Examinando por Materia "Pesticides"

Mostrando 1 - 3 de 3
  • Miniatura
    PublicaciónDesconocido
    Coupling of Heterogeneous Photocatalysis and Aerobic Biological Process of Activated Sludge to treat Wastewater Containing Chlorpyrifos.
    (Universidad del Valle, 2020-01-03) Becerra Moreno, Dorance; Arteaga, Brenda L.; Ochoa, Yuriney E.; Barajas Solano, Andrés F.; García Martínez, Janet B .; Ramírez, Luisa F.
    (Eng) Chlorpyrifos is one of the most commonly used pesticides in Colombia, being the most commonly used in the department of Norte de Santander, where its usefulness has been proven to protect crops of rice, coffee, etc. However, due to improper use by farmers, this has brought negative consequences for the environment and the health of people, which is why in 2014 there were 715 cases of poisoning by this substance in the department. In order to generate a technically viable alternative for the treatment of agricultural wastewater containing Chlorpyrifos and advancing in the decontamination of receiving water bodies, the effectiveness of the heterogeneous photocatalysis coupling in a Composite Parabolic Collector - CPC and an aerobic biological process of activated sludge in batch. The photocatalysis was performed in a CPC of 0.83 m2, using sunlight as a source of energy (20, 40 and 60 KJ.L-1) and titanium dioxide - TiO2 Degussa P25 as a catalyst (100, 350 and 600 mg. L-1), at a pH of 3, 6 and 9 and as an aerobic biological process the Zahn-Wellens Test was used. The photocatalytic process achieved a maximum DQO removal of 44.2% and COD of 35.3%, for optimal conditions 159.19 mg.L-1 of TiO2 and 3.47 pH units. The biological process managed to degrade 17.0% of DQO and 9.3% of COD for wastewater without pretreatment. After pretreatment by photocatalysis, the removal of the biological process increased to 88.2% DQO and 67.8% COD. From the results obtained, it is established that the coupling of heterogeneous photocatalysis and an aerobic biological process is a viable alternative for the treatment of agricultural wastewater with the presence of Chlorpyrifos.
  • Miniatura
    PublicaciónDesconocido
    Efectos letales y subletales luego de exposición a insecticidas convencionales y biorracionales sobre huevos de Chrysoperla externa (Neuroptera: Chrysopidae).
    (Universidad del Valle, 2017-12-30) Haramboure, Marina
    The neuropteran Chrysoperla externa is a generalist predator of many important agricultural pests in the Neotropical region. It occurs on several agricultural crops, and therefore it can be affected by pesticides. Here, the lethal and sublethal effects of conventional and biorational insecticides were assessed against C. externa eggs. The exposure method consisted on immersion of eggs in solutions with the maximum field recommended concentration of 25 mg a.i./L cypermethrin, 200 mg a.i./L acetamiprid, 40 mg a.i./L azadirachtin and 75 mg a.i./L pyriproxyfen. The viability of the eggs was not affected, but 100 % of the neonates from eggs treated with cypermethrin died after 48 h. Larvae from eggs treated with acetamiprid, azadirachtin and pyriproxyfen survived to the adult stage, with survival rates of 75 %, 70.6 % and 84.6 %, respectively. Regarding the reproductive parameters, the preoviposition period was not affected but the fecundity and fertility were lower with acetamiprid and pyriproxyfen, showing the sublethal effects of the insecticides acting in the adult stage.
  • Miniatura
    PublicaciónDesconocido
    Management of Aceria litchii (Acari: Eriophyidae) on Litchi chinensis.
    (Universidad del Valle, 2018-07-08) Monteiro de Castro e Castro, Bárbara; Plata Rueda, Angelica; Meloni Silva, Wiane; Guimarães de Menezes, Claubert Wagner; Wilcken, Carlos Frederico; Cola Zanuncio, José; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle
    Litchi chinensis fruits are very popular in the international market. The erinose mite, Aceria litchii (Eriophyidae), a major pest of this crop, feeds on the leaves and on all parts of the plants forming erinea. The purpose of this review is to present the most common control methods and to propose integrated management techniques for L. chinensis production systems. A. litchii infestations were detected in Brazilian orchards in 2008. Chemical pesticides are currently the main control measure for this pest; however, the combination of biological, chemical and cultural methods are more promising in the long term. Controlling and preventing the erinose mite are key factors for reducing its spread and establishment