Pollution on electrical insulators is one of the greatest causes of failure of substations subjected to high levels of salinity and environmental pollution. Considering leakage current as the main indicator of pollution on insulators, this paper focuses on establishing the effect of the environmental conditions on the risk of failure due to pollution on insulators and determining the significant change in the magnitude of the pollution on the insulators during dry and humid periods. Hierarchical segmentation analysis was used to establish the effect of environmental conditions on the risk of failure due to pollution on insulators. The Kruskal-Wallis test was utilized to determine the significant changes in the magnitude of the pollution due to climate periods. An important result was the discovery that leakage current was more common on insulators during dry periods than humid ones. There was also a higher risk of failure due to pollution during dry periods. During the humid period, various temperatures and wind directions produced a small change in the risk of failure. As a technical result, operators of electrical substations can now identify the cause of an increase in risk of failure due to pollution in the area. The research provides a contribution towards the behaviour of the leakage current under conditions similar to those of the Colombian Caribbean coast and how they affect the risk of failure of the substation due to pollution.

Pollution control initiatives in Greater Sudbury, Ontario, Canada, resulted in the decommissioning of the Coniston Smelter in 1972. The last assessment of the effects from the smelter on the surrounding lichen biota was in 1990, which showed an overall improvement in richness following these initiatives, but still few species were present close to the smelter. We examined five sites along this gradient to determine if this pattern is still present on the landscape. Sixty-four macrolichen species in 15 genera were found. Lichen richness and Shannon diversity increased at all sites, but the increase was no longer linear with distance from the smelter. There was no significant difference between lichen richness and diversity at sites at increasing distances from the smelter. We show that past air pollution from the Coniston Smelter is no longer restricting lichen growth and development in the Greater Sudbury area as it was historically. Lichen populations are, therefore, now shaped by other environmental variables.

Soil with high levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) is found at contaminated sites all over the world. Transfer of PCDD/Fs from contaminated soil to the food chain could lead to elevated human exposure. As a complement to available monitoring data, multimedia fate and exposure modeling can be applied to support risk assessment of sites with PCDD/F contaminated soil. In this study, we evaluated the performance of the CalTOX fate and exposure model for 2,3,7,8-substituted PCDD/Fs against measured concentrations in air, soil, grass, carrots, potatoes, milk, meat, and eggs from a contaminated site in northern Sweden. The calculated total toxic equivalent (TEQ) concentrations agree with measurements within a factor of 10 for all exposure media but one. Results for individual congeners demonstrated that the model did not always perform well at describing key processes that mobilize PCDD/Fs out of soils, such as transfer into root crops and ingestion of soil by chickens. Uncertainty in only a small subset of input parameters affects the model output. Improved information and models describing transfer of soil particles onto leafy vegetation by rain splash and biotransfer factors for PCDD/Fs to milk, meat, and eggs are particular research needs to reduce uncertainties in model-based assessments.

Contaminants of emerging concern (CECs) are not commonly monitored in the environment, but they can enter the environment from a variety of sources. The most worrying consequence of their wide use and environmental diffusion is the increase in the possible exposure pathways for humans. Moreover, knowledge of their behavior in the environment, toxicity, and biological effects is limited or not available for most CECs. The aim of this work is to edit the state of the art on few selected CECs having the potential to enter the soil and aquatic systems and cause adverse effects in humans, wildlife, and the environment: bisphenol A (BPA), nonylphenol (NP), benzophenones (BPs), and benzotriazole (BT). Some reviews are already available on BPA and NP, reporting about their behavior in surface water and sediments, but scarce and scattered information is available about their presence in soil and groundwater. Only a few studies are available about BPs and BT in the environment, in particular in soil and groundwater. This work summarizes the information available in the literature about the incidence and behavior of these compounds in the different environmental matrices and food. In particular, the review focuses on the physical-chemical properties, the environmental fate, the major degradation byproducts, and the environmental evidence of the selected CECs.

