The effects of sulfur compounds on the migration of a semi-volatile heavy metal (cadmium) during sludge incineration were investigated with two methods, i.e., experiments in a tubular furnace reactor and thermodynamic equilibrium calculations. The representative typical sludge with and without the addition of sulfur compounds was incinerated at 850 °C. The partitioning of Cd among the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that sulfur compounds in the elemental form and a reduced state could stabilize Cd in the form of CdS, aluminosilicate minerals, and polymetallic sulfides, whereas sulfur in the oxidized forms slightly increases Cd volatilization during incineration. For Cd solidification points, the inhibition effect on the volatilization of Cd is as follows: S > Na₂SO₄> Na₂S. Chemical equilibrium calculations indicate that sulfur binds with Cd and alters Cd speciation at low temperatures (<950 K). Furthermore, SiO₂- and Al₂O₃-containing minerals can function as sorbents stabilizing Cd as condensed phase solids (CdSiO₄and CdAl₂O₄) according to the results of equilibrium calculations. These findings provide useful information for understanding the partitioning of Cd and thus facilitate the development of strategies to control Cd volatilization during sludge incineration.

Brominated flame retardants (BFRs, including polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol-A (TBBPA)) and metals (Cu, Zn, Pb, Cd, Ni, Hg and As) in sediments, soils and herb plants from unregulated e-waste disposal sites were examined. The metal concentrations, ∑PBDE and TBBPA concentrations in all samples from the examined e-waste dismantling sites were relatively high in comparison with those of rural and urban areas around the world. The PBDE and TBBPA levels in soils significantly decreased with increasing distance from the e-waste dismantling sites, indicating that PBDEs and TBBPA had similar transport potential from the e-waste dismantling process as a point source to the surrounding region. BDE-209 and TBBPA predominated in all samples, which is consistent with the evidence that the deca-BDE and TBBPA commercial mixtures were extensively used in electronic products. Metals, PBDEs and TBBPA displayed significant positive correlations with TOC, whereas the correlations with pH were insignificant, indicating that TOC was a major factor governing the spatial distribution, transportation and fate in sediments and soils. A significant relationship between log-transformed metals and BFR concentrations indicated common pollution sources. Moreover, cluster analysis and principal component analysis further confirmed that the metals and BFRs had a common source, and penta- and deca-BDE commercial products may be two sources of PBDEs in this region.

The performance of different solar-driven advanced oxidation processes (AOPs), such as TiO₂/UV, TiO₂/H₂O₂/UV, and Fe²⁺/H₂O₂/UV–visible in the treatment of a real textile effluent using a pilot plant with compound parabolic collectors (CPCs), was investigated. The influence of the main photo-Fenton reaction variables such as iron concentration (20–100 mg Fe²⁺L⁻¹), pH (2.4–4.5), temperature (10–50 °C), and irradiance (22–68 WUV m⁻²) was evaluated in a lab-scale prototype using artificial solar radiation. The real textile wastewater presented a beige color, with a maximum absorbance peak at 641 nm, alkaline pH (8.1), moderate organic content (dissolved organic carbon (DOC) = 129 mg C L⁻¹and chemical oxygen demand (COD) = 496 mg O₂L⁻¹), and high conductivity mainly associated to the high concentration of chloride (1.1 g Cl⁻L⁻¹), sulfate (0.4 g SO₄² ⁻ L⁻ ¹), and sodium (1.2 g Na⁺L⁻¹) ions. Although all the processes tested contributed to complete decolorization and effective mineralization, the most efficient process was the solar photo-Fenton with an optimum catalyst concentration of 60 mg Fe2+ L−1, leading to 70 % mineralization (DOCfinal = 41 mg C L−1; CODfinal < 150 mg O2 L−1) at pH 3.6, requiring a UV energy dose of 3.5 kJUV L−1 (t 30 W = 22.4 min; T =30 ∘ C ; UV(G,n) =44W m −2 ) and consuming 18.5 mM of H2O2.

