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Leaching techniques for saline wastes composts used as growing media in organic agriculture: assessment and modelling
2015
Illera-Vives, Marta | López-Mosquera, María Elvira | Salas Sanjuán, María del Carmen | López-Fabal, Adolfo
The purpose of this work was to examine solute release by the effect of leaching of a saline compost with two main objectives: (1) to identify the most efficient method for this purpose, in order to minimize the environmental impact of this process in terms of water consumption and (2) to study the composition of the leachates to manage them properly and avoid possible contamination. A laboratory method involving column leaching with distilled water (CL) and two field methods involving saturation leaching (SL) and drip leaching (DL) were compared to this end. In order to more accurately assess nutrient release and compare the three leaching techniques, the cumulative amounts of ions leached were processed by using an exponential growth model. All target ions fitted properly, and so did the curve for the ions as a whole. Salts were removed mainly by effect of the leaching of major ions in the substrate (Na⁺, Cl–, inorganic N, SO₄²–and K⁺). SL and CL proved similarly efficient and reduced the salt content of the substrate to an electrical conductivity below 2 dS m–¹in the saturation extract, which is the optimum level for nursery crops. By contrast, the DL method provided poor results: salt contents were reduced to an electrical conductivity of only 8 dS m–¹in the saturation extract, so the resulting substrate can only be useful to grow highly salt-tolerant crops.
Afficher plus [+] Moins [-]Source, profile, and carcinogenic risk assessment for cohorts occupationally exposed to dust-bound PAHs in Lahore and Rawalpindi cities (Punjab province, Pakistan)
2015
Kamal, Atif | Malik, Riffat Naseem | Martellini, Tania | Cincinelli, Alessandra
In this study, the occurrence and concentrations of PAHs in dust samples, which were collected from the traffic police cabins/working spots, located on the main busy roads of Lahore (TP-L) and Rawalpindi (TP-R) cities (Punjab province, Pakistan) and from the public transport vehicles in the same cities (named as AM-L and AM-R, respectively) were determined. The mean and median concentrations of ∑PAHs were observed in the following descending order: AM-L (1340 and 774 ng g⁻¹ d.w., respectively), TP-L (866 and 854 ng g⁻¹ d.w.), TP-R (504 and 379 ng g⁻¹ d.w.), and AM-R (393 and 290 ng g⁻¹ d.w. Source apportionment of the soil/dust-bound PAHs was also performed. In all the sampling areas, the diagnostic ratios, principal component analysis (PCA) followed by multiple linear regression (MLR) analysis indicated signatures of mixed sources of PAHs (including vehicular exhaust emission, gasoline/diesel, and coal/wood combustion). Estimated results of incremental lifetime cancer risk (ILCR) indicated that the traffic policemen and drivers, especially those in the urban area of Lahore, were at high risk of cancer via routes of dust ingestion and dermal contact. The results of this research could be very useful for the local Government in order to control the exposure and promote actions to alleviate PAH contamination and to manage health both at work places in the big cities of Pakistan.
Afficher plus [+] Moins [-]Green alga Ulva pertusa—a new source of bioactive compounds with antialgal activity
2015
Ying-ying, Sun | Hui, Wang | Gan-lin, Guo | Yin-fang, Pu | Bin-lun, Yan | Chang-hai, Wang
We tested the effects of solvent fractions (FA, FB, FC, and FD), which partitioned by liquid-liquid extraction from the methanol extract of Ulva pertusa, on the growth of red tide microalgae (Karenia mikimitoi, Skeletonema costatum, Alexandrium tamarense, Heterosigma akashiwo, Prorocentrum donghaiense), and FA, FB, and FC exhibited significantly antialgal activity. The chemical constituent analysis showed the existence of bioactive compounds such as phenols and alkaloids. Further, four solvent fractions were applied to silica gel column and repeated preparative TLC to produce 13 samples and their purity qualified as thin-layer chromatographic grade. Among these purified samples, FA₁₁₁, FB₄₁₁, FC₄₁₁, FD₁₁₁, and FD₂₁₁ exhibited stronger antialgal activity. Furthermore, their functional groups were analyzed by colorimetric methods and UV spectra data. FD₁₁₁ and FD₂₁₁ were temptatively identified as alkaloids; the others were initially identified as phenolic acids. This is a preliminary study and the structure identification of these purified samples requires further investigation. While concentration of these purified samples in this algae was very small, they showed excellent effects against red tide microalgae.
Afficher plus [+] Moins [-]Tributyltin—critical pollutant in whole water samples—development of traceable measurement methods for monitoring under the European Water Framework Directive (WFD) 2000/60/EC
2015
Richter, Janine | Fettig, Ina | Philipp, Rosemarie | Jakubowski, Norbert
Tributyltin is listed as one of the priority substances in the European Water Framework Directive (WFD). Despite its decreasing input in the environment, it is still present and has to be monitored. In the European Metrology Research Programme project ENV08, a sensitive and reliable analytical method according to the WFD was developed to quantify this environmental pollutant at a very low limit of quantification. With the development of such a primary reference method for tributyltin, the project helped to improve the quality and comparability of monitoring data. An overview of project aims and potential analytical tools is given.
