Influence of soil inorganic amendments on heavy metal accumulation by leafy vegetables

Environmental Science and Pollution Research - The present study aims to assess the effect of four inorganic soil amendments, such as lime (CaCO3), red mud consisting of 75% hematite (Fe2O3),...     

Key parameters and practices controlling pesticide degradation efficiency of biobed substrates

We studied the contribution of each of the components of a compost-based biomixture (BX), commonly used in Europe, on pesticide degradation. The impact of other key parameters including pesticide dose, temperature and repeated applications on the degradation of eight pesticides, applied as a mixture, in a BX and a peat-based biomixture (OBX) was compared and contrasted to their degradation in soil. Incubation studies showed that straw was essential in maintaining a high pesticide degradation capacity of the biomixture, whereas compost, when mixed with soil, retarded pesticide degradation. The highest rates of degradation were shown in the biomixture composed of soil/compost/straw suggesting that all three components are essential for maximum biobed performance. Increasing doses prolonged the persistence of most pesticides with biomixtures showing a higher tolerance to high pesticide dose levels compared to soil. Increasing the incubation temperature from 15 °C to 25 °C resulted in lower t(1/2) values, with biomixtures performing better than soil at the lower temperature. Repeated applications led to a decrease in the degradation rates of most pesticides in all the substrates, with the exception of iprodione and metalaxyl. Overall, our results stress the ability of biomixtures to perform better than soil under unfavorable conditions and extreme pesticide dose levels.     

Leaching of the organophosphorus nematicide fosthiazate

Fosthiazate is an organophosphorus nematicide which was recently included in Annex I of the Directive 91/414/EEC under the clause that it should be used with special care in soils vulnerable to leaching. Thus, the leaching of fosthiazate was investigated in columns packed with three different soils which represented situations of high (site 2), intermediate (site 1) and low (site 3) leaching potential. The recommended dose of fosthiazate was applied at the surface of the soil columns and fosthiazate fate and transport was investigated for the next two months. Fosthiazate concentrations in the leachate collected from the bottom of the columns packed with soil from site 2 exceeded 0.1 microgl(-1) in most cases. This soil was characterized as acidic, indicating longer fosthiazate persistence, with low organic matter content, indicating weak adsorption, thus representing a situation vulnerable to leaching. In contrast, the lowest concentrations of fosthiazate in the leachate were evident in the columns packed with soil from site 3. This soil was characterized as alkaline, indicating faster degradation, with higher organic matter content, indicating stronger adsorption, thus representing a situation not favoring leaching of fosthiazate. The highest concentration of fosthiazate in the leachate from the columns packed with soil from site 2 was 3.44 microgl(-1) compared to 1.17 and 0.16 microgl(-1), which were the corresponding maximum values measured in columns packed with soil from sites 1 and 3, respectively. The results of the current study further suggest that fosthiazate is mobile in soil and can leach under conducive soil conditions like acidic soils with low organic matter content.     

Water Quality Assessment by Ecotoxicological and Chemical Methods in Magnesia,Greece

The fresh- and seawater quality in Magnesia, Greece, was evaluated in this work, using a combination of bioassays and chemical analytical techniques. The crustacean and the invertebrate saline water shrimp Artemia franciscana were used as test species for monitoring the quality of fresh- and seawater samples respectively. Furthermore, chemical analysis was performed in the samples, for the assessment of pollutants loading. In general, both fresh- and seawater toxicity was low, indicating the good environmental conditions in the area. However, two seawater samples and one freshwater sample, presented high toxicity values, which is in agreement with the chemical measurements.