Aqueous film-forming foams (AFFF) are used to extinguish hydrocarbon fuel fires. Certain AFFF products such as 3M Lightwater contain perfluorooctane sulfonate (PFOS) as the active ingredient which is highly persistent in the environment and is thus globally prevalent. With thousands of tons of soils potentially contaminated with PFOS stockpiled at a number of sites in Australia, the lack of reliable information on bioavailability of this recalcitrant contaminant constrains the application of a risk-based strategy for managing such soils. In this study, the PFOS release pattern from soils collected from the contaminated sites of fire training areas and its bioaccumulation potential in earthworm were investigated. The study was conducted at two temperatures (25 and 37 °C) and 60 % of the maximum water-holding capacity of soils. The greatest release into water was found to occur from the soil having the highest PFOS concentration, 16.17 μg g⁻¹ (Tindal FTA064), thereby demonstrating the role of contaminant loading on release behaviour. The release could also be related to the soil physico-chemical properties. The maximum amount of PFOS was desorbed from the soil with the lowest clay and organic matter content. Bioaccumulation of PFOS in earthworms (Eisensia fetida) as expressed by the bioaccumulation factor (BAF) was found to be highest from soil with the lowest PFOS concentration (RBD soil). The range of BAF found in our study was 1.23 (spiked Tindal SS01 soil) to 13.9 (field contaminated RBD soil). Our study suggests that PFOS could indeed pose a potential risk to ecological safety of soil if present even at concentrations as low as 0.8 μg g⁻¹ since the highest bioaccumulation factor was found to be from such a soil (field contaminated RBD).

There is a compelling evidence in support of negative associations between essential trace and toxic elements in different types of cancer. The aim of the present study was to investigate the relationship between carcinogenic (As, Cd, Ni) and anti-carcinogenic (Se, Zn) trace elements in scalp hair samples of different male cancerous patients (esophagus, lung, mouth, and urinary bladder). For comparative purposes, the scalp hair samples of healthy males of the same age group (ranged 35–65 years) as controls were analyzed. Both controls and patients have the same socioeconomic status, localities, dietary habits, and smoking locally made cigarette. The scalp hair samples were oxidized by 65 % nitric acid: 30 % hydrogen peroxide (2:1) ratio in microwave oven followed by atomic absorption spectrometry. The validity and accuracy of the methodology were checked using certified reference material of human hair BCR 397. The mean concentrations of As, Cd, and Ni were found to be significantly higher in scalp hair samples of patients having different cancers as compared to the controls, while reverse results were obtained in the case of Se and Zn levels (p < 0.01). The study revealed that the carcinogenic processes are significantly affecting the trace elements burden and mutual interaction of essential trace and toxic elements in the cancerous patients.

Lead pollution was evaluated in 17 urban soils from parks and gardens in the city of Vigo (NW Spain). The Pb isotope ratios (²⁰⁷Pb/²⁰⁶Pb,²⁰⁸Pb/²⁰⁴Pb,²⁰⁶Pb/²⁰⁴Pb and²⁰⁸Pb/²⁰⁶Pb) were determined after being measured by MC-ICP-MS. The association of the isotopes (²⁰⁴Pb,²⁰⁶Pb,²⁰⁷Pb and²⁰⁸Pb) with the different components of the soil was studied using TOF-SIMS. The isotopic ranges obtained for the samples were between 1.116 and 1.203 (²⁰⁶Pb/²⁰⁷Pb), 2.044–2.143 (²⁰⁸Pb/²⁰⁶Pb), 37.206–38.608 (²⁰⁸Pb/²⁰⁴Pb), 15.5482–15.6569 (²⁰⁷Pb/²⁰⁴Pb) and 17.357–18.826 (²⁰⁶Pb/²⁰⁴Pb). The application of the three-end-member model indicates that the Pb derived from petrol is the main source of Pb in the soils (43.51 % on average), followed by natural or geogenic Pb (39.12 %) and industrial emissions (17.37 %). The emissions derived from coal combustion do not appear to influence the content of Pb in the soil. TOF-SIMS images show that the Pb mainly interacts with organic matter. This technique contributes to the understanding of the association of anthropogenic Pb with the components of the soil, as well as the particle size of these associations, thus allowing the possible sources of Pb to be identified.