Afficher plus [+] Moins [-]Is the toxicity of pesticide mixtures on river biofilm accounted for solely by the major compounds identified?
2015
Kim Tiam, Sandra | Morin, Soizic | Bonet, Berta | Guasch, Helena | Feurtet-Mazel, Agnès | Eon, Mélissa | Gonzalez, Patrice | Mazzella, Nicolas
Comparative effects of long-term exposure to Polar Organic Chemical Integrative Sampler (POCIS) extracts (PE) and to a reconstituted mixture based on the major compounds quantified in the PE were evaluated on river biofilm communities. The study aimed to characterize the effects of long-term and low-dose exposure to pesticides on natural biofilm communities and to evaluate if the effects due to PE exposure could be explained solely by the major compounds identified in the extracts. Biofilms from an uncontaminated site were exposed in artificial channels to realistic environmental concentrations using diluted PE, with the 12 major compounds quantified in the extracts (Mix) or with water not containing pesticides (Ctr). Significant differences between biofilms exposed to pesticides or not were observed with regard to diatom density, biomass (dry weight and ash-free dry mass), photosynthetic efficiency (ΦpsII) and antioxidant enzyme activities. After 14 days of exposure to the different treatments, the observed trend towards a decrease of mean diatom cell biovolumes in samples exposed to pesticides was related to the control biofilms’ higher relative abundance of large species like Cocconeis placentula or Amphora copulata and lower relative abundance of small species like Eolimna minima compared to the contaminated ones. Principal component analyses clearly separated contaminated (PE and Mix) from non-contaminated (Ctr) biofilms; on the contrary, the analyses did not reveal separation between biofilms exposed to PE or to the 12 major compounds identified in the extract.
Afficher plus [+] Moins [-]Effect of peat on the accumulation and translocation of heavy metals by maize grown in contaminated soils
2015
Stanislawska-Glubiak, Ewa | Korzeniowska, Jolanta | Kocon, Anna
Incorporation of organic materials into soil improves the soil sorption capacity, while limiting the mobility of metals in soil and their availability to plants. These effects can be taken advantage for remediation of soils polluted with heavy metals. The objective of this study is to assess the remediatory potential of peat applied to soils with concomitant pollution with Cd, Pb, and Zn. Two 1-year experiments were run in microplots in which maize was grown as the test plant. The following treatments were compared on two soils (sandy soil and loess): (1) control, (2) heavy metals (HM), (3) HM + peat in a single dose, and (4) HM + peat in a double dose. Maize was harvested in the maturity stage; the biomass of roots and aerial parts, including grain and cobs, was measured. Besides, concentration of metals in all those plant parts and the net photosynthetic rate and transpiration rate were determined. The approach of using peat in soil remediation led to satisfactory results on sandy soil only. The application of peat to sandy soil caused significant changes in the accumulation of the metals and their translocation from roots to other parts of plants, which resulted in a higher intensity of photosynthesis and an increase in the maize biomass compared to the HM treatment.
Afficher plus [+] Moins [-]Derivation of marine water quality criteria for metals based on a novel QICAR-SSD model
2015
Chen, Cheng | Mu, Yunsong | Wu, Fengchang | Zhang, Ruiqing | Su, Hailei | Giesy, John P.
Establishment of water quality criteria (WQC) is one procedure for protection of marine organisms and their ecosystems. This study, which integrated two separate approaches, quantitative ion character–activity relationships (QICARs) and species sensitivity distributions (SSDs), developed a novel QICAR-SSD model. The QICARs predict relative potencies of individual elements while SSDs integrate relative sensitivities among organisms. The QICAR-SSD approach was applied to derive saltwater WQC for 34 metals or metalloids. Relationships between physicochemical properties of metal ions and their corresponding potencies for acute toxicity to eight selected marine species were determined. The softness index (σp) exhibited the strongest correlation with the acute toxicity of metals (r² > 0.66, F > 5.88, P < 0.94 × 10⁻²). Predictive criteria maximum concentrations for the eight metals, derived by applying the SSD approach to values predicted by use of QICARs, were within the same order of magnitude as values recommended by the US EPA (2009). In general, the results support that the QICAR-SSD approach is a rapid method to estimate WQC for metals for which little or no information is available for marine organisms.
