Bulk deposition close to a Municipal Solid Waste incinerator: one source among many

Exorbitant signatures of pesticides and pharmaceuticals in municipal solid wastes (MSWs): Novel insights through risk analysis, dissolution dynamics, and model-based source identification

Studies on the occurrence and fates of emerging organic micropollutants (EOMPs) like pharmaceuticals and pesticides in MSWs are scarce in the literature. Therefore, MSWs were sampled from 20 Indian landfills and characterized for five widely consumed EOMPs (chlorpyrifos, cypermethrin, carbofuran, carbamazepine, and sodium diclofenac), physicochemical, and biological properties. The pesticide (median: 0.17-0.44 mg kg-1) and pharmaceutical (median: 0.20-0.26 mg kg-1) concentrations significantly fluctuated based on landfill localities. Eventually, principal component and multi-factor (MFA) models demonstrated close interactions of EOMPs with biological (microbial biomass and humification rates) and chemical (N, P, K, Ca, S, etc.) properties of MSWs. At the same time, the MFA resolved that EOMPs' fates in MSWs significantly differ from bigger cosmopolitan cities to smaller rural townships. Correspondingly, the concentration-driven ecological risks were high in 15 MSWs with EOMP-toxicity ranks of diclofenac > carbofuran = chlorpyrifos > cypermethrin > carbamazepine. The EOMPs' dissolution dynamics and source apportionments were evaluated using the positive matrix factorization (PMF) model for the first time on experimental data, extracting four anthropogenic sources (households, heterogeneous business centers, agricultural, and open drains). The most significant contribution of EOMPs to MSWs was due to heterogeneous business activity. Notably, the aging of soluble chemical fractions seems to influence the source characteristics of EOMPs strongly.

Environmental and health impacts assessment of long-term naturally-weathered municipal solid waste incineration ashes deposited in soil-old burden in Bratislava city, Slovakia

Municipal solid waste incineration (MSWI) is an effective method for reducing the volume/mass of waste. However, MSWI ashes contain high concentrations of many substances, including trace metal (loid)s, that could be released into the environment and contaminate soils and groundwater. In this study, attention was focused on the site near the municipal solid waste incinerator where MSWI ashes are deposited on the surface without any control. Here, combined results (chemical and mineralogical analyses, leaching tests, speciation modelling, groundwater chemistry and human health risk assessment) are presented to assess the impact of MSWI ash on the surrounding environment. The mineralogy of ∼forty years old MSWI ash was diverse, and quartz, calcite, mullite, apatite, hematite, goethite, amorphous glasses and several Cu-bearing minerals (e.g. malachite, brochantite) were commonly detected. In general, the total concentrations of metal (loid)s in MSWI ashes were high, following the order: Zn (6731 mg/kg) > Ba (1969 mg/kg) ≈ Mn (1824 mg/kg) > Cu (1697 mg/kg) > Pb (1453 mg/kg) > Cr (247 mg/kg) > Ni (132 mg/kg) > Sb (59.4 mg/kg) > As (22.9 mg/kg) ≈ Cd (20.6 mg/kg). Cadmium, Cr, Cu, Pb, Sb and Zn exceeded the indication or even intervention criteria for industrial soils defined by the Slovak legislation. Batch leaching experiments with diluted citric and oxalic acids that simulate the leaching of chemical elements under rhizosphere conditions documented low dissolved fractions of metals (0.00-2.48%) in MSWI ash samples, showing their high geochemical stability. Non-carcinogenic and carcinogenic risks were below the threshold values of 1.0 and 1 × 10^-6, respectively, with soil ingestion being the most important exposure route for workers. The groundwater chemistry was unaffected by deposited MSWI ashes. This study may be useful in determining the environmental risks of trace metal (loid)s in weathered MSWI ashes that are loosely deposited on the soil surface.

