Multivariate effect of inorganic wastewater matrix on the removal of pesticides by solar photo-Fenton.

An amount of works has reported the effect of wastewater matrix composition on pollutants removal by different AOPs. The biggest challenge is that each wastewater source has a challenging composition (organic and inorganic compounds, pollutants, etc.) and not only the concentration of all these species but also the interaction between them may affect the effectiveness of the studied process. This work has been carried out to evaluate the photo-degradation kinetics of six different pesticides (flutriafol, imidacloprid, myclobutanil, pirimicarb, thiamethoxam and triadimenol) by solar photo-Fenton (SPF) process at acidic pH. First, oxidant concentration (H2O2) was optimized with an actual WWTP effluent. Then, the process was validated with two different secondary and tertiary WWTP effluents, in which main intermediate transformation by-products were identified. Finally, the effect of the inorganic water matrix components (bicarbonate, chloride, sulphate, nitrate and phosphate) was evaluated by a multivariate analysis. Once H2O2 has been optimized at 30 mg L-1, the photo-degradation efficiency of pesticides in real wastewater samples was compared. DOC content of both secondary and tertiary WWTP effluents was dropped by 67%. The identification of the main intermediate transformation by-products (such as 1H-1,2,4-triazole, desmethyl-formamido pirimicarb, thiamethoxam urea, chloronicotinic acid and imidacloprid urea) was reviewed. Following, the multivariate analysis on pesticides photo-degradation, generally, predicted four significant effects in common for the studied pesticides: a positive effect (interaction bicarbonate/nitrate) and three negative ones (chloride, phosphate and the interaction chloride/sulphate); among others. In addition, optimum values of inorganic ion concentrations, to obtain an optimum desirability on studied pesticides removal by SPF at acidic pH, were also evaluated.

Remediation of pesticides in commercial farm soils by solarization and ozonation techniques.

Soil contamination by pesticides is a growing environmental problem. Even though nowadays numerous soil remediation technologies are available, most of them have not been tested at field scale. This study attempts to demonstrate the efficiency of solarization-ozonation techniques for the removal of twelve pesticides at full scale. Initial solarization and ozonation trials were conducted in plots located in a greenhouse using freshly and aged contaminated soils under controlled pilot conditions. The combination of solarization and ozonation treatment was efficient for all the studied pesticides both in freshly and in aged contaminated soils, being the lower degradation values found for the second type. This low removal suggests that the increase of pesticides' adsorption on soil resulting from ageing decreases their availability. Once the essays were carried out at pilot scale, the solarization-ozonation applicability was evaluated in a commercial farm soil. This trial was carried out in a greenhouse whose soil had previously been contaminated with some of the pesticides studied. A significant degradation (53.8%) was observed after 40 days of treatment. Pesticides' main metabolites were identified during the different remediation experiments. In addition, the cost of the combined solarization and ozonation technology was evaluated. Finally, our results suggest that this combination of techniques could be considered a promising technology to degrade pesticides in soil.

Remediation of triazole, anilinopyrimidine, strobilurin and neonicotinoid pesticides in polluted soil using ozonation and solarization.

This study aimed to investigate the effectiveness of ozonation and solarization techniques for the removal of different types of pesticides from soil during the summer season. The effect of two experimental parameters (temperature and ozone application mode) on the pesticide degradation was evaluated. The results showed that solarization (S), solarization with surface ozonation (SOS), and solarization with deep ozonation (SOD) enhanced pesticide degradation rates in comparison with the control (untreated soil, C). The triazole, anilinopyrimidine, strobilurin and neonicotinoid pesticides showed similar behaviour under S and SOS conditions. The highest decrease was found in SOD, indicating the significant effect of temperature and ozone application mode on the efficiency of the ozonation treatment. Thus, a higher soil temperature and a longer accumulated time at high temperature in treatments S, SOS and SOD were observed due to solarization process. In addition, the removal efficiency was enhanced with exposure time. Finally, the main 15 transformation products were identified during SOD treatment. The results suggest that solarization combined with ozonation techniques allows decontamination of soil containing pesticide residues.