Afficher plus [+] Moins [-]Plant-assisted rhizoremediation of decabromodiphenyl ether for e-waste recycling area soil of Taizhou, China
2015
He, Yan | Li, Xinfeng | Shen, Xinquan | Jiang, Qin | Chen, Jian | Shi, Jiachun | Tang, Xianjin | Xu, Jianming
To develop an effective phytoremediation approach to purify soils polluted by decabromodiphenyl ether (BDE-209) in e-waste recycling area, pot experiments were conducted through greenhouse growth of seven plant species in BDE-209-polluted soils. The hygrocolous rice (Oryza sativa L.) cultivars (XiuS and HuangHZ) and the xerophyte ryegrass (Lolium perenne L.) were found to be as the most effective functional plants for facilitating BDE-209 dissipation, with the removal of 52.9, 41.9, and 38.7 % in field-contaminated soils (collected directly from field, with an average pollution concentration of 394.6 μg BDE-209 kg⁻¹ soil), as well as 21.7, 27.6, and 28.1 % in freshly spiked soils (an average pollution concentration of 4413.57 μg BDE-209 kg⁻¹ soil, with additional BDE-209 added to field-contaminated soils), respectively. Changes in soil phospholipid fatty acid (PLFA) profiles revealed that different selective enrichments of functional microbial groups (e.g., arbuscular mycorrhizal fungi and gram-positive bacteria) were induced due to plant growth under contrasting water management (flooded-drained sequentially, flooded only, and drained only, respectively). The abundance of available electron donors and acceptors and the activities of soil oxido-reductases were also correspondingly modified, with the activity of catalase, and the content of NO₃ ⁻ and Fe³⁺ increased generally toward most of the xerophyte treatments, while the activity of dehydrogenase and the content of dissolved organic carbon (DOC) and NH₄ ⁺ increased toward the hygrophyte treatments. This differentiated dissipation of BDE-209 in soils as function of plant species, pollution doses and time, and water-dependent redox condition. This study illustrates a possibility of phytoremediation for BDE-209-polluted soils by successive cultivation of rice followed by ryegrass coupling with suitable water management, possibly through dissipation pathway of microbial reductive debromination and subsequent aerobic oxidative cleavage of benzene ring.
Afficher plus [+] Moins [-]Removal of acetaminophen and naproxen by combined coagulation and adsorption using biochar: influence of combined sewer overflow components
2015
Jung, Chanil | Oh, Jeill | Yoon, Yeomin
The combined coagulation and adsorption of targeted acetaminophen and naproxen using activated biochar and aluminum sulfate were studied under various synthetic “combined sewer overflow” (CSO) conditions. The biochar demonstrated better adsorption performance for both acetaminophen and naproxen (removal, 94.1 and 97.7 %, respectively) than that of commercially available powdered activated carbon (removal, 81.6 and 94.1 %, respectively) due to superior carbonaceous structure and surface properties examined by nuclear magnetic resonance analysis. The adsorption of naproxen was more favorable, occupying active adsorption sites on the adsorbents by naproxen due to its higher adsorption affinity compared to acetaminophen. Three classified CSO components (i.e., representing hydrophobic organics, hydrophilic organics, and inorganics) played different roles in the adsorption of both adsorbates, resulted in inhibition by humic acid complexation or metal ligands and negative electrostatic repulsion under adsorption and coagulation combined system. Adsorption alone with biochar was determined to be the most effective adsorptive condition for the removal of both acetaminophen and naproxen under various CSO conditions, while both coagulation alone and combined adsorption and coagulation failed to remove the acetaminophen and naproxen adequately due to an increase in ionic strength in the presence of spiked aluminum species derived from the coagulant.
Afficher plus [+] Moins [-]Mercury in the eggs of aquatic birds from the Gulf of Gdansk and Wloclawek Dam (Poland)
2015
Grajewska, Agnieszka | Falkowska, Lucyna | Szumiło-Pilarska, Emilia | Hajdrych, Julia | Szubska, Marta | Frączek, Tomasz | Meissner, Włodzimierz | Bzoma, Szymon | Bełdowska, Magdalena | Przystalski, Andrzej | Brauze, Tomasz
The aim of this paper was to assess the influence of diet on the concentrations of total mercury (HgTOT) in the eggs of aquatic birds. Trophic level was determined using stable isotopes (δ¹⁵N, δ¹³C). Analysis was carried out on eggs (laid in 2010–2012) belonging to two species of terns nesting at the River Vistula outlet on the Gulf of Gdansk and on herring gulls nesting both in Gdynia harbour and on the Vistula dam in Wloclawek. The results show that seafood diet causes the highest load of mercury, that which is transferred into terns eggs. The amounts of accumulated mercury obtained were found to be different in the particular egg components with Hgₐₗbᵤₘₑₙ > Hgyₒₗₖ > Hgₘₑₘbᵣₐₙₑ > Hgₛₕₑₗₗ. In the herring gull eggs, three stages of embryo development with varying levels of mercury were determined. It was observed that mercury received from the albumen and yolk was most effectively removed when developing embryo into down.
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