RESUMO
A composting-accelerating bio-inoculant (Bacillus subtilis, Talaromyces sayulitensis (HC1), Steinernema sp., and Heterorhabditis sp.) was evaluated in a composting process made up of a different mix of wood chips, pig manure, urine, and swine mortality (raw material RM). Three different treatments (T1, T2, and T3) were assessed, and physicochemical, microbiological, and entomological evaluations were carried out at 0 and 45 days of the composting process. The highest organic nitrogen (1.34 %) concentration was detected in swine mortality, whereas the highest total oxidizable organic carbon (39.1 %) concentration was observed in wood chips. Salmonella spp., was not identified in any of the raw materials. Clostridium spp., count was 5.5, 2.0, and 1.0 Log10 unit, for pig manure, wood chips, and swine mortality, respectively. Pig manure, swine mortality, and wood chip total coliform count was 6.21, 5.32, and 1 Log10 unit, respectively. Helminth eggs were not detected in any of the RM and Cryptosporidium spp., oocysts were occasionally found in pig manure and wood chips. Several types of flies were identified, Musca domestica, Muscina stabulans, Stomoxys calcitrans, Fannia canicularis, Sarcophaga sp., and Calliphora sp. Treatment 3 (45.11 % swine mortality, 33.33 % wood chips, and 21.55 %, urine and bio-inoculant) had the greatest total oxidizable organic carbon availability, the highest carbon/nitrogen (C/N) ratio (20.67, p < 0.05), and the lowest dipterous larvae count. Moreover, Salmonella sp., was not observed and had only low Clostridium spp., and fecal coliform count. The bio-inoculant's effect on C/N ratio, cation exchange capacity, and electrical conductivity were beneficial, and resulted in production of a fertilizer complying with EPA 600/1-87-014, EPA 40 CFR Part 258, and NTC5167/11 norms. According to the characterization protocols used in this study the compost was apparently free from bacterial and parasitic pathogens and minimal dipteran counts. Last, maturation time was 15 days shorter compared with control (C4).
RESUMO
The objective of this study was to evaluate the potential of eight fungal isolates obtained from soils in rice crops for straw degradation in situ. From the initial eight isolates, Pleurotus ostreatus T1.1 and Penicillium sp. HC1 were selected for further characterization based on qualitative cellulolytic enzyme production and capacity to use rice straw as a sole carbon source. Subsequently, cellulolytic, xylanolytic, and lignolytic (Pleurotus ostreatus) activity on carboxymethyl cellulose, oat xylan, and rice straw with different nitrogen sources was evaluated. From the results obtained it was concluded both isolates are capable to produce enzymes necessary for rice straw degradation. However, their production is dependent upon carbon and nitrogen source. Last, it was established that Pleurotus ostreatus T1.1 and Penicillium sp. HC1 capability to colonize and mineralize rice straw, in mono-and co-culture, without affecting nitrogen soil content.
Assuntos
Celulase/biossíntese , Celulose/metabolismo , Fungos/metabolismo , Oryza/metabolismo , Microbiologia do Solo , Biodegradação Ambiental , Carbono/metabolismo , Celulase/metabolismo , Fungos/classificação , Fungos/enzimologia , Fungos/isolamento & purificação , Hidrólise , Lignina/metabolismo , Penicillium/enzimologia , Penicillium/isolamento & purificação , Penicillium/metabolismo , Caules de Planta/metabolismo , Pleurotus/enzimologia , Pleurotus/isolamento & purificação , Pleurotus/metabolismoRESUMO
Objetivo. Evaluar tres tratamientos (lagunaje, fotocatálisis con TiO2 y desinfección química) para la inactivación de coliformes totales y Escherichia coli presentes en agua residual doméstica empleada para riego agrícola. Materiales y métodos. El agua residual fue caracterizada por medio de análisis físicos, químicos y microbiológicos. Posteriormente fue sometida a un tratamiento de lagunaje facultativo (TLF), pos tratamiento fotocatalítico (PTFTiO2/UV) y pos tratamiento químico (PTQ NaClO). Valorando la capacidad desinfectante de cada uno de ellos para inactivar coliformes totales y E. coli. A continuación se procesaron tres nuevos lotes de agua residual y se utilizaron para realizar pruebas de riego a escala de laboratorio por 30 días, empleando como modelo plantas de Lactuca sativa variedad Batavia y evaluando la concentración inicial y final de los dos grupos. Resultados. El PTFTiO2/UV fue significativamente superior que TLFLF y el PTQ NaClO (p<0,0001) obteniendo 100% de inactivación para coliformes y E. coli a los 30 minutos de irradiación a escala de reactor. Respecto a las pruebas de riego de L. sativa se demostró que al utilizar el agua tratada por PTFTiO2/UV no se presentó contaminación con E. coli y coliformes a los 30 días de proceso. Por el contrario en las plantas regadas con agua tratada por TLF y PTQ NaClO se observó un incremento en las dos poblaciones generando un problema de contaminación de las hortalizas al finalizar la prueba de laboratorio. Conclusión. La fotocatálisis heterogénea TiO2 fue un método eficaz para la reducción de coliformes y E.coli en aguas residuales domésticas.
Objective. To evaluate three treatments (facultative stabilization ponds, heterogeneous photocatalysis with TiO2 and chemical disinfection with sodium hypochlorite) for the inactivation of coliforms and Escherichia coli presen in domestic wastewaters used in agricultural irrigation. Materials and methods. Wastewater was characterized by physical, chemical and microbiological analyses and was then exposed to a facultative pond treatment (FPT), post-photocatalytic treatment (PTFTiO2/UV) and post-chemical treatment (PTQNaClO) to assess the disinfecting capacity of each method in the inactivation of total coliforms and E. coli. Three new samples of wastewater were processed and used in irrigation tests on a laboratory-scale basis for 30 days, using Lactuca sativa cultivar. Batavia as a model plant and evaluating the initial and final concentrations of the two groups. Results. PTFTiO2/UV was significantly higher than FPT and PTQNaClO (p<0.0001), obtaining 100% of inactivation of coliforms and E. coli after 30 minutes of irradiation at a reactor scale. Regarding the irrigation tests with L. sativa, we showed that using water treated by PTFTiO2/UV there is no contamination with E. coli and coliforms after 30 days. On the contrary, plants irrigated with water treated by FPT and PTQNaClO showed an increase in the two populations originating a contamination problem in the vegetable by the end of the laboratory experiments. Conclusion. The heterogeneous photocatalysis with TiO2 was an effective method in the reduction of coliforms and E. coli present in domestic wastewater.
Objetivo. Avaliar três tratamentos (lagoas, fotocatálise com TiO2 e desinfecção química) para inativação de coliformes totais e Escherichia coli presentes em águas residuais domésticas utilizadas na irrigação dos cultivos. Materiais e métodos. O efluente foi caracterizado por analises físicos, químicos e microbiológicos. Posteriormente foi submetido a tratamento de lagoas facultativas (TLF), pós-tratamento fotocatalítico (PTF TiO2/UV) e pós-tratamento químico (PTQ NaClO). Avaliando a capacidade desinfetante de cada um para inativar coliformes totais e E. coli. Posteriormente, foram processados três novos lotes de águas residuais para testar a irrigação em escala de laboratório por 30 dias, utilizando-se como modelo plantas de Lactuca sativa variedade Batavia e avaliando a concentração inicial e final dos dois grupos. Resultados. O PTFTiO2/UV foi significativamente maior a TLFLF e PTQ NaClO (p<0,0001) apresentando 100% de inativação para coliformes e E. coli em 30 minutos de irradiação a escala do reator. Quanto aos testes de irrigação de L. sativa foi demonstrado que, ao utilizar a água tratada com PTFTiO2/UV não se apresentou contaminação com E. coli e coliformes a 30 dias do tratamento. Em contrapartida, em plantas irrigadas com água tratada por TLF e PTQ NaClO observou-se um aumento nas duas populações gerando um problema de contaminação de hortaliças no final do teste de laboratório. Conclusão. A fotocatálise heterogênea TiO2 foi um método eficaz para reduzirem coliformes e E. coli em águas residuais domésticas.