Optimization of Physicochemical Parameters during the Electrocoagulation Cadmium Elimination

The increased use of fertilizers from phosphates in agriculture generates water pollution by heavy metals contained in these phosphates at levels higher than the standards. In our study, we used a cadmium nitrate Cd(NO3)2 solution to simulate artificially polluted water, whose decontamination efficiency will be evaluated by an electrocoagulation/flotation process. During this work, we aimed to optimize the electrocoagulation process according to the following factors: initial pH of the solution, density of the electrolysis current, cell time, and nature of the supporting electrolyte and its concentration. The criteria adopted during the optimization of the process are relatively different from those used in similar studies. Indeed, we have tried to achieve maximum efficiency and also seeking to minimize costs and facilitate implementation. We achieved a 98% Cd removal efficiency from the solution at pH = 7, J = 6.25 A/m2, t = 10 min, and [K2SO4] = 0.01 M. In addition, during the characterization of the flocs obtained as a supernatant, we first highlighted the presence of Cd in this gelatinous body and then the relatively easy volatility of Cd as well as that of aluminum oxide (Al2O3).

Numerical Modeling for the Accidental Dispersion of Hazardous Air Pollutants in the Urban Metropolitan Area

A numerical simulation system is developed to predict the dispersion of hazardous air pollutants (HAPs) over a populated city due to accidental release. Ulsan, as one of the megacities in Korea, is chosen as an ideal testbed for the simulation, as it is located in complex terrain and hosts a national industrial complex on the outskirts of the city. The system is based on the California puff model (CALPUFF) for simulating a HAP’s dispersion, in which the three-dimensional atmospheric circulation derived from the observed weather station data is specified at a fine horizontal resolution of 200 m. A test scenario is developed for the accidental release of benzene during the daytime and nighttime, respectively, by a fictitious explosion of a storage container, and the injection amount is determined arbitrarily yet comparable to those in the past accidents. In attempting a quantitative assessment and zoning the level of potential risk over the impacted area, multiple simulations have been conducted each day with different hourly varying meteorological conditions in August. The dispersion characteristics of the air pollutant depend largely on the local wind patterns that vary substantially from day to day. Nevertheless, the composite analysis sufficiently identifies the impacted area by the HAP’s dispersion due to the local prevailing wind such as the land–sea breeze circulation. An immediate hazardous area is determined based on the vulnerability map constructed by zoning the level of risk determined by the spatial distribution of the HAPs’ concentration and the harmfulness standard to the human body.

Combined use of daily and hourly data sets for the source apportionment of particulate matter near a waste incinerator plant

A particulate matter (PM) source apportionment study was carried out in one of the most polluted districts of Tuscany (Italy), close to an old waste incinerator plant. Due to the high PM10 levels, an extensive field campaign was supported by the Regional Government to identify the main PM sources and quantify their contributions. PM10 daily samples were collected for one year and analysed by different techniques to obtain a complete chemical characterisation (elements, ions and carbon fractions). Hourly fine (<2.5 μm) and coarse (2.5-10 μm) aerosol samples were collected by a Streaker sampler for a shorter period and hourly elemental concentrations were obtained by PIXE. Positive Matrix Factorization (PMF) analysis of daily and hourly data allowed the identification of 10 main sources: six anthropogenic (Biomass Burning, Traffic, Secondary Nitrates, Secondary Sulphates, Incinerator, Heavy Oil combustion), two natural (Saharan Dust and Fresh Sea Salt) and two mixed sources (Local Dust and Aged Sea Salt). Biomass burning turned out to be the main source of PM, accounting for 30% of the PM10 mass as annual average, followed by Traffic (18%) and Secondary Nitrates (14%). Emissions from the Incinerator turned out to be only 2% of PM10 mass on average. PM10 composition and source apportionment have been assessed in a polluted area near a waste incinerator, by PMF analysis on daily and hourly compositional data sets.

