Introducción del curso y temática de trabajo

Fortalecimiento de las capacidaded científicas y técnicas de las instituciones involucradas en la investigación sobre resíduos de pesticidas.CONACYT - Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Desarrollo de un programa de silvicultura intensiva y de precisión para el aumento de la productividad de plantaciones forestales. Fase 1. Preparación de sitio y aplicación de enmiendas en plantaciones recién establecidas

Proyecto de Investigación (Código: 1401066) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Ingeniería Forestal, Escuela de Ingeniería Agrícola, Escuela de Química. Maderas Cultivadas de Costa Rica, 2020Este proyecto de investigación cumple con el objetivo número 15 de la Agenda 2030 “PROTEGER, RESTABLECER Y PROMOVER EL USO SOSTENIBLE DE LOS ECOSISTEMAS TERRESTRES, GESTIONAR SOSTENIBLEMENTE LOS BOSQUES, LUCHAR CONTRA LA DESERTIFICACIÓN, DETENER E INVERTIR LA DEGRADACIÓN DE LAS TIERRAS Y DETENER LA PÉRDIDA DE LA BIODIVERSIDAD" con la meta número 2: " Para el año 2020, promover la gestión sostenible de todos los tipos de bosques, poner fin a la deforestación, recuperar los bosques degradados e incrementar la forestación y la reforestación a nivel mundial".La falta de paquetes tecnológicos referentes a las técnicas correctas y eficientes de preparación de sitios y manejo nutricional de las plantaciones es una de las serias deficiencias que presenta el sector reforestador costarricense. Con la finalidad de revertir esta situación esta propuesta de investigación tuvo como objetivo principal aumentar la productividad y calidad de plantaciones forestales en Costa Rica. Como primera fase, este proyecto evaluó mediante ensayos individuales con diseños estadísticos robustos el efecto de labrar el suelo en profundidad y de la aplicación de cal en distintas formas en el crecimiento inicial de los árboles y en las propiedades físicas y químicas del suelo. Se realizaron mediciones periódicas donde se evaluó el crecimiento de los árboles, las propiedades físicas y químicas del suelo. Adicionalmente se evaluó mediante un estudio de tiempos y movimientos y determinación de costos, cuál de los tratamientos es financieramente más rentable. Adicionalmente se realizaron los primeros vuelos con aeronaves piloteadas a distancia para la determinación de un flujo de trabajo. En lo resultados se evidenció un efecto positivo en las propiedades del suelo al mecanizar y encalar, pero no se detectaron diferencias entre tratamientos para el crecimiento de los árboles. El poco tiempo de establecimiento del ensayo de labranza y deficiencias en el manejo de malezas en el ensayo de cal afectaron los resultados. Con relación a los costos se determinó que los costos de utilizar maquinaria pesada para realizar procesos de mecanización son elevados. Los tratamientos que realizan dos pasadas de subsolador son mucho más caros que realizar el proceso de labranza una sola vez. Encalar solo la rodaja de los árboles es más barato que realizar una aplicación en banda o total Mediante el uso de aeronaves piloteadas a distancia se logró realizar un flujo correcto para la planificación de vuelos con RPAS y se lograron calcular áreas y estimar alturas con precisión. Una de las principales recomendaciones para futuros estudios es el continuar estudiando y mejorando las limitantes de las plantaciones forestales con el objetivo de obtener mayor crecimiento en menor tiempo

Residuos de acaricidas en leche entera bovina de Costa Rica

Introducción: En Costa Rica se procesan anualmente 681 millones de litros de leche, debido al alto consumo per cápita que es de 216 kilogramos, por lo que es particularmente importante evitar los efectos tóxicos de la leche contaminada, asociados a vómitos, parálisis y calambres, y, a largo plazo, cáncer, trastornos endocrinos, diabetes y alteraciones cromosómicas, entre otros. Objetivo:Determinar los niveles de residuos de cinco acaricidas usados en Costa Rica: Amitraz, Coumafós, Clorpirifós, Ciflutrina y Cipermetrina, en muestras de leche entera bovina de Costa Rica. Métodos:De enero a setiembre del 2018 tomamos muestras en 200 sistemas de producción de seis provincias y aplicamos técnicas de cromatografía de gases y de líquidos, acopladas a espectrometría de masas. Resultados:no hallamos residuos de Coumafós y la Ciflutrina, pero en 19 fincas detectamos Amitraz, Cipermetrina y Clorpirifós (este último, 0,01mg/kg). Pocos encargados conocen alternativas al control químico, y la mayoría ni respetael periodo de retiro del garrapaticida, ni hace la rotación del ingrediente activo. Conclusión:Se debe mejorar la educación y el monitoreo sobre el uso de garrapaticidas en los sistemas de producción de leche.“Acaricide residues in whole bovine milk from Costa Rica”. Introduction:Because of the high per capita consumption of 216 kilograms, in Costa Rica, 681 million liters of milk are processed annually, and it is particularly important to avoid the toxic effects of contaminated milk, associated with vomiting, paralysis and cramps, and, in the long term, cancer, endocrine disorders, diabetes and chromosomal alterations, among others. Objective:To determine the residue levels of five acaricides used in Costa Rica: Amitraz, Coumafos, Chlorpyrifos, Cyfluthrin and Cypermethrin, in samples of whole bovine milk. Methods:From January to September 2018, we collected samples from 200 production systems in six provinces and applied gas and liquid chromatography techniques coupled with mass spectrometry. Results:We did not findresidues of Coumafos and Cyfluthrin, but in 19 farms we detected Amitraz, Cypermethrin and Chlorpyrifos (the latter, 0.01mg/kg). Few managers know alternatives to chemical control, and most do not respect the withdrawal period of the tick, and do not rotate the active ingredient. Conclusion:Education and monitoring on tick control should be improved in dairyfarmsUniversidad de Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de ZootecniaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigación en Nutrición Animal (CINA)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA

Degradation of selected agrochemicals by the white rot fungus Trametes versicolor

Use of agrochemicals is a worldwide practice that exerts an important effect on the environment; therefore the search of approaches for the elimination of such pollutants should be encouraged. The degradation of the insecticides imiprothrin (IP) and cypermethrin (CP), the insecticide/nematicide carbofuran (CBF) and the antibiotic of agricultural use oxytetracycline (OTC) were assayed with the white rot fungus Trametes versicolor. Experiments with fungal pellets demonstrated extensive degradation of the four tested agrochemicals, at rates that followed the pattern IP > OTC > CP > CBF. In vitro assays with laccase-mediator systems showed that this extracellular enzyme participates in the transformation of IP but not in the cases of CBF and OTC. On the other hand, in vivo studies with inhibitors of cytochrome P450 revealed that this intracellular system plays an important role in the degradation of IP, OTC and CBF, but not for CP. The compounds 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA) and 3-phenoxybenzoic acid (PBA) were detected as transformation products of CP, as a result of the breakdown of the molecule. Meanwhile, 3-hydroxycarbofuran was detected as a transformation product of CBF; this metabolite tended to accumulate during the process, nonetheless, the toxicity of the system was effectively reduced. Simultaneous degradation of CBF and OTC showed a reduction in toxicity; similarly, when successive additions of OTC were done during the slower degradation of CBF, the fungal pellets were able to degrade both compounds. The simultaneous degradation of the four compounds successfully took place with minimal inhibition of fungal activity and resulted in the reduction of the global toxicity, thus supporting the potential use of T. versicolor for the treatment of diverse agrochemicals

Simultaneous removal of neonicotinoid insecticides by a microbial degrading consortium: Detoxification at reactor scale

Neonicotinoid insecticides show high persistence in the environment, and standard biological approaches such as biopurification systems have shown mostly inefficient removal of such compounds. In this work, soil pre-exposed to imidacloprid was used to obtain presumptive imidacloprid-degrading consortia. Cometabolic enrichment yielded a microbial consortium composed of eight bacterial and one yeast strains, capable of degrading not only this compound, but also thiamethoxam and acetamiprid, as demonstrated in cross-degradation assays. The biological removal process was scaled-up to batch stirred tank bioreactors (STBR); this configuration was able to simultaneously remove mixtures of imidacloprid + thiamethoxam or imidacloprid + thiamethoxam + acetamiprid, reaching elimination of 95.8% and 94.4% of total neonicotinoids, respectively. Removal rates in the bioreactors followed the pattern imidacloprid > acetamiprid > thiamethoxam, including >99% elimination of imidacloprid in 6 d and 17 d (binary and ternary mixtures, respectively). A comprehensive evaluation of the detoxification in the STBR was performed using different biomarkers: seed germination (Lactuca sativa), bioluminescence inhibition (Vibrio fischeri), and acute oral tests in honeybees. Overall, ecotoxicological tests revealed partial detoxification of the matrix, with clearer detoxification patterns in the binary mixture. This biological approach represents a promising option for the removal of neonicotinoids from agricultural wastewater; however, optimization of the process should be performed before application in farms.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA

Simultaneous degradation of pharmaceuticals in fixed and fluidized bed reactors using iron-modified diatomite as heterogeneous Fenton catalyst

The aim of this study was to evaluate the use of pelletized iron-modified diatomite as heterogeneous Fenton catalyst for the removal of carbamazepine, clindamycin, gemfibrozil, ketoprofen, florfenicol, and sulfamethazine, and to compare its performance in fixed and fluidized bed reactor configurations. The prepared catalyst pellets were characterized by XRD, SEM, ED-XRF, BET, and compression strength analysis. Applying a Taguchi L9 design of experiments, the oxidation of a mixture of six common pharmaceuticals was studied under different operating conditions (initial pH, particle size, space time, and H2O2 initial concentration) for both reactor configurations. Under the best operating conditions, overall pharmaceutical degradations by the Fenton reaction were 32.6 % and 31.8 % in the fluidized and fixed bed reactors, respectively. Among the analyzed pharmaceuticals, clindamycin was the one presenting the highest removal (88.8 % fixed, 89.7 % fluidized), followed by gemfibrozil (70.4 % fixed, 100 % fluidized), ketoprofen (36.2 % fixed, 35.1 % fluidized), carbamazepine (19.0 % fixed, 21.1 % fluidized), sulfamethazine (18.1 % fixed, 21.1 % fluidized), and florfenicol (4.6 % fixed, 7.0 % fluidized). The initial pH was the most sensitive variable, presenting the best performance at pH 3. After 10 h of operation, the catalyst suffered a 27.9 % decrease in its activity when operated in the fixed bed reactor, whereas in the fluidized bed reactor its deactivation was 52.1 %. The catalyst was also evaluated in a real wastewater matrix, showing basically the same activity as in synthetic wastewater; TOC overall removal was 31 % for the fixed bed and 36 % for the fluidized bed reactor. Finally, the electrical energy per order (EEO) consumed in both reactors was calculated to compare their energy efficiency; the fixed bed configuration presented the lowest value (1.01 Wh/m3/order), suggesting that this is a more energy-efficient configuration for commercial wastewater treatment applications.Universidad de Costa Rica/[802-B7-A09]/UCR/Costa RicaUniversidad de Costa Rica/[802-B8-510]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[FI-197B-17]/MICITT/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Impact of oxytetracycline and bacterial bioaugmentation on the efficiency and microbial community structure of a pesticide-degrading biomixture

UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA

Removal of triazines, triazoles and organophophates in biomixtures and application of a biopurification system for the treatment of laboratory wastewaters - ScienceDirect

Biopurification systems (BPS) have been barely explored for removing complex mixtures of pesticides. In this study, the potential of a biomixture to remove simultaneously a mixture of herbicides (triazines), fungicides (triazoles) and insecticides (organophosphates) is presented. Also, a BPS using the same biomixture was used for treating a pesticide testing laboratory wastewater containing a mixture of 38 compounds. Ecotoxicological assays were conducted on the BPS elutriates to investigate the mixture detoxification. A mixture (concentrations of 4–8 mg kg−1) run in small–scale biomixture systems (SSB) for 128 d showed 59.3% removal of triazines, 68.5% of organophosphates and no elimination of triazoles. The treatment of the laboratory wastewater (individual concentrations range: 0.0036–0.25 mg kg−1) in the pilot-scale BPS for 281 d resulted in the elimination pattern of organophosphates (90.0%) > triazoles (73.4%) > carbamates (71.3%) > triazines (54.3%). Complete detoxification towards Daphnia magna and partial detoxification in Lactuca sativa seeds germination occurred in the BPS. Although the pesticide mixture complexity is higher in the BPS, the lower concentrations found in this matrix, could explain removal differences between SSB and BPS and the apparent inhibition in the elimination of carbamates and some triazines observed in the latter. These findings suggest that disposal of pesticide–containing laboratory–wastewater should be done in separate containers, according to chemical groups before their treatment in separate BPS, in order to reduce treatment periods. Monitoring the treatment process in the BPS with a battery of ecotoxicological tests is strongly recommended.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA

Ecotoxicological test based on inhibition of fungal laccase activity: Application to agrochemicals and the monitoring of pesticide degradation processes

Ecotoxicological evaluations require the use of assays with several bioindicators from different trophic levels. Only a few ecotoxicological tests using fungi have been developed, reason why, detection of adverse effects from compounds that exert fungicide action may be overlooked. This work developed a toxicity test based on the inhibition of laccase enzymatic activity in the fungus Trametes versicolor. The test was applied to several fungicides and succeeded to determine inhibition values (half maximum effective concentration, EC50) for most of them (flusilazole, imazalil, pyrimethanil, tetraconazole), though a clear dose-response was not evident for others (thiabendazole, metalaxyl). The application on atrazine (herbicide), imidacloprid (insecticide) and oxytetracycline (antibiotic), proved the proposed test is suitable towards other agrochemicals. The test was also used to estimate the detoxification resulting from two different approaches employed in the removal of agrochemicals. (a) First, in the liquid-phase elimination by fungal biomass simultaneously removing atrazine, imazalil, tebuconazole and triadimenol, the test showed a significant decrease in toxicity by biodegradation (adsorption contribution to detoxification was negligible). (b) Second, a solid-phase biomixture (used for pesticide degradation from agricultural wastewater) partially removed atrazine, imazalil, metalaxyl and pyrimethanil after 33 d; nonetheless, this system could not reduce the toxicity of the matrix, and higher laccase inhibition was detected after the treatment. The design test increases the battery of available bioassays to determine the toxicity of agrochemicals, and provides an interesting tool to monitor biodegradation processes.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

An integrative water quality evaluation in two surface water bodies from a tropical agricultural region in Cartago, Costa Rica

A monitoring study was carried out in two micro-catchments in the Reventazón basin, in Northern Cartago, Costa Rica; pesticide occurrence and water quality were analyzed. Twelve pesticides were detected, fve insecticides (chlorpyrifos, carbofuran, cypermethrin, imidacloprid, and oxamyl), four fungicides (carbendazim, imazalil, metalaxyl, and thiabendazole), and three herbicides (diuron, linuron, and terbutryn); eight of them presented risk quotients RQ >1, which implies a high risk for the environment. The water quality evaluation included fourteen physicochemical and microbiological parameters, out of which thermotolerant coliforms, nitrate, and total phosphorus exceeded a selected threshold value in every sample. Five metals were also included in the evaluation, Pb was the most frequent, followed by few detections of Cd, Cu, and Cr. Four water quality indexes (WQIs) were applied, two of them, the CCME WQI, based on physicochemical parameters, and the BMWP-CR WQI, based on benthic macroinvertebrate recount adapted to Costa Rican species, categorized all the sampling points as “bad” and “very bad” quality. This work of monitoring is important in the Latin American region, where there is a lack of information for regulation improvement and management decisions. These results showed poor management of the micro-catchments in this agricultural rural area.Universidad de Costa Rica/[802-B5-400]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA