Leaching of S-metolachlor,terbuthylazine, desethyl-terbuthylazine,mesotrione, flufenacet,isoxaflutole, and diketonitrile in field lysimeters as affected by the time elapsed between spraying and first leaching event

The effect of elapsed time between spraying and first leaching event on the leaching behavior of five herbicides (terbuthylazine, S-metolachlor, mesotrione, flufenacet, and isoxaflutole) and two metabolites (desethyl-terbuthylazine and diketonitrile) was evaluated in a 2011–2012 study in northwest Italy. A battery of 12 lysimeters (8.4 m² long with a depth of 1.8 m) were used in the study, each filled with silty-loam soil and treated during pre-emergence with the selected herbicides by applying a mixture of commercial products Lumax (4 L ha^?1) and Merlin Gold (1 L ha^?1). During treatment periods, no gravity water was present in lysimeters. Irrigation events capable of producing leaching (40 mm) were conducted on independent groups of three lysimeters on 1 day after treatment (1 DAT), 7 DAT, 14 DAT, and 28 DAT. The series was then repeated 14 days later. Leachate samples were collected a few days after irrigation; compounds were extracted by solid phase extraction and analyzed by high-performance liquid chromatography and gas chromatography–mass spectrometry. Under study conditions, terbuthylazine and S-metolachlor showed the highest leaching potentials. Specifically, S-metolachlor concentrations were always found above 0.25 µg L^?1. Desethyl-terbuthylazine was often detected in leached waters, in most cases at concentrations above 0.1 µg L^?1. Flufenacet leached only when irrigation occurred close to the time of herbicide spraying. Isoxaflutole and mesotrione were not measured (<0.1 µg L^?1), while diketonitrile was detected in concentrations above 0.1 µg L^?1 on 1 DAT in 2011 only.     

Evaluation of the MIDTAL microarray chip for monitoring toxic microalgae in the Orkney Islands, U.K.

Harmful or nuisance algal blooms can cause economic damage to fisheries and tourism. Additionally, toxins produced by harmful algae and ingested via contaminated shellfish can be potentially fatal to humans. The seas around the Orkney Islands, UK currently hold a number of toxic algal species which cause shellfishery closures in most years. Extensive and costly monitoring programs are carried out to detect harmful microalgae before they reach action levels. However, the ability to distinguish between toxic and non-toxic strains of some algae is not possible using these methods. The microarrays for the detection of toxic algae (MIDTAL) microarray contains rRNA probes for toxic algal species/strains which have been adapted and optimized for microarray use. In order to investigate the use of the chip for monitoring in the Orkney Islands, samples were collected between 2009 and 2011 from Brings Deep, Scapa Flow, Orkney Islands, UK; RNA was extracted and hybridized with generation 2 and 3.1 of the chip. The data were then compared to cell counts performed under light microscopy and in the case of Alexandrium tamarense to qPCR data targeting the saxitoxin gene and the LSU-rRNA gene. A good agreement between cell numbers and microarray signal was found for A. tamarense, Pseudo-nitzschia sp., Dinophysis sp. (r?<?0.5, for all) in addition to this there the chip successfully detected a large bloom of Karenia mikimotoi (r?<?0.70) in August and September 2011. Overall, there was good improvement in probe signal between generation 2 and generation 3.1 of the chip with much less variability and more consistent results and better correlation between the probes. The chip performed well for A. tamarense group I signal to cell numbers in calibrations (r?>?0.9). However, in field samples, this correlation was slightly lower suggesting interactions between all species in the sample may affect signal. Overall, the chip showed it could identify the presence of target species in field samples although some work is needed to improve the quantitative nature of the chip before it would be suitable for monitoring in the Orkney Islands.     

Sorption and desorption of sulfentrazone in Brazilian soils

This study was undertaken to obtain information about the behavior of sulfentrazone in soil by evaluating the sorption and desorption of the herbicide in different Brazilian soils. Batch equilibrium method was used and the samples were analyzed by high performance liquid chromatography. Based on the results obtained from the values of Freundlich constants (Kf), we determined the order of sorption (Haplic Planosol < Red-Yellow Latosol < Red Argisol < Humic Cambisol < Regolitic Neosol) and desorption (Regolitic Neosol < Red Argisol < Humic Cambisol < Haplic Planosol < Red-Yellow Latosol) of sulfentrazone in the soils. The process of pesticide sorption in soils was dependent on the levels of organic matter and clay, while desorption was influenced by the organic matter content and soil pH. Thus, the use of sulfentrazone in soils with low clay content and organic matter (low sorption) increases the probability of contaminating future crops.     