Characteristics of filterable and condensable particulate matter emitted from two waste incineration power plants in China

Incineration technology is an effective treatment method for municipal solid waste (MSW). In this study, fine particulate matter emissions from two waste incineration power plants (WIPP) were characterized. Both filterable particulate matter (FPM_2.5) and condensable particulate matter (CPM_2.5) were collected using a direct sampling method. The FPM_2.5 concentrations from stacks #1 and #2 in WIPP A were 0.87 ± 0.10 and 0.68 ± 0.19 mg/m³, respectively, and 3.30 ± 0.65 mg/m³ was measured at stack #3 in WIPP B. Fe was the most abundant elemental component in the FPM_2.5, followed by Na, Ca, Al, and K. Ca²⁺, SO₄^2-, Cl^-, and NH₄⁺ accounted for the largest fraction of the total detected water-soluble ions in the FPM_2.5. In the CPM_2.5, Na was the most abundant elemental component, followed by Ca, Mg, and K. The total detected water-soluble ions accounted for 22.2% and 27.3% of the CPM_2.5 collected from stack #1 and #2, respectively. High concentrations of NH₄⁺ and NO₃^- were found in CPM_2.5, which could be derived from the escape of excessive NH₃ in the denitrification unit and that of the NOx in the flue gas, respectively. Alcohols, aromatic compounds, and ketones were the major organic species in the CPM_2.5. Both fly ash and bottom ash were collected from WIPP A. Ca was the dominant element, followed by K, Mg, Na, and Fe. The enrichment of elements in the fly ash and bottom ash were analyzed. The enrichment factors of most elements were higher than 1, except for the Ti and Sn in the bottom ash. The fly ash had a higher enrichment of Cd, As, and Ti than the bottom ash. In contrast, Cu, Ni, and Cr had higher enrichments in the bottom ash because of their low volatility.

Concentrations of trace elements and PCDD/Fs around a municipal solid waste incinerator in Girona (Catalonia, Spain). Human health risks for the population living in the neighborhood

Previously to the modernization of the municipal solid waste incinerator (MSWI) of Campdorà (Girona, Catalonia, Spain) two sampling campaigns (2015 and 2016) were conducted. In each campaign, 8 soil and 4 air samples (PM₁₀ and total particle phase and gas phase) were collected. The levels of As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl and V, and PCDD/Fs were analysed at different distances and wind directions around the MSWI. Environmental levels of trace elements and PCDD/Fs were used to assess exposure and health risks (carcinogenic and non-carcinogenic) for the population living around the facility. In soils, no significant differences were observed for trace elements and PCDD/Fs between both campaigns. In air, significant higher levels of As, Cd, Co, Mn, Ni, Pb, Tl and V were detected in 2016. Regarding soil levels, only Cd (distances) and As, Cu, Mn, and Ni (wind directions) showed significant differences. No differences were noted in the concentrations of trace elements and PCDD/Fs in air levels with respect to distances and directions to the MSWI. No differences were registered in air levels (elements and PCDD/Fs) between points influenced by MSWI emissions and background point. However some differences in congener profile were noted regarding from where back-trajectories come from (HYSPLIT model results), pointing some influence of Barcelona metropolitan area. The concentrations of trace elements and PCDD/Fs were similar -or even lower- than those reported around other MSWIs in Catalonia and various countries. Non-carcinogenic risks were below the safety limit (HQ<1). In turn, carcinogenic risks due to exposure to trace elements and PCDD/Fs were in acceptable ranges, according to national and international standard regulations.

Fine particulate speciation profile and emission factor of municipal solid waste incinerator established by dilution sampling method

In this study, fine particulate matter (PM2.5) emitted from a municipal solid waste incinerator (MSWI) was collected using dilution sampling method. Chemical compositions of the collected PM2.5 samples, including carbon content, metal elements, and water-soluble ions, were analyzed. Traditional in-stack hot sampling was simultaneously conducted to compare the influences of dilution on PM2.5 emissions and the characteristics of the bonded chemical species. The results, established by a dilution sampling method, show that PM2.5 and total particulate matter (TPM) emission factors were 61.6 ± 4.52 and 66.1 ± 5.27 g ton-waste(-1), respectively. The average ratio of PM2.5/TPM is 0.93, indicating that more than 90% of PM emission from the MSWI was fine particulate. The major chemical species in PM2.5 included organic carbon (OC), Cl(-), NH4(+), elemental carbon (EC) and Si, which account for 69.7% of PM2.5 mass. OC was from the unburned carbon in the exhaust, which adsorbed onto the particulate during the cooling process. High Cl(-) emission is primarily attributable to wastes containing plastic bags made of polyvinyl chloride, salt in kitchen refuse and waste biomass, and so on. Minor species that account for 0.01-1% of PM2.5 mass included SO4(2-), K(+), Na, K, NO3(-), Al, Ca(2+), Zn, Ca, Cu, Fe, Pb, and Mg. The mean ratio of dilution method/in-stack hot method was 0.454. The contents of water-soluble ions (Cl(-), SO4(2-), NO3(-)) were significantly enriched in PM2.5 via gas-to-particle conversion in the dilution process. Results indicate that in-stack hot sampling would underestimate levels of these species in PM2.5.

