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Preconcentration of Cd(II) and Cu(II) ions by coprecipitation without any carrier element in some food and water samples Texte intégral
2011
Duran, Celal | Ozdes, Duygu | Sahin, Deniz | Bulut, Volkan Numan | Gundogdu, Ali | Soylak, Mustafa
A simple, rapid, sensitive and environmentally friendly separation and preconcentration procedure, based on the carrier element free coprecipitation (CEFC) of Cu(II) and Cd(II) ions by using an organic coprecipitant, 2-{[4-(4-fluorophenyl)-5-sulphanyl-4H-1,2,4-triazol-3-yl]methyl}-4-{[(4-fluorophenyl) methylene]amino}-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (MEFMAT) was developed. The analyte ions were determined by flame atomic absorption spectrometric (FAAS) determinations. The optimum conditions for the coprecipitation process were investigated on several commonly tested experimental parameters such as pH of the solution, amount of MEFMAT, sample volume, standing time, centrifugation rate and time. The influences of some anions, cations and transition metals on the recoveries of analyte ions were also investigated, and no considerable interference was observed. The preconcentration factor was found to be 50. The detection limits for Cu(II) and Cd(II) ions based on the three times the standard deviation of the blanks (N:10) were found to be 1.49 and 0.45μgL⁻¹, respectively. The relative standard deviations were found to be lower than 3.5% for both analyte ions. The method was validated by analyzing two certified reference materials (CRM-TMDW-500 Drinking Water and CRM-SA-C Sandy Soil C) and spike tests. The procedure was successfully applied to sea water and stream water as liquid samples and tobacco, hazelnut and black tea as solid samples.
Afficher plus [+] Moins [-]Can raingardens produce food and retain stormwater? Effects of substrates and stormwater application method on plant water use, stormwater retention and yield Texte intégral
2017
Richards, Paul J. | Williams, Nicholas S.G. | Fletcher, Tim D. | Farrell, Claire
Raingardens capture and filter urban stormwater using sandy soils and drought-tolerant plants. An emerging question is whether raingardens can also be used as vegetable gardens, potentially increasing their popularity and implementation. A successful vegetable raingarden will need to both retain stormwater and produce vegetables, despite potential water deficits between rainfall events. To determine whether raingardens can provide this dual functionality, we undertook a greenhouse pot experiment using two different substrates (loamy sand raingarden substrate and potting mix typical of containerised vegetable growing) and two methods of stormwater application (‘sub-surface’ and ‘surface’ watering) with the water quantity at each application determined by average Melbourne summer rainfall. Overall, potting mix produced bigger plants (biomass and leaf area) and greater yield than did the loamy sand. Yield effects were variable: tomato yield was unaffected by treatment, bean yield was greatest in potting mix, beetroot yield was greatest with sub-surface watering and parsley yield was greatest with surface watering. Bigger plants also had greater transpiration, which meant that stormwater retention was greatest for parsley and tomato plants growing in potting mix with surface watering. Although, a raingarden with potting mix and surface application of stormwater was optimal for producing food and retaining stormwater under our rainfall regime, potting mix could be problematic due to higher nutrient leaching and breakdown over time. Therefore, we recommend using a mix of loamy sand and potting mix. However, the choice of substrate and watering treatment require trade-offs between yield, stormwater retention and potential implications for water quality and long-term stability of hydraulic properties.
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