Mineral dissolution plays an essential role in controlling geogenic arsenic (As) contamination in groundwater. Although reductive dissolution of Fe oxyhydroxides is generally considered a key As release mechanism in many aquifers, some recent studies argue that silicate minerals, normally considered “inert” in As release, are the primary source of As contamination under certain conditions. The objective of this study is to determine As distribution in different minerals in a natural sediment and identify As release mechanisms and the role of silicate minerals in As release. A sediment sample was collected, characterized, and tested using leaching experiments at a range of pH and redox potentials. Our results showed that silicate minerals, which make up the bulk of the sediment, are the main As reservoir, containing 75 % of As. Fe–Mn oxyhydroxides, which are minor components in the sediment, are the second largest As reservoir and hold 16 % of As. Leaching experiments showed that silicate mineral dissolution is an important As-releasing mechanism and that high pH and low redox potential promoted silicate mineral dissolution and As release.

The extent of endosulfan sulfate removal from soils by different planting pattern with sweet corn (Zea mays), cowpea (Vigna sinensis), and cucumber (Cucumis sativus) either cultivated alone or together was investigated in pot experiments. Endosulfan sulfate was removed to the greatest extent in the treatment in which sweet corn was grown alone; only 11.3 and 27.2 % of the initial endosulfan sulfate remained in rhizospheric and bulk soil, respectively, of sweet corn grown alone at day 60. Endosulfan sulfate was also removed from soil to a great extent in treatments where cucumber or cowpea was grown alone; only 30.3 and 38.8 % of endosulfan sulfate remained in their respective rhizospheric soil after 45 days. However, cucumber did not tolerate the toxicity of endosulfan sulfate well and died around 50–55 days when it was cultivated either alone or together with another plant. Cultivation of sweet corn and cowpea together was less effective in removing endosulfan sulfate from soil; about 41.7 and 52.3 % of endosulfan sulfate remained in their respective rhizospheric soils after 60 days. The results showed that single cultivation of the plants was the most efficient way to remediate endosulfan sulfate-contaminated soil in this study. Endosulfan sulfate was detected in both the root and shoot of plants but given the low levels found, bioaccumulation was judged to be a relatively minor factor in endosulfan sulfate removal from soil.

The paper reports ultraviolet matrix-assisted laser desorption/ionization mass spectroscopy (UVMALDI-MS) protocol for determination of complex heterogeneous emulsion or suspension formulations. The active agents and surfactants are morpholine fungicide fenpropimorph (1), amorolfine (2), tridemorph (mixture of 2,6-dimethyl-4-alkylmorpholins 3–6), 2,6-dimethyl-4-[2-methyl-3-(6-methyl-decahydro-naphthalen-2-yl)-propyl]-morpholine (7), dodemorph (8), main metabolite of 1 fenpropimorph acid (9), sodium dodecyl sulfate (10), and stearate (11). The full method and techniques validation as well as method performance parameters are discussed in terms of their maximal representativeness toward real environmental and foodstuff assay problems. These are additionally complicated by heterogeneous laterally, vertically, and time distribution of pesticide contaminants and their major metabolites in environmental samples. The real environmental heterogeneous distribution is elucidated, studying sterilized soil fractions with particle size 2.0 μm, clay content 11.5 %, silt 23.0 %, sand 8.1 %, and pH ∈ 6.0–8.1. A statistical sampling cluster approach is used. The method performance parameters are concentration LODs of 0.026 mg kg⁻¹(res. LOQs 0.08666 mg kg⁻¹). Concentration linear dynamic ranges are ∈ 0.025–7.3 mg kg⁻¹(r² = 0.99822 and 0.99421) and ∈ 2.3–7.4 mg kg⁻¹(level of confidence of 99.33₁ %) for complex spiked heterogeneous soil samples. The data illustrates the great capability of method and its promising application for environmental contamination monitoring and controlling programs for assessment.

Plants of the black nightshade (Solanum nigrum L.) Korean ecotype were exposed to a gradient of cadmium (Cd) concentrations (0, 10, 30, 50, and 80 mg kg⁻¹of dry sand). The results showed a significant (p < 0.05) reduction in biomass, root-shoot length, and chlorophyll contents in the plants exposed to Cd compared to the control. Cd concentrations significantly increased in different parts of the plants as indicated by inductively coupled plasma mass spectrometry (ICP-MS) analysis. The amount of Cd accumulated by the plants in the leaves, stems, and roots was 307, 1536, and 3163 mg kg⁻¹of dry matter, respectively, when treated with Cd 80 mg kg⁻¹. The translocation factor (TF) declined with higher Cd concentrations, whereas the bioconcentration factor (BCF) increased with elevated Cd levels. The response to oxidative stress induced by Cd was modulated by the enzymatic activity of peroxidase and polyphenol peroxidase. In terms of non-enzymatic antioxidant biochemicals such as reduced glutathione and polyphenols, its contents in the leaves significantly increased in a dose-dependent manner. The overall increased antioxidant defense response in leaves might have contributed to the higher accumulation and tolerance of plants against Cd-induced oxidative stress. The Korean ecotype of S. nigrum has potential phytoremediation utility for phytostabilization of Cd-contaminated marginal land. However, further genomic insights could contribute to the identification of potential Cd translocation genes.