IMPLICATIONS

PM2.5 samples from a municipal solid waste incinerator (MSWI) were collected simultaneously by a dilution sampling technique and a traditional in-stack method. PM2.5 emission factors and chemical speciation profiles were established. Dilution sampling provides more reliable data than in-stack hot sampling. The results can be applied to estimate the PM2.5 emission inventories of MSWI, and the source profile can be used for contribution estimate of chemical mass balance modeling.

Weathering steel as a potential source for metal contamination: Metal dissolution during 3-year of field exposure in a urban coastal site

Surface and building runoff can significantly contribute to the total metal loading in urban runoff waters, with potential adverse effects on the receiving ecosystems. The present paper analyses the corrosion-induced metal dissolution (Fe, Mn, Cr, Ni, Cu) from weathering steel (Cor-Ten A) with or without artificial patinas, exposed for 3 years in unsheltered conditions at a marine urban site (Rimini, Italy). The influence of environmental parameters, atmospheric pollutants and surface finish on the release of dissolved metals in rain was evaluated, also by means of multivariate analysis (two-way and three-way Principal Component Analysis). In addition, surface and cross-section investigations were performed so as to monitor the patina evolution. The contribution provided by weathering steel runoff to the dissolved Fe, Mn and Ni loading at local level is not negligible and pre-patination treatments seem to worsen the performance of weathering steel in term of metal release. Metal dissolution is strongly affected by extreme events and shows seasonal variations, with different influence of seasonal parameters on the behaviour of bare or artificially patinated steel, suggesting that climate changes could significantly influence metal release from this alloy. Therefore, it is essential to perform a long-term monitoring of the performance, the durability and the environmental impact of weathering steel.

Two Decades of Environmental Surveillance in the Vicinity of a Waste Incinerator: Human Health Risks Associated with Metals and PCDD/Fs

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), as well as the levels of a number of heavy metals, have been periodically measured in samples of soil and vegetation collected around a municipal solid waste incinerator (MSWI) in Tarragona (Catalonia, Spain) for approximately 20 years. Since 2007, the levels of the above-mentioned pollutants have also been determined in air samples by means of either active or passive samplers. In the present study, data regarding the environmental impact of the MSWI, in terms of PCDD/Fs and heavy metals, are updated. The temporal trends of these pollutants were evaluated by comparison with data from previous surveys. In the current survey (2013-2014), mean concentrations of PCDD/Fs in soil, vegetation, and air were 0.63 ng I-TEQ/g, 0.07 ng I-TEQ/g, and 10.1 fg WHO-TEQ/m(3), respectively. Decreases of 47 and 35 % of PCDD/Fs in soil and vegetation, respectively, were observed in relation to the background study (1999). Regarding air samples, a slight temporal decrease of the PCDD/F levels was also found with the remaining concentrations staying nearly constant through time. With respect to metals, notable fluctuations in the concentrations were noted, being dependent on each specific environmental monitor. Overall, the current exposure to PCDD/Fs and metals does not mean any additional health risks for the population living near the facility. In conclusion, the results of the present study show that the environmental impact of the Tarragona MSWI is not significant, in terms of PCDD/Fs and heavy metals, after >20 years of continuous operation.

Source apportionment and location by selective wind sampling and Positive Matrix Factorization

In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis.