Cocamidopropyl hydroxysultaine (CAS) has been used in a pilot plant study as a biodegradable surfactant for the extraction of polycyclic aromatic hydrocarbons (PAHs) and lead (Pb) from contaminated soils. The soil treatment has been done in flotation cells with a concentration of 0.20 g CAS L−1 in saline conditions (3 M NaCl) and using a pulp density of 20% (w/w). The process integrates the recirculation of the liquid phases separated from the soil by centrifugation or filtration. Thus, it was necessary to understand CAS-PAHs micellar behavior and to follow the behavior and the fate of the surfactant in the process. 1-8-anilino-naphthalene sulfonate (ANS) is used as a fluorophor compound in the ANS enhanced fluorescence technique. A three-dimensional model detailing the change in the micellar behavior at high NaCl concentration and at different pH has been established. Fluorescence results of centrifuged soil matrix containing CAS have been compared to the results from synthetic solutions assays. A method allowing an accurate titration of the CAS has been developed by using the exact same matrix of the soil as the tested samples for the preparation of the calibration curves. The study of the surfactant concentration in the process has been performed and allows the adjustment of the CAS concentration in the recirculated water.

The objective of this study was to assess the removal of the endocrine disruptor 4-nonylphenol (NP) at a concentration of 1 mg L⁻¹ by ryegrass and radish during germination and growth. The decontamination process was evaluated in water only or in water containing two organic fractions, a soil humic acid (HA) and a river natural organic matter (NOM) at concentrations of 10 and 200 mg L⁻¹. The addition of these fractions aimed to simulate the organic content of real aqueous systems. At the end of germination and growth, residual NP was measured by chromatographic analysis. Also, NP phytotoxicity was evaluated during germination. In germination experiments, NP in water only was not toxic for ryegrass and radish which removed, respectively, 37 and 51 % of the initial NP added. In water added with HA or NOM at both doses, in general, NP did not influence or inhibited seed germination. Both doses of HA in water promoted the removal of NP by germinating seeds, whereas NOM exerted differentiated results in the two species as a function of the dose applied. After 2 days of growth, in all treatments both species almost completely removed NP and accumulated a very little fraction of product. This study demonstrated that both ryegrass and radish possess a relevant capacity to remove the endocrine disruptor NP from water also in the presence of different organic fractions, thus suggesting their use in the decontamination of real aquatic systems.

Surfactants have been used for environmental remediation to remove hydrophobic organic compounds (HOCs) in water and soil. However, there are limited studies on the use of surfactants in confined micelle arrays to remove pesticides and polycyclic aromatic hydrocarbons from water. We studied the recovery of HOCs using two confined surfactants: nonionic Triton X-100 and cationic 3-(trimethoxysily)propyl-octadecyldimethyl-ammonium chloride (TPODAC). The micelle arrays were confined on a mesoporous silica matrix deposited onto a magnetic iron core. These magnetic, dispersible sorbents can be used to recover HOCs, minimizing the application of surfactants when compared to soil-washing techniques. The TPODAC-based sorbent had better average recovery of the HOCs studied compared to the Triton-X sorbent, and was, in general, comparable to activated carbon. It performed well with the chlorinated pesticides, in part due to additional interactions between the cationic sites and the polar compounds.

Lead forms stable compounds with phosphate and the immobilized Pb becomes less available to soil biota. In this study, we tested the bioavailabilty of Pb using earthworms (Eisenia fetida) and plants after immobilization of Pb by a soluble P compound and an insoluble rock phosphate compound in the presence of phosphate-solubilizing bacteria (Enterobacter sp.). Rock phosphate in the presence of phosphate-solubilizing bacteria and a soluble P compound enhanced Pb immobilization as measured by NH4NO3-extractable Pb concentration, thereby reduced its bioavailability as evaluated by earthworm Pb loading and sunflower (Helianthus annuus) Pb uptake under greenhouse conditions. However, soluble P treatment increased the concentration of Pb in soil solution thereby inhibited the root elongation of mustard (Brassica hirta) seedlings. Sunflower plants in the Pb-spiked soil without P amendments showed symptoms of necrosis and stunting because of Pb toxicity. Both soluble and insoluble P treatments significantly increased shoot and root weight and decreased Pb concentration in shoot by more than 50% compared to the control. However, high Pb concentration in soil solution was found in soluble P treatment, which can be attributed to dissolved organic carbon–Pb complex formation, thereby increasing Pb mobility. The inoculation of phosphate-solubilizing bacteria can facilitate phytostabilization of Pb-contaminated site.

Alpine areas in north-western Italy are subject to high deposition of atmospheric pollutants. Chemical investigations on high-altitude lakes indicate that most of them are recovering from acidification; however, they are still affected by the deposition of pollutants from the atmosphere, especially of heavy metals. This study compares the concentrations of heavy metals in alpine lake waters with those found in atmospheric depositions, to identify the possible contribution of deposition inputs to surface water ecosystems. The results were analysed by multivariate statistical techniques to identify the main emission sources of the various metals. Levels of trace metals in alpine lakes are generally low, and bedrock and surficial geology proved to be a major factor controlling metal concentrations in lake water. In fact, terrigenous elements show a wide range of concentrations while metals of anthropogenic origin, such as lead and cadmium, are often below the detection limits of the method; chrome and nickel are also present in very low concentrations. The median values of heavy metals in Italian alpine lakes are similar to those found in other lake surveys performed in remote areas, especially as regards metals of anthropogenic origin. The Visual MINTEQ model was applied to long-term chemical data of selected alpine lakes, to calculate aluminium speciation and to simulate its change in response to gradual modifications in a unit of pH. The ultimate aim of the modelling was to evaluate the possible threat to aquatic organisms of these highly toxic compounds.

N-nitrosodimethylamine (NDMA) is one of the most important disinfection by-products (DBPs) due to its carcinogenicity even at low concentrations which correspond to the levels occurring in drinking water and wastewater effluents. Therefore, NDMA is a candidate DBP that is expected to be regulated in the near future. However, the measurement of NDMA in the low nanogram per liter range is challenging because of the limitations of analytical techniques including both the sample preparation and the LC-MS/MS. Moreover, the accuracy of most of the current methods is only tested for drinking water and no information is present for other matrices. In this study, a combination of solid-phase extraction (SPE) and LC-MS/MS method that does not require high-resolution MS or advanced techniques for sample pretreatment is developed. Moreover, important factors that affect the optimization of the SPE method are provided to enable readers to optimize their own SPE procedures if necessary. The proposed method was validated for surface water, groundwater, and wastewater samples and the method quantification limit was 2 ng/L. In addition, the proposed method was used to determine the concentration of NDMA precursors measured as NDMA formation potential (NDMAFP) throughout a drinking water treatment plant at two different sampling periods. NDMAFP decreased by approximately 40 % in both samples. The concentrations ranged between 4 and 11.5 ng/L and the presence of these low concentrations underlines the need for an easy to use, yet sensitive method for the determination of NDMA in environmental matrices.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]DTAM [Axe_IRSTEA]DTAM1-REPRO | International audience | L’identification des zones des bassins versants, potentiellement contributrices en contaminants d’origine agricole, est effectuée par une modélisation spatiale (méthode PIXAL) en croisant des indicateurs spatialisés de la vulnérabilité des eaux de surface avec ceux de la pression agricole. Ces indicateurs qui traduisent les facteurs de risque sont choisis d’abord suivant leur pertinence à l’égard des milieux sur les espaces géographiques considérés, mais aussi suivant la disponibilité des données nécessaires en ce qui concerne l’évaluation de la vulnérabilité des eaux de surface. Les pressions anthropiques d’origine agricole résultent du croisement entre l’occupation du sol et les pratiques agricoles pour une campagne donnée. L’occupation du sol est obtenue soit à partir d’images satellitales pour les grands bassins versants tels que Save, Flumen, soit à partir des données parcellaires du SIG-PAC pour les petits bassins tels qu’Alegria, Enxoe.

PURPOSE: The potential of using waste Saccharomyces cerevisiae as adsorbent for the adsorption of As(III) from aqueous solution was assessed. METHODS: The biosorbent was characterized by Fourier transform infrared (FTIR) spectroscopy analysis. Various parameters including pH, biosorbent dosage, contact time, and temperature were systematically investigated. RESULTS AND CONCLUSIONS: The FTIR results of S. cerevisiae biomass showed that biomass has different functional groups, and these functional groups are able to react with metal ion in aqueous solution. Several biosorption isotherms were used to fit the equilibrium data, showing sorption to be monolayer on the heterogeneous surface of the biosorbent. The maximum biosorption capacity calculated using Langmuir model was found to be 62.908 μg/g at pH 5.0, biosorbent dosage 5 g/L, contact time 240 min, and temperature 35 °C. The kinetic studies indicated that the biosorption process of the As(III) followed well the pseudo-second-order equation. The intraparticle diffusion and Richenberg models were applied to the data, and we found that the biosorption of As(III) was governed by film diffusion followed by intraparticle diffusion. The thermodynamics constants indicated that the biosorption of As(III) onto S. cerevisiae was spontaneous and endothermic under examined conditions. Biosorbent could be regenerated using 0.5 M NaOH solution, with up to 75 % recovery.

INTRODUCTION: Meristematic mitotic cells of Allium cepa constitute an adequate material for cytotoxicity and genotoxicity evaluation of environmental pollutants, such as phenol, which is a contaminant frequently found in several industrial effluents. RESULTS AND DISCUSSION: In the present work, Brassica napus hairy roots (HR) were used for phenol removal assays. The toxicity of post-removal solutions (PRS) and phenol solutions was analyzed. These HR removed the contaminant with high efficiency (100–80% for phenol solutions containing 10–250 mg/L, respectively). Phenol solutions treated with B. napus HR showed a significant reduction of general toxicity compared to untreated phenol solutions, since the IC50 values were 318.39 and 229.02 mg/L, respectively. Moreover, PRS presented lower cytotoxicity and genotoxicity than that found in phenol solutions untreated. The mitotic index (MI) observed in meristematic cells treated with PRS (100 and 250 mg/L of phenol) showed an increase of 35% and 42%, whereas the chromosome aberrations showed a significant decrease. According to these results, B. napus HR cultures could be used for the treatment of solutions contaminated with phenol, since we observed not only high removal efficiency, but also an important reduction of the general toxicity, cytotoxicity, and genotoxicity.

BACKGROUND, GOAL, AND SCOPE: Natural radioactivity in phosphate rock (PR) is transferred to phosphate fertilizer (PF) during the manufacturing process of the PF. The continuous addition of the PF to the cultivated soil accumulates the radionuclides in the land and increases the level of radioactivity in the soil. The purpose of the present study was to investigate the enhanced level of accumulated radioactivity due to the continuous addition of the PF in the farmlands of Nuclear Institute of Agriculture and Biology (NIAB) at Faisalabad in Pakistan. The selected study area consisted of the highly fertilized farmlands and an unfertilized barren land of the NIAB. INTRODUCTION: The understudy area is very fertile for the growth of various types of crops; therefore, four agricultural research institutes have been established at Faisalabad and NIAB is one of those. The NIAB has developed various research farmlands at different places in Pakistan. The crop yield has been increased by adding various fertilizers in the farmlands. The addition of the PF accompanied with the radionuclides enhances radioactivity in the fields. Human being is exposed directly or indirectly to this radiological hazard. A prolong exposure may become a cause of health risk. MATERIALS AND METHODS: The area of study consisted of three types of lands: the land under cultivation for the last 40 and 30 years called Site 1 and Site 2, respectively, and the barren land was called Site 3. A total of 75 soil samples were collected within the crop rooting zone (up to 25 cm deep) of the soil of the NIAB farms. The samples were dried, pulverized to powder, sealed in plastic containers, and stored to achieve equilibrium between 226Ra and 222Rn. Activity concentrations of the radionuclides 238U (226Ra), 232Th, and 40K in soil samples were determined by using a high resolution gamma ray spectrometry system, consisting of an high purity germanium detector coupled through a spectroscopy amplifier with a PC based MCA installed with Geni-2000 software. RESULTS: The measured activity concentration levels of 40K were 662 ± 15, 615 ± 17, and 458 ± 20 Bq kg−1, 226Ra were 48 ± 6, 43 ± 5, and 26 ± 4 Bq kg−1, and that of 232Th were 39 ± 5, 37 ± 5, 35 ± 5 Bq kg−1, respectively, in the soil of the Sites 1, 2, and 3. Gamma dose rate 1 m above the soil surface was 55, 51, and 40 nGy h−1 from Sites 1, 2, and 3, respectively. External dose rates in the rooms constructed of the bricks made of the soil from Sites 1, 2, and 3 were 161, 149, and 114 nGyh−1, respectively. DISCUSSIONS: Activity concentration values of 40K and 226Ra in the soil of Sites 1 and 2 were higher than that in the soil of Site 3. The relative rise of 40K was 43 % and 34 % and that of 226Ra was 85 % and 65 % respectively in these sites. Activity concentrations of 232Th in all these sites were in the background range. Gamma dose rate 1 m above soil surface of Sites 1 and 2 was 40 % and 30 % respectively higher than that from the soil of Site 3. The rise in activity of 40K and 226Ra and gamma dose from the Site 1 was greater than that from the Site 2. The least activity and dose were observed from the Site 3. Gamma dose in the dwellings made of fertilized soil bricks of Site 1 and Site 2 were respectively calculated to be 41 % and 32 % higher than that in the abodes made of unfertilized soil bricks of Site 3. CONCLUSIONS: Activity concentrations of 226Ra and 40K were observed to be enhanced in the fertilized farmlands of the NIAB. Outdoor and indoor gamma dose as radiological hazard were found to be increasing with the continuous addition of PF in the understudy farmlands. RECOMMENDATIONS: It is recommended that naturally occurring radioactive metal should be removed during the process of manufacturing of the PF from the PR. PROSPECTIVE: The rise in radioactivity in the farmlands due to the addition of the PF can be a source of direct or indirect exposure to radiation that may enhance cancer risk of the exposed individuals.