The n-octanol/water partition coefficient (KOW) is a physical/chemical property that is extensively used for regulatory and environmental risk and exposure assessments. The KOW value can estimate various chemical properties such as water solubility, bioavailability, and toxicity using quantitative structure-activity relationships which demands an accurate knowledge of this property. The present investigation aims to compare outcomes of three commonly cited methods of KOW measurement in the literature for six hydrophobic chemicals with insecticidal functions as well as highly volatile petroleum constituents. This measurement has been difficult to obtain for the selected pyrethroid insecticides, cypermethrin, and bifenthrin and is a novel measurement for the latter: polycyclic aromatic sulfur heterocycles, dibenzothiophene (DBT), and three of its alkyl derivatives except for DBT. The KOW values were obtained using two liquid chromatographic methods with isocratic and gradient programming, and the slow-stirring method following OECD 117 and 123 guidelines, respectively. The mean log KOW values of bifenthrin, cypermethrin, DBT, methyl-DBT, dimethyl-DBT, and diethyl-DBT were 8.4 ± 0.1, 6.0 ± 0.3, 4.8 ± 0.0, 5.4 ± 0.1, 6.0 ± 0.1, and 6.8 ± 0.0 using the HPLC method with gradient programing. The KOW values were significantly reproducible within a method, however, not between the methods. Results suggest assessing a chemical’s property and environmental risk and exposure solely based on the KOW value should be practiced with caution.

Since the authorization of the Clean Air Act Amendments of 1990, the air quality in the USA has significantly improved because of strong public support. The lessons learned over the last 25 years are being shared with the policy analysts, technical professionals, and scientist who endeavor to improve air quality in their communities. This paper will review how the USA has achieved the “high” standard of air quality that was envisioned in the early 1990s. This document will describe SO₂ gas emission reduction technology and highlight operation of emission monitoring technology. This paper describes the basic process operation of an air pollution control scrubber. A technical review of measures required to operate and maintain a large-scale pollution control system will be described. Also, the author explains how quality assurance procedures in performance of continuous emission monitoring plays a significant role in reducing air pollution.

This work is focused on the development of an innovative multi-analytical methodology to estimate the impact suffered by building materials in coastal environments. With the aim of improving the in situ spectroscopic assessment, which is often based on XRF and Raman spectrometers, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy was implemented in the diagnosis study. In this way, the additional benefits from DRIFT were compared to the usual in situ analyses of building materials, which often have interferences from fluorescence and reststrahlen effects. The studies were extended to the laboratory scale by μ-X-ray fluorescence (μ-XRF) cross-section mapping and ion chromatography (IC), and the IC quantitative data were employed to develop thermodynamic models using the ECOS-RUNSALT program, with the aim of rationalizing the behavior of soluble salts with variations in the temperature and the relative humidity (RH). The multi-analytical methodology allowed identification of the most significant weathering agents and classification of the severity of degradation according to the salt content. The suitability of a DRIFT portable device to analyze these types of matrices was verified. Although the Kramers-Kronig algorithm correction proved to be inadequate to decrease the expected spectral distortions, the assignment was successfully performed based on the secondary bands and intensification of the overtones and decreased the time needed for in situ data collection. In addition, the pollutants’ distribution in the samples and the possible presence of dangerous compounds, which were not detected during the in situ analysis campaigns, provided valuable information to clarify weathering phenomena.

This study evaluated the effects of a hyperaccumulator plant (Arabidopsis halleri), containing surplus of cadmium (Cd) and zinc (Zn) and being an admixture to the rat feed, on concentrations of copper (Cu), iron (Fe), and manganese (Mn) in the tissues of experimental rats infected/uninfected with the tapeworm (Hymenolepis diminuta). Male Wistar rats were divided into three groups (00, P0, and PT); the P0 and PT animals were fed a standard mixture for rats (ST-1) supplemented with the plant A. halleri at a weekly Zn and Cd dosage of 123 and 1 mg, respectively. Moreover, rats from the group PT were infected with the tapeworm. The group 00 served as control animals fed only ST-1 having no tapeworm infection. Rats were euthanized after 6 weeks, and Cu, Fe, and Mn levels were determined in rat and tapeworm tissues. The results indicated that both the consumption of hyperaccumulator plant and/or presence of tapeworms did have significant effect on Cu, Fe, and Mn concentrations in the host tissues. Concentrations of all the elements were higher in the rat liver and partially kidneys than in the tapeworms, and the concentrations of Cu, Fe, and Mn were affected by the consumption of Cd/Zn hyperaccumulator plants. Particularly, Fe concentrations in all rat tissues were significantly increased by consumption of A. halleri while decreased by the presence of tapeworms. Overall, the consumption of a Cd/Zn hyperaccumulator plant and tapeworm infection cause an imbalance in Cu, Fe, and Mn concentrations in the tissues of a consumer (experimental rats).

