals in two megacities of Korea, focusing on each event held in Seoul (the second highest population in the world, as a metropolitan area) and Busan (the second highest population in Korea) in 2023. We used self-matched exposure-crossover design to compare ambient air pollution trends on exposure-event days (firework festival dates) with those on reference days (one week before and after festival dates) to evaluate a sole contribution of firework display. We analyzed data from air quality monitoring stations and visualized spatiotemporal changes in concentrations of air pollutants (i.e., PM2.5, PM10, and SO2) during the festival period. Analysis of the Seoul festival revealed significant increases in PM2.5 and PM10 concentrations following fireworks, with peaks reaching 320 and 371μg/m3. Similar patterns were observed after the Busan festival, with peak concentrations of 241 and 253μg/m3 for PM2.5 and PM10. These concentrations were 7.4-12.2 times higher than those observed on reference days. Spatiotemporal analysis demonstrated that PM2.5 and PM10 emitted from fireworks dispersed in the direction of wind. In contrast to high increases in PM2.5 and PM10, SO2 levels showed light increases after both festivals, with a peak concentration of 4.9ppb in Seoul and 5.7ppb in Busan. Considering the estimated attendance of about a million at each festival and the high-density population area around two firework locations, the potential health risk posed by firework-related air pollution is a significant public health concern.

Extraction of polycyclic aromatic hydrocarbons (PAHs) from surface soils of East Kolkata wetland, India, and its distribution, sources, and risk assessment.

The East Kolkata wetland (EKW) in West Bengal, India is a Ramsar site and has ecological importance to the city. The booming urbanization history of Kolkata city causes increase in concentration of persistent air pollutants like polycyclic aromatic hydrocarbons (PAHs) which got adsorbed eventually in the wetland soil due to their hydrophobicity and lipophilicity. Therefore, current study aims to investigate PAHs pollution level along with associated ecological health risk and optimization of PAHs extraction to develop standard analysis protocol. Three different extraction methods including Soxhlet extraction (SE), Ultrasound-assisted extraction (UAE) and Mechanical stirring extraction (MSE), four different organic solvents with different polarity (acetone, n-Hexane, DCM and Toluene) and varying extraction time between 6 and 24h are used in the optimization study. The SE method outperformed among them with toluene as most effective solvent with maximum yield at 12h of time. Concerning risk assessment study, total PAHs concentration (288.47±14.52μgg-1) exceeded the effect range median (ERM, 44.79μgg-1) and probable effect levels (PEL, 16.77μgg-1) based on sediment quality guidelines (SQGs) indicating adverse biological effects on the ecosystems. The values of Benzo[a]Pyrene-toxicity equivalent quotient (BaP-TEQcar=70.54±4.83μgg-1; BaP-MEQ=64.51±6.30μgg-1) suggest high level of risk. On the contrary, the total carcinogenic PAHs concentration suggests very low risk via the ingestion. The source apportionment study using different diagnostic ratios (DRs) reveal pyrogenic and petrogenic origins along with biomass. Hence, the findings of the present investigation could aid in enhancing the sustainable management of EKW area.

Impact of gaseous smoke pollutants from modelled fires on air and soil quality

Forest fires produce large volumes of pollutants in the atmospheric air. Fires contribute significantly to greenhouse gas emissions worldwide apart from industrial and traffic pollutants. The study reports the results of research on the effect of gaseous substances from burning forest combustibles on air quality and deposition of emissions on soil. It was determined a significant excess in smoke of such substances as carbon monoxide (3570 mg/m3), nitrogen oxide and dioxide (40 mg/m3 and 60 mg/m3) saturated hydrocarbons – methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane nonadecane. The obtained results evidence the increased concentrations of pollutants, including climate-active substances in the air. They can affect negatively both the climate and ecological state of soils. A negative effect of gaseous products of combustion on soil (Haplic Chernozem) by deposition was determined, which caused changes in soil properties. It was reliably established that the enzymatic activity of soil (Haplic Chernozem) significantly decreased under the influence from smoke of fire during 60 min. Catalase appeared to be the most sensitive indicator. The catalase activity decreased by 25% compared to control values. Peroxidase activity decreased by 15%, urease by 20% and phosphatase by 16%. The pH changed from 7.8 to 6.3 after exposure of the soil to smoke. Soil microbiota was also adversely affected by smoke. High sensitivity was recorded for microscopic fungi. Their abundances decreased by 26%–87% after 10–60 min of smoke exposure. Bacteria were found to be more resistant to toxic smoke (28%–33% decrease in abundance). Therefore, smoke from fires can be considered as one of the factors that can affect soil.Graphical

Estimate the Concentrations of Some Heavy Metals in Industrial Wastewater in Al-Dora Oil Refinery

Industrial wastewater is discharged in large quantities into water bodies, and different treatment processes are employed to reduce pollutant levels. This study quantifies copper, iron, cadmium, cobalt, lead, and nickel levels in industrial wastewater samples at Al-Dora refinery. Results showed variations before and after treatment, with physical and chemical tests conducted in summer and winter. The measured values ​​were (pH, T, Turbidity, EC, TSS, TDS ), respectively (8.23, 34.8 °C, 60.88 NTU, 2883 ms/cm, 575 mg/L, 1441 mg/L) in summer, while in the winter it was (7.516, 28.6 °C, 100.6 NTU, 1147 ms/cm, 780 mg/L, 569.8 mg/L), respectively. Heavy metals were measured and showed a slight decrease during the treatment units, nevertheless, they continue to be among the environmental determinants of the Iraqi river maintenance system (1967). The measured elements were (Cu, Fe, Cd, Co, Pb, and Ni), and their concentrations in the treated water and discharged to the river were (0.064, 0.020, 0.109, 0.031, 0.029, 0.092) mg/L, respectively, in the winter. While in summer, their concentrations were (0.017, 0.018, 0.0105, 0.017, 0.138, 0.078) mg/L, respectively. The values of pollutant concentrations were a key environmental factor in the maintenance of Iraqi rivers, as the treatment plant effectively reduced or removed these pollutants from the water before discharging it into the river, without impacting water quality.

Joint exposure to multiple air pollutants and residual cardiovascular risk in hypertension.

Despite the widespread availability of antihypertensive medications, residual cardiovascular risk of hypertension remained high. Limited studies have investigated the link between air pollution, particularly joint exposure to multiple air pollutants, with residual cardiovascular risk of hypertension. 1981 hypertensive patients (≥ 18 years) from an ongoing longitudinal cohort in China, were enrolled between 2013 and 2019. Using high-quality datasets from China, the ground-level air pollutants concentrations, including PM2.5, PM2.5-10, SO2, O3, CO and NO2, at each participant's residence were calculated. The relationships between individual and multiple air pollutants with the residual cardiovascular risk were assessed by Cox proportional hazards models, air pollution score analyses and Bayesian Kernel Machine Regression model. Over an average follow-up period of 2.24 years (SD, 1.25), 706 hypertensive patients developed cardiovascular disease. In the single-pollutant analysis, higher concentrations of PM2.5, PM2.5-10, SO2 and CO were linked to increased residual cardiovascular risk. The air pollution score analyses and Bayesian kernel machine regression suggested that combined exposure to multiple air pollutants had a positive association with the residual cardiovascular risk, and NO2 played a dominant role. With higher NO2 concentrations, the hazard ratio of individual pollutants to residual cardiovascular risk increased. Prolonged exposure to a mixture of various air pollutants is linked to elevated residual cardiovascular risk in individuals with hypertension. Apart from taking antihypertensive medication and adopting healthy lifestyle behaviors, hypertensive patients should lower air pollutant exposure to decrease residual cardiovascular risk.

Air Quality and Energy Use in a Museum

Museums play a vital role in preserving cultural heritage and for this reason, they require strict indoor environmental controls. Balancing indoor environmental quality with reduced energy consumption poses significant challenges. Over the course of a year (2023), indoor microclimate conditions, atmospheric pollutant concentrations (O3, TVOC, CO, CO2, particulate matter), and energy use were monitored at the Archaeological Museum of Kavala. Maximum daily fluctuations in relative humidity were 15% in summertime, while air temperature variations reached 2.0 °C, highlighting unstable microclimatic conditions. Particulate matter was the primary threat to the preservation of artworks, followed by indoor O3 and NO2, whose concentrations exceeded recommended limits for cultural conservation. In 2023, the Energy Use Intensity (EUI) was 86.1 kWh m−2, a value that is significantly correlated with the number of visitors and the outdoor air temperature. Every person visiting the museum was assigned an average of 7.7 kWh of energy. During the hottest days and when the museum was crowded, the maximum amount of energy was consumed. Over the past decade (2013–2023), the lowest EUI was recorded during the COVID-19 pandemic at 53 kWh m−2. Energy consumption is linked to indoor environmental quality; thus, both must be continuously monitored.

Biofiltration for odor mitigation in water resource recovery facilities.

Odor emissions, primarily from anthropogenic activities like waste treatment and industrial processes, pose significant challenges in urban areas, particularly near water resource recovery facilities. While these emissions are generally not toxic, they can adversely affect community wellbeing and investment, prompting stricter regulations in some regions. For example, New York State's hydrogen sulfide guidelines are more stringent than federal standards. Hydrogen sulfide, along with other reduced sulfur compounds, volatile organic compounds, and nitrogen compounds, are among the key odorants produced by water resource recovery facilities. Various methods have been explored to mitigate these odors, including chemical treatments, operational modifications, and air treatment strategies like biofiltration, activated carbon adsorption, and regenerative incineration. Among these, biofiltration stands out as an environmentally friendly option due to its high efficiency in removing hydrogen sulfide and other odorants without the need for chemicals. Biofiltration systems, including biofilters and biotrickling filters, use microorganisms immobilized in a bed of porous media to degrade odorous compounds. Biofilters, which operate with intermittent water supply, are highly effective at total odor removal. In contrast, biotrickling filters, which use continuous nutrient and water flow, are better suited for higher pollutant loads but struggle with compounds of low solubility. Key factors influencing biofilter performance include the empty bed residence time, media type, moisture content, and microbial diversity. This review explores recent advancements in biofilter technology, with a focus on the removal of hydrogen sulfide and organic sulfur compounds. It also highlights real-world applications in water resource recovery facilities and discusses critical design and operational parameters for improving odor control, such as media selection, residence time, pH regulation, and microbial management. Key studies underscore the importance of media composition and nutrient supply in optimizing biofilter performance, especially at higher pollutant concentrations. Understanding these factors will help inform future improvements in odor management for water resource recovery facilities.

Abatement of methylene blue and diazinon pesticide from synthetic solutions using magnetic biochar from pistachio shells modified with MOF-808.

This study develops a magnetic composite from pistachio shell biochar (PSBC/CoFe₂O₄) modified with MOF-808 for removing methylene blue (MB) dye and diazinon (DA) pesticide from water. The composite, with a surface area of 151.53m2/g and magnetic saturation of 19.653 emu/g, allowed easy separation from solutions. Key adsorption factors such as pH, temperature, contact time, adsorbent dosage, and initial pollutant concentration were optimized. Maximum removal efficiencies of 99.32% for MB and 99.14% for DA were achieved at adsorbent dosages of 1g/L for MB and 1.5g/L for DA, initial concentrations of 5mg/L, temperatures of 55°C, contact times of 60min for MB and 80min for DA, and pH levels of 9 for MB and 6 for DA. Thermodynamic analysis confirmed that the adsorption process is spontaneous and endothermic, with enthalpy values of 55.091kJ/mol for MB and 42.028kJ/mol for DA, while entropy values indicated increased randomness during adsorption. Kinetic studies revealed that adsorption involved both physical and chemical interactions, with intraparticle diffusion not being the rate-limiting step. The Freundlich isotherm model provided the best fit (R2=0.971 for MB and 0.988 for DA), highlighting heterogeneous surface interactions. The composite showed higher adsorption capacities for MB (31.44mg/g) than for DA (21.49mg/g) and exhibited excellent regeneration potential, performing better in deionized water due to the inhibitory effects of salts in non-deionized water.

Forecasting the air pollution concentration with neural networks

Forecasting the air pollution concentration with neural networks

Wastewater quality evaluation in terms of wastewater quality index using hybrid constructed wetland for treatment of dairy and municipal wastewater.

The world's most pressing problem is water shortage, which is made worse by fast industrialization and urbanization, especially in places like India where untreated effluent presents serious threats to human health and the environment. In order to treat dairy and municipal wastewater, this study assesses the efficacy of a two-stage hybrid constructed wetland (CW) system. The WWQI is the primary focus of this evaluation over a range of mixing ratios. Before and after treatment, many physicochemical parameters were examined, including pH, total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphorus (TP), ammonia nitrogen ( ), and nitrate nitrogen ( ). The hybrid CWs system dramatically lowers pollutant concentrations, according to the results, with combinations containing higher amounts of MWW showing the best results. The WWQI values, which change from "unfit for any uses" in untreated DWW to "excellent" quality in treated MWW, show these advancements. The results highlight the potential of hybrid CWs as an effective and sustainable wastewater treatment method, especially when it comes to maximizing the proportion of dairy to municipal wastewater. This study adds to our knowledge of efficient wastewater treatment techniques and highlights the significance of incorporating eco-friendly technologies to tackle water scarcity issues. PRACTITIONER POINTS: Hybrid Constructed Wetlands (HCWs) are effective in removing TSS, BOD, COD, TP, ammonia nitrogen, and nitrate nitrogen from dairy and municipal wastewater. On the basis of HCWs performance determine the Wastewater Quality Index (WWQI) for four different ratio proportions of dairy and municipal wastewater. This index is more useful for water quality status determination and treated water reuse for various purposes. This also benefits sustainable treatment technology and contributes to achieving SDGs.

Air Pollution Concentrations and Their Determinants in the Top Ten Most Polluted Countries in the World in 2010-2020

This study analyzes air pollution concentration and its determinants in ten countries with the highest levels of air pollution from 2010 to 2020. Air pollution has become a global issue affecting both human health and the environment. The study uses secondary data and applies two analytical tools: a concentration index to identify countries with the highest air pollution levels, and panel data regression to analyze its determinants. Air pollution is proxied by CO2 emissions. The results indicate that eight out of ten countries have a concentration index greater than one, with Japan, South Korea, and Germany ranking as the top three countries with the highest air pollution concentrations. The population variable has a positive and significant impact on air pollution concentration in these countries. Conversely, the energy consumption variable has a negative and significant effect on air pollution concentration. On the other hand, economic growth does not have a significant effect on air pollution concentration. The study's implications highlight the need for a transition to more efficient and renewable energy sources as a crucial step in reducing the negative impacts of air pollution. Stricter environmental policies and increased investments in eco-friendly technologies are highly recommended to address this issue