Accumulation Of Pollutants Research Articles

Treatment of methanol-containing wastewater at gas condensate production

The purpose of the study was to assess the impact of industrial wastewater on the concentration of methanol in the considered section of the Ob River basin, present proposals for the implementation of a new treatment system and analyse the implementation results. On the basis of the results of the analysis of the known methods for reducing the concentration of methanol in water, a new technological scheme for post-treatment of effluents using biological treatment with methylotrophic Methylomonas methanica Dg bacteria was proposed. The calculation of the dilution of treated wastewater using the “NDS Ecolog” program was carried out on the basis of the detailed calculation method of Karaushev, the results of which showed a decrease in the concentration of methanol in the control section to 0.0954 mg∙dm –3 (permissible concentration is 0.1 mg∙dm –3). During the period of the flood of the Glukhaya channel, it ceases to be a separate water body and, in fact, becomes part of the flood channel of the Ob River. Certain parts of the flooded areas, due to elevation changes, communicate with the channel only during a short period of time when the water level rises, i.e. 3–5 weeks during the flood period, and in fact remain isolated reservoirs for the rest of the time, potentially acting as zones of accumulation and concentration of pollutants.

Усовершенствованная технология прогноза метеорологических параметров и условий, влияющих на загрязнение воздуха

An improved technology for calculating the forecast of the meteorological indicator of pollution dispersion (MIPD) is described. The changes in the algorithm for calculating the MIPD, adopted on the basis of the results of verification of the algorithm using data on the concentrations of pollutants, are shown. Taking into account the model forecasts of wind speed and temperature obtained in assessing the quality, methods for their correction at the preprocessing stage have been developed and presented in the APS, the procedure for spatial averaging of the parameters included in the calculation of the MIPD has been optimized. The improvement in technology has reduced the number of false forecasts of MIPD in the range of meteorological conditions that contribute to the accumulation of pollution in surface air. Keywords: methodological indicator of pollution dispersion, meteorological conditions of air pollution, adverse weather conditions, hydrodynamic forecast, model horizontal resolution, verification of forecasts data

Research on the spatial correlation and drivers of industrial agglomeration and pollution discharge in the Yellow River Basin

The spatial auto-correlation analysis approach is used to examine the agglomeration features and geographical correlation of industrial agglomeration and pollutant discharge using 91 prefecture-level cities in the Yellow River Basin from 2005 to 2020 as the research target. The Yellow River Basin and the upper, middle, and lower reaches were investigated for the effects of industrial agglomeration on industrial pollution emissions. The Dubin model of the spatial panel is used to investigate the drivers of industrial pollution from both indirect effects and direct effects. The findings indicated that ① the spatial pattern of industrial pollution agglomeration and industrial agglomeration in the Yellow River Basin has spatial convergence; ② the global clustering characteristics of industrial pollution in the Yellow River Basin are apparent. The global correlations of the three pollutants are industrial wastewater > industrial smoke and dust > industrial SO2; there is a spatial association between industrial agglomeration and pollution agglomeration, and there are differences in the spatial interconnection between industrial agglomeration and the accumulation of different pollutants; ③ from the overall point of view of the Yellow River Basin, industrial agglomeration will reduce the pollution levels of industrial wastewater, industrial SO2, and industrial smoke and dust. From the perspective of different regions, industrial agglomeration in the upper, middle, and lower reaches is conducive to the decline of industrial pollution, and the role is in the middle, downstream, and upstream in order from large to small; and ④ the Yellow River Basin’s industrial pollution is primarily caused by population agglomeration, industrial structure, environmental regulation, opening to the outside world, and economic development. Their effects on industrial wastewater, industrial SO2, industrial smoke, and dust pollution vary.

Usability of Some Landscape Plants in Biomonitoring Technique: an Anaysis With Special Regard to Heavy Metals

As a result of the widespread industrial activities in today's cities and the increase in the urban population and building density, the pollution values in the urban geography are increasing. The accumulation of environmental pollutants is one of the most important problems to be considered in the construction of cities. Heavy metal pollution from various activities in urban areas is one of the riskiest environmental problems. Heavy metals are concentrated due to human activities and it is necessary to monitor and determine their accumulation levels. Detection and reduction studies of heavy metal levels in regions and areas with population density are of critical importance, as accumulation above a certain dose can cause vital problems. Studies on the accumulation of heavy metals are affected by parameters of quite different sizes, and determination of the level and identification of the source is quite complex. However, due to the high accumulation of pollutants in some landscape areas due to the effect of their type, it reveals the course of pollutants in these regions. This study aimed to determine the concentrations of Copper (Cu) and Iron (Fe) in leaves, bark and wood in various landscape species by biomonitoring heavy metals. By comparing the Cu and Fe concentrations, the heavy metal holding capacities of the species used varied significantly in plant species and in different organs of the same plant. As a result of the study, it has been determined that Schinus molle L. can be preferred in urban areas and can be used as a biomonitor in Cu and Fe accumulation.

A Comparative Study of the Simulation Accuracy and Efficiency for the Urban Wind Environment Based on CFD Plug-Ins Integrated into Architectural Design Platforms

The deterioration of the urban environment is a problem which has captured the attention of governmental departments and researchers, who are committed to improving the urban environment from the perspective of optimizing urban morphology. Although many researchers have applied computational fluid dynamics (CFD) plug-ins to study the problems of urban ventilation and pollutant accumulation, studies on the reliability and simulation accuracy verification of CFD plug-ins are currently scarce. Therefore, we used three CFD plug-ins based on different architectural design platforms to evaluate and compare their operation difficulty, simulation accuracy, and efficiency through the analysis of the simulation results of urban ventilation. This study complements the reliability validation of CFD plug-in simulations and guides urban planners and architects in the selection and application of CFD plug-ins. The results show that the CFD plug-in generally underestimates the wind speed at the pedestrian level and the prediction accuracy is poor in the wake area of obstacles, especially with the GH_Wind plug-in. Under the 0° inflow direction, the simulation results of the Butterfly plug-in were the most consistent with the experimental values. When the inflow direction increased to 22.5° and 45°, the Autodesk CFD showed the best simulation accuracy. Overall, Autodesk CFD achieves a balance between simulation accuracy and speed in urban airflow simulation.

Influence of Environmental and Dietary Exposures on Trace Metals and Organochlorine Pollutants Accumulation Among the Residents of a Major Industrial Harbour (Fos-sur-Mer, France)

Influence of Environmental and Dietary Exposures on Trace Metals and Organochlorine Pollutants Accumulation Among the Residents of a Major Industrial Harbour (Fos-sur-Mer, France)

High nitrogen addition after the application of sewage sludge compost decreased the bioavailability of heavy metals in soil

Nitrogen (N) fertilizer is highly significant in agricultural production, but long-term N addition causes changes in quality indicators, such as soil organic matter (SOM), thus affecting the absorption and accumulation of organic pollutants. Therefore, paying more attention to organic fertilizers in the development of green agriculture is necessary. However, the accumulation of heavy metals (HMs) contained in organic fertilizers (especially sewage sludge compost (SSC)) in the soil can cause environmental contamination, but how this cumulative reaction changes with the long-term N addition remains unclear. Here the SSC impact on the bioavailability of five typical HMs (cadmium–Cd, chromium–Cr, copper–Cu, lead–Pb and arsenic–As) in the soil-plant system before and after SSC application was demonstrated through a field study in soils with different application rates of 0, 100 and 300 kg N ha−1yr−1, respectively. Our results showed that SSC application increased the concentration of most HMs in soil profiles and plant systems (wheat roots and grains), but the accumulation rate of HMs and most bioaccumulation values (BAC–bioaccumulation coefficient and BCF–bioconcentration factor) in plant systems were both lower in high-N addition soil than that in the low-N group. Moreover, speciation distribution results further indicated that SSC application increased the LB (liable available form, including F1–water soluble, F2–ion exchangeable, and F3–bound to carbonates) form of HMs and decreased the PB (potentially available form, including F4–humic acids and F6–fraction bound to organic matter) form of HMs in high-N addition soil, respectively. Those results suggested that HM bioavailability in high-N addition soil was lower than that in low-N addition soil when applied with SSC. Overall, this study found that increasing soil N content can inhibit the bioavailability of HMs when applying SSC, providing suggestions for optimizing the trialability and risk assessment of SSC application.

Quantifying the drivers of PM2.5 variation in Shenyang, China: A factor decomposition model

Taking variations in PM2.5 as indicators for assessing the performance of authority in air quality management will probably lead to misjudgment, as PM2.5 concentration is affected not only by anthropogenic emissions but also by uncontrollable circumstances. To solve this problem, we proposed a decomposition method to attribute the variations in PM2.5 to the contributions of meteorological conditions, cross-regional transports of pollutants, secondary aerosols, and local emissions. This method estimated the relationship between PM2.5 concentration and the various influencing factors using a semi-parametric generalized additive model. A case study was conducted in Shenyang, a heavily polluted city in northeast China, based on up to 595,000 hourly data samples from 2014 to 2017. The decomposition results indicated that the average PM2.5 in 2017 decreased by 39.80% compared with 2014, far exceeding the government's target of 15%, but only 11.79% of the decrease was benefited from the control of local emissions. The severe pollution event that occurred in November 2015 was induced by the combination of massive emissions from heating and meteorological conditions conducive to pollutant accumulation. Furthermore, the approach we proposed can be extended to any location that has monitoring data on air pollutant concentrations and meteorological conditions.

Long-term application of nitrogen fertilizer alters the properties of dissolved soil organic matter and increases the accumulation of polycyclic aromatic hydrocarbons

Soil is a key component of terrestrial ecosystems, as it provides nutrients and energy for all terrestrial organisms and is the site of various physical, chemical, and biological processes. Soil organic matter is particularly important for the role that it plays in element cycling, as well as the adsorption and degradation of soil pollutants. Nitrogen (N) fertilizer is an important nutrient element in the soil microenvironment. Applications of N fertilizer can improve soil quality, but the long-term excessive application of N fertilizer can lead to the deterioration of the soil environment, alter the properties of organic matter, and affect the adsorption and accumulation of soil pollutants. In recent years, several pollutants, especially polycyclic aromatic hydrocarbons (PAHs), have accumulated in farmland soil due to long-term sewage irrigation. However, few studies have examined the response of soil PAHs accumulation to long-term N application, as well as the relationship between this response and changes in soil microenvironmental indicators caused by N application. Here, we conducted field experiments to study changes in soil pH, total organic carbon, and dissolved organic matter (DOM) under long-term N application, as well as their effects on PAHs accumulation. The application of N fertilizer resulted in the aromatization and humification of soil DOM, enhanced the accumulation response ratio (−0.05–0.32) and the amount of PAHs accumulated in soil (more than 30%), and exacerbated the environmental risks of PAHs. Our findings provide new insights that could aid the management and control of PAHs pollution of soil in sewage-irrigated areas.

Study of the Applicability of the Root Wastewater Treatment Plants with the Possibility of the Water Recirculation in Terms of the Surfactant Content

Anthropogenic activities cause the accumulation of pollutants in the aquatic environment. Conventional wastewater treatment plants do not completely remove emergent pollutants, including personal care products, in which the surfactants are an essential ingredient. The results of our study confirm the presence of the surfactants in the aquatic environment, which represents an ecological and environmental risk. It was confirmed by ecotoxicological tests (test with using Daphnia magna and Lemna minor) and the specified content of the surfactants in the samples. The content of the surfactants in personal care products is significant and their impact on the aquatic environment is not sufficiently monitored. Root wastewater treatment plants, as innovative cleaning methods, represent effective cleaning methods, which can be used as a separate object or as an object for further cleaning already cleaned water from conventional wastewater treatment plants. Purified water from these devices can be recycled and used again as utility water (according to the model presented in the article). A significant benefit from the point of view of global warming and the effect of anthropogenic activity is the saving of drinking water as a natural resource. Root wastewater treatment plants ensure the required quality of discharged water in the aquatic environment.

Spatiotemporal characterization of aerosols and trace gases over the Yangtze River Delta region, China: impact of trans-boundary pollution and meteorology

BackgroundThe spatiotemporal variation of observed trace gases (NO2, SO2, O3) and particulate matter (PM2.5, PM10) were investigated over cities of Yangtze River Delta (YRD) region including Nanjing, Hefei, Shanghai and Hangzhou. Furthermore, the characteristics of different pollution episodes, i.e., haze events (visibility < 7 km, relative humidity < 80%, and PM2.5 > 40 µg/m3) and complex pollution episodes (PM2.5 > 35 µg/m3 and O3 > 160 µg/m3) were studied over the cities of the YRD region. The impact of China clean air action plan on concentration of aerosols and trace gases is examined. The impacts of trans-boundary pollution and different meteorological conditions were also examined.ResultsThe highest annual mean concentrations of PM2.5, PM10, NO2 and O3 were found for 2019 over all the cities. The annual mean concentrations of PM2.5, PM10, and NO2 showed continuous declines from 2019 to 2021 due to emission control measures and implementation of the Clean Air Action plan over all the cities of the YRD region. The annual mean O3 levels showed a decline in 2020 over all the cities of YRD region, which is unprecedented since the beginning of the China’s National environmental monitoring program since 2013. However, a slight increase in annual O3 was observed in 2021. The highest overall means of PM2.5, PM10, SO2, and NO2 were observed over Hefei, whereas the highest O3 levels were found in Nanjing. Despite the strict control measures, PM2.5 and PM10 concentrations exceeded the Grade-1 National Ambient Air Quality Standards (NAAQS) and WHO (World Health Organization) guidelines over all the cities of the YRD region. The number of haze days was higher in Hefei and Nanjing, whereas the complex pollution episodes or concurrent occurrence of O3 and PM2.5 pollution days were higher in Hangzhou and Shanghai.The in situ data for SO2 and NO2 showed strong correlation with Tropospheric Monitoring Instrument (TROPOMI) satellite data.ConclusionsDespite the observed reductions in primary pollutants concentrations, the secondary pollutants formation is still a concern for major metropolises. The increase in temperature and lower relative humidity favors the accumulation of O3, while low temperature, low wind speeds and lower relative humidity favor the accumulation of primary pollutants. This study depicts different air pollution problems for different cities inside a region. Therefore, there is a dire need to continuous monitoring and analysis of air quality parameters and design city-specific policies and action plans to effectively deal with the metropolitan pollution.

Three-dimensional hydrodynamic modelling of the Moroccan Atlantic coast: A case study of Agadir bay

Coastal areas are a noteworthy source of commercial and economic fortunes for surrounding municipalities throughout the Moroccan Atlantic coast. Thus, a deep knowledge of local hydrodynamics and environmental processes associated is integral to effective coastal management. 3D hydrodynamic model that includes a Lagrangian particle simulation can participate to this understanding of dynamics. The model was calibrated and validated against meteorological conditions, sea surface level, harmonic tidal constituents, water temperature and salinity using a combination of available in-situ measurements, satellite, and ARGO floats data. Subsequently, it was used to determine the pathway of passive tracers and estimate the local residence time (RT). Despite some discrepancies, the findings revealed a good match between simulations and observations, which underlines the feasibility of the model in predicting the main dynamic features of the Agadir bay. Overall, the hydrodynamics of the area is tidal dominated by semidiurnal tides (M2) and governed by westerly and northwesterly winds. Passive tracer simulations showed strong seasonal and spatial variability, conditioning the obtained RTs, with mean values much shorter during summer (3 to 9 days) than winter (5 to 15 days). The tracers look to be trapped inside a coastal cyclonic eddy that increases the RTs in the southern bay, making it an area with highest likelihood of accumulation of pollutants while favoring the northward transport and decrease RTs in the northern bay.

Environmental hazard assessment of metals in marine sediments of Sabah and Sarawak, Malaysia

The fractionation of 10 metals (As, Co, Cr, Cu, Mn, Ni, Pb, Se, V, and Zn) within labile fractions in shallow marine sediments collected from the coasts of Sabah and Sarawak, Malaysia, was evaluated. Spatial distribution revealed that coastal sediments from Sabah were approximately 10% higher in metal content than sediments from Sarawak. Risk assessment code, enrichment factor, and pollution accumulation index calculations were used to investigate the environmental hazards of elements. For the risk assessment code, the modified Tessier sequential extraction procedure was applied. The risk assessment code values showed that metal V recorded the lowest environment risk (~ 10%) while As, Co, Cr, Cu, Mn, and Zn exhibited medium risk (Risk assessment code range of 11%–30%). The element Ni displayed no risk (0.67%) to the environment, whereas Se and Pb recorded the highest risk with values of 47% and 52%, respectively. For the enrichment factor calculation, the continental crust data presented by Taylor (Taylor, Geochim Cosmochim Acta 28:1273–1285, 1964) were used as background, with metal Al used as a reference element. Results illustrated that most of the metals show enrichment (enrichment factor > 1). However, Se was considered extremely severe to the environment (enrichment factor > 50). While the pollution accumulation index calculation demonstrated that all metals under study can be considered as non-contaminant elements except for Ni, V, and Co. These findings indicated that marine sediments in Sabah are more polluted with metal contaminants than the sediments in Sarawak, despite both states having numerous active oil- and gas-related production facilities.

Quality of first flush of rainwater from urban area: short review

As a result of changes in social, economic, and political relations, undesirable phenomena are created that have an adverse effect on the urban environment. Surface runoff represents one of several risks to environmental policy, causing the major problem in urban agglomerations. In an urbanized area, it causes an increased runoff volume and the flood peak. Also, it affects increasing the contamination of urban rainwater. The significant problem of surface runoff formation in urban river basins is the accumulation of pollutants on the surface of paved areas during the rainless period. In the case of the formation of surface runoff, these substances come into movement. It is assumed that the most polluted rainwater is in the initial phase of runoff formation. However, not all authors agree with the statement. In some literature, this phenomenon is termed the first flush. Given the above facts, the study focuses on surface runoff characteristics in terms of its quality and quantity in the initial phase of surface runoff formatting. The study aims to summarize and compare the results of several studies to evaluate the first rainwater flush in an urbanized area.

Monitoring the state of snow cover in the Khabarovsk Territory

In the article, the authors considered the issues of snow cover monitoring in the conditions of the Khabarovsk Territory. An analysis was made of the main pollutants in the period from 2014 to 2020, the impact of snow cover on the environment was studied, and the ways in which pollutants entered were analyzed. The presented work is of an analytical and research nature — to trace the accumulation of pollutants in the snow cover, for further development of solutions to improve the atmospheric air monitoring system in the cities of the region. The work was carried out within the framework of research work 3.21-TOGU. The state of protection of the environment and vital human interests from the possible negative impact of economic and other activities on the territory of the Khabarovsk Territory at the present time cannot be considered satisfactory. Environmental problems are global in nature and do not have territorial, state borders, but to date, a unified system for monitoring and assessing the ecological state of the ecosystem with the prolongation of the dynamics of changes in the future has not been created in the region. And the known set of methods and tools for assessing the environmental situation does not provide the required level of reliability. Snow cover is a natural accumulator of a large amount of aerosol substances, in which atmospheric precipitation is accumulated and preserved; in addition, it can be considered a natural indicator of both the state of the atmosphere and pollution of soils, water, and biosphere objects. At present, under the conditions of an ever-increasing anthropogenic load on the environment, high-quality, timely information about the state of the environment is needed. Although interest in research on the chemical composition of the snow cover has recently grown, it should be noted that in the territory of the Khabarovsk Territory, little is done in depth research in this area. The territory of this region is located in the form of a narrow strip on the eastern outskirts of Asia, the climate of the region is monsoon. It is characterized by cold, snowy winters and wet, hot summers. Climatic conditions change significantly both from north to south, and depending on the proximity to the sea, as well as on the nature of the relief. The period of snow occurrence is from 4 months, mainly in the southern, southwestern regions, to 6 months in the northern regions, which, according to the authors, is a good help for a detailed study of accumulated pollutants. In addition, in the region, more than 83.14 % of the population lives in cities with high and very high levels of air pollution, which primarily affects health (among the common types of diseases, respiratory diseases are in first place, circulatory system diseases are in second, third disease of the musculoskeletal system). To reduce the technogenic load on the atmosphere, it is necessary to install more efficient cleaning systems at thermal power plants and introduce effective technical control of the transport composition in the region, review and improve the atmospheric air monitoring system.

The effect of rhizospheric bacteria Ochrobactrum cytisi IPA 7.2 on the resistance of white mustard plants to heavy metals and herbicides

In modern agriculture, the problem of the use of various pesticides, including non-selective herbicides and copper-containing fungicides, is acute. Rhizospheric bacteria can serve as one of the factors of increasing the resistance of plants to adverse chemical influences. The subject of this research was study the effect of bacteria Ochrobactrum cytisi IPA 7.2 on the white mustard (Sinapis alba L.) resistance to copper ions (Cu(II)), glyphosate and copper complexes with glyphosate [Cu(II)-GL]; as well as on the accumulation and translocation of pollutants in plants. It was shown that the combination of glyphosate or its complexes [Cu(II)-GL] and IPA 7.2 inoculation inhibited the growth of mustard more intensively than in the variants with pollutants alone. In the case of copper, on the contrary, an increase in the accumulation of wet and dry root mass by 1.8 times was found in inoculated plants. Colonization of mustard with strain IPA 7.2 reduced the accumulation of Cu(II) in the plant’s shoot system by two times and simultaneously stabilized the metal in the root zone. However, IPA 7.2 did not effect on the accumulation and translocation of chelated copper in the complexes. The current result is important for understanding about processes of interaction in the plant-rhizosphere bacteria-pollution system and can be used in the technology of growing environmentally friendly products.

The study on contamination of bottom sediments from the Odra River estuary (SW Baltic Sea) by tributyltin using environmetric methods

We present the first comprehensive study on the occurrence of tributyltin (TBT) in the Odra River estuary (SW Baltic Sea) that encompasses both densely populated and urbanized agglomeration Szczecin city, and sparsely populated biosphere reserves “Natura 2000”. Relationship between TBT and physicochemical parameters of bottom sediments such as granulometry total organic carbon (TOC), total nitrogen (TN), acid volatile sulfide (AVS), As, and metals: Ba, Cd, Co, Cr, Cu, Fe, Hg, Ni, Mn, Mo, Pb, Sn, and Zn was investigated in 120 samples collected in 2017 and 2018. The highest TBT concentrations were over 3000 ng g−1 (dry weight). They were observed in samples collected in the vicinity of the ship maintenance zones of the Szczecin city. Despite the EU ban on its use since 2003, TBT is still present in the environment. Environmetrics analyses such as correlation, cluster, and principal component analysis of obtained results revealed that the main source of sediments contamination by TBT, metalloids, and metals is likely related to the maritime industry: shipyards, ship maintenance as well as ports and marines. TBT is still present in the bottom sediments because of its emission to the environment with dust and paint chips formed during sandblasting cleaning of ship surfaces. The pollutant is further transported with water current to remote localization in the Szczecin Lagoon. Slow water exchange between the Szczecin Lagoon and the Baltic Sea favors accumulation of pollutants in the lagoon sediments. Therefore, it is necessary to implement environmentally friendly methods into ship maintenance and management of the materials from dredged waterways, harbors, and marinas.

Quantitative evaluation of impacts of the steadiness and duration of urban surface wind patterns on air quality

The complexity and heterogeneity of urban land surfaces result in inconsistencies in near-surface winds, which in turn influence the diffusion and dispersion of air pollutants. In this study, we classified urban surface wind fields, quantified their steadiness, duration, and influence on air quality using hourly wind observations from 50 meteorological stations, as well as hourly PM2.5 and NO2 concentrations from 18 monitoring stations during 2017–2018 in Shenzhen, a mega city in southern China. We found that the K-means clustering technique was reliable for distinguishing surface wind patterns within the city. Urban surface-wind patterns greatly affected pollutant concentrations. When dominated by calm, northerly wind, high PM2.5/NO2 concentration episodes occurred more frequently than those during other surface wind patterns. The urban surface transport index (USTI) was used to quantify the steadiness of surface wind classes. High pollutant concentrations were present during both high wind speed periods with a large USTI, indicating external pollutant transport, and during low wind speed periods with a small USTI, indicating pollutant accumulation. The threshold durations for surface wind fields (TDSWF) was proposed to quantify the impacts of surface wind persistence on air quality. We found that poor air quality occurred during the first several hours of a dominant wind pattern, indicating that transitions between wind patterns should be a particular focus when assessing air-quality deterioration. USTI and TDSWF are potentially applicable to other urban areas, owing to their clear definitions and simple calculation. In combination with wind speeds, these indices are likely to improve air quality forecasting and strategic decisions on air pollution emergencies, based on long time series of multiple wind and pollutant concentration observations.

Application of a Wind Environment Simulation Generation Technology in Urban Planning

With the acceleration of urbanization, cities have shown a development trend of high density, high height, and high intensity, which significantly weakens the airflow in the city, resulting in the accumulation of heat and pollutants, and in the urban environment, the problem is getting worse. Therefore, it is particularly necessary to strengthen urban ventilation in the urban environment. However, in the real urban environment, the building layouts are diverse, the building forms are different, and the interaction of the building wind environment is complex due to the lack of relevant research on the complex building spatial form in the urban mesoscale area on the outdoor pedestrian. The research results are difficult to be applied in actual urban construction, and it is difficult to guide the optimization of the urban wind environment. To solve this problem, this paper adopts the CFD method in a real-scale (1 : 1) urban mesoscale regional wind environment simulation study. On this basis, the influencing factors of the urban pedestrian wind environment are analyzed, and the optimization strategy of the wind environment is proposed, which can provide practical guidance for the planning practice of enhancing urban wind comfort.

Trend in Particulate air pollutants in Visakhapatnam city for 2018-2020: A case study

Rapid industrialization aided by urbanization led to severe air pollution in Visakhapatnam city, withprominent pollutant being particulate matter (PM10). This paper aims to anlyse the trend in particulatematter over a three year period, 2018-20. The results indicate high mass concentrations of PM10 in winter,mostly exceeding NAAQS limits. Clearer air quality is observed in summer and monsoon seasons. Thecity’s bowl-shaped area promotes the accumulation of pollution in winter.