There are multiple stressors derived from urbanizations that result in frequent disturbances on streams and rivers reducing water quality and threatens aquatic biota. P-glycoprotein (P-gp)-mediated multixenobiotic resistance (MXR) is a defence mechanism analogous to multidrug resistance (MDR), which has been demonstrated in several aquatic organisms. This system protects cells against the entry and the accumulation of xenobiotics and has been proposed as a biomarker for pollution assessment. We conducted a study in a post-urban reach of Esquel stream (Chubut Province) downstream a wastewater treatment plant, in order to assess the presence and activity of MXR in five freshwater macroinvertebrate species (Helobdella michaelseni, Helobdella simplex, Patagoniobdella variabilis, Hyalella curvispina and Chironomus riparius). We measured the accumulation of the model P-gp substrate rhodamine B (RB) in organisms previously exposed to pollution. Our results described the activity of the MXR system in the three species of leeches suggesting their suitability as the in vivo biomonitoring. We also identified a dependence of the transporter activity with the development stage in H. simplex, highlighting the importance of using organisms of similar size classes since it may affect observed results. Finally, we concluded that benthic freshwater macroinvertebrates possess different species-specific levels of MXR activity possibly influencing their natural distribution as well as their survival.

This work has evaluated the efficiency of two coagulants, aluminum sulfate (AS) and polyaluminum chloride (PACl), combined with the adsorption process using powdered activated carbon (PAC) on the removal of diclofenac (DCF), sulfamethoxazole (SMX), ethinylestradiol (EE2), estradiol (E2), estrone (E1), estriol (E3), and bisphenol-A (BPA) from low- and high-turbidity waters. The results have shown that the concomitant application of PAC and either coagulant has worsened the removal efficiency for all pharmaceuticals and endocrine disruptors tested, which might have occurred due to the covering of adsorption sites by aluminum hydroxide particles. In this configuration (coagulation in the presence of PAC, 10 mg L⁻¹), the best removal efficiency (∼40 %) was obtained for E1 and EE2 when AS was used as coagulant in contact times that varied from 13.5 to 23.5 min. When the coagulant was the PACl, contact times were lower (8.5 to 13.5 min) and the highest removal efficiency was observed for EE2 (∼52 %). When PAC was added as a pre-treatment (before addition of coagulant), the removal efficiency was greatly increased for all microcontaminants and the application of 2.5 mg L⁻¹of PAC with 120 min of contact led to removal efficiencies varying from 30 to 99.9 %.

A column experiment was conducted to evaluate the effectiveness of nanoscale zerovalent iron (nZVI) for the in situ immobilization of Pb and Zn in an acidic soil. The impact of nZVI on soil was evaluated by monitoring the physicochemical characteristics of the leachates and their ecotoxicological effects on three species, Vibrio fischeri, Artemia franciscana, and Caenorhabditis elegans. Treatment with nZVI resulted in more effective Pb immobilization in comparison to Zn and reduced the leachability by 98 and 72 %, respectively; the immobilization was stable throughout the experiment. Leachates from nZVI-treated soils showed lower toxicity than leachates from untreated ones. The highest toxicity in treated soils was observed in the first leachate, which presented high values of electrical conductivity due to the leachability of soil ions and those provided by the commercial nanoparticle suspension (Na and Fe). V. fischeri and C. elegans were more sensitive to leachates from nZVI-treated soils polluted with Zn than those from soils polluted with Pb; A. franciscana showed the opposite trend.

The article, Pilot-Scale Test for a Phosphate Treatment Using Sulfate-Coated Zeolite at a Sewage Disposal Facility by Jae-Woo Choi, Kyu-Sang Kwon, Soonjae Lee, Byungryul An, Seok-Won Hong, Sang-Hyup Lee, is replete with some fundamental scientific flaws which have the potential to misinform readers. This comment seek to correct these flaws.

Cyanobacterial toxins have caused worldwide concern because of their lethal effects, which has led to intensive search of cost-effective removal techniques. With the application of a Box–Behnken experimental design combined with response surface methodology, the adsorption process of the potent and commonly occurring microcystin-LR (MC-LR) onto nano-sized montmorillonite (NMMT) K10 was investigated through the HPLC-UV system. The quadratic statistical model was established to predict the interactive effects of pH (1–12), NMMT K10 dose (1–10 mg mL⁻¹), and MC-LR initial concentration (100–1,000 μg L⁻¹) on MC-LR adsorption and to optimize the controlling parameters. The MC-LR adsorption by NMMT K10 was pH dependent and was found to reach a maximum at pH 2.96 with a removal peak of 186.37 μg g⁻¹. The range of optimal pH for MC-LR adsorption was 2.96–3.48, and higher adsorption capacities were achieved with increasing adsorbent dose and MC-LR initial concentration. Sorption kinetics revealed that the sorption process of MC-LR on NMMT K10 was rapid (short equilibrium time) and involved several kinetic stages. The Langmuir isotherm model predicted that the theoretical maximum adsorption capacity at pH 3 was 285.20 μg g⁻¹. Alkali eluting media (0.1 M NaOH) showed the highest desorption percentage (75.3 %) during regeneration studies. The high Brunauer–Emmett–Teller (BET) specific surface area (204.65 m² g⁻¹) of NMMT K10 was also characterized. NMMT K10 was determined to be an effective and economic adsorbent for MC-LR removal on a large scale.

Evaluation of variation in the concentration of heavy metal provides vital information about the spatial behavior of the metals affecting the air quality. In the present study, lichen samples of the species Pyxine subcinerea Stirton were collected in the Rudraprayag valley to investigate the metal profile that bioaccumulated in lichens. Multivariate statistical analysis was carried out to elucidate possible contribution of various sources of pollution including anthropogenic sources on heavy metal profile of lichens. Cluster analysis successfully grouped geogenic and anthropogenic inputs represented by Al and Mn and Cu, Cd, Pb, and Zn, respectively. Principal component analysis also segregated sites based on the origin (major contributors).