Waste rocks from gold mining in northeastern Thailand are classified as sandstone, siltstone, gossan, skarn, skarn-sulfide, massive sulfide, diorite, and limestone/marble. Among these rocks, skarn-sulfide and massive sulfide rocks have the potential to generate acid mine drainage (AMD) because they contain significant amounts of sulfide minerals, i.e., pyrrhotite, pyrite, arsenopyrite, and chalcopyrite. Moreover, both sulfide rocks present high contents of As and Cu, which are caused by the occurrence of arsenopyrite and chalcopyrite, respectively. Another main concern is gossan contents, which are composed of goethite, hydrous ferric oxide (HFO), quartz, gypsum, and oxidized pyroxene. X-ray maps using electron probe micro-analysis (EPMA) indicate distribution of some toxic elements in Fe-oxyhydroxide minerals in the gossan waste rock. Arsenic (up to 1.37 wt.%) and copper (up to 0.60 wt.%) are found in goethite, HFO, and along the oxidized rim of pyroxene. Therefore, the gossan rock appears to be a source of As, Cu, and Mn. As a result, massive sulfide, skarn-sulfide, and gossan have the potential to cause environmental impacts, particularly AMD and toxic element contamination. Consequently, the massive sulfide and skarn-sulfide waste rocks should be protected from oxygen and water to avoid an oxidizing environment, whereas the gossan waste rocks should be protected from the formation of AMD to prevent heavy metal contamination.

The toxicity of engineered nanoparticles (ENPs) on bacteria has aroused much interest. However, few studies have focused on the effects of low-level ENPs on bacterial group behaviors that are regulated by quorum sensing (QS). Herein, we investigated the effects of nine ENPs (Ag, Fe, ZnO, TiO₂, SiO₂, Fe₂O₃, single-wall carbon nanotubes (SWCNTs), graphene oxide (GO), and C₆₀) on QS in Pseudomonas aeruginosa PAOl. An ENP concentration of 100 μg L⁻¹ did not impair bacterial growth. However, concentrations of 100 μg L⁻¹ of Ag and GO ENPs induced significant increases in 3OC₁₂–HSL in the culture and significantly promoted protease production and biofilm formation of PAO1. C₄–HSL synthase and its transcription factors were less sensitive to 100 μg L⁻¹ Ag and GO ENPs compared with 3OC₁₂-HSL. Fe ENPs induced a significant increase in the 3OC₁₂–HSL concentration, similar to Ag and GO ENPs. However, Fe ENPs did not induce any significant increase in protease production or biofilm formation. Different size distributions, chemical compositions, and aggregation states of the ENPs had different effects on bacterial QS. These whole circuit indicators could clarify the effects of ENPs on bacterial QS. This study furthers our understanding of the effects of low-level ENPs on bacterial social behaviors.

Most African countries have ratified the Stockholm Convention on persistent organic pollutants (POPs) and are expected to reduce emissions of POPs such as organochlorine pesticides (OCPs) to the atmosphere. Emerging evidence, however, suggests that there are contemporary sources of OCPs in African countries despite the global ban on these products. This study investigated the atmospheric contamination from OCPs in four West African countries—Togo, Benin, Nigeria, and Cameroon—to ascertain the emission levels of OCPs and the characteristic signatures of contamination. Polyurethane foam (PUF) disk passive air samplers (PAS) were deployed in each country for ca. 55 days in 2012 and analyzed for 25 OCPs. Hexachlorocyclohexanes (HCHs) and DDTs constituted the highest burden of atmospheric OCPs in the target countries, at average concentrations of 441 pg m⁻³ (range 23–2718) and 403 pg m⁻³ (range 91–1880), respectively. Mirex had the lowest concentration, ranged between 0.1 and 3.3 pg m⁻³. The concentration of OCPs in rainy season was higher than in dry season in Cameroon, and presupposed inputs from agriculture during the rainy season. The concentrations of ∑25 OCPs in each country were in the following order: Cameroon > Nigeria > Benin > Togo. There was significant evidence, based on chemical signatures of the contamination that DDT, aldrin, chlordane, and endosulfan were recently applied at certain sites in the respective countries.

