Time filter

Source Type

Araya F.,University of Concepcion | Vera I.,University of Concepcion | Vera I.,Research Center y Desarrollo en Recursos Hidricos | Vera I.,Arturo Prat University | And 2 more authors.
Environmental Technology (United Kingdom) | Year: 2016

The objective was to evaluate the effects of intermittent artificial aeration cycles and natural zeolite as a support medium, in addition to the contribution of plants (Schoenoplectus californicus) on NH4 +–N removal during sewage treatment by Constructed Wetlands (CW). Two lines of Mesocosm Constructed Wetland (MCW) were installed: (a) gravel line (i.e. G-Line) and (b) zeolite line (i.e. Z-Line). Aeration increased the NH4 +–N removal efficiency by 20–45% in the G-Line. Natural zeolite increased the NH4 +–N removal efficiency by up to 60% in the Z-Line. Plants contributed 15–30% of the NH4 +–N removal efficiency and no difference between the G-Line and the Z-Line. Conversely, the NH4 +–N removal rate was shown to only increase with the use of natural zeolite. However, the MCW with natural zeolite, the NH4 +–N removal rate showed a direct relationship only with the NH4 +–N influent concentration. Additionally, relationship between the oxygen, energy and area regarding the NH4 +–N removal efficiency was established for 2.5–12.5 gO2/(kWh-m2) in the G-Line and 0.1–2.6 gO2/(kWh-m2) in the Z-Line. Finally, it was established that a combination of natural zeolite as a support medium and the aeration strategy in a single CW could regenerate the zeolite’s adsorption sites and maintain a given NH4 +–N removal efficiency over time. © 2016 Taylor & Francis

Herrera C.,Catolica del Norte University | Custodio E.,University of Barcelona | Chong G.,Catolica del Norte University | Lamban L.J.,Geological Institute of Spain IGME | And 8 more authors.
Science of the Total Environment | Year: 2016

Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water-rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ18O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano. © 2015 Elsevier B.V.

Santander C.,Research Center y Desarrollo en Recursos Hidricos | Santander C.,Arturo Prat University | Olave J.,Research Center y Desarrollo en Recursos Hidricos | Olave J.,Arturo Prat University
Idesia | Year: 2014

This research was performed in a semi-controlled greenhouse at the Canchones Experimental Station, where the interactive effect of arbuscular mycorrhizal fungi (AMF) Glomus intraradices (GI) and Trichoderma harzianum (Th) on the parameters of growth, differentiation, stress indicators and biochemical parameters, as well as the percentage of mycorrhization and colony forming units Th (CFU). The plant material used corresponded to melon cv. Honeydew Inodorus type. The treatments were: control (T0), inoculation with GI at doses of 40 spores per plant (T1), inoculation with GI at doses of 40 spores per plant + 1.5 * 108 CFU of Th per tray (T2) and Th dose inoculation with 1.5*108 per tray (T3). Inoculation with GI was performed at the time of sowing and inoculation with Th was performed 15 days later. We used a design performing completely randomized multifactorial variance analysis (ANOVA) and mean separation test was used LSD, using the statistical software INFOSTAT α = 0.05. The results obtained in the destructive sampling at 50 days of sowing determined that co-inoculation with GI + Th (T2) decreased the percentage of mycorrhizal colonization by an antagonistic action of Th on GI, compared with the highest percentage of mycorrhizal determined in T1, in T0 and T3 treatments not mycorrhizal colonization was determined. As for the treatments inoculated with Th (T2 and T3), no significant differences between treatments were determined inoculated, but a decrease in the population of Th between days 1 and 50 was determined. The only inoculation with GI had higher root biomass production, higher root dry weight ratio: stem dry weight and lower rate of etiolation. The nitrate reductase (NRI/NRE) activity was affected only in the treatments inoculated with GI, determining a higher ratio in these treatments. Co-inoculation between AMF and Trichoderma not determine an effect in promoting growth in melon plants, is Trichoderma had a detrimental effect on mycorrhizal colonization. Unlike GI inoculated individually had an effect on root growth which is determined by the high level of colonization.

Discover hidden collaborations