Accumulation of potentially harmful elements (PHEs) in lettuce (Lactuca sativa L.) and coriander (Coriandrum sativum L.) irrigated with wastewater: a systematic review and meta-analysis and probabilistic health risk assessment

Environmental Science and Pollution Research - Water shortage and stress around the world lead to increasing wastewater reuse for the agricultural sector. In addition to its benefits, it can be a...     

Radioactivity and radiological risk associated with effluent sediment containing technologically enhanced naturally occurring radioactive materials in amang (tin tailings) processing industry

The processing of amang, or tin tailings, for valuable minerals has been shown to technologically enhance NORM and this has stirred significant radiological safety and health concerns among Malaysia's regulatory authority. A growing radiological concern is now focused on the amang effluent containing NORM in recycling ponds, since these ponds may be reclaimed for future residential developments. A study was carried out to assess the radiological risk associated with amang processing and the accumulated effluent in the recycling ponds. Twenty-six sediment samples from the recycling ponds of two amang plants in the states of Selangor and Perak, Malaysia, were collected and analyzed. The maximum activity concentrations of (238)U, (226)Ra, (232)Th and (40)K recorded in sediments from these ponds were higher than Malaysia's and the world's natural highest. Correspondingly, the mean radium equivalent activity concentration indices, Ra(eq), and gamma radiation representative level index, I(gammar), were higher than the world's average. The enhancement of NORM in effluent sediments as a consequence of amang processing, and the use of a closed water management recycling system created Effective Dose Rates, E (nSv h(-1)), that signal potential environmental radiological risks in these ponds, should they be reclaimed for future land use.     

Preparation and Optimization of Starch/Poly Vinyl Alcohol/ZnO Nanocomposite Films Applicable for Food Packaging

Pollution and destruction of the environment due to the accumulation of non-degradable plastics are some of the most important concerns in the world. A significant amount of this waste is related to the polymers used in food packaging. Therefore, experts in the food industry have been looking for suitable biodegradable alternatives to synthetic polymers. Preparing biocompatible and biodegradable films based on starch is a good choice. In this study, various factors affecting films of starch/polyvinyl alcohol (PVA)/containing ZnO nanoparticles such as the amount of starch, PVA, glycerol, and ZnO were evaluated by response surface methodology (RSM). Film formation by solvent casting method, mechanical properties, swelling, solubility, and water vapor permeability (WVP) were selected as responses of RSM. The results showed that hydrogen bonding interactions between polyvinyl alcohol and starch improved the film formation. The effect of glycerol and PVA content on the mechanical strength was contrary to each other. As the amount of PVA increased, the tensile strength first decreased and then increased. The value of WVP was for all Runs from 0 to 6.77?×?10^??8 g m^??1 s^??1 Pa^??1. Finally, films with high film formation, maximum tensile strength, and high elongation at break, minimum solubility, permeability, and swelling were optimized.

     

Embedded large eddy simulation approach for pollutant dispersion around a model building in atmospheric boundary layer

In the present article, the potential of embedded large eddy simulation (ELES) approach to reliably predict pollutant dispersion around a model building in atmospheric boundary layer is assessed. The performance of ELES in comparison with large eddy simulation (LES) is evaluated in several ways. These include a number of qualitative and quantitative comparisons of time-averaged and instantaneous results with wind tunnel measurements supplemented by statistical data analyses using scatter plots and standard evaluation metrics. Results obtained by both LES and ELES approaches show very good agreement with the experiment. However, addition of turbulence to mean flow at Reynolds averaged Navier–Stokes (RANS)–LES interface in ELES approach not only increases the turbulence intensity, it also results in larger values of turbulent kinetic energy (TKE) as well as a shorter reattachment length in the wake region. Accordingly, higher levels of TKE predicted by ELES increase the local intensity of concentration leading to shorter plume shapes as compared with LES. In general, ELES shows better agreement with experiment on the surfaces of model building and also in the downstream wake region. In terms of computational costs, the CPU time required to obtain statistical values in ELES is about 49 % lower than that of LES and the number of iterations per time step is also reduced by 55 % as compared with LES.     

Effect of acid rain on the fractionation of heavy metals and major elements in contaminated soils

Acid rain is a serious environmental problem worldwide. In the present study, we investigated the effect of acid rain (1:1 equivalent basis H₂SO₄:HNO₃) at pH values of 2.0, 4.0 and 7.0 on the fractionation of heavy metals (Cd, Cu, Fe, Mn, Ni, Pb and Zn) and major elements (K, Na, Ca, and Mg) in contaminated calcareous soils over a 2084 h period. Heavy metals and major elements in soil samples were fractionated before and after 2084 h kinetic release using a sequential extraction procedure. Before kinetic studies the predominant fractions of K, Na, Ca, Mg, Cd and Ni were mainly associated with carbonate fraction (CARB), whereas Fe, Mn and Zn were associated with the Fe–Mn oxide fraction (Fe–Mn oxide). The highest percentage of Pb and Cu were found in the exchangeable (EXC) and organic matter (OM) fractions, respectively. After kinetic study using different simulated acid rain solutions, the major fractions of heavy metals (expect of Cu) and Na was the same as before release. Upon the application of different acid rain solutions, K and Mg were found dominantly in Fe–Mn oxide fraction, whereas Ca was in the EXC fraction. The results provide valuable information regarding metal mobility and indicated that speciation of metals (Cu and Zn) and major elements in contaminated calcareous soils can be affected by acid rain.     