Clay-sewage sludge co-pyrolysis. A TG-MS and Py-GC study on potential advantages afforded by the presence of clay in the pyrolysis of wastewater sewage sludge

Wastewater sewage sludge was co-pyrolyzed with a well characterized clay sample, in order to evaluate possible advantages in the thermal disposal process of solid waste. Characterization of the co-pyrolysis process was carried out both by thermogravimetric-mass spectrometric (TG-MS) analysis, and by reactor tests, using a lab-scale batch reactor equipped with a gas chromatograph for analysis of the evolved gas phase (Py-GC).Due to the presence of clay, two main effects were observed in the instrumental characterization of the process. Firstly, the clay surface catalyzed the pyrolysis reaction of the sludge, and secondly, the release of water from the clay, at temperatures of approx. 450-500 °C, enhanced gasification of part of carbon residue of the organic component of sludge following pyrolysis.Moreover, the solid residue remaining after pyrolysis process, composed of the inorganic component of sludge blended with clay, is characterized by good features for possible disposal by vitrification, yielding a vitreous matrix that immobilizes the hazardous heavy metals present in the sludge.     

Rheological Studies of Microfibrillar Cellulose Water Dispersions

The rheological behaviour of microfibrillar cellulose (MFC) water dispersions has been investigated. For the first time a detailed study of shear dependent viscosity at low and high shear rate is presented. A peculiar time dependent behaviour measured in the area between 0 and 1000 s⁻¹ was identified. The study shows a hysteresis loop in the shear rate–viscosity relationship at low shear rate. Additional time dependent shear rate measurements were performed, and a hypothesis for a mechanism of interaction and formation of a fibrils network was suggested. Higher temperature caused lower viscosity values, and this difference was increased at higher shear rate values. Oscillatory measurements showed how the closeness of the fibrils helps network creations. Data obtained from high shear measurements showed that 1% MFC water dispersions had a dilatant behaviour at ultra high shear rates with values increasing from 120 to 300 Pa s in the area between 180,000 and 330,000 s⁻¹ .     

Biologic impact on the coastal belt of the province of Venice (Italy,Northern Adriatic Sea): preliminary analysis for the characterization of the bathing water profile

Background, aim and scope  

This paper presents a preliminary study of the water profile with reference to microbiological parameters, required by Directive 2006/07/EC (European Community 2006) concerning the management of bathing water quality, in the coastal belt of the Province of Venice (Italy, Northern Adriatic Sea). A historical database has been implemented with monitoring data for the period 2000–2006 (data on rivers, bathing and marine coastal waters and on the characterization of Wastewater Treatment Plant (WWTP) discharges) from the institutional activity of Veneto Regional Environmental Prevention and Protection Agency (ARPAV). An integrated areal analysis for the microbiological investigation of homogeneous stretches along the coast of the Province of Venice was performed for a preliminary characterization of the bathing water profile considering water quality status and existing pressure sources.     

Insecticidal activity and fungitoxicity of plant extracts and components of horseradish (Armoracia rusticana) and garlic (Allium sativum)