In this study, antibiotic resistance and major phenol and genotypes of non-typhoid Salmonella spp. from riversheds in Taiwan were examined. In 236 water samples tested, 54 (22.9 %) contained Salmonella spp. Fifteen Salmonella serovars were identified from the Salmonella isolates, and some common serovars are associated with infections of human and livestock, including Albany (27.8 %), Newport (14.8 %), Bareilly (13.0 %), Derby (11.1 %), and Typhimurium (7.4 %). Various environmental factors may also affect the presence and proportion of different serovars in the receiving waters. In contrast, serovars with narrower range of hosts, e.g., Dublin, were rarely detected. The Salmonella isolates were subjected to eight antibiotics for drug resistance, and 51.9 % of the samples were resistant to at least one tested antibiotics. Tetracycline and sulfadiazine were the two most ineffective antibiotics against the Salmonella isolates, and the results were indicative of long-term antibiotics abuse as fodder supplements in animal husbandry. The more commonly detected serovars such as Albany, Derby, and Typhimurium were also more likely to be resistant to multiple antibiotics. Finally, a significant correlation was observed between resistance to chloramphenicol and the resistance gene cmlA, suggesting that the resistance genotypes could persist in the environment even long after prohibition of the drug use. The high prevalence of antibiotic-resistant Salmonella spp. infers elevated infection risks that must be further examined.

In this study, Cu-doped ZnO nanoparticles were investigated as an efficient synthesized catalyst for photodegradation of humic substances in aqueous solution under natural sunlight irradiation. Cu-doped ZnO nanocatalyst was prepared through mild hydrothermal method and was characterized using FT-IR, powder XRD and SEM techniques. The effect of operating parameters such as doping ratio, initial pH, catalyst dosage, initial concentrations of humic substances and sunlight illuminance were studied on humic substances degradation efficiency. The results of characterization analyses of samples confirmed the proper synthesis of Cu-doped ZnO nanocatalyst. The experimental results indicated the highest degradation efficiency of HS (99.2 %) observed using 1.5 % Cu-doped ZnO nanoparticles at reaction time of 120 min. Photocatalytic degradation efficiency of HS in a neutral and acidic pH was much higher than that at alkaline pH. Photocatalytic degradation of HS was enhanced with increasing the catalyst dosage and sunlight illuminance, while increasing the initial HS concentration led to decrease in the degradation efficiency of HS. Conclusively, Cu-doped ZnO nanoparticles can be used as a promising and efficient catalyst for degradation of HS under natural sunlight irradiation.

Municipal solid waste disposal is a major environmental concern throughout the world. Proper landfill siting involves many environmental, economic, technical, and sociocultural challenges. In this study, a new quantitative method for landfill siting that reduces the number of evaluation criteria, simplifies siting procedures, and enhances the utility of available land evaluation maps was proposed. The method is demonstrated by selecting a suitable landfill site near the city of Marvdasht in Iran. The approach involves two separate stages. First, necessary criteria for preliminary landfill siting using four constraints and eight factors were obtained from a land classification map initially prepared for irrigation purposes. Thereafter, the criteria were standardized using a rating approach and then weighted to obtain a suitability map for landfill siting, with ratings in a 0–1 domain and divided into five suitability classes. Results were almost identical to those obtained with a more traditional environmental landfill siting approach. Because of far fewer evaluation criteria, the proposed weighting method was much easier to implement while producing a more convincing database for landfill siting. The classification map also considered land productivity. In the second stage, the six best alternative sites were evaluated for final landfill siting using four additional criteria. Sensitivity analyses were furthermore conducted to assess the stability of the obtained ranking. Results indicate that the method provides a precise siting procedure that should convince all pertinent stakeholders.

Ultraviolet (UV) filters are widely used in the formulation of personal care products (PCPs) to prevent damage to the skin, lips, and hair caused by excessive UV radiation. Therefore, large amounts of these substances are released daily into the aquatic environment through either recreational activities or the release of domestic sewage. The concern regarding the presence of such substances in the environment and the exposure of aquatic organisms is based on their potential for bioaccumulation and their potential as endocrine disruptors. Although there are several reports regarding the occurrence and fate of UV filters in the aquatic environment, these compounds are still overlooked in tropical areas. In this study, we investigated the occurrence of the organic UV filters benzophenone-3 (BP-3), ethylhexyl salicylate (ES), ethylhexyl methoxycinnamate (EHMC), and octocrylene (OC) in six water treatment plants in various cities in Southeast Brazil over a period of 6 months to 1 year. All of the UV filters studied were detected at some time during the sampling period; however, only EHMC and BP-3 were found in quantifiable concentrations, ranging from 55 to 101 and 18 to 115 ng L⁻¹, respectively. Seasonal variation of BP-3 was most clearly noticed in the water treatment plant in Araraquara, São Paulo, where sampling was performed for 12 months. BP-3 was not quantifiable in winter but was quantifiable in summer. The levels of BP-3 were in the same range in raw, treated and chlorinated water, indicating that the compound was not removed by the water treatment process.