Carbon dioxide separation and capture by adsorption: a review

Environmental Chemistry Letters - Rising adverse impact of climate change caused by anthropogenic activities is calling for advanced methods to reduce carbon dioxide emissions. Here, we...     

Life cycle assessment of clinker production using refuse‐derived fuel: A case study using refuse‐derived fuel from Tehran municipal solid waste

One of the techniques used to dispose of 4,000 tons per day (TPD) of non‐recyclable waste from Tehran is to burn it as an alternative fuel in cement kilns. This practice reduces emissions from landfills, prevents the loss of waste energy, and conserves fossil fuel resources. The aim of our study was to conduct a life cycle assessment (LCA) of clinker production in cement kilns using a combination of natural gas, mazut, a form of heavy, low‐quality fuel oil, and refuse‐derived fuel (RDF) from Tehran. We used SimaPro 7.1 software to perform an LCA of 1 kilogram (kg) of clinker produced using the following fuel combinations: the first scenario involved natural gas consumption alone, the second scenario involved a combination of natural gas and mazut, with the mazut providing 5% to 30% of the heating value needed to produce cement clinker in the kiln, and the third scenario involved a combination of natural gas and RDF (providing 5% to 30% of the heating needed in the kiln). The impact categories in the LCA of global warming, eutrophication, and acidification were assessed by the Center of Environmental Science of Leiden University (Centrum voor Milieukunde Leiden—CML) CML 2000 method. The results indicated that the third scenario, involving natural gas and RDF, reduced acidification by 2.14–11.5% and global warming by 0–1.3% relative to the first scenario involving the use of only natural gas. In addition, we observed a 0.65–3.81% reduction in acidification and a 0.9–3.8% reduction in global warming under the third scenario compared with the second scenario (co‐firing of natural gas and mazut). The amount of nitrogen oxides (NO_X) emitted from the combustion of the Tehran RDF was greater than that was emitted when burning mazut. Therefore, reduction of nitrogen from the RDF composition is necessary. This study indicates that the use of Tehran RDF (with reduced nitrogen) in Tehran cement kilns does not increase cement kiln NO_X, sulfur dioxide (SO₂), and carbon dioxide (CO₂) emissions; however, we need to conduct additional investigation into the chemical composition of the Tehran waste before using solid waste in place of fossil fuels.     

Assessment of seasonal variations of carbon dioxide concentration in Iran using GOSAT data

Global warming and climate change have been identified as the most important challenges of the 21st century. Greenhouse Gases Observation Satellite (GOSAT) measures the concentrations of carbon dioxide (CO ₂) and methane (CH ₄) in the atmosphere column from the earth's surface to the upper atmosphere. In this research, GOSAT Thermal And Near Infrared Sensor for Carbon Observation – Fourier Transform Spectrometer (TANSO‐FTS) level 2 data and meteorological parameters were used in the assessment of changes in CO ₂ concentration (XCO ₂) from 2009 to 2015. We investigated the relationship between XCO ₂ and meteorological parameters (temperature and precipitation) obtained from weather stations and the Normalized Difference Vegetation Index (NDVI) in the year 2013 in Iran. The results reveal a steady increase in the mean atmospheric CO ₂ concentration, from 384.89 to 400.39 ppm. It was observed that the XCO ₂ varied significantly depending on the month, with the highest concentration of CO ₂ in April/May and the lowest concentration in August/September. The correlation between XCO ₂ and average monthly air temperature is negative, which means that a reduction in XCO ₂ with an increase in temperature is dependent on photosynthetic activities in the growing seasons. The highest and lowest correlation coefficient between the NDVI and XCO ₂ was obtained in the spring and in the fall, respectively. These findings are useful for recognizing factors that affect CO ₂ concentration in different seasons in arid and semi‐arid regions, and as an initial step toward sustainable management.     

Correction to: Effect of organic and inorganic phosphorus fertilizers on phosphorus availability and its leaching over incubation time

Environmental Science and Pollution Research - The correct presentation of the equations in Table 6 footnote is presented in this paper     

Laboratory studies defining flow regimes for negatively buoyant surface discharges into crossflow

Surface discharges of negatively buoyant jets into moving ambient water create a range of complex flow patterns. These complexities arise through the interplay between the discharge’s initial fluxes and the motion of the ambient current. In this study a series of laboratory experiments were conducted for negatively buoyant surface discharges into crossflow to investigate flow patterns under different discharge and ambient conditions. The results compared with simulations of the CORMIX model, an expert system for ocean outfall design. In CORMIX, the simulation module DHYDRO for dense discharges has been used. Finally the flow different patterns were arranged in a dimensionless diagram to propose a modified flow classification system with new criteria.