Is groundwater fauna impacted by swine effluent fertigation?

Neste estudo, testamos uma fertirrigação de efluente suíno que afeta a fauna aquática subterrânea do aqüífero livre poroso. Os parâmetros químicos e químicos das águas subterrâneas foram determinados e correlacionados com a fauna que não apresentam fator aquático em áreas fertigadas e não fertigadas com efluentes que não são biodigestores. Como influências da sazonalidade na qualidade da água também foram testadas. Para esse fim, como águas subterrâneas de poços de água e piezômetros preexistentes de propriedade de agricultores, usando o ventilador e a rede de malha de 65 micra para filtrar os organismos. Os resultados físicos e químicos podem mostrar algumas alterações nos parâmetros de qualidade.Registramos doze táxons de invertebrados, sendo Acari e Copepoda os mais prevalentes. A colonização de espécies aquáticas pode ter sido limitada pelo surgimento de organismos exóticos e pela qualidade da água.

Evaluation of a Nanocomposite Based on Reduced Graphene Oxide and Gold Nanoparticles as an Electrochemical Platform for Detection of Sulfamethazine

A nanocomposite based on reduced graphene oxide (rGO) and gold nanoparticles (AuNPs) was synthesized by the microwave-assisted hydrothermal method and applied in the determination of sulfamethazine (SMZ) in swine effluent using a glassy carbon (GC) electrode. The rGO-AuNPs nanocomposite was characterized morphologically, electrochemically and spectrochemically, showing that rGO was modified with the AuNPs. The GC/rGO-AuNPs electrode was optimized for the determination of SMZ, achieving detection limits of 0.1 μmol L−1. The proposed sensor was successfully applied to the determination of SMZ in synthetic swine effluent samples.

Flow rate variation and biological agents that obstruct drippers of swine effluent

Emitter clogging is the major problem of drip irrigation systems operating with wastewater. The objective of this study was to evaluate the alteration of the flow rate variation coefficient (FVC) and to identify the biological agents that cause obstruction in drip units operating with swine effluent and public water supply. The experiment was set up in a split-plot scheme, with the times of application of swine effluent and public water supply in the main plots and dripper types in the secondary parcels, evaluating times of FVC in the tertiary parcels, using a completely randomized design (CRD) with three repetitions. The FVC of the drip subunits was calculated on every 40 hours as well as the microscopic analysis of the biological agents of clogging, until 160 h. At the end of the tests, biofilm samples were collected in each drip unit to identify the groups of predominant bacteria. The results indicated that the FVC was effective in detecting the clogging of the emitters, evidencing that the construction characteristics and the times of application of swine effluent and of the public water supply interfere in this process. Microscopic analyzes of the biofilm indicated that the main biological agents that caused obstruction were algae, bacteria, fungi and protozoa.