To avoid environmental pollution and health problems caused by the use of traditional synthetic pesticides, there is a trend to search for naturally occurring toxicants from plants. Among the compounds discussed for anti-fungal and insecticidal activity, the natural extracts from garlic and horseradish have attracted considerable attention. The objective of this study is to determine the insecticidal and anti-fungal activity of Armoracia rusticana and Allium sativum L. extracts against larvae of Aedes albopictus (Skuse) and some pathogenic fungi. For the insecticidal test, horseradish and garlic extracts were prepared from fresh plants (cultivated in Emilia Romagna region) in a solution of ethanol 80 % and the two different solutions were used at different concentrations (for the determination of the lethal dose) against the fourth instar mosquito's larvae. The fungicidal test was carried out by the agar plates technique using garlic and horseradish extracts in a 10 % ethanol solution against the following organisms: Sclerotium rolfsii Sacc., Trichoderma longibrachiatum, Botrytis cinerea Pers., Fusarium oxysporum Schlecht. and Fusarium culmorum (Wm. G. Sm.) Sacc. The first results demonstrated that the horseradish ethanol extracts present only a fungistatic activity against Sclerotium rolfsii Sacc., Fusarium oxysporum Schlecht. and F. culmorum (Wm.G. Sm) Sacc. while garlic extracts at the same concentration provided a good fungicidal activity above all against Botrytis cinerea Pers. and S. rolfsii. A. rusticana and A. sativum preparations showed also an interesting and significant insecticidal activity against larvae of A. albopictus, even if horseradish presented a higher efficacy (LC?? value of 2.34 g/L), approximately two times higher than garlic one (LC?? value of 4.48 g/L).     

Preliminary evaluation of insecticide resistance in a strain of Musca domestica (Diptera: Muscidae) from an intensive chicken farm of Northern Italy

The house fly, Musca domestica L., a relevant sanitary pest, is mainly controlled by insecticides. However, an inappropriate use of chemicals may induce resistance, treatment efficacy decline and environmental damages. We evaluated toxicity of some organophosphates, pyrethroids, spinosad and neonicotinoids by topical applications on adults of a M. domestica strain (OcRo) collected from an intensive chicken farm in Northern Italy, in comparison to a susceptible strain (s-DBF). The OcRo strain exhibited higher levels of resistance (RR??) to four pesticides in comparison to s-DBF. Spinosad and imidacloprid had very low RR??, thus were still efficient in OcRo control. We also tested resistance to pesticides in OcRo after topical applications of synergistic compounds. Hydrolases were involved in phosphorganic detoxification and cytochrome P450 monoxygenases in that of pyrethroids. These results indicate that OcRo strain is now multiresistant to organophosphates and pyrethroids, and this should be considered for an environmentally safe pest management.     

Pesticide removal from waste spray-tank water by organoclay adsorption after field application to vineyards

Purpose

The main objective of this work was to develop and test a pilot scheme for decontaminating pesticide-containing water derived from pesticide mixtures used to protect vineyards, in which the scheme comprises adsorption by an organoclay and includes a system where an enhanced or rapid microbial degradation of the adsorbed residues can occur.

Methods

In laboratory experiments, the Freundlich adsorption coefficients of formulations of two fungicides, penconazole and cyazofamid, onto the organoclay Cloisite 20 A were measured in order to predict the efficiency of this organoclay in removing these fungicides from the waste spray-tank water. Subsequently, the adsorption tests were repeated in the pilot system in order to test the practical operation of the depuration scheme.

Results

The adsorption tests with the pilot system show 96% removal of both fungicides over a few hours, similar to the efficiency of removal predicted from the laboratory adsorption tests. The formulation type may influence the efficiency of clay recovered after adsorption. Regarding the waste disposal, for instance, the organoclay composted after the treatment, cyazofamid showed significant dissipation after 90?days, whereas the dissipation of penconazole was negligible.

Conclusion

The depuration scheme developed showed to be efficient for decontaminating pesticide-containing water derived from vineyards, but additional treatments for the adsorbed residues still appear to be necessary for persistent pesticides. However, future decontamination research should be attempted for water contaminated with pesticides containing antifoaming agents in their formulations, in which case the present pilot system could not be applied.     

Visible injury, crown condition, and growth responses of selected Italian forests in relation to ozone exposure

The impact of ozone on forest ecosystems in Italy is monitored within the CONECOFOR programme. Ozone levels are measured in 30 plots using passive samplers. Response parameters used are: crown condition (transparency), BAI (basal area increment), and visible symptoms on spontaneous vegetation. Levels of AOT40 are above the concentration-based critical level of 5 ppmh in all sites, but the evidence of impact on forest vegetation remains limited. Ozone is a predictor of crown transparency residuals in beech sites over two consecutive years, but the variance explained amounts to less than 10%. The relation between BAI reduction and ozone is even less certain. Transparency and BAI are more readily explainable in terms of ecological conditions of the site and climate fluctuations. The interpretation of visible symptoms is doubtful, and is conditioned by the prevailing ecological factors in the areas.