Germanium (Ge) is widespread in the Earth’s crust. As a cognate element to silicon (Si), Ge shows very similar chemical characteristics. Recent use of Ge/Si to trace Si cycles and changes in weathering over time, growing demand for Ge as raw material, and consequently an increasing interest in Ge phytomining have contributed to a growing interest in this previously rather scarcely considered element in geochemical studies. This review deals with the distribution of Ge in primary minerals and surface soils as well as the factors influencing the mobility of Ge in soils including the sequestration of Ge in secondary mineral phases and soil organic matter. Furthermore, the uptake and accumulation of Ge in plants and effects of plant-soil relationships on the availability of Ge in soils and the biogeochemical cycling of Ge are discussed. The formation of secondary soil minerals and soil organic matter are of particular importance for the concentration of Ge in plant-available forms. The transfer from soil to plant is usually low and shows clear differences between species belonging to the functional groups of grasses and forbs. Possible uptake mechanisms in the rhizosphere are discussed. However, the processes that are involved in the formation of plant-available Ge pools in soils and consequently its biogeochemical cycling are not yet well understood. There is, therefore, a need for future studies on the uptake mechanisms and stoichiometry of Ge uptake under field conditions and plant-soil-microbe interactions in the rhizosphere as well as the chemical speciation in different plant parts.

This comparative study investigates pre-concentration/separation procedure for the magnetic solid phase extraction of Hg(II) species by a new green materials: naked magnetic chitosan flakes coated Fe₃O₄ micro-particles (NMCFs) and magnetic chitosan flakes coated Fe₃O₄ micro-particles embedded ethylenediaminetetraacetic-disodium (MCFs-EDTA-Na₂) in a batch process. The sorption procedure was optimized by using model solutions containing mercury(II) ions in chloride medium. The influence of experimental parameters like pH, time reaction, initial Hg(II) concentration, and ionic strength was investigated. The SEM micrograph indicates a good dispersion of magnetite micro-particles onto chitosan flakes. The FTIR spectrum reveals that EDTA-Na₂ moieties have been successfully cross-linked onto magnetic chitosan flakes. Vibration magneto-metric measurements confirm the paramagnetic (without remanence) behavior of NMCFs and MCFs-EDTA-Na₂. The experimental sorption data show that Hg(II) ions extraction yield decreases in acidic medium in both NMCFs and MCFs-EDTA-Na₂. The found optimum pH values are near 4.5 using NMCFs and 4.7 when the Hg(II) ion sorption occurs onto MCFs-EDTA-Na₂ micro-particles. The results also showed that Hg(II) ion sorption kinetic was very fast at the initial stage of contact time. The maximal sorption capacity was found to be 454 ± 13 mg g⁻¹, under optimum conditions, using NMCFs and 495 ± 14 mg g⁻¹ when MCFs-EDTA-Na₂ was used.

In this paper, a highly copper-resistant fungal strain NT-1 was characterized by morphological, physiological, biochemical, and molecular biological techniques. Physiological response to Cu(II) stress, effects of environmental factors on Cu(II) biosorption, as well as mechanisms of Cu(II) biosorption by strain NT-1 were also investigated in this study. The results showed that NT-1 belonged to the genus Gibberella, which exhibited high tolerance to both acidic conditions and Cu(II) contamination in the environment. High concentrations of copper stress inhibited the growth of NT-1 to various degrees, leading to the decreases in mycelial biomass and colony diameter, as well as changes in morphology. Under optimal conditions (initial copper concentration: 200 mg L⁻¹, temperature 28 °C, pH 5.0, and inoculum dose 10%), the maximum copper removal percentage from solution through culture of strain NT-1 within 5 days reached up to 45.5%. The biosorption of Cu(II) by NT-1 conformed to quasi-second-order kinetics and Langmuir isothermal adsorption model and was confirmed to be a monolayer adsorption process dominated by surface adsorption. The binding of NT-1 to Cu(II) was mainly achieved by forming polydentate complexes with carboxylate and amide group through covalent interactions and forming Cu-nitrogen-containing heterocyclic complexes via Cu(II)-π interaction. The results of this study provide a new fungal resource and key parameters influencing growth and copper removal capacity of the strain for developing an effective bioremediation strategy for copper-contaminated acidic orchard soils.