Assessment of reclaimed agro-wastewater polluted with insecticide residues for irrigation of growing lettuce (Lactuca sativa L) using solar photocatalytic technology.

Scientific literature is full of works studying the removal of different pollutants from water through different Advanced Oxidation Processes (AOPs). Many of them only suggest it is reused for agricultural purposes or for small crops in pots. This study is based on the reuse of reclaimed agricultural wastewater contaminated with four insecticides (chlorantraniliprole, imidacloprid, pirimicarb and thiamethoxam) for growing lettuce in field conditions. First, solar photocatalysis with TiO2/Na2S2O8 was used on a pilot plant in a sunny area (Murcia, SE of Spain) as an environmentally friendly technology to remove insecticide residues and their main reaction intermediates from contaminated water. The necessary fluence (H, kJ m-2) to accomplish 90% removal (H90) ranged from 0.12 to 1212 kJ m-2 for pirimicarb and chlorantraniliprole, respectively. Only six (derived from imidacloprid, pirimicarb and thiametoxam) of 18 transformation intermediate products studied were detected in reclaimed water during the photoperiod (2000 kJ m-2 of accumulated UVA radiation) although all of them were totally photodegraded after a fluence of 1250 kJ m-2. Secondly, reclaimed agro-wastewater was used to irrigate two lettuce crops grown under greenhouse conditions and under agricultural field conditions. In no cases, insecticide residues nor their TIPs were noticed above their respective LOQs (limits of quantification) in soil and lettuce samples (between 0.03 and 0.04 µg kg-1 for pirimicarb and 2.49 and 2.23 µg kg-1 for thiamethoxam, respectively) when they were irrigated with reclaimed water, while residues of the four insecticides and some of their intermediates were found in soil and lettuce by the end of cultivation when they were irrigated with non-reclaimed contaminated water. According to the results, this technology can be applied in a sustainable way, mainly in areas with water scarcity and high solar radiation, contributing to water utilisation in drought areas and the use of renewable energy.

Reclamation of agro-wastewater polluted with thirteen pesticides by solar photocatalysis to reuse in irrigation of greenhouse lettuce grown.

In Mediterranean countries, reuse of reclaimed water is essential for crop irrigation. The occurrence of pesticides in agro-wastewater may represent a risk for human health and environment owing to their release in soil and translocation to plants. The novelty of this work relies on the reuse of reclaimed agro-wastewater polluted with thirteen pesticides for lettuce irrigation. Removing of pesticide residues in agro-wastewater was carried out using natural sunlight and TiO2/Na2S2O8 in a pilot facility located in Murcia (SE of Spain). The studied pesticides were azoxystrobin, boscalid, chlorpropham, flutolanil, flutriafol, isoxaben, methoxyfenozide, myclobutanil, napropamide, prochloraz, propamocarb, propyzamide and triadimenol, which are commonly used in southeast Spain to treat lettuces grown. Different heterogeneous and homogeneous processes were studied and compared. Previously, the optimization of the process for the selection of the best catalytic system was performed at lab-scale. TiO2+ S2O82- was selected due to the greater effectiveness, achieving almost complete disappearance after about 400 kJ m-2 of cumulative UVA exposure. No significant differences were observed in quality parameters of lettuce grown using treated and non-treated agro-wastewater.

Solar reclamation of agro-wastewater polluted with eight pesticides by heterogeneous photocatalysis using a modular facility. A case study.

In this work, we have studied the removal of eight pesticides, commonly used in fruit crops, in agro-wastewater generated in commercial farms by the cleaning of trace of phytosanitary products in containers and tanks from treatment equipment. The studied pesticides were acetamiprid, cyproconazole, cyprodinil, difenoconazole, fenhexamid, hexythiazox, myclobutanil and thiamethoxam. The trials were performed in a pilot facility located in Murcia (SE of Spain), using natural sunlight and titanium dioxide (TiO2) in tandem with Na2S2O8. Five photocatalytic treatments were carried out during autumn 2017. Results show that the mean (n = 5) final amount was about 13% of the initial pesticide mass present in agro-wastewater. Therefore, we have proved that this technology could be used for tackling the elimination of pesticide residues in agro-wastewater and has favourable prospects of being applied in the water treatment sector.

Sexual reproduction of Zymoseptoria tritici on durum wheat in Tunisia revealed by presence of airborne inoculum, fruiting bodies and high levels of genetic diversity.

Septoria tritici blotch (STB) caused by the heterothallic ascomycete Zymoseptoria tritici is currently one of the most devastating diseases of wheat worldwide. The extent of sexual reproduction of this pathogen is well documented on bread wheat, but not on durum wheat. The objective of the present study was to quantify the occurrence of Z. tritici sexual reproduction on durum wheat in the Tunisian environment. The assessment was undertaken using a triple approach combining fruiting body assessment, ascospore trapping and population genetic analyses. The results highlighted the formation of pseudothecia on leaves and stubble from the autumn until the end of the growing season. Likewise, qPCR monitoring highlighted a constant release of Z. tritici airborne inoculum during the wheat-growing season, with a peak of production at the end of the season. Genetic investigations using microsatellites revealed high levels of gene and genotypic diversities, an equal distribution of mating types, and a lack of genetic clustering within and between growing seasons. Taken together, these findings indicate that Z. tritici undergoes sexual reproduction on durum wheat in Tunisia at least to the same extent than on bread wheat in Western Europe, and that the dry and warm climate does not affect the mating process of the fungus. Frequent occurrence of sexual reproduction is a valuable knowledge to take into account in STB control strategies on durum wheat.

NFC as a Childhood Obesity Treatment Tool.

Childhood Obesity is associated with a wide range of serious health complications and constitutes an increased risk of premature syndromes, including diabetes or heart diseases. Its treatment seems to be complicated. So, in order to help parents we have developed a system that will try to make easier the process of choosing foodstuff for overweight and obese children at the supermarket. To interact with the system, Near Field Communication mobile phones and tags are used. Those tags would have nutritional information such as energy or fat contain of each product. When the interaction takes place, the system will generate an alert determining if the product is adequate for the user diet or not. Decision will be influenced by specific prescript diets, which would have been previously generated by the system based on user profile parameters. At the same time the diet is established, the shopping list would be generated automatically. Therefore, the user could download and print both things at home easily by the PC application. The system also takes into account physical activity of the user. Children mobile phone includes an accelerometer that will detect and collect user activities in order to modify calorical requirements and, if necessary, to change physical activity too. In the future, it would be possible to extend this project system for adults, managing diets not just for obese and overweight, but also to diabetic or celiac people.

FUSARIUM HEAD BLIGHT SYMPTOM DISCRIMINATION: A USEFUL TOOL IN THE FIELD EVALUATION OF FUNGICIDE TREATMENTS.

Fusarium head blight (FHB) is one of the major diseases affecting wheat. It is caused by a complex of fungal species, resulting in yield losses and health problems due to mycotoxin production. The presence of multiple fungal species on wheat ears, with varying responses to active fungicide ingredients used in the field, makes the disease difficult to manage. In order to evaluate the efficacy of the timing of applications (at GS 39, GS 61 and GS 39+61) of a prothioconazole + fluoxastrobin-based fungicide, a 2-year field trial was conducted in Belgium. In both years, applications at GS 61 and GS 39+61 resulted in a significant reduction in symptom severity on ears and in deoxynivalenol (DON) content compared with the untreated control in 2013. In 2012, when Microdochium spp. were the most prevalent species, the treatment at GS 39 significantly reduced ear symptoms. Fusarium graminearum was predominant in the second year (2013) and caused significant DON accumulation in the grain after a single foliar spraying. The two genera were characterized by distinct types of symptoms: grouped bleached spikelet's for F. graminearum and isolated bleached spikelet's for Microdochium spp. This difference enabled the significant effect of the double treatments on symptoms caused by Microdochium spp. to be determined in the second year. This effect, which was also visible on leaf symptoms, suggests that Microdochium spp. epidemics in wheat might be polycyclic. Discrimination between symptoms caused by F. graminearum and Microdochium spp. could be a useful tool to study FHB management using fungicide treatments.

Use of farming and agro-industrial wastes as versatile barriers in reducing pesticide leaching through soil columns.

Increased interest has been recently focused on assessing the influence of the addition of organic wastes related to movement of pesticides in soils of low organic matter (OM) content. This study reports the effect of two different amendments, animal manure (composted sheep manure) and agro-industrial waste (spent coffee grounds) on the mobility of 10 pesticides commonly used for pepper protection on a clay-loam soil (OM = 0.22%). The tested compounds were azoxystrobin, cyprodinil, fludioxonil, hexaconazole, kresoxim-methyl, pyrimethanil, tebuconazole, and triadimenol (fungicides), pirimicarb (insecticide), and propyzamide (herbicide). Breakthrough curves were obtained from disturbed soil columns. Cumulative curves obtained from unamended soil show a leaching of all pesticides although in different proportions (12-65% of the total mass of compound applied), showing triadimenol and pirimicarb the higher leachability. Significant correlation (r = 0.93, p<0.01) was found between the observed and bibliographical values of GUS index. The addition of the amendments used drastically reduced the movement of the studied pesticides. Only two pesticides were found in leachates from amended soils, pyrimethanil (<1%) for both, and pirimicarb (44%) in the soil amended with spent coffee grounds. A decrease in pesticide leaching was observed with the increase in dissolved organic matter (DOM) of leachates. The results obtained point to the interest in the use of organic wastes in reducing the pollution of groundwater by pesticide drainage.

Effect of ripening on protein content and enzymatic activity of Crimson Seedless table grape.

The evolution of °Brix, protein content, polyphenoloxidase activity and peroxidase activity during the ripening of Crimson Seedless table grape was studied in three consecutive years (2006, 2007 and 2008). The total protein content was determined according to Bradford's dye binding method, and polyphenoloxidase (PPO) and peroxidase (POD) were extracted using Triton X-114 and characterised using spectrophotometric methods. The year had a statistically significant effect on all the studied parameters and there was an interannual correlation in the evolution of protein, PPO, POD and °Brix. All the studied parameters were statistically correlated, except POD activity with protein content. Weather conditions during the ripening period had a greater effect on protein content than PPO and POD activity.

Isolation and characterisation of resistant-to-fermentation carbohydrate polymers from cultures of Rhizopus nigricans grown on agrofood waste materials.

Rhizopus nigricans was cultivated in a liquid medium using lemon, mandarin, orange, pear and melon peel or artichoke bracts as the carbon source. In all cultures, a carbohydrate polymer fraction remained resistant to fermentation. These fractions were isolated in gram amounts and characterised. The molecular weight distribution of the fractions and its sugar composition resembles those of the hairy-regions of the pectins. In the fractions, four main carbohydrates were found: 4-7 mol% Rha, 42-59 mol% Ara, 7-14 mol% Gal, 17-33 mol% GalA.

Plasmovirus: replication cycle of a novel nonviral/viral vector for gene transfer.

We recently described a novel nonviral/viral vector for gene transfer, the plasmovirus (Noguiez-Hellin P, Robert-le Meur M, Laune S, et al. C R Acad Sci Paris, Sciences de la Vie. 1996;319:45-50; Noguiez-Hellin P, Robert-le Meur M, Salzmann J-L, et al. Proc Natl Acad Sci USA. 1996;93:4175-4180). Plasmoviruses are plasmids capable of expressing all the viral genes required for generating infectious particles and packaging a defective genome containing a transgene. Transfected as plasmids, plasmoviruses transform the transduced cells into packaging cells that release infectious replication-defective retrovirus vectors (RV) containing a transgene, which are capable of infecting nearby cells. We previously showed that such a vector can efficiently "propagate" the transgene after transfection. Here we examine in greater detail the different steps of plasmovirus replication in vitro in human (143 B TK-) and murine (NIH 3T3 TK-) cells. Molecular-biological analysis revealed plasmovirus-coded protein expression starting from 24 hours post-transfection, followed by the detection of infectious RV 48 hours post-transfection. The gag proteins were correctly processed in the released particles. Electron microscopic analysis revealed typical type C particles. Nonintegrated plasmovirus DNA was not toxic for the cells and could be detected for at least 14 days post-transfection. While the transfected gag gene and the transgene could also be detected throughout this period, we observed that env-coded proteins decreased after 72 hours post-transfection. Nevertheless, the production of RV resulted in the propagation of the transgene in the culture, with stable integration of plasmovirus proviral DNA into the host genome of infected cells. We show that this propagation results in a major improvement in therapeutic efficacy using an HSV1-TK transgene and ganciclovir treatment, when compared to that of plasmovirus constructs that cannot propagate. Altogether, these results demonstrate the functionality of this gene transfer method and suggest that improvements in the vector design enhance its efficacy.

Plasmoviruses: nonviral/viral vectors for gene therapy.

We have generated a chimeric gene transfer vector that combines the simplicity of plasmids with the infectivity and long-term expression of retroviruses. We replaced the env gene of a Moloney murine leukemia virus-derived provirus by a foreign gene, generating a plasmid that upon transfer to tumor cells generates noninfectious retroviral particles carrying the transgene. We added to this plasmid an independent expression cassette comprising a cytomegalovirus promoter, an amphotropic retroviral envelope, and a polyadenylylation signal from simian virus 40. These constructs were designed to minimize the risk of recombination generating replication-competent retroviruses. Their only region of homology is a 157-bp sequence with 53% identity. We show that the sole transfection of this plasmid in various cell lines generates infectious but defective retroviral particles capable of efficiently infecting and expressing the transgene. The formation of infectious particles allows the transgene propagation in vitro. Eight days after transfection in vitro, the proportion of cells expressing the transgene is increased by 10-60 times. There was no evidence of replication-competent retrovirus generation in these experiments. The intratumoral injection of this plasmid, but not of the control vector lacking the env gene, led to foci of transgene-expressing cells, suggesting that the transgene had propagated in situ. Altogether, these "plasmoviruses" combine advantages of viral and non-viral vectors. They should be easy to produce in large quantity as clinical grade materials and should allow efficient and safe in situ targeting of tumor cells.

[Generation of a trans-complementable defective recombinant provirus and loading a transgene]. / Génération d'un provirus recombinant défectif complémentable en trans et véhiculant un transgène.

This work was aimed at generating a novel system for gene transfer to tumor cell, combining the advantages of non-viral gene transfer methods with those of transfer by recombinant retroviruses. We replaced the env gene of an infectious Moloney murine leukemia provirus with the gene coding for the thymidine kinase of Herpes Simplex Virus 1 (HSV1-TK). The sole transfection of this construction allows the production of viral particles, and the encapsidation of a viral genome carrying transgene. We show that this gene is expressed at a level sufficient for conferring sensitivity to ganciclovir, a nucleoside analog that is metabolised in a toxic compound by HSV1-TK. We also show that the complementation of this recombinant defective provirus with a gene coding for a retroviral envelope, either expressed constitutively by the transduced cell, or by co-transfection, leads to the formation of infectious viral particles capable of transducing HSV1-TK into tumor cells.