This paper estimated the mercury (Hg), emission factor, and mass balance from caged fish farming in the Castanhão Reservoir, NE Brazil, based on monitoring of a typical farm of Nile tilapia (Oreochromis niloticus). The total Hg input to the farm reached 1.45 gHg ha⁻¹ year⁻¹, from which 0.21 gHg ha⁻¹ year⁻¹ was exported out as fish biomass, ultimately resulting in an emission factor of 1.24 gHg ha⁻¹ year⁻¹ for the reservoir or approximately 8.27 mgHg ton fish⁻¹ year⁻¹ produced. Most of the input came from aquafeeds with concentrations varying from 1.4 to 31.1 ng g⁻¹, depending on the type of aquafeed. The Hg concentrations in fish were very low and varied from 1.0 to 2.9 ng g⁻¹. These values are two orders of magnitude lower than the legal limit for human consumption. The estimated total annual discharge of Hg from farming into the reservoir is 174 g for 18,000 tons of fish produced and may reach 387 g when the reservoir reaches its total capacity (40,000 tons), which is expected to occur in 2020. The mass balance, considering the deposition and accumulation rates, showed that approximately 40 % of the total Hg input accumulate in farm sediments (0.72 g ha⁻¹ year⁻¹), which is approximately 60 % of the deposition rate estimated through the sediment traps and suggests that 0.54 gHg ha⁻¹ year⁻¹ could eventually be transported out of the farm to the reservoir. Notwithstanding these facts, the total annual input of Hg from fish farming to the Castanhão Reservoir is less than 1.0 % of the total input from anthropogenic sources.

Acrylamide is a hazardous substance having irritant and toxic properties as well as carcinogen, mutagen, and impaired fertility possible effects. Acrylamide might be found in the environment as a consequence of the use of polyacrylamides (PAMs) widely added as a flocculant for water treatment. Acrylamide is a monomer used to produce polyacrylamide (PAM) polymers. This reaction of polymerization can be incomplete, and acrylamide molecules can be present as traces in the commercial polymer. Thus, the use of PAMs may generate a release of acrylamide in the environment. In aggregate industries, PAM is widely involved in recycling process and water reuse (aggregate washing). Indeed, these industries consume large quantities of water. Thus, European and French regulations have favored loops of recycling of water in order to reduce water withdrawals. The main goal of this article is to study the occurrence and fate of acrylamide in water-recycling process as well as in the sludge produced by the flocculation treatment process in aggregate production plants. Moreover, to strengthen the relevance of this article, the objective is also to demonstrate if the recycling system leads to an accumulation effect in waters and sludge and if free acrylamide could be released by sludge during their storage. To reach this objective, water sampled at different steps of recycling water process has been analyzed as well as different sludge corresponding to various storage times. The obtained results reveal no accumulation effect in the water of the water-recycling system nor in the sludge.

Microbe-assisted phyto-remediation approach is widely applied and appropriate choice to reduce the environmental risk of heavy metals originated from contaminated soils. The present study was designed to screen out the nested belongings of Eruca sativa plants and Pseudomonas putida (ATCC 39213) at varying cadmium (Cd) levels and their potential to deal with Cd uptake from soils. We carried out pot trial experiment by examining the soil containing E. sativa seedlings either treated with P. putida and/or untreated plants subjected to three different levels (ppm) of Cd (i.e., 150, 250, and 500). In all studied cases, we observed an increase in Cd uptake for E. sativa plants inoculated with P. putida than those of un-inoculated plants. Cd toxicity was assessed by recording different parameters including stunted shoot growth, poor rooting, and Cd residual levels in the plants that were not inoculated with P. putida. Significant difference (p < 0.05) of different growth parameters for inoculated vs non-inoculated plants was observed at all given treatments. However, among the different treatments, E. sativa exhibited increased values for different growth parameters (except proline contents) at lower Cd levels than those of their corresponding higher levels, shoot length (up to 27 %), root length (up to 32 %), whole fresh plant (up to 40 %), dry weight (up to 22 %), and chlorophyll contents (up to 26 %). Despite the hyperaccumulation of Cd in whole plant of E. sativa, P. putida improved the plant growth at varying levels of Cd supply than those of associated non-inoculated plants. Present results indicated that inoculation with P. putida enhanced the Cd uptake potential of E. sativa and favors the healthy growth under Cd stress.

Organochlorine pesticides (OCPs) are persistent organic pollutants that could cause deleterious effects on human health. Breast milk represents a noninvasive specimen source to assess maternal and infant exposure to OCPs. This study recruited 142 pregnant mothers in 2011–2012 in Shanghai, China, and their breast milk samples were collected during lactation and analyzed for 27 OCP compounds. Detection rates were in a range of 65.5 to 100 %. In particular, metabolites of 2,2-bis(chlorophenyl)-1,1,1-trichloroethane (DDT) such as 2-chloro-1,1-bis(4-chlorophenyl)ethylene (DDMU), 2,2-bis(4-chlorophenyl)ethanol (DDOH), bis(4-chlorophenyl)ketone (DBP), and 4,4′-dichlorodiphenylmethane (DDM) were detected in most milk samples. DDTs, hexachlorobenzene (HCB), and hexachlorocyclohexane (HCH) were dominant OCPs with mean levels of 316, 49.8, and 41.5 ng/g lipid content, respectively, whereas levels of methoxychlor, ∑Drins, ∑Heptachlor, ∑Chlordane, and ∑Endosulfan were fairly low (0.87–5.6 ng/g lipid content). Milk concentrations of OCPs were weakly correlated with maternal age, body weight, and body mass indexes (BMIs). ∑OCPs in this study were much lower than those in human breast milk samples collected in 2002 and 2007. Consumption of higher amounts of fish was associated with higher milk levels of OCPs. Specific OCP patterns in breast milk samples from migrant mothers in Shanghai reflected features of OCP production, use, and exposure in their home provinces. The probabilistic exposure assessment model reveals that Shanghai infants were exposed to low levels of OCPs through breast milk consumption. However, infants as the vulnerable group might be subject to the potential additive and/or synergistic health effects from complex OCP exposure.

Nitric oxide (NO) and nitrous oxide (N₂O) emitted from wetland systems contribute an important proportion to the global warming effect. In this study, four wetland microcosms vegetated with Myriophyllum elatinoides (WM), Alternanthera philoxeroides (WA), Eichhornia crassipes (WE), or without vegetation (NW) were compared to investigate the emissions of NO and N₂O during nitrogen (N) removal process when treating swine wastewater. After 30-day incubation, TN removal rates of 96.4, 74.2, 97.2, and 47.3 % were observed for the WM, WA, WE, and NW microcosms, respectively. Yet, no significant difference was observed in WM and WE (p > 0.05). The average NO and N₂O emissions in WE was significantly higher than those in WM, WA, and NW (p < 0.05). In addition, the emission of N₂O in WE accounted for 2.10 % of initial TN load and 2.17 % of the total amount of TN removal, compared with less than 1 % in the other microcosms. These findings indicate that wetland vegetated with M. elatinoides may be an optimal system for swine wastewater treatment, based on its higher removal of N and lower emissions of NO and N₂O.

Renewable biomass has attracted great attention for the production of biooil, biogas, and biochar, a carbon residual applicable for carbon sequestration and environmental remediation. Rice straw is one of the most common biomasses among agricultural wastes in South Korea. As part of our advanced and environmentally friendly research, we applied biochar derived from rice straw as the anode material for lithium-ion batteries (LIBs). Porous carbons with a high surface area were prepared from rice straw. Such porous carbons have exhibited particularly large reversible capacity and hence proven to be a candidate anode material for high-rate and high-capacity LIBs. Rice straw-derived biochars were synthesized at four different temperatures: 400, 550, 700, and 900 °C. The surface was modified by using HCl and H₂O₂ on the 550 °C biochar in order to increase the surface area. The resulting biochar was characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The surface area was measured by Brunauer–Emmett–Teller (BET) method. The electrochemical characterizations were investigated by galvanostatic charge–discharge (CD) curves, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). All samples exhibited reversible capacities of below 200 mAh g⁻¹. The surface-modified biochars exhibited improved cycle performance. Surface modification using HCl showed better cycle performance than H₂O₂. However, the capacities of the treated 550 °C biochar were similar to those of non-surface-modified biochar.