International Journal of Environment and Pollution (17 papers in press)
Biological denitrification and dephosphorization of a fixed bed reactor packed with long-term carbon release composite under magnetic field
by Shuchen Tu, Fengzhu Lv, Zilin Meng, Rui Zhang, Yihe Zhang
Abstract: A novel multiple-component carbon source mainly with hemp fibre (HF) and biodegradable polybutylene succinate (PBS) was prepared and filled into two fixed bed bioreactors to remove nitrate nitrogen and phosphorus from simulated groundwater. A 121 days monitoring indicates the denitrification and dephosphorisation of bacteria are influenced by temperature. But a magnetic field can decrease the influence. As the operation temperature was 30-36 oC, the average nitrate nitrogen and total phosphorus (TP) removal degree in reactor 1 (without electromagnetic field) was 91.05% and 71.34%, while nitrite remained at low levels (less than 0.2 mg/L). As a magnetic field was introduced, the average nitrogen and phosphorus removals were improved to 93.18% and 78.68%, respectively. Meanwhile, the average effluent concentration of chemical oxygen demand (COD), decreased from 51.2 mgL-1 to 30.8 mgL-1. The morphology and the biofilm attaching amount measurement indicated more bacteria were attached onto the composite and more composite was consumed correspondingly but inhomogeneously. These data show that a magnetic field could improve the growth of bacteria and their attachment onto the composites. The prepared composite is a long-term carbon-release material and the fabricated fixed bed reactors are high performance reactors for NO3-N removal.
Keywords: denitrification; biofilm; magnetic field; carbon sources; water treatment.
Identification of dust transport patterns and sources by using MODIS: a technique developed to discriminate dust and clouds
by Zaibun Nisa, Salman Atif, Faheem Khokhar
Abstract: This study focuses on exploring the meteorological factors behind dust emergence and spread over Baluchistan in the post-monsoon season, as much of the existing research has been done on spring episodes. With the integration of remote sensing and meteorological methods, efforts were made to explore the relationship of dust storms with land-atmospheric conditions, such as surface temperature and aerosol optical depth (AOD) in the selected season. To map dust spatial distribution, a cloud-free product of Brightness Temperature Difference (BTD) composite from MODIS terra level 1B emissive bands were prepared and classified using the maximum likelihood technique. Two case studies of October 2004 and December 2011 exhibited the short-term cooling effect on the surface due to increased AOD. Dominant synoptic patterns of cold trough front formation with low-pressure centre development over eastern Iran were found as a significant feature of dust mobility towards warmer Baluchistan. Back trajectory analysis revealed that dust from south western Kazakhstan and eastern Europe converged over land of Kyrgyzstan and Tajikistan, which may have instigated its uplift over Helmand Basin. Evidence of a dominant effect of air masses from Middle East, Iran and Iraq was found in post-monsoon dust episodes.
Keywords: dust transport; dust-enhanced composite; aerosol thickness; back trajectories; dust storm meteorology; Pakistan.
Urban emission inventory optimisation using sensor data, an urban air quality model and inversion techniques
by David Carruthers, Amy Stidworthy, Dan Clarke, Jo Dicks, Rod Jones, Ian Leslie, Olalekan Popoola, Martin Seaton
Abstract: An optimisation scheme has been developed that applies a Bayesian inversion technique to a high resolution (street-level) atmospheric dispersion model to modify pollution emission rates based on sensor data. The scheme minimises a cost function using a non-negative least squares solver. For the required covariance matrices assumptions are made regarding the magnitude of the uncertainties in source emissions and measurements and the correlation in uncertainties between different source emissions and different measurement sites. The scheme has been tested in an initial case study in Cambridge, UK, using monitored data from four reference monitors and twenty AQMesh sensor pods for the period, 30 June 2016 30 September 2016. Hourly NOx concentrations from road sources modelled using ADMS-Urban and observed concentrations were processed using the optimisation scheme and the adjusted emissions were re-modelled. The optimisation scheme reduced average road emissions on average by 6.5% compared to the original estimates, changed the diurnal profile of emissions and improved model accuracy at four reference sites.
Keywords: inversion; optimisation; emissions; ADMS-Urban; sensors.
Independent analysis of time-varying hydrogen cyanide gas exposures on rats using toxic load-based modelling
by Alexander Slawik, James Silva, Kevin Axelrod, Jeffry Urban, Nathan Platt
Abstract: The US Defence Threat Reduction Agency (DTRA) sponsored a two-year set of experiments, conducted in 2012 and 2013, that were designed and executed by the US Armys Edgewood Chemical and Biological Center (ECBC) and the Naval Medical Research Unit Dayton (NAMRU-D) to explore time-varying inhalation exposures of hydrogen cyanide gas on rats. Our analysis, detailed in a separate paper, finds that a single set of fitted parameters for the toxic load model (i.e., the toxic load exponent n, probit slope m, and median lethal exposure TL50) cannot accurately model the single exposure experimental data across the experiments full range of time from 2.3 to 30 minutes but can on the longer timescales of 10 to 30 minutes. However, none of the toxic load models that we considered fit the experimental data for the novel, time-varying exposures well, with the Average Concentration and Griffiths-Megson models providing the least inaccurate casualty predictions.
