Mineralización y/o solubilización del fósforo contenido en lodos provenientes de residuos salmonícolas marinos bioaumentados con cepas de aspergillus niger Y trichoederma pseudokoningi / Mineralization and/or solubilization phosphorus content from salmon waste sludge marine bioincreased with strains aspergillus niger and trichoederma pseudokoningi

Se evaluó un lodo salmonícola, proveniente de centros de cultivo marinos, con el objetivo de evaluar el aumento en la mineralización y/o solubilización del fósforo del lodo salmonícola tratado con la inoculación de cepas chilenas de hongos. El lodo fue pretratado mediante esterilización, pasteurización y sin pretratar. Posteriormente, fue inoculado con cepas nativas de Aspergillus niger y Trichoderma pseudokoningii, usando dos controles: sin adición de inóculo y otro, con la cepa control A. niger ANC. Estas muestras fueron incubadas por 60 días, determinándose el pH y la disponibilidad de fósforo (P) en los lodos pretratados. Luego de esta primera fase, las muestras fueron incubadas en tubos de lixiviación a temperatura controlada durante 6 semanas evaluando la cinética de mineralización de P de los lodos. Los pretratamientos aplicados al lodo aumentaron la disponibilidad de P con la disminución del pH. La esterilización del lodo influyó en la colonización microbial, presentando la mayor colonización de las cepas inoculadas y la mayor liberación de P a la solución. El pretratamiento de esterilización inoculado con la cepa control A. niger presentó el mayor potencial de mineralización de P, siendo significativamente mayor a las cepas nativas y al control evaluado.

A salmon sludge from marine farming centers was evaluated with the aim to increase the mineralization and/or solubilization of their phosphorus (P) content through the inoculation of Chilean fungi strains. The sludge was pretreated through sterilization, pasteurization and without any pretreatment. After were inoculated with native strains of Aspergillus niger and Trichoderma pseudokoningii, using two controls: without inoculum and with inoculation with A. niger ANC. The samples were incubated for 60 days at room temperature and pH and P availability was determined. After this first phase, the samples were additionally incubated for other 6 weeks, in leaching tubes, at controlled temperature (25 ºC) evaluating the sludge kinetics of P mineralization. The pretreatment applied to the sludge increased P availability with a pH value decline. The sludge sterilization had an influence on the microbial colonization, presenting high colonization of the inoculated strains and more P was available. The pretreatment of sterilization inoculated with the control strain A. niger presented the biggest potential for mineralization of P, being significantly higher than the native strains and control evaluated in this study.

Kinetic analysis of enhanced biological phosphorus removal in a hybrid integrated fixed film activated sludge process

Hybrid integrated fixed film activated sludge is a promising process for the enhancement of nitrification, denitrification and phosphorus removal in conventional activated sludge systems that can be used for upgrading biological nutrient removal, particularly when they have space limitations or need modifications that will require large monetary expenses. In this research, successful implementation of hybrid integrated fixed film activated sludge process at temperate zone wastewater treatment facilities has been studied by the placement of fixed film media into aerobic, anaerobic and anoxic zones. The primary objective of this study was to investigate the incorporation of enhanced biological phosphorus removal into hybrid integrated fixed film activated sludge systems and study the interactions between the fixed biomass and the mixed liquor suspended solids with respect to substrate competition and nutrient removal efficiencies. A pilot-scale anaerobic-anoxic-oxic configuration system was used. The system was operated at different mean cell residence times and influent chemical oxygen demand/total phosphorus ratios and with split influent flows. The experimental results confirmed that enhanced biological phosphorus removal could be incorporated successfully into hybrid integrated fixed film activated sludge system, but the redistribution of biomass resulting from the integration of fixed film media and the competition of organic substrate between enhanced biological phosphorus removal and denitrification would affect performances. Also, kinetic analysis of the reactor with regarding to phosphorus removal has been studied with different kinetic models and consequently the modified Stover-Kincannon kinetic model has been chosen for modeling studies and experimental data analysis of the hybrid integrated fixed film activated sludge reactor

The interactive effect of phosphorus and nitrogen on "In vitro" spore germination of glomus etunicatum Becker & Gerdemann, root growth and mycorrhizal colonization

The effects of P and N amendment and its interactions on spore germination, root growth and colonized root length by Glomus etunicatum Becker & Gerdemann (INVAM S329) was studied "in vitro"in RiT-DNA transformed roots of Anthylis vulneraria sub sp. Sampaiana (Kidney vetch). Three N media concentrations (5, 10 and 50 mg/l) at P constant level (2 mg/l) and three P media concentrations (2, 10 and 20 mg/l) at N constant level (5 mg/l) were utilized as a treatment. Bécard & Fortin medium was used as a basal medium for root growth and colonized root length, and water/agar 0.8(per cent) media was the control for spore germination. Spore germination of G. etunicatum at low P level was reduced by N addition in relation to the control media, and at low N level addition of P stimulated spore germination. Total root length was stimulated by N addtion at low P level, but no significant difference (p<0.05) was observed among P concentrations. Colonized root lenght by G. etunicatum increased significantly (pz0,05) with P additions at low N levels. Under low P level no significant differences was found between 10 and 50 mg/l of N. These results demonstrate that the interaction between P and N affect differently spore germination, root growth and colonized root lenght.