Keywords: casualty assessment; consequence assessment; Haber’s law; toxic load modelling.
Rising environmental awareness in Central Asia: an empirical study from Nursultan, Kazakhstan
by Ferhat Karaca, John Machell, Ali Turkyilmaz, Dina Kaskina, Kamshat Tussupova
Abstract: This paper is the first comprehensive study to assess public environmental awareness on drinking water, household waste management practices, urban air quality, and other environmental issues in Kazakhstan. It aims to assess the findings of an investigation into public environmental awareness within the local society in Nursultan (formerly known as Astana), the capital city of Kazakhstan, and defines major environmental problems, as perceived by the public, using a survey-based research methodology. A series of crossover assessments were carried out to evaluate the level of public awareness on the major environmental issues. Almost a quarter of the respondents stated that they have already begun waste separation, even though there is no penalty system if the waste is not separately collected or recycled. Almost all the respondents agreed that hazardous substances should be treated separately from other waste types. It was also found that the public perception of tap water quality is strongly related to personal experiences, which correspondingly influences the use of tap water as drinking water. As a result of the perceived water quality, bottled water is the preferred alternative drinking water option among the householders. As for peoples perception regarding the major sources of air pollution in their cities, half of respondents, 50%, recognised motor vehicles as the main cause of pollution. Industrial sources, waste disposal, and power plants were considered as other contributors with 35%, 11%, and 11%, respectively.
Keywords: environmental awareness; waste management; household waste; drinking water; water quality; urban air quality; Kazakhstan.
Special Issue on: Challenges in the Development of Large-scale Pollution Models
Urban areas parameterisation for CFD simulation and cities air quality analysis.
by Maria Grazia Badas, Luca Salvadori, Michela Garau, Giorgio Querzoli, Simone Ferrari
Abstract: The aim of this work is to highlight the importance of a site-specific characterisation of urban areas needed for Computational Fluid Dynamics (CFD) simulations and urban air quality studies. As a case study, we consider Cagliari, an Italian town, whose heterogeneous urban form can be representative of many European historical towns, quite different from large American cities that are generally analysed in the literature. Basic steps needed to compute the main morphometric and fluid dynamics parameters from Digital Elevation Models (DEM) are reviewed and some possible caveats on using gridded DEM analysis are highlighted. Results show how site-specific analysis provides quite different parametrisations from those obtained by literature results, which cannot be transposed to other urban contexts. Morphometric site-specific analysis represents a key issue in urban numerical simulations, since the application of non-representative morphometric input data may dramatically affect their results.
Keywords: morphometric parameters; urban aerodynamic roughness; urban canopy model.
On convergence of difference schemes for Dirichlet IBVP for two-dimensional quasilinear parabolic equations
by Piotr Matus, Dmitriy Poliakov, Dorota Pylak
Abstract: For the Dirichlet initial boundary value problem (IBVP) for two-dimensional quasilinear parabolic equations, a monotone linearised difference scheme is constructed. The uniform parabolicity condition is assumed to be fulfilled for the sign-alternating solution only in the domain of exact solution values (unbounded nonlinearity). On the basis of the proved new corollaries of the maximum principle not only two-sided estimates for the approximate solution y but also its belonging to the domain of exact solution values are established. We assume that the solution is continuous and its first derivatives have discontinuities of the first kind in the neighborhood of the finite number of discontinuity lines. An existence of a time derivative in any sense is not assumed. Convergence of the approximate solution to a generalized solution of differential problem in the grid norm L2 is proved.
Keywords: difference schemes ; generalised solution ; initial boundary valuernproblem ; 2D quasilinear parabolic equation ; unbounded nonlinearity ; two-sided estimates.
The treatment method of general heat treatment of waste water from metal manufacturing based on photocatalysis
by Ning Qiu
Abstract: Photocatalytic treatment of emulsified waste liquid after pretreatment is carried out using TiO2 as catalyst, and the influence of crystal structure, particle size, amounts of catalyst and the initial pH value on the removal ratio of the chemical oxygen demand (COD) are studied. The results show that in the conditions that 0.5% quality point, P25-1 photocatalyst, 6.5 pH value and 90 min processing, the treatment effect is most ideal.
Keywords: heat treatment cleaning; emulsion; photocatalysis; post-treatment.
Assaying SARIMA and generalised regularised regression for particulate matter PM10 modelling and forecasting
by Snezhana Gocheva-Ilieva, Atanas Ivanov
Abstract: Two different predictive modelling approaches classical SARIMA time series methodology and the new Generalized PathSeeker (GPS) regularized regression method - supported by stochastic gradient boosting trees, RuleLearner and other data mining techniques, are used to examine the concentration of particulate matter PM10 in the town of Kardzhali, Bulgaria. Empirical models are developed to simulate and forecast pollution levels based on hourly PM10 data from 1 January 2011 to 28 February 2014 in dependence on six meteorological variables. The constructed models have been used for 5-days-ahead hourly forecasts, compared with actual data from 1 to 5 March 2014. The obtained SARIMA and GPS models fit very well to historical data with coefficients of determination R2 = 90% and 82%, and root mean square error RMSE = 0.114 and 0.151, respectively. But in forecasting GPS models outperform SARIMA approach. This could be explained by the preliminary classification provided by the data mining techniques and cross-validation procedure.
Keywords: air pollution; particulate matter PM10; seasonal ARIMA; generalised PathSeeker regularised regression; stochastic gradient boosting; data mining; forecasting.
An approach for selection of solid waste disposal site by rapid impact assessment matrix and environmental performance index analysis
by Nekram Rawal
Abstract: The selection of a suitable landfill site for disposal of municipal solid waste is an important challenge for the engineered system. The physical, biological, sociological and economic aspects should be examined with the aim to measure the overall impact of the waste disposal issues before the selection of an appropriate landfill site. In this study, the selection procedure of appropriate landfill site among four landfill sites, i.e Kareli, Alopibagh, Phaphamau and Ganja landfill sites for disposal of waste in Allahabad (India) is highlighted. A questionnaire comprising physical/chemical, biological/ecological, social/cultural and economic/operational aspects was prepared. A survey was conducted among the residents and local public residing near all four landfill sites. The responses were analysed with the Rapid Impact Assessment Matrix (RIAM) tool to quantify the intangible effects in terms of environmental score. The results were used to compare the cumulative impacts in a rational manner. Environmental Performance Index (EPI) was computed for all four sites to intelligibly ascertain the efficacy of the systems/methodologies involved in the solid waste disposal facility. The results revealed that Ganja landfill site was the best site compared with the Kareli, Alopibagh and Phaphamau landfill sites. The EPI of four sites, viz., Kareli, Alopibagh, Phaphamau and Ganja, were -110.315, -123.541, 98.867 and -54.586, respectively. The EPI of all the four sites had negative values indicating that these are not appropriate for landfilling or dumping.
Keywords: municipal solid waste; waste disposal; rapid impact assessment matrix; environmental score; environmental performance index.
Advanced algorithms for studying the impact of climate changes on ozone levels in the atmosphere
by Istvan Farago, Zahari Zlatev, Ivan Dimov, Agnes Havasi, Krassimir Georgiev
Abstract: The problem caused by the rapid climate changes is very challenging for modern society. The steady increase of the global temperature, especially in the Arctic areas, has different consequences. Most of them are at least potentially dangerous. Some aspects of the impact of the increased temperature on some pollution levels, which could be harmful for some groups of human beings (primarily for people suffering from asthmatic diseases) has been studied by developing climate scenarios and by running them over a period of 16 consecutive years. The mathematical model used in the experiments is a system of nonlinear partial differential equations (PDEs) and the space domain contains the whole of Europe together with some of its surroundings. Difficult computational problems will arise after the direct discretisation of the spatial derivatives, because this results in huge systems of linear algebraic equations, containing often hundreds of millions of equations, which have to be handled numerically during many time-steps for each of the selected scenarios and for each of the chosen years. The enormous computational problems can be treated successfully only by resolving simultaneously five important tasks. More precisely, it is necessary (a) to apply accurate and efficient numerical algorithms, (b) to select an appropriate splitting procedure, (c) to develop parallel codes, (d) to use high-speed computers in the runs, and (e) to exploit as well as possible the cache memories of the available parallel computer. Selected numerical results will be presented in this paper in order to illustrate both the fact that the developed code is efficient and the fact that the future climate changes will result in consistent increase of some pollution levels.
Keywords: large-scale environmental models; systems of non-linear PDEs; numerical algorithms; splitting techniques; parallel codes; high-speed computers; climate changes; ozone levels; damaging effects.
Applying WRF-CMAQ models for assessment of sulphur and nitrogen deposition in Bulgaria for the years 2016 and 2017
by Dimiter Syrakov, Maria Prodanova, Emilia Georgieva, Elena Hristova
Abstract: Wet, dry and total depositions of sulphur (S) and nitrogen (N) in Bulgaria are simulated on an annual and seasonal basis for the years 2016 and 2017 using WRF-CMAQ (9 km grid resolution). The mean annual values for wet depositions are about 1300 kg km-2, the dry depositions are slightly lower for S and significantly lower for N (180 kg km-2). The highest modelled wet depositions are in the western and south-western part of the country, and the highest dry depositions are in the northern and eastern parts. The comparison for the wet depositions at three sites with precipitation chemistry data indicates overestimation. A precipitation bias adjustment applied to the modelled depositions results in decrease of the normalised mean bias by a factor of 3. Comparison with modelled deposition data from literature for this region of the country is also provided.
Keywords: depositions; WRF-CMAQ; precipitation chemistry; Bulgaria; comparison; bias adjustment.
Analysis of regional climate model simulations for Central Europe as a potential tool to assess weather-related air quality conditions
by Ildiko Pieczka, Rita Pongracz, Csilla Peline Nemeth, Timea Kalmar
Abstract: Potentially adverse air quality is discussed in the present paper via its relation with wind conditions and boundary layer thickness. The main goal of the study is to evaluate different RegCM simulations (using two different model versions) for the 1981-1990 period, driven by either reanalysis data or global climate models output. For the validation purpose, wind speed, temperature, planetary boundary layer (PBL) height, and a derived index, the so-called Holst stagnation index are analysed and compared with the reference data. According to the results, wind is overestimated throughout the year, temperature is overestimated in the plain areas, whereas it is underestimated in the mountains. The height of the PBL is generally overestimated, and substantial differences are identified between RegCM4.5 and RegCM4.3 simulations. Consequently, these result in the substantial underestimations of the Holst stagnation index, and the frequency of potential adverse air quality, although the annual cycles are reproduced well. In order to prepare reliable projections, newer RegCM model versions and/or different model setups must be further tested as to whether they are able to reproduce past meteorological conditions related to air quality. We found potential in using a different PBL parameterisation scheme instead of the previously widely used Holtslag scheme.
Keywords: planetary boundary layer; wind; Holst stagnation index; RegCM; regional climate model; validation; air pollution; Carpathian Basin; Central Europe.
Current trends in nanotechnology for bioremediation
by Stephen Rathinaraj Benjamin, Fabio De Lima, Eridan Orlando Pereira Tramontina Florean, Maria Izabel Florindo Guedes
Abstract: Nanotechnology is an emerging field to produce nano-scale products with more efficient reactivity and larger surface area than the bulk phase. These unique attributes of nanoparticles offer immense potential for their application to clean up sites contaminated with petroleum hydrocarbons, pesticides, and metals. Compared with the conventional physicochemical methods of remediation of contaminated sites, bioremediation has been drawing increasing attention owing to its economic, eco-friendly and self-propelling attributes. Nanoparticles (NPs) can be applied directly for removal of organic contaminants through adsorption or chemical modification. They can also serve as a facilitator in microbial remediation of contaminants either by immobilising or through the induced production of remediating microbial enzymes. The present review provides an overview of different types of nanotechnology with biological and plant-based bioremediation approaches.
Keywords: bioremediation; nanotechnology; genetic engineering; recombinant DNA technology.
Assessment of fluoride hazard in groundwater of Palghat District, Kerala: a GIS approach
by Thangavelu Arumugam, R. Prabitha, K. Sapna
Abstract: Groundwater is a dynamic and replenishable natural resource all over the Earth's surface. Groundwater moves downward due to the pull of gravity and it can also move up because it will flow from higher pressure areas to lower pressure areas. The rate of groundwater flow is controlled by two properties of the rocks present: the porosity and the permeability. Generally, the groundwater quality depends on the quality of recharged water, atmospheric precipitation, inland surface water and subsurface geochemical processes. Fluoride contamination of groundwater is a growing problem in many parts of the world. The major sources of fluoride in groundwater are fluoride-bearing minerals, such as fluorspar, cryolite, fluorapatite and hydroxylapatite, in rocks. The problem of high fluoride concentration in groundwater resources has now become one of the most important toxicological and geo-environmental issues in India.
Keywords: groundwater; fluoride; GIS; IDW; statistical analysis.
Global climate-driven effects on urban air pollution simulations using very high spatial resolution
by Roberto San Jose, Juan L. Perez, Libia Perez, Rosa M. Gonzalez
Abstract: The city's response to future climate scenarios is an important issue to which this study contributes an attempt to improve the understanding of the relationships between climate and air quality in urban areas. A dynamic downscaling tool has been implemented that uses global climate data with 1
Keywords: dynamical downscaling; CFD; climate scenario; air pollution.
Special Issue on: Dioxins, Sources and Effects, Formation and Abatement
GC-HRMS analysis for POPs and new POPs with GC-Tof/MS techniques
